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Oral Transmission of Chagas Disease Has Severe Effects
Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.
“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.
In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”
In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.
Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”
Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.
He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.
“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”
Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.
In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
Unique Clinical Manifestations
The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
Seven Things to Know About Orally Transmitted Chagas Disease
1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.
2. Most patients (71%-100%) with acute oral Chagas present with fever.
3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.
4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.
5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.
6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.
7. Patients need antiparasitic drugs immediately.
Thinking Epidemiologically
Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.
“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.
Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”
One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.
An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).
The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
Deadly Yet Easily Treatable
In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.
“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”
“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”
Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.
“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.
In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”
In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.
Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”
Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.
He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.
“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”
Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.
In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
Unique Clinical Manifestations
The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
Seven Things to Know About Orally Transmitted Chagas Disease
1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.
2. Most patients (71%-100%) with acute oral Chagas present with fever.
3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.
4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.
5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.
6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.
7. Patients need antiparasitic drugs immediately.
Thinking Epidemiologically
Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.
“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.
Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”
One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.
An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).
The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
Deadly Yet Easily Treatable
In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.
“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”
“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”
Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Thanks to decades of successful vector control strategies, vector-borne transmission of Chagas disease has significantly decreased in many regions. Oral ingestion of Trypanosoma cruzi through contaminated food and beverages, however, is increasing. Unlike vector transmission, oral transmission of Chagas disease entails high lethality in pediatric and adult populations.
“The oral transmission of Chagas disease is becoming a much more recognized route, and it is crucial to understand that people can die from this type of transmission,” Norman L. Beatty, MD, assistant professor of infectious diseases and global medicine at the University of Florida College of Medicine in Gainesville, Florida, told this news organization. Dr. Beatty is the lead author of a recent article on the subject.
In regions where the parasite circulates in the environment, people are consuming foods, fruit juices, and possibly wild animal meat that may be contaminated. “As we experience changes in our environment and in the way we consume food, it is crucial to consider how food preparation is carried out in areas where T cruzi transmission occurs in the environment,” said Dr. Beatty. “And as organic farming methods without insecticides become increasingly common, more research is needed in these areas, both in Latin America and in the United States, to understand if oral transmission of T cruzi is occurring.”
In the Amazon basin, foodborne transmission is already the leading cause of acute Chagas disease. It has been described in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, and Venezuela.
Dr. Beatty’s colleagues recently treated a Brazilian patient at the hospital in Florida. “He came to our hospital very ill, with acute myocarditis after consuming contaminated açaí.” Clarifying that there is widespread awareness about oral transmission in Brazil, he stated, “We are concerned that it may not be recognized in other areas of Latin America.”
Mexico and regions of Central America have little to no information on oral transmission, but it is likely occurring, and cases may be going undetected in the region, said Dr. Beatty.
He investigated the issue in Colombia as part of an international collaboration involving the University of Antioquia, aiming to find ways to mitigate oral transmission and create a model that can be used throughout Latin America and the United States. For the Colombia study, they reviewed all cases reported to the Ministry of Health and Social Protection, and oral transmission turned out to be more common than the research group expected. “Still, I imagine that in certain areas with limited resources…there are many more cases that are not being reported.
“A myth I would like to dispel is that Chagas disease is not being transmitted in the United States,” Dr. Beatty added. He mentioned that at least 30 American states have vectors, and in Florida, it was documented that triatomines invaded homes and bit residents. In addition, 30% of these insects are infected with T cruzi. Research is underway to determine whether Floridians are becoming infected and if they are also at risk of contracting Chagas disease orally, said Dr. Beatty. “In the United States, we know very little about how many people are infected and what the infection routes are. Much more research is needed.”
Roberto Chuit, MD, PhD, a doctor in public health and an external consultant for the Pan American Health Organization (PAHO), agreed that this route of food contamination, which occurs because of vector-borne parasites, was until recently masked or hidden by the predominance of vector presence. Just as it began to gain importance as other transmission routes were controlled, “it now has extremely high importance in the Americas, as does vertical transmission,” he said.
In 2023, more than 50 years after the first description of oral transmission, the PAHO expert meeting proposed to alert health services and the broader community about the severity and potential lethality of oral Chagas disease outbreaks to elicit immediate responses and mitigation measures. The body also proposed conducting studies to provide detailed information on the contamination source and the wild vectors present in oral transmission foci.
Unique Clinical Manifestations
The exacerbated signs and symptoms of oral infection (see sidebar) are attributed to the high parasite loads in contaminated food and beverages. A single crushed triatomine along with a food or beverage harboring T cruzi can contain an estimated 600,000 metacyclic trypomastigotes, compared with 3000-4000 per µL when infection occurs by triatomine fecal matter. The robust systemic immune response observed in patients with acute oral Chagas disease is thought to result from more efficient transmission after penetration through the oral, pharyngeal, and gastric mucosae.
Seven Things to Know About Orally Transmitted Chagas Disease
1. It presents with exacerbated symptoms and rapid disease progression in immunocompetent individuals. This presentation is not common in vector-borne, congenital, or transfusion-related transmission. It can cause fulminant myocarditis and heart failure, meningoencephalitis, or potentially fatal shock due to parasitemia.
2. Most patients (71%-100%) with acute oral Chagas present with fever.
3. Electrocardiographic abnormalities, specifically ventricular depolarization alterations and pericardial involvement, are observed in most patients.
4. Facial edema, which typically affects the entire face and parts of the lips, is present in 57%-100% of patients with acute oral Chagas disease. In those with acute symptoms from vector transmission, unilateral periorbital swelling (Romaña’s sign) is more common.
5. Other notable systemic symptoms include edema of the lower extremities, myalgia, generalized lymphadenopathy, abdominal discomfort, dyspnea, vomiting, diarrhea, hepatomegaly, splenomegaly, headache, chest pain, cutaneous erythematous rash, jaundice, arthralgia, epistaxis, hematemesis, melena, and palpitations.
6. The incubation period after oral ingestion of products contaminated with Trypanosoma cruzi is approximately 3-22 days, in contrast to 4-15 days for vector-borne transmission and 8-160 days for transfusion and transplant-related transmission.
7. Patients need antiparasitic drugs immediately.
Thinking Epidemiologically
Dr. Chuit recalled that suspicion of food contamination should be based on epidemiology, especially in outbreaks affecting several people and in regions where Chagas vectors have been described. Sometimes, however, a single careless tourist consumes contaminated products.
“The difficulty is that many times it is not considered, and if it is not considered, the search for the parasite is not requested,” said Dr. Chuit. He added that it is common for the professional to consider Chagas disease only if viral and bacterial isolation tests are negative. Clinicians sometimes consider Chagas disease because the patient has not responded to regular treatments for other causes, such as antibiotics and hydration.
Epidemiology is important, especially when Chagas disease is diagnosed in groups or a family, because they are usually not isolated cases but outbreaks of 3-40 cases, according to Dr. Chuit. “Under these conditions, it must be quickly considered…that this parasite may be involved.”
One of the difficulties is that the source of these oral transmissions is not recognized most of the time. In general, the sources are usually foods that are more likely to be contaminated by insects or insect feces, such as orange juice or sugarcane. But in fact, any food or beverage left unattended could be contaminated by vectors or possible secretions from infected marsupial odoriferous glands.
An analysis of 32 outbreaks from 1965 to 2022 showed that the main foods involved in oral transmission were homemade fruit juices. But different vector species were identified, and the reservoirs were mainly dogs, rodents, and large American opossums (Didelphis).
The largest oral Chagas outbreak was linked to the consumption of contaminated guava juice in a primary school in Caracas, Venezuela. Nonindustrially produced açaí is a common source of orally acquired Chagas disease in Brazil. In Colombia, Chagas disease has been associated with the consumption of palm wine, sugar cane, and tangerine juice. Other oral transmission routes include consuming meat from wild animals and ingesting blood from infected armadillos, which is related to a traditional medicine practice.
Deadly Yet Easily Treatable
In the outbreak of 119 confirmed and suspected cases in Venezuela, 20.3% required hospitalization, and a 5-year-old child died of acute myocarditis. These percentages differ from those reported in vector transmission, which is asymptomatic in the acute phase for 95%-99% of cases or will only develop a mild febrile illness that resolves on its own.
“Not all cases will present as severe, because depending on the inoculum, there may be individuals with subclinical situations. But any food poisoning that occurs in endemic areas, where food is not properly controlled, and these street foods are associated with processes in jungle areas, raises the possibility that T cruzi is involved and should be considered as a differential diagnosis,» noted Dr. Chuit. “The treatment is highly effective, and people recover quickly.”
“The most important thing about oral transmission of Chagas is that someone infected in this way needs antiparasitic drugs immediately. We can cure them if we treat them immediately,” said Dr. Beatty, adding that treatment is sometimes delayed due to lack of access to appropriate antiparasitic drugs. “Here in the United States and in Latin America, it is quite common for healthcare professionals not to understand the differences between vector, vertical, and oral transmission. By not treating these patients, they become ill quickly.”
Dr. Beatty and Dr. Chuit declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Reduced-Dose Vaccines Protect Patients With HIV Against Mpox
The smallpox vaccine effectively induces immunity against mpox virus infection (formerly simian smallpox) in patients with human immunodeficiency virus (HIV) infection, although patients with lymphocyte counts below 500 cells/mm3 require booster doses, according to data from a study published in the Journal of Medical Virology.
The data come from the prospective observational study conducted by researchers at the Infection Biology Laboratory of the Department of Medicine and Life Sciences at Pompeu Fabra University and the HIV Unit of the Hospital del Mar Medical Research Institute in Barcelona, Spain. The investigators analyzed T-cell responses induced by vaccination with JYNNEOS.
Despite the substantial decrease in the reporting frequency of mpox cases from the global peak in August 2022 (30,894 cases) to 804 monthly cases in the last six months of 2023, mpox continues to circulate, and there is no specific vaccine. The JYNNEOS vaccine, with protective cross-reactivity against orthopoxviruses, is approved by the US Food and Drug Administration and the European Medicines Agency for the prevention of smallpox and mpox in adults at high risk for infection.
During the 2022 outbreak in the United States and Europe, vaccine shortages led to the emergency use authorization of a lower intradermal dose. This strategy was aimed at increasing vaccine supply up to fivefold.
Further clinical trials are needed to evaluate responses to JYNNEOS vaccination and compare different administration routes in patients with HIV infection. Protecting this population against mpox is a priority because people with high viral loads or loCD4+ T-lymphocyte counts are especially susceptible to severe disease.
Vaccination Responses
The study assessed the immune response to the JYNNEOS vaccine in patients with HIV who were receiving antiretroviral therapy as outpatients at the Infectious Diseases Unit of Hospital del Mar in Barcelona, Spain. Participants had viral loads controlled by antiretroviral therapy and CD4+ T-lymphocyte counts ≤ 500/mm3 (loCD4 group) or ≥ 500/mm3 (hiCD4 group) in blood. Vaccine responses were compared with those of vaccinated controls without the disease. The study included cases that received the standard subcutaneous vaccine (before August 2022) or the emergency dose-saving intradermal vaccine after its approval in August 2022.
The results demonstrated that the intradermal dose-saving vaccination route is preferable to the subcutaneous route and that patients in the loCD4 group may require at least one booster to generate an efficient response of specific T cells for mpox, wrote the authors.
“This study has two relevant points,” study author Robert Güerri-Fernandez, MD, PhD, head of infectious diseases at the Hospital del Mar Medical Research Institute, told this news organization. “In the subgroup of patients with HIV with effective treatment but without an immune response (ie, loCD4), the vaccine response is worse than in people who have recovered immunity or do not have HIV. Therefore, they need a booster dose.
“The second point is that the intradermal route with one-fifth of the standard subcutaneous dose has a better immune response than the standard subcutaneous route.” He added that it was a good strategy to save doses and be able to vaccinate many more people when vaccine shortages occurred.
“A general conclusion cannot be drawn,” he said. “It needs to be validated with many more subjects, of course, but in some way, it reinforced our confidence in the strategy of health authorities to promote intradermal vaccination. There we had evidence that the patients we were vaccinating intradermally were responding well.”
In Spain, although there is no shortage of vaccines today, they continue to be administered intradermally with a fractionated dose equivalent to one fifth of a standard dose, said Dr. Güerri-Fernandez.
However, in his opinion, observations regarding the two administration routes signal a need for further research. The main message should be that for patients with HIV infection who do not have an immune response, the vaccine response is incomplete, and they need booster doses as well as monitoring of the vaccine immune response, said Dr. Güerri-Fernandez.
More Studies Required
The research, which prospectively collected data and blood samples from patients with HIV who received the JYNNEOS vaccine, is small and included only 24 patients with HIV infection, with seven hospital workers who also received the vaccine and seven unvaccinated individuals as controls. “I am one of the control subjects of the study, and intradermal vaccination is not especially pleasant,” said Dr. Güerri-Fernandez. “It is a very innervated area, and the moment of introducing the liquid is uncomfortable. But it is perfectly bearable.”
Outpatient HIV-infected patients from the Infectious Diseases Unit of Hospital del Mar on antiretroviral therapy and with undetectable viral loads were grouped according to their CD4+ T-lymphocyte counts. Those with CD4+ T-lymphocyte counts ≤ 500/mm3 required at least one booster vaccine to exhibit efficient virus-specific T-lymphocyte responses. The magnitude of the T-cell response after this booster correlated directly with the CD4+ T-lymphocyte count of those vaccinated.
For Argentine infectious disease specialist Julián García, MD, clinical researcher at the Huésped Foundation in Buenos Aires, Argentina, who did not participate in the study, it is always productive to know that T-cell responses develop in patients with HIV infection, with CD4+ T-lymphocyte counts > and < 500/mm3, through an intradermal administration route.
Dr. García emphasized that the most novel aspect is that the JYNNEOS vaccine induces a specific T-cell response in patients with HIV infection that increases with higher CD4+ T-lymphocyte levels. However, he noted that the number of patients was less than 10 in most study groups, and the control group had only intradermal administration, which limits the interpretation of the results. “It will be necessary to verify this in studies with larger groups with control groups from all routes and with a correlate of protection.”
Dr. García referred to this latter point as a significant source of uncertainty. “The study is fundamentally based on the cellular response, but nowadays, there is no immune correlate of real-life protection.” He concluded that the study builds knowledge, which is essential for a vaccine that began to be used for mpox and the effectiveness of which is based on estimates.
Dr. Güerri-Fernandez and Dr. Garcia declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
The smallpox vaccine effectively induces immunity against mpox virus infection (formerly simian smallpox) in patients with human immunodeficiency virus (HIV) infection, although patients with lymphocyte counts below 500 cells/mm3 require booster doses, according to data from a study published in the Journal of Medical Virology.
The data come from the prospective observational study conducted by researchers at the Infection Biology Laboratory of the Department of Medicine and Life Sciences at Pompeu Fabra University and the HIV Unit of the Hospital del Mar Medical Research Institute in Barcelona, Spain. The investigators analyzed T-cell responses induced by vaccination with JYNNEOS.
Despite the substantial decrease in the reporting frequency of mpox cases from the global peak in August 2022 (30,894 cases) to 804 monthly cases in the last six months of 2023, mpox continues to circulate, and there is no specific vaccine. The JYNNEOS vaccine, with protective cross-reactivity against orthopoxviruses, is approved by the US Food and Drug Administration and the European Medicines Agency for the prevention of smallpox and mpox in adults at high risk for infection.
During the 2022 outbreak in the United States and Europe, vaccine shortages led to the emergency use authorization of a lower intradermal dose. This strategy was aimed at increasing vaccine supply up to fivefold.
Further clinical trials are needed to evaluate responses to JYNNEOS vaccination and compare different administration routes in patients with HIV infection. Protecting this population against mpox is a priority because people with high viral loads or loCD4+ T-lymphocyte counts are especially susceptible to severe disease.
Vaccination Responses
The study assessed the immune response to the JYNNEOS vaccine in patients with HIV who were receiving antiretroviral therapy as outpatients at the Infectious Diseases Unit of Hospital del Mar in Barcelona, Spain. Participants had viral loads controlled by antiretroviral therapy and CD4+ T-lymphocyte counts ≤ 500/mm3 (loCD4 group) or ≥ 500/mm3 (hiCD4 group) in blood. Vaccine responses were compared with those of vaccinated controls without the disease. The study included cases that received the standard subcutaneous vaccine (before August 2022) or the emergency dose-saving intradermal vaccine after its approval in August 2022.
The results demonstrated that the intradermal dose-saving vaccination route is preferable to the subcutaneous route and that patients in the loCD4 group may require at least one booster to generate an efficient response of specific T cells for mpox, wrote the authors.
“This study has two relevant points,” study author Robert Güerri-Fernandez, MD, PhD, head of infectious diseases at the Hospital del Mar Medical Research Institute, told this news organization. “In the subgroup of patients with HIV with effective treatment but without an immune response (ie, loCD4), the vaccine response is worse than in people who have recovered immunity or do not have HIV. Therefore, they need a booster dose.
“The second point is that the intradermal route with one-fifth of the standard subcutaneous dose has a better immune response than the standard subcutaneous route.” He added that it was a good strategy to save doses and be able to vaccinate many more people when vaccine shortages occurred.
“A general conclusion cannot be drawn,” he said. “It needs to be validated with many more subjects, of course, but in some way, it reinforced our confidence in the strategy of health authorities to promote intradermal vaccination. There we had evidence that the patients we were vaccinating intradermally were responding well.”
In Spain, although there is no shortage of vaccines today, they continue to be administered intradermally with a fractionated dose equivalent to one fifth of a standard dose, said Dr. Güerri-Fernandez.
However, in his opinion, observations regarding the two administration routes signal a need for further research. The main message should be that for patients with HIV infection who do not have an immune response, the vaccine response is incomplete, and they need booster doses as well as monitoring of the vaccine immune response, said Dr. Güerri-Fernandez.
More Studies Required
The research, which prospectively collected data and blood samples from patients with HIV who received the JYNNEOS vaccine, is small and included only 24 patients with HIV infection, with seven hospital workers who also received the vaccine and seven unvaccinated individuals as controls. “I am one of the control subjects of the study, and intradermal vaccination is not especially pleasant,” said Dr. Güerri-Fernandez. “It is a very innervated area, and the moment of introducing the liquid is uncomfortable. But it is perfectly bearable.”
Outpatient HIV-infected patients from the Infectious Diseases Unit of Hospital del Mar on antiretroviral therapy and with undetectable viral loads were grouped according to their CD4+ T-lymphocyte counts. Those with CD4+ T-lymphocyte counts ≤ 500/mm3 required at least one booster vaccine to exhibit efficient virus-specific T-lymphocyte responses. The magnitude of the T-cell response after this booster correlated directly with the CD4+ T-lymphocyte count of those vaccinated.
For Argentine infectious disease specialist Julián García, MD, clinical researcher at the Huésped Foundation in Buenos Aires, Argentina, who did not participate in the study, it is always productive to know that T-cell responses develop in patients with HIV infection, with CD4+ T-lymphocyte counts > and < 500/mm3, through an intradermal administration route.
Dr. García emphasized that the most novel aspect is that the JYNNEOS vaccine induces a specific T-cell response in patients with HIV infection that increases with higher CD4+ T-lymphocyte levels. However, he noted that the number of patients was less than 10 in most study groups, and the control group had only intradermal administration, which limits the interpretation of the results. “It will be necessary to verify this in studies with larger groups with control groups from all routes and with a correlate of protection.”
Dr. García referred to this latter point as a significant source of uncertainty. “The study is fundamentally based on the cellular response, but nowadays, there is no immune correlate of real-life protection.” He concluded that the study builds knowledge, which is essential for a vaccine that began to be used for mpox and the effectiveness of which is based on estimates.
Dr. Güerri-Fernandez and Dr. Garcia declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
The smallpox vaccine effectively induces immunity against mpox virus infection (formerly simian smallpox) in patients with human immunodeficiency virus (HIV) infection, although patients with lymphocyte counts below 500 cells/mm3 require booster doses, according to data from a study published in the Journal of Medical Virology.
The data come from the prospective observational study conducted by researchers at the Infection Biology Laboratory of the Department of Medicine and Life Sciences at Pompeu Fabra University and the HIV Unit of the Hospital del Mar Medical Research Institute in Barcelona, Spain. The investigators analyzed T-cell responses induced by vaccination with JYNNEOS.
Despite the substantial decrease in the reporting frequency of mpox cases from the global peak in August 2022 (30,894 cases) to 804 monthly cases in the last six months of 2023, mpox continues to circulate, and there is no specific vaccine. The JYNNEOS vaccine, with protective cross-reactivity against orthopoxviruses, is approved by the US Food and Drug Administration and the European Medicines Agency for the prevention of smallpox and mpox in adults at high risk for infection.
During the 2022 outbreak in the United States and Europe, vaccine shortages led to the emergency use authorization of a lower intradermal dose. This strategy was aimed at increasing vaccine supply up to fivefold.
Further clinical trials are needed to evaluate responses to JYNNEOS vaccination and compare different administration routes in patients with HIV infection. Protecting this population against mpox is a priority because people with high viral loads or loCD4+ T-lymphocyte counts are especially susceptible to severe disease.
Vaccination Responses
The study assessed the immune response to the JYNNEOS vaccine in patients with HIV who were receiving antiretroviral therapy as outpatients at the Infectious Diseases Unit of Hospital del Mar in Barcelona, Spain. Participants had viral loads controlled by antiretroviral therapy and CD4+ T-lymphocyte counts ≤ 500/mm3 (loCD4 group) or ≥ 500/mm3 (hiCD4 group) in blood. Vaccine responses were compared with those of vaccinated controls without the disease. The study included cases that received the standard subcutaneous vaccine (before August 2022) or the emergency dose-saving intradermal vaccine after its approval in August 2022.
The results demonstrated that the intradermal dose-saving vaccination route is preferable to the subcutaneous route and that patients in the loCD4 group may require at least one booster to generate an efficient response of specific T cells for mpox, wrote the authors.
“This study has two relevant points,” study author Robert Güerri-Fernandez, MD, PhD, head of infectious diseases at the Hospital del Mar Medical Research Institute, told this news organization. “In the subgroup of patients with HIV with effective treatment but without an immune response (ie, loCD4), the vaccine response is worse than in people who have recovered immunity or do not have HIV. Therefore, they need a booster dose.
“The second point is that the intradermal route with one-fifth of the standard subcutaneous dose has a better immune response than the standard subcutaneous route.” He added that it was a good strategy to save doses and be able to vaccinate many more people when vaccine shortages occurred.
“A general conclusion cannot be drawn,” he said. “It needs to be validated with many more subjects, of course, but in some way, it reinforced our confidence in the strategy of health authorities to promote intradermal vaccination. There we had evidence that the patients we were vaccinating intradermally were responding well.”
In Spain, although there is no shortage of vaccines today, they continue to be administered intradermally with a fractionated dose equivalent to one fifth of a standard dose, said Dr. Güerri-Fernandez.
However, in his opinion, observations regarding the two administration routes signal a need for further research. The main message should be that for patients with HIV infection who do not have an immune response, the vaccine response is incomplete, and they need booster doses as well as monitoring of the vaccine immune response, said Dr. Güerri-Fernandez.
More Studies Required
The research, which prospectively collected data and blood samples from patients with HIV who received the JYNNEOS vaccine, is small and included only 24 patients with HIV infection, with seven hospital workers who also received the vaccine and seven unvaccinated individuals as controls. “I am one of the control subjects of the study, and intradermal vaccination is not especially pleasant,” said Dr. Güerri-Fernandez. “It is a very innervated area, and the moment of introducing the liquid is uncomfortable. But it is perfectly bearable.”
Outpatient HIV-infected patients from the Infectious Diseases Unit of Hospital del Mar on antiretroviral therapy and with undetectable viral loads were grouped according to their CD4+ T-lymphocyte counts. Those with CD4+ T-lymphocyte counts ≤ 500/mm3 required at least one booster vaccine to exhibit efficient virus-specific T-lymphocyte responses. The magnitude of the T-cell response after this booster correlated directly with the CD4+ T-lymphocyte count of those vaccinated.
For Argentine infectious disease specialist Julián García, MD, clinical researcher at the Huésped Foundation in Buenos Aires, Argentina, who did not participate in the study, it is always productive to know that T-cell responses develop in patients with HIV infection, with CD4+ T-lymphocyte counts > and < 500/mm3, through an intradermal administration route.
Dr. García emphasized that the most novel aspect is that the JYNNEOS vaccine induces a specific T-cell response in patients with HIV infection that increases with higher CD4+ T-lymphocyte levels. However, he noted that the number of patients was less than 10 in most study groups, and the control group had only intradermal administration, which limits the interpretation of the results. “It will be necessary to verify this in studies with larger groups with control groups from all routes and with a correlate of protection.”
Dr. García referred to this latter point as a significant source of uncertainty. “The study is fundamentally based on the cellular response, but nowadays, there is no immune correlate of real-life protection.” He concluded that the study builds knowledge, which is essential for a vaccine that began to be used for mpox and the effectiveness of which is based on estimates.
Dr. Güerri-Fernandez and Dr. Garcia declared no relevant financial conflicts of interest.
This story was translated from the Medscape Spanish edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Should women of childbearing age eat a plant-based diet?
The prospective cohort study followed 11,459 women older than 18 years and evaluated their diet from the beginning using a validated questionnaire about the frequency and quality of plant-based foods. The participants had taken part in the Nurses’ Health Study II (1991-2009). From responses on the questionnaire, the investigators calculated the plant-based diet index (PDI) even among participants with an omnivorous diet. A higher score indicated greater adherence to the PDI.
“We wanted to know how one’s diet leading up to pregnancy influences the pregnancy, so we monitored women for virtually their entire reproductive life – almost 20 years – and gained an awareness of their typical diet before pregnancy,” study author Jorge E. Chavarro, MD, ScD, told this news organization. Dr. Chavarro is a professor of nutrition, epidemiology, and medicine at Harvard Medical School, Boston, and Harvard University’s School of Public Health in Cambridge, Mass. He researches how nutrition and lifestyle influence reproductive health and overall lifelong health in women.
Analysis of the data from the Nurses’ Health Study II revealed that as the proportion of animal products in diets decreased and the proportion of plant-based products increased, the risk of women experiencing hypertensive disorders of pregnancy decreased as well. Women in the highest PDI quintile had a significantly lower risk of hypertensive disorders of pregnancy, in comparison with those in the lowest quintile (relative risk, 0.76). This association was slightly stronger for pregnancy-related hypertension (RR, 0.77) than for preeclampsia (RR, 0.80).
Women in the highest PDI quintile had a 24% lower risk of hypertensive disorders of pregnancy than those in the lowest quintile; the risk of pregnancy-related hypertension decreased in a linear fashion as PDI increased, while the relationship of PDI to preeclampsia was restricted to women in the quintile with the highest adherence.
“It was clearer for pregnancy-related hypertension than for preeclampsia, but a diet made up primarily of plant-based foods seemed to be protective for both,” said Dr. Chavarro. He added that in addition to the problems these conditions cause during pregnancy, both increase the risk of subsequently developing other chronic diseases. “Could it be that modifiable lifestyle factors before and during pregnancy may not only help reduce problems during gestation but also prevent women’s health problems years later? That was the general motivation for this study.”
Mercedes Sotos-Prieto, PhD, a researcher at the Autonomous University of Madrid and an associate professor at Harvard University’s School of Public Health, told this news organization that the study’s methodology was very robust and that the investigators utilized appropriate statistical techniques for the analysis. She highlighted the fact that they used a validated food frequency questionnaire. She believes the study is also important because of the population group it focused on. “There has always been greater resistance when it comes to the diet of pregnant women, and the same is true for older adults. But we have seen that this type of diet, if it’s a quality diet, may be associated with health benefits.” She did not participate in the study.
Dr. Sotos-Prieto has a doctorate in nutritional epidemiology and public health. She works with large epidemiologic cohorts, such as the cohort of American nurses on which this study was based, and ENRICA, a cohort that is representative of the Spanish population and the population of older adults. She is the author of other studies that, like this one, found an association between a plant-based diet and a lower risk of frailty, both in the study involving American nurses and in a study involving a cohort of individuals aged 60 years or older in Spain (ENRICA-1).
Dr. Sotos-Prieto is also principal investigator on a project assessing the risk of cardiovascular disease based on modifiable lifestyles. For this project, the researchers created a tool, the healthy heart test, that can be used to evaluate diet quality “in 5 minutes, because we all know that doctors don’t have any time.” She thinks this test could be implemented in clinical practice to identify lifestyle behaviors that can be improved, such as by replacing refined cereals with whole grains or increasing legume consumption.
Tomatoes and French fries
The greatest benefit of a plant-based diet comes from the diet overall, not from any single food item. That said, these studies use a scoring system to reflect which items are healthy and which are not.
Diet was assessed every 4 years, starting in 1991, using a semiquantitative food frequency questionnaire that recorded the consumption of 131 foods and drinks during the previous year. The researchers determined the average frequency with which participants consumed each food. Eighteen food groups were sorted into three categories: healthy plant-based foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea, and coffee), unhealthy plant-based foods (fruit juices, refined grains, potatoes, sugary drinks, sweets, and desserts), and animal-based foods (dairy, eggs, fish or shellfish, meat, and various foods of animal origin).
Healthy plant-based foods were given positive scores, while less healthy plant-based foods and the animal-based food groups were given negative scores. The consumption of each food group was classified into PDI using quintiles.
Women in the highest PDI quintile had a significantly lower risk for hypertensive disorders of pregnancy, compared with women in the lowest quintile. There was a negative dose-response relationship between PDI and risk of the disease. “A vegetarian diet isn’t necessarily healthier than a nonvegetarian diet if it’s made up of superfluous foods like French fries and soft drinks,” said Dr. Sotos-Prieto. “The difference lies in the quality of the plant-based foods. That’s what makes the difference between a healthy and an unhealthy diet.”
Give up meat?
Dr. Chavarro said that removing meat from his dinner menu 22 years ago was one of the hardest things he ever did. “Now, it’s no problem,” he said. But he understands that there are people for whom changing the diet by replacing animal products with nonanimal products is difficult. But meat need not be entirely abandoned.
“The women in the highest quintile aren’t necessarily vegetarian or vegan, but they consume much fewer animal-based foods than the others,” he noted. He added that vegetarian or vegan diets are not incompatible with a healthy pregnancy. “All vegans know how to get vitamin B12 from supplements.”
Diet or weight loss?
Much of the benefit observed in the study appears to be related to better weight control. The body mass index between dietary assessment and pregnancy accounted for 39% of the relationship between PDI and hypertensive disorders of pregnancy and 48% of the relationship between PDI and pregnancy-related hypertension.
“Part of the association seems to be explained by better weight control over long periods,” explained Dr. Chavarro. Women who adopted diets with more plant-based foods gained weight more slowly than those who consumed more animal-based foods. “They are different in terms of their weight trajectory over many years. So, part of the association that we observe is related to better long-term weight control. But the other half of the association is attributable to the diet itself and not necessarily to weight.” The authors suggest mechanisms of action such as endothelial dysfunction, inflammation, or blood pressure before pregnancy to explain the association.
Dr. Sotos-Prieto believes that this point is “extremely relevant.” In her opinion, it reveals that controlling weight at the start of pregnancy is important for pregnant women. Weight control may also improve other factors, like gestational diabetes. “I think preventive measures should focus on that. These results show that interventions are needed to increase the likelihood of going into pregnancy with an appropriate weight. And this includes modifying diet.”
Generalizable results?
More than 90% of the participants in the Nurses’ Health Study were White, not Hispanic. Can the results be extrapolated to other populations? “The answer: The study needs to be repeated in other populations,” said Dr. Chavarro, “and that’s going to take time. But even without that information, I think we can use this study to inform other populations, regardless of ethnicity.”
Dr. Sotos-Prieto admitted that this hypothesis has not yet been tested in the Spanish population, but she is the author of a similar study that followed nearly 12,000 Spanish adults for a decade using the same PDI. In this study, every 10-point increase in PDI was associated with a 14% lower risk of mortality from any cause (hazard ratio, 0.86) and a 37% lower risk of death from cardiovascular disease (HR, 0.63). She also believes that the recommendations derived from the study could be generalized to other populations “as long as each country’s culture is taken into account, to see how it can be culturally adapted. If it’s a population that consumes a lot of refined cereals, for example, make small changes to whole grains.”
Weighing the evidence
The study has strengths and limitations, owing to its methodology, and Dr. Chavarro himself recognizes that “in terms of hypertensive disorders of pregnancy specifically, this won’t be the last word.” But there is a pressing need to find answers.
The American College of Obstetricians and Gynecologists and the World Health Organization encourage women to follow healthy diets before and during pregnancy. But they provide little guidance on what constitutes a healthy diet when it comes to minimizing the risks of adverse pregnancy outcomes. “They are quite ambiguous and vague,” said Dr. Chavarro.
These new findings suggest that plant-based diets may be one such strategy, particularly because some evidence was found that these diets may be beneficial for women older than 35 years, who are considered a high-risk group.
“There are certainly many ways to eat healthily, but if we think about these pregnancy complications that can have serious consequences for the mother and the fetus, we might consider this as a healthy diet option,” Dr. Chavarro noted.
But is the evidence robust enough to recommend that patients make changes? “Ideally, there will be more studies,” stated Dr. Chavarro. “There are two ways to understand the problem. One is not making recommendations until you have three controlled clinical trials, which, even with the willingness and funding to do so, will take 15-20 years. But if we have to provide the best available information to those who need it today, I think these are solid results for guiding behavior.
“It’s always better if we can make decisions based on solid, incontrovertible information. But it’s not always available, and you must learn to live in both worlds and make decisions with uncertainties,” he concluded.
Dr. Sotos-Prieto and Dr. Chavarro have disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish Edition. A version of this article first appeared on Medscape.com.
The prospective cohort study followed 11,459 women older than 18 years and evaluated their diet from the beginning using a validated questionnaire about the frequency and quality of plant-based foods. The participants had taken part in the Nurses’ Health Study II (1991-2009). From responses on the questionnaire, the investigators calculated the plant-based diet index (PDI) even among participants with an omnivorous diet. A higher score indicated greater adherence to the PDI.
“We wanted to know how one’s diet leading up to pregnancy influences the pregnancy, so we monitored women for virtually their entire reproductive life – almost 20 years – and gained an awareness of their typical diet before pregnancy,” study author Jorge E. Chavarro, MD, ScD, told this news organization. Dr. Chavarro is a professor of nutrition, epidemiology, and medicine at Harvard Medical School, Boston, and Harvard University’s School of Public Health in Cambridge, Mass. He researches how nutrition and lifestyle influence reproductive health and overall lifelong health in women.
Analysis of the data from the Nurses’ Health Study II revealed that as the proportion of animal products in diets decreased and the proportion of plant-based products increased, the risk of women experiencing hypertensive disorders of pregnancy decreased as well. Women in the highest PDI quintile had a significantly lower risk of hypertensive disorders of pregnancy, in comparison with those in the lowest quintile (relative risk, 0.76). This association was slightly stronger for pregnancy-related hypertension (RR, 0.77) than for preeclampsia (RR, 0.80).
Women in the highest PDI quintile had a 24% lower risk of hypertensive disorders of pregnancy than those in the lowest quintile; the risk of pregnancy-related hypertension decreased in a linear fashion as PDI increased, while the relationship of PDI to preeclampsia was restricted to women in the quintile with the highest adherence.
“It was clearer for pregnancy-related hypertension than for preeclampsia, but a diet made up primarily of plant-based foods seemed to be protective for both,” said Dr. Chavarro. He added that in addition to the problems these conditions cause during pregnancy, both increase the risk of subsequently developing other chronic diseases. “Could it be that modifiable lifestyle factors before and during pregnancy may not only help reduce problems during gestation but also prevent women’s health problems years later? That was the general motivation for this study.”
Mercedes Sotos-Prieto, PhD, a researcher at the Autonomous University of Madrid and an associate professor at Harvard University’s School of Public Health, told this news organization that the study’s methodology was very robust and that the investigators utilized appropriate statistical techniques for the analysis. She highlighted the fact that they used a validated food frequency questionnaire. She believes the study is also important because of the population group it focused on. “There has always been greater resistance when it comes to the diet of pregnant women, and the same is true for older adults. But we have seen that this type of diet, if it’s a quality diet, may be associated with health benefits.” She did not participate in the study.
Dr. Sotos-Prieto has a doctorate in nutritional epidemiology and public health. She works with large epidemiologic cohorts, such as the cohort of American nurses on which this study was based, and ENRICA, a cohort that is representative of the Spanish population and the population of older adults. She is the author of other studies that, like this one, found an association between a plant-based diet and a lower risk of frailty, both in the study involving American nurses and in a study involving a cohort of individuals aged 60 years or older in Spain (ENRICA-1).
Dr. Sotos-Prieto is also principal investigator on a project assessing the risk of cardiovascular disease based on modifiable lifestyles. For this project, the researchers created a tool, the healthy heart test, that can be used to evaluate diet quality “in 5 minutes, because we all know that doctors don’t have any time.” She thinks this test could be implemented in clinical practice to identify lifestyle behaviors that can be improved, such as by replacing refined cereals with whole grains or increasing legume consumption.
Tomatoes and French fries
The greatest benefit of a plant-based diet comes from the diet overall, not from any single food item. That said, these studies use a scoring system to reflect which items are healthy and which are not.
Diet was assessed every 4 years, starting in 1991, using a semiquantitative food frequency questionnaire that recorded the consumption of 131 foods and drinks during the previous year. The researchers determined the average frequency with which participants consumed each food. Eighteen food groups were sorted into three categories: healthy plant-based foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea, and coffee), unhealthy plant-based foods (fruit juices, refined grains, potatoes, sugary drinks, sweets, and desserts), and animal-based foods (dairy, eggs, fish or shellfish, meat, and various foods of animal origin).
Healthy plant-based foods were given positive scores, while less healthy plant-based foods and the animal-based food groups were given negative scores. The consumption of each food group was classified into PDI using quintiles.
Women in the highest PDI quintile had a significantly lower risk for hypertensive disorders of pregnancy, compared with women in the lowest quintile. There was a negative dose-response relationship between PDI and risk of the disease. “A vegetarian diet isn’t necessarily healthier than a nonvegetarian diet if it’s made up of superfluous foods like French fries and soft drinks,” said Dr. Sotos-Prieto. “The difference lies in the quality of the plant-based foods. That’s what makes the difference between a healthy and an unhealthy diet.”
Give up meat?
Dr. Chavarro said that removing meat from his dinner menu 22 years ago was one of the hardest things he ever did. “Now, it’s no problem,” he said. But he understands that there are people for whom changing the diet by replacing animal products with nonanimal products is difficult. But meat need not be entirely abandoned.
“The women in the highest quintile aren’t necessarily vegetarian or vegan, but they consume much fewer animal-based foods than the others,” he noted. He added that vegetarian or vegan diets are not incompatible with a healthy pregnancy. “All vegans know how to get vitamin B12 from supplements.”
Diet or weight loss?
Much of the benefit observed in the study appears to be related to better weight control. The body mass index between dietary assessment and pregnancy accounted for 39% of the relationship between PDI and hypertensive disorders of pregnancy and 48% of the relationship between PDI and pregnancy-related hypertension.
“Part of the association seems to be explained by better weight control over long periods,” explained Dr. Chavarro. Women who adopted diets with more plant-based foods gained weight more slowly than those who consumed more animal-based foods. “They are different in terms of their weight trajectory over many years. So, part of the association that we observe is related to better long-term weight control. But the other half of the association is attributable to the diet itself and not necessarily to weight.” The authors suggest mechanisms of action such as endothelial dysfunction, inflammation, or blood pressure before pregnancy to explain the association.
Dr. Sotos-Prieto believes that this point is “extremely relevant.” In her opinion, it reveals that controlling weight at the start of pregnancy is important for pregnant women. Weight control may also improve other factors, like gestational diabetes. “I think preventive measures should focus on that. These results show that interventions are needed to increase the likelihood of going into pregnancy with an appropriate weight. And this includes modifying diet.”
Generalizable results?
More than 90% of the participants in the Nurses’ Health Study were White, not Hispanic. Can the results be extrapolated to other populations? “The answer: The study needs to be repeated in other populations,” said Dr. Chavarro, “and that’s going to take time. But even without that information, I think we can use this study to inform other populations, regardless of ethnicity.”
Dr. Sotos-Prieto admitted that this hypothesis has not yet been tested in the Spanish population, but she is the author of a similar study that followed nearly 12,000 Spanish adults for a decade using the same PDI. In this study, every 10-point increase in PDI was associated with a 14% lower risk of mortality from any cause (hazard ratio, 0.86) and a 37% lower risk of death from cardiovascular disease (HR, 0.63). She also believes that the recommendations derived from the study could be generalized to other populations “as long as each country’s culture is taken into account, to see how it can be culturally adapted. If it’s a population that consumes a lot of refined cereals, for example, make small changes to whole grains.”
Weighing the evidence
The study has strengths and limitations, owing to its methodology, and Dr. Chavarro himself recognizes that “in terms of hypertensive disorders of pregnancy specifically, this won’t be the last word.” But there is a pressing need to find answers.
The American College of Obstetricians and Gynecologists and the World Health Organization encourage women to follow healthy diets before and during pregnancy. But they provide little guidance on what constitutes a healthy diet when it comes to minimizing the risks of adverse pregnancy outcomes. “They are quite ambiguous and vague,” said Dr. Chavarro.
These new findings suggest that plant-based diets may be one such strategy, particularly because some evidence was found that these diets may be beneficial for women older than 35 years, who are considered a high-risk group.
“There are certainly many ways to eat healthily, but if we think about these pregnancy complications that can have serious consequences for the mother and the fetus, we might consider this as a healthy diet option,” Dr. Chavarro noted.
But is the evidence robust enough to recommend that patients make changes? “Ideally, there will be more studies,” stated Dr. Chavarro. “There are two ways to understand the problem. One is not making recommendations until you have three controlled clinical trials, which, even with the willingness and funding to do so, will take 15-20 years. But if we have to provide the best available information to those who need it today, I think these are solid results for guiding behavior.
“It’s always better if we can make decisions based on solid, incontrovertible information. But it’s not always available, and you must learn to live in both worlds and make decisions with uncertainties,” he concluded.
Dr. Sotos-Prieto and Dr. Chavarro have disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish Edition. A version of this article first appeared on Medscape.com.
The prospective cohort study followed 11,459 women older than 18 years and evaluated their diet from the beginning using a validated questionnaire about the frequency and quality of plant-based foods. The participants had taken part in the Nurses’ Health Study II (1991-2009). From responses on the questionnaire, the investigators calculated the plant-based diet index (PDI) even among participants with an omnivorous diet. A higher score indicated greater adherence to the PDI.
“We wanted to know how one’s diet leading up to pregnancy influences the pregnancy, so we monitored women for virtually their entire reproductive life – almost 20 years – and gained an awareness of their typical diet before pregnancy,” study author Jorge E. Chavarro, MD, ScD, told this news organization. Dr. Chavarro is a professor of nutrition, epidemiology, and medicine at Harvard Medical School, Boston, and Harvard University’s School of Public Health in Cambridge, Mass. He researches how nutrition and lifestyle influence reproductive health and overall lifelong health in women.
Analysis of the data from the Nurses’ Health Study II revealed that as the proportion of animal products in diets decreased and the proportion of plant-based products increased, the risk of women experiencing hypertensive disorders of pregnancy decreased as well. Women in the highest PDI quintile had a significantly lower risk of hypertensive disorders of pregnancy, in comparison with those in the lowest quintile (relative risk, 0.76). This association was slightly stronger for pregnancy-related hypertension (RR, 0.77) than for preeclampsia (RR, 0.80).
Women in the highest PDI quintile had a 24% lower risk of hypertensive disorders of pregnancy than those in the lowest quintile; the risk of pregnancy-related hypertension decreased in a linear fashion as PDI increased, while the relationship of PDI to preeclampsia was restricted to women in the quintile with the highest adherence.
“It was clearer for pregnancy-related hypertension than for preeclampsia, but a diet made up primarily of plant-based foods seemed to be protective for both,” said Dr. Chavarro. He added that in addition to the problems these conditions cause during pregnancy, both increase the risk of subsequently developing other chronic diseases. “Could it be that modifiable lifestyle factors before and during pregnancy may not only help reduce problems during gestation but also prevent women’s health problems years later? That was the general motivation for this study.”
Mercedes Sotos-Prieto, PhD, a researcher at the Autonomous University of Madrid and an associate professor at Harvard University’s School of Public Health, told this news organization that the study’s methodology was very robust and that the investigators utilized appropriate statistical techniques for the analysis. She highlighted the fact that they used a validated food frequency questionnaire. She believes the study is also important because of the population group it focused on. “There has always been greater resistance when it comes to the diet of pregnant women, and the same is true for older adults. But we have seen that this type of diet, if it’s a quality diet, may be associated with health benefits.” She did not participate in the study.
Dr. Sotos-Prieto has a doctorate in nutritional epidemiology and public health. She works with large epidemiologic cohorts, such as the cohort of American nurses on which this study was based, and ENRICA, a cohort that is representative of the Spanish population and the population of older adults. She is the author of other studies that, like this one, found an association between a plant-based diet and a lower risk of frailty, both in the study involving American nurses and in a study involving a cohort of individuals aged 60 years or older in Spain (ENRICA-1).
Dr. Sotos-Prieto is also principal investigator on a project assessing the risk of cardiovascular disease based on modifiable lifestyles. For this project, the researchers created a tool, the healthy heart test, that can be used to evaluate diet quality “in 5 minutes, because we all know that doctors don’t have any time.” She thinks this test could be implemented in clinical practice to identify lifestyle behaviors that can be improved, such as by replacing refined cereals with whole grains or increasing legume consumption.
Tomatoes and French fries
The greatest benefit of a plant-based diet comes from the diet overall, not from any single food item. That said, these studies use a scoring system to reflect which items are healthy and which are not.
Diet was assessed every 4 years, starting in 1991, using a semiquantitative food frequency questionnaire that recorded the consumption of 131 foods and drinks during the previous year. The researchers determined the average frequency with which participants consumed each food. Eighteen food groups were sorted into three categories: healthy plant-based foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea, and coffee), unhealthy plant-based foods (fruit juices, refined grains, potatoes, sugary drinks, sweets, and desserts), and animal-based foods (dairy, eggs, fish or shellfish, meat, and various foods of animal origin).
Healthy plant-based foods were given positive scores, while less healthy plant-based foods and the animal-based food groups were given negative scores. The consumption of each food group was classified into PDI using quintiles.
Women in the highest PDI quintile had a significantly lower risk for hypertensive disorders of pregnancy, compared with women in the lowest quintile. There was a negative dose-response relationship between PDI and risk of the disease. “A vegetarian diet isn’t necessarily healthier than a nonvegetarian diet if it’s made up of superfluous foods like French fries and soft drinks,” said Dr. Sotos-Prieto. “The difference lies in the quality of the plant-based foods. That’s what makes the difference between a healthy and an unhealthy diet.”
Give up meat?
Dr. Chavarro said that removing meat from his dinner menu 22 years ago was one of the hardest things he ever did. “Now, it’s no problem,” he said. But he understands that there are people for whom changing the diet by replacing animal products with nonanimal products is difficult. But meat need not be entirely abandoned.
“The women in the highest quintile aren’t necessarily vegetarian or vegan, but they consume much fewer animal-based foods than the others,” he noted. He added that vegetarian or vegan diets are not incompatible with a healthy pregnancy. “All vegans know how to get vitamin B12 from supplements.”
Diet or weight loss?
Much of the benefit observed in the study appears to be related to better weight control. The body mass index between dietary assessment and pregnancy accounted for 39% of the relationship between PDI and hypertensive disorders of pregnancy and 48% of the relationship between PDI and pregnancy-related hypertension.
“Part of the association seems to be explained by better weight control over long periods,” explained Dr. Chavarro. Women who adopted diets with more plant-based foods gained weight more slowly than those who consumed more animal-based foods. “They are different in terms of their weight trajectory over many years. So, part of the association that we observe is related to better long-term weight control. But the other half of the association is attributable to the diet itself and not necessarily to weight.” The authors suggest mechanisms of action such as endothelial dysfunction, inflammation, or blood pressure before pregnancy to explain the association.
Dr. Sotos-Prieto believes that this point is “extremely relevant.” In her opinion, it reveals that controlling weight at the start of pregnancy is important for pregnant women. Weight control may also improve other factors, like gestational diabetes. “I think preventive measures should focus on that. These results show that interventions are needed to increase the likelihood of going into pregnancy with an appropriate weight. And this includes modifying diet.”
Generalizable results?
More than 90% of the participants in the Nurses’ Health Study were White, not Hispanic. Can the results be extrapolated to other populations? “The answer: The study needs to be repeated in other populations,” said Dr. Chavarro, “and that’s going to take time. But even without that information, I think we can use this study to inform other populations, regardless of ethnicity.”
Dr. Sotos-Prieto admitted that this hypothesis has not yet been tested in the Spanish population, but she is the author of a similar study that followed nearly 12,000 Spanish adults for a decade using the same PDI. In this study, every 10-point increase in PDI was associated with a 14% lower risk of mortality from any cause (hazard ratio, 0.86) and a 37% lower risk of death from cardiovascular disease (HR, 0.63). She also believes that the recommendations derived from the study could be generalized to other populations “as long as each country’s culture is taken into account, to see how it can be culturally adapted. If it’s a population that consumes a lot of refined cereals, for example, make small changes to whole grains.”
Weighing the evidence
The study has strengths and limitations, owing to its methodology, and Dr. Chavarro himself recognizes that “in terms of hypertensive disorders of pregnancy specifically, this won’t be the last word.” But there is a pressing need to find answers.
The American College of Obstetricians and Gynecologists and the World Health Organization encourage women to follow healthy diets before and during pregnancy. But they provide little guidance on what constitutes a healthy diet when it comes to minimizing the risks of adverse pregnancy outcomes. “They are quite ambiguous and vague,” said Dr. Chavarro.
These new findings suggest that plant-based diets may be one such strategy, particularly because some evidence was found that these diets may be beneficial for women older than 35 years, who are considered a high-risk group.
“There are certainly many ways to eat healthily, but if we think about these pregnancy complications that can have serious consequences for the mother and the fetus, we might consider this as a healthy diet option,” Dr. Chavarro noted.
But is the evidence robust enough to recommend that patients make changes? “Ideally, there will be more studies,” stated Dr. Chavarro. “There are two ways to understand the problem. One is not making recommendations until you have three controlled clinical trials, which, even with the willingness and funding to do so, will take 15-20 years. But if we have to provide the best available information to those who need it today, I think these are solid results for guiding behavior.
“It’s always better if we can make decisions based on solid, incontrovertible information. But it’s not always available, and you must learn to live in both worlds and make decisions with uncertainties,” he concluded.
Dr. Sotos-Prieto and Dr. Chavarro have disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish Edition. A version of this article first appeared on Medscape.com.
FROM AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
What happens if we sit for more than 8 hours per day?
according to a recent Latin American study published in BMC Public Health.
These data come from almost 8,000 people aged 20-65 years (half of whom are women) who participated in the Latin American Study on Nutrition and Health (ELANS). The cross-sectional survey included representative samples from urban populations in Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela. The average time spent sitting was 420 min/d. Ecuador had the lowest time (300 min/day), and Argentina and Peru had the highest (480 min/day).
No amount of sitting time has been associated with a greater health risk, but the World Health Organization recommends that sitting time be minimal.
“We used to believe that any intense physical exercise could compensate for a sedentary life. But now we know that a sedentary lifestyle in general and sitting time in particular have a direct effect and are an independent risk factor for chronic diseases,” said study author Irina Kovalskys, PhD, a pediatric specialist in nutrition and a professor of nutrition at the Catholic University of Argentina, Buenos Aires, and a principal investigator of ELANS.
Dr. Kovalskys stated that the 420-min average sitting time is worrying in a population such as the one studied, in which 60% of adults are obese and there are high rates of cardiometabolic risk factors. She affirmed that it is important to raise awareness among the population and focus on adolescents.
Felipe Lobelo, PhD, is a Colombian physician, an associate professor of global health at Emory University and director of epidemiology at Kaiser Permanente Georgia, both in Atlanta. He did not participate in this study but promotes the concept of exercise in medicine. The activity of the patient must be included in a clinical setting, and improving the level of physical activity can have a positive impact on health prognosis, he said.
“To make public health recommendations or even advise patients, a cutoff point is needed. Guidelines recommend 150 minutes per week of moderate to vigorous physical activity, and some countries have started to indicate that we should be concerned about people’s sitting time. There is still no equivalent to the 150 minutes, therefore, these studies are important, especially in the Latin American population,” said Dr. Lobelo.
He explained that the concept of an increased risk of death or chronic disease because of a lack of physical activity arose in the past 50 years, but only in the past 2 decades have we started thinking about sitting time.
“Spending more than 8 hours sitting per day clearly causes a much higher risk of chronic diseases, including obesity and diabetes. It may be a continuous and progressive association, and the point at which this increase becomes exponential is clearly between 6 and 8 hours of sitting time,” Dr. Lobelo added.
The authors expected to find a linear association with risk for being overweight or obese after 4 hours, but they did not find one. “This study has limitations. Among them was that other indicators were not considered, such as health indicators. Collaborations are starting with other research groups, and other studies are being designed,” said study author Gerson Ferrari, PhD, an associate professor at Santiago de Chile University.
Comparing indicators
The Latin American study tried to establish a sitting cutoff time after which the risk of becoming overweight or obese increases. It used three indicators of excess weight: body mass index (BMI), waist circumference, and neck circumference.
Sitting for more than 8 hours increased the chances of excess weight by 10% when measured by BMI and by 13% when neck circumference was used.
Dr. Ferrari stated that the result obtained measuring BMI is the one that should be considered, because it is used in public policy. Neck circumference is a more recent measurement of detection and it is less studied, but it is a valid indicator, with good sensitivity and advantages over others, such as ease of measurement and lack of variation over time.
According to the results of this study, measuring neck circumference may be the most sensitive method of the three. Neck circumference was proportionally greater in people who sat for at least 4, at least 6, and at least 8 hours/day than in those who sat for less than 4, less than 6, and less than 8 hours/day. This relationship was not observed with the other indicators.
Broaching the topic
“What is important is uninterrupted sitting time. The recommendation is to break up those sitting times with active periods. Health professionals have already incorporated the concept of moderate to vigorous physical exercise, but nonintense activities are sufficient to reduce sitting time. Yoga may not be vigorous, but it is valuable at reducing sitting time,” said Dr. Kovalskys.
Dr. Ferrari recommended giving patients concrete messages so that they spend as little time possible sitting. “It is better to stand on the bus or the subway even when there is a place to sit. Are you going to talk on the phone? It is better to do it while walking or at least standing instead of sitting.”
A recent literature review conducted by investigators of the University of Birmingham (England) studied the possible molecular and physiologic mechanisms of inactivity time, health consequences, and protection strategies. It offers an evaluation of interventions that can compensate for the immediate negative consequences of inactivity.
Physical activity
Some studies suggest that more than 60 min/day of moderate-intensity exercise or more than 150 min/week of moderate to vigorous exercise may be effective at mitigating the increased risk for mortality associated with sitting time, but reduced intensity may not be enough.
Active pauses
Interrupting sitting every 30-60 min to walk or cycle (2-10 min), performing 3 minutes of simple resistance activities every 30 minutes, such as calf or knee lifts, performing intermittent leg movements (1 minute of activity for every 4 minutes of inactivity during a 3-hour protocol session), or pausing to climb stairs (5 minutes every hour) may be beneficial for vascular health. However, not all studies have demonstrated these positive effects, therefore, some populations may need exercise of greater intensity or duration to counteract the negative vascular effects of acute inactivity periods.
Standing workstations
Standing workstations are effective at reducing sitting time in offices but may be ineffective at reducing vascular alterations related to sitting time. Although some experimental studies indicate vascular benefits, epidemiologic studies suggest that long periods of standing can be harmful to vascular health, especially for venous diseases. Recommendations for use should be accompanied by specific regimens on the frequency and duration of the position to attain the maximum benefits and minimize other vascular complications.
One problem that Dr. Lobelo noted is that some doctors ask their patients how active they are, but they do so in a nonstandardized manner. This observation led him to publish, together with the American Heart Association, an article on the importance for health systems of considering physical activity as a vital sign and including it in records in a standardized manner.
He said that “one advantage of having physical activity as a vital sign in patient medical records is that it allows us to identify individuals who are at greater risk.”
Kaiser Permanente asks the following questions: how many minutes of physical activity do you perform regularly per week, and what is the average intensity of that activity? Patients can be classified into the following three groups: those who follow the recommendations, those with almost no activity, and those who perform some physical activity but do not meet the recommended 150 min/week of moderate to vigorous activity.
Recording sitting time is more difficult. Dr. Lobelo indicated that “it is easier for a person to remember how much time they spent running than how long they were sitting.” Regarding the use of technology, he commented that most watches provide a good estimate. Without technology, it can be estimated by asking how much time is spent in the car, on the bus, or in front of the computer or television and then adding up these times.
Dr. Lobelo emphasized that the two behaviors, lack of physical activity and excessive sitting time, have independent associations with health outcomes. But if both are combined, the risk of obesity, diabetes, and cardiovascular diseases is not just added but rather is multiplied. These behaviors contribute to the epidemic of obesity and diabetes, since most people do not follow either of the two recommendations.
“Studies show that of the two behaviors, the more negative for health would be not following the physical activity recommendations,” said Dr. Lobelo. “If the recommendation of 150 min/week of moderate to vigorous physical activity is followed, the associated risk of sitting too much declines by 80%-90%. Additionally, we can prevent, help to manage, and decrease the risk of complications in more than 100 diseases, including infections. During the pandemic, it was observed that more active people had a lower risk of dying or of being hospitalized due to COVID-19 than less active people, independently of other factors, such as hypertension, diabetes, and obesity.”
Moreover, Dr. Lobelo believes in “practicing what you preach” and advocates that doctors become healthy models.
Dr. Lobelo, Dr. Ferrari, and Dr. Kovalskys disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish edition. A version appeared on Medscape.com.
according to a recent Latin American study published in BMC Public Health.
These data come from almost 8,000 people aged 20-65 years (half of whom are women) who participated in the Latin American Study on Nutrition and Health (ELANS). The cross-sectional survey included representative samples from urban populations in Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela. The average time spent sitting was 420 min/d. Ecuador had the lowest time (300 min/day), and Argentina and Peru had the highest (480 min/day).
No amount of sitting time has been associated with a greater health risk, but the World Health Organization recommends that sitting time be minimal.
“We used to believe that any intense physical exercise could compensate for a sedentary life. But now we know that a sedentary lifestyle in general and sitting time in particular have a direct effect and are an independent risk factor for chronic diseases,” said study author Irina Kovalskys, PhD, a pediatric specialist in nutrition and a professor of nutrition at the Catholic University of Argentina, Buenos Aires, and a principal investigator of ELANS.
Dr. Kovalskys stated that the 420-min average sitting time is worrying in a population such as the one studied, in which 60% of adults are obese and there are high rates of cardiometabolic risk factors. She affirmed that it is important to raise awareness among the population and focus on adolescents.
Felipe Lobelo, PhD, is a Colombian physician, an associate professor of global health at Emory University and director of epidemiology at Kaiser Permanente Georgia, both in Atlanta. He did not participate in this study but promotes the concept of exercise in medicine. The activity of the patient must be included in a clinical setting, and improving the level of physical activity can have a positive impact on health prognosis, he said.
“To make public health recommendations or even advise patients, a cutoff point is needed. Guidelines recommend 150 minutes per week of moderate to vigorous physical activity, and some countries have started to indicate that we should be concerned about people’s sitting time. There is still no equivalent to the 150 minutes, therefore, these studies are important, especially in the Latin American population,” said Dr. Lobelo.
He explained that the concept of an increased risk of death or chronic disease because of a lack of physical activity arose in the past 50 years, but only in the past 2 decades have we started thinking about sitting time.
“Spending more than 8 hours sitting per day clearly causes a much higher risk of chronic diseases, including obesity and diabetes. It may be a continuous and progressive association, and the point at which this increase becomes exponential is clearly between 6 and 8 hours of sitting time,” Dr. Lobelo added.
The authors expected to find a linear association with risk for being overweight or obese after 4 hours, but they did not find one. “This study has limitations. Among them was that other indicators were not considered, such as health indicators. Collaborations are starting with other research groups, and other studies are being designed,” said study author Gerson Ferrari, PhD, an associate professor at Santiago de Chile University.
Comparing indicators
The Latin American study tried to establish a sitting cutoff time after which the risk of becoming overweight or obese increases. It used three indicators of excess weight: body mass index (BMI), waist circumference, and neck circumference.
Sitting for more than 8 hours increased the chances of excess weight by 10% when measured by BMI and by 13% when neck circumference was used.
Dr. Ferrari stated that the result obtained measuring BMI is the one that should be considered, because it is used in public policy. Neck circumference is a more recent measurement of detection and it is less studied, but it is a valid indicator, with good sensitivity and advantages over others, such as ease of measurement and lack of variation over time.
According to the results of this study, measuring neck circumference may be the most sensitive method of the three. Neck circumference was proportionally greater in people who sat for at least 4, at least 6, and at least 8 hours/day than in those who sat for less than 4, less than 6, and less than 8 hours/day. This relationship was not observed with the other indicators.
Broaching the topic
“What is important is uninterrupted sitting time. The recommendation is to break up those sitting times with active periods. Health professionals have already incorporated the concept of moderate to vigorous physical exercise, but nonintense activities are sufficient to reduce sitting time. Yoga may not be vigorous, but it is valuable at reducing sitting time,” said Dr. Kovalskys.
Dr. Ferrari recommended giving patients concrete messages so that they spend as little time possible sitting. “It is better to stand on the bus or the subway even when there is a place to sit. Are you going to talk on the phone? It is better to do it while walking or at least standing instead of sitting.”
A recent literature review conducted by investigators of the University of Birmingham (England) studied the possible molecular and physiologic mechanisms of inactivity time, health consequences, and protection strategies. It offers an evaluation of interventions that can compensate for the immediate negative consequences of inactivity.
Physical activity
Some studies suggest that more than 60 min/day of moderate-intensity exercise or more than 150 min/week of moderate to vigorous exercise may be effective at mitigating the increased risk for mortality associated with sitting time, but reduced intensity may not be enough.
Active pauses
Interrupting sitting every 30-60 min to walk or cycle (2-10 min), performing 3 minutes of simple resistance activities every 30 minutes, such as calf or knee lifts, performing intermittent leg movements (1 minute of activity for every 4 minutes of inactivity during a 3-hour protocol session), or pausing to climb stairs (5 minutes every hour) may be beneficial for vascular health. However, not all studies have demonstrated these positive effects, therefore, some populations may need exercise of greater intensity or duration to counteract the negative vascular effects of acute inactivity periods.
Standing workstations
Standing workstations are effective at reducing sitting time in offices but may be ineffective at reducing vascular alterations related to sitting time. Although some experimental studies indicate vascular benefits, epidemiologic studies suggest that long periods of standing can be harmful to vascular health, especially for venous diseases. Recommendations for use should be accompanied by specific regimens on the frequency and duration of the position to attain the maximum benefits and minimize other vascular complications.
One problem that Dr. Lobelo noted is that some doctors ask their patients how active they are, but they do so in a nonstandardized manner. This observation led him to publish, together with the American Heart Association, an article on the importance for health systems of considering physical activity as a vital sign and including it in records in a standardized manner.
He said that “one advantage of having physical activity as a vital sign in patient medical records is that it allows us to identify individuals who are at greater risk.”
Kaiser Permanente asks the following questions: how many minutes of physical activity do you perform regularly per week, and what is the average intensity of that activity? Patients can be classified into the following three groups: those who follow the recommendations, those with almost no activity, and those who perform some physical activity but do not meet the recommended 150 min/week of moderate to vigorous activity.
Recording sitting time is more difficult. Dr. Lobelo indicated that “it is easier for a person to remember how much time they spent running than how long they were sitting.” Regarding the use of technology, he commented that most watches provide a good estimate. Without technology, it can be estimated by asking how much time is spent in the car, on the bus, or in front of the computer or television and then adding up these times.
Dr. Lobelo emphasized that the two behaviors, lack of physical activity and excessive sitting time, have independent associations with health outcomes. But if both are combined, the risk of obesity, diabetes, and cardiovascular diseases is not just added but rather is multiplied. These behaviors contribute to the epidemic of obesity and diabetes, since most people do not follow either of the two recommendations.
“Studies show that of the two behaviors, the more negative for health would be not following the physical activity recommendations,” said Dr. Lobelo. “If the recommendation of 150 min/week of moderate to vigorous physical activity is followed, the associated risk of sitting too much declines by 80%-90%. Additionally, we can prevent, help to manage, and decrease the risk of complications in more than 100 diseases, including infections. During the pandemic, it was observed that more active people had a lower risk of dying or of being hospitalized due to COVID-19 than less active people, independently of other factors, such as hypertension, diabetes, and obesity.”
Moreover, Dr. Lobelo believes in “practicing what you preach” and advocates that doctors become healthy models.
Dr. Lobelo, Dr. Ferrari, and Dr. Kovalskys disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish edition. A version appeared on Medscape.com.
according to a recent Latin American study published in BMC Public Health.
These data come from almost 8,000 people aged 20-65 years (half of whom are women) who participated in the Latin American Study on Nutrition and Health (ELANS). The cross-sectional survey included representative samples from urban populations in Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela. The average time spent sitting was 420 min/d. Ecuador had the lowest time (300 min/day), and Argentina and Peru had the highest (480 min/day).
No amount of sitting time has been associated with a greater health risk, but the World Health Organization recommends that sitting time be minimal.
“We used to believe that any intense physical exercise could compensate for a sedentary life. But now we know that a sedentary lifestyle in general and sitting time in particular have a direct effect and are an independent risk factor for chronic diseases,” said study author Irina Kovalskys, PhD, a pediatric specialist in nutrition and a professor of nutrition at the Catholic University of Argentina, Buenos Aires, and a principal investigator of ELANS.
Dr. Kovalskys stated that the 420-min average sitting time is worrying in a population such as the one studied, in which 60% of adults are obese and there are high rates of cardiometabolic risk factors. She affirmed that it is important to raise awareness among the population and focus on adolescents.
Felipe Lobelo, PhD, is a Colombian physician, an associate professor of global health at Emory University and director of epidemiology at Kaiser Permanente Georgia, both in Atlanta. He did not participate in this study but promotes the concept of exercise in medicine. The activity of the patient must be included in a clinical setting, and improving the level of physical activity can have a positive impact on health prognosis, he said.
“To make public health recommendations or even advise patients, a cutoff point is needed. Guidelines recommend 150 minutes per week of moderate to vigorous physical activity, and some countries have started to indicate that we should be concerned about people’s sitting time. There is still no equivalent to the 150 minutes, therefore, these studies are important, especially in the Latin American population,” said Dr. Lobelo.
He explained that the concept of an increased risk of death or chronic disease because of a lack of physical activity arose in the past 50 years, but only in the past 2 decades have we started thinking about sitting time.
“Spending more than 8 hours sitting per day clearly causes a much higher risk of chronic diseases, including obesity and diabetes. It may be a continuous and progressive association, and the point at which this increase becomes exponential is clearly between 6 and 8 hours of sitting time,” Dr. Lobelo added.
The authors expected to find a linear association with risk for being overweight or obese after 4 hours, but they did not find one. “This study has limitations. Among them was that other indicators were not considered, such as health indicators. Collaborations are starting with other research groups, and other studies are being designed,” said study author Gerson Ferrari, PhD, an associate professor at Santiago de Chile University.
Comparing indicators
The Latin American study tried to establish a sitting cutoff time after which the risk of becoming overweight or obese increases. It used three indicators of excess weight: body mass index (BMI), waist circumference, and neck circumference.
Sitting for more than 8 hours increased the chances of excess weight by 10% when measured by BMI and by 13% when neck circumference was used.
Dr. Ferrari stated that the result obtained measuring BMI is the one that should be considered, because it is used in public policy. Neck circumference is a more recent measurement of detection and it is less studied, but it is a valid indicator, with good sensitivity and advantages over others, such as ease of measurement and lack of variation over time.
According to the results of this study, measuring neck circumference may be the most sensitive method of the three. Neck circumference was proportionally greater in people who sat for at least 4, at least 6, and at least 8 hours/day than in those who sat for less than 4, less than 6, and less than 8 hours/day. This relationship was not observed with the other indicators.
Broaching the topic
“What is important is uninterrupted sitting time. The recommendation is to break up those sitting times with active periods. Health professionals have already incorporated the concept of moderate to vigorous physical exercise, but nonintense activities are sufficient to reduce sitting time. Yoga may not be vigorous, but it is valuable at reducing sitting time,” said Dr. Kovalskys.
Dr. Ferrari recommended giving patients concrete messages so that they spend as little time possible sitting. “It is better to stand on the bus or the subway even when there is a place to sit. Are you going to talk on the phone? It is better to do it while walking or at least standing instead of sitting.”
A recent literature review conducted by investigators of the University of Birmingham (England) studied the possible molecular and physiologic mechanisms of inactivity time, health consequences, and protection strategies. It offers an evaluation of interventions that can compensate for the immediate negative consequences of inactivity.
Physical activity
Some studies suggest that more than 60 min/day of moderate-intensity exercise or more than 150 min/week of moderate to vigorous exercise may be effective at mitigating the increased risk for mortality associated with sitting time, but reduced intensity may not be enough.
Active pauses
Interrupting sitting every 30-60 min to walk or cycle (2-10 min), performing 3 minutes of simple resistance activities every 30 minutes, such as calf or knee lifts, performing intermittent leg movements (1 minute of activity for every 4 minutes of inactivity during a 3-hour protocol session), or pausing to climb stairs (5 minutes every hour) may be beneficial for vascular health. However, not all studies have demonstrated these positive effects, therefore, some populations may need exercise of greater intensity or duration to counteract the negative vascular effects of acute inactivity periods.
Standing workstations
Standing workstations are effective at reducing sitting time in offices but may be ineffective at reducing vascular alterations related to sitting time. Although some experimental studies indicate vascular benefits, epidemiologic studies suggest that long periods of standing can be harmful to vascular health, especially for venous diseases. Recommendations for use should be accompanied by specific regimens on the frequency and duration of the position to attain the maximum benefits and minimize other vascular complications.
One problem that Dr. Lobelo noted is that some doctors ask their patients how active they are, but they do so in a nonstandardized manner. This observation led him to publish, together with the American Heart Association, an article on the importance for health systems of considering physical activity as a vital sign and including it in records in a standardized manner.
He said that “one advantage of having physical activity as a vital sign in patient medical records is that it allows us to identify individuals who are at greater risk.”
Kaiser Permanente asks the following questions: how many minutes of physical activity do you perform regularly per week, and what is the average intensity of that activity? Patients can be classified into the following three groups: those who follow the recommendations, those with almost no activity, and those who perform some physical activity but do not meet the recommended 150 min/week of moderate to vigorous activity.
Recording sitting time is more difficult. Dr. Lobelo indicated that “it is easier for a person to remember how much time they spent running than how long they were sitting.” Regarding the use of technology, he commented that most watches provide a good estimate. Without technology, it can be estimated by asking how much time is spent in the car, on the bus, or in front of the computer or television and then adding up these times.
Dr. Lobelo emphasized that the two behaviors, lack of physical activity and excessive sitting time, have independent associations with health outcomes. But if both are combined, the risk of obesity, diabetes, and cardiovascular diseases is not just added but rather is multiplied. These behaviors contribute to the epidemic of obesity and diabetes, since most people do not follow either of the two recommendations.
“Studies show that of the two behaviors, the more negative for health would be not following the physical activity recommendations,” said Dr. Lobelo. “If the recommendation of 150 min/week of moderate to vigorous physical activity is followed, the associated risk of sitting too much declines by 80%-90%. Additionally, we can prevent, help to manage, and decrease the risk of complications in more than 100 diseases, including infections. During the pandemic, it was observed that more active people had a lower risk of dying or of being hospitalized due to COVID-19 than less active people, independently of other factors, such as hypertension, diabetes, and obesity.”
Moreover, Dr. Lobelo believes in “practicing what you preach” and advocates that doctors become healthy models.
Dr. Lobelo, Dr. Ferrari, and Dr. Kovalskys disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish edition. A version appeared on Medscape.com.
FROM BMC PUBLIC HEALTH
Infant BCG vaccine protects only those under age 5 years
Bacillus Calmette-Guérin (BCG) vaccines are given to more than 100 million children every year, but there is considerable debate regarding the effectiveness of BCG vaccination in preventing tuberculosis and death, particularly among older children and adults.
The most extensive study ever conducted on the efficacy of the BCG vaccine for protection against tuberculosis, stratified by age and history of previous tuberculosis, was published in September 2022 in The Lancet Global Health. The study, which comprises a systematic review and meta-analysis, analyzed individual-level data from 26 case-contact cohort studies published over the past 20 years. The studies included data from 70,000 participants. The primary outcome was a composite of prevalent (diagnosed at or within 90 days of baseline) and incident (diagnosed more than 90 days after baseline) tuberculosis in contacts exposed to tuberculosis. Secondary outcomes were pulmonary tuberculosis, extrapulmonary tuberculosis, and mortality.
Participants were characterized as having been exposed to tuberculosis if they were reported to have been a close contact (either living in the same household or having substantial interaction outside the household) of a person with microbiologically or radiologically diagnosed pulmonary tuberculosis. Previous tuberculosis was defined as a positive interferon-gamma (IFN-gamma) release assay or tuberculin skin test, also known as PPD or Mantoux test.
Most studies included in the analysis were conducted in the past 10 years in countries with a high tuberculosis burden. Those countries included India, South Africa, China, Vietnam, Indonesia, Uganda, the Gambia, and Brazil.
Primary outcomes
The study’s main findings included the following:
- The overall effectiveness of BCG vaccination against all forms of tuberculosis was 18% (adjusted odds ratio, 0.82; 95% CI, 0.74-0.91).
- Stratified by age, BCG vaccination only significantly protected against all tuberculosis in children younger than 5 years (aOR, 0.63; 95% CI, 0.49-0.81).
- There was no protective effect among those whose previous tests for tuberculosis were negative unless they were younger than 5 years (aOR, 0.54; 95% CI, 0.32-0.90).
- Among contacts who had a positive tuberculin skin test or IFN-gamma release assay, BCG vaccination significantly protected against tuberculosis among all participants (aOR, 0.81; 95% CI, 0.69-0.96), participants younger than 5 years (aOR, 0.68; 95% CI, 0.47-0.97), and participants aged 5-9 years (aOR, 0.62; 95% CI, 0.38-0.99).
- BCG vaccination was protective against pulmonary tuberculosis (19% effectiveness), but this effect was only seen in children younger than 3 years (42% effectiveness) when stratified by age.
- Protection against all tuberculosis and pulmonary tuberculosis was greater among female participants than male participants.
“This is a definitive BCG protection study because it involves a significant number of individuals evaluated using this meta-analysis. Protection is clearly lost with age. From as early as age 5, no protective effect can be observed. Protection, including against pulmonary tuberculosis, can be observed up to 3 years of age,” stated study author Julio Croda, MD, PhD, chair of the Brazilian Society of Tropical Medicine.
Dr. Croda emphasized that the findings from their study indicate that BCG vaccine protects against pulmonary tuberculosis and that those results differ from results of some previous studies.
“Every physician believes the BCG vaccine protects against serious forms of tuberculosis up to age 5. That fact is not surprising at all,” Dr. Croda remarked. “However, the fact that it protects against pulmonary tuberculosis, especially in children younger than 3, was surprising. In medical practice, we did not believe in this protection.”
Currently, 1.2% of new tuberculosis cases in Brazil occur among those younger than 5. Nevertheless, these cases represent 40.1% of new diagnoses recorded among those younger than 15, highlighting the importance of protection for this age group. An increase in extrapulmonary tuberculosis cases was recently observed in patients younger than 5.
Isabella Ballalai, MD, PhD, is deputy chair of the Brazilian Society of Immunizations. Although she did not participate in this study, she commented on its findings. “All publications are welcome; they help us think,” she explained. She emphasized that the BCG vaccine is not optimal. “There are studies indicating 80% efficacy and others indicating 0%. So, what we can look at is decades of effectiveness in practice.”
Dr. Ballalai explained that the BCG vaccine could keep severe forms of tuberculosis, meningitis, and miliary tuberculosis at bay. She shared her experience of caring for several patients with tuberculous meningitis shortly after she had graduated. “Today, thanks to the BCG vaccine, we don’t see it anymore.” However, she pointed out that the vaccine›s efficacy and effectiveness against pulmonary tuberculosis are low and that pulmonary tuberculosis remains the most significant problem among adults.
Dr. Ballalai also emphasized a few shortcomings of the study. “One is the definition of ‘vaccinated’ and ‘unvaccinated,’ which was based on the presence or absence of a mark on the arm. Today, we know that the absence of a mark does not indicate that the child has not been vaccinated, nor that the vaccine has not been effective. Therefore, several vaccinated participants may have been included amongst the unvaccinated participants.”
The authors emphasized that the definition of “vaccinated” and “unvaccinated” was based on a scar and on vaccination records, and they recognized that participants who did not have a scar on their arm could have been misclassified. Regardless, it is still considered a sensitive indicator. “Few vaccinated children from various settings do not show a scar years after vaccine administration,” they stated in their article.
Adults unprotected
Dr. Ballalai also shared her concerns regarding the lack of protection for older individuals. “We know those older than 60 are at greater risk for complications of tuberculosis. Individuals in this age group naturally have a lower immunity, and they usually have comorbidities. From this study, I can only conclude what was already expected: that adults who received a BCG vaccine as infants are not clear of pulmonary tuberculosis.”
Dr. Croda agreed that it was already evident that the BCG vaccine administered at birth did not provide protection for adults. “In the past, even with 80%-90% vaccine coverage, there were numerous tuberculosis cases in adults in Brazil.”
Are boosters needed?
The authors concluded that immunoprotection needs to be boosted in older populations, as vaccination at birth is ineffective for adolescents and adults. They have also discussed whether children older than 10 years and adults could benefit from a booster shot.
Dr. Croda emphasized that there is no indication for this, because there are no data regarding protection with a booster dose during adulthood. However, he cited a study conducted in South Africa in which the BCG vaccine was compared with another vaccine, and another study, which is being conducted in India, is assessing whether a BCG booster offers protection against pulmonary tuberculosis. “There are few studies. Perhaps the revaccination of more vulnerable groups could be of interest, but additional studies are needed first.”
Dr. Croda intends to assess revaccination in those deprived of liberty, in which the incidence of tuberculosis is very high. From 2015 to 2021, many new cases were recorded in this population in Brazil. The number rose from 5,860 to 6,773 during that period.
“However, BCG revaccination carries a significant risk of patients presenting with serious adverse events,” Dr. Ballalai pointed out. He noted that several years ago, to extend protection, Brazil adopted a booster program for persons aged 10 years or older, but the program was discontinued owing to the numerous adverse events reported and the absence of evidence of benefit from increased protection against tuberculosis.
“The adult groups at greater risk for severe tuberculosis manifestations normally presented with an underlying disease, particularly in immunocompromised patient groups. The [administration of the] BCG [vaccine] is contraindicated for those who are immunocompromised. And, for the older population, we do not have data on [vaccine] safety,” she emphasized.
Nonspecific immune protection
One of the study’s secondary outcomes regarded mortality. Four studies in the meta-analysis followed up tuberculosis contacts for death. In these studies, which evaluated 20,000 participants, BCG vaccination was shown to be significantly protective against death for participants younger than 15 years.
However, the authors urged caution in interpreting these data. They emphasized that they were unable to identify specific mechanisms by which BCG vaccination might have reduced mortality, and there are possible study biases that could have led to an overestimation of mortality benefit. Moreover, given the observational nature of the included studies, vaccinated children might have had higher socioeconomic status and greater access to health care, and they may have been more likely to have received other vaccinations, compared with children who did not receive BCG vaccines.
Nevertheless, previous experimental and observational studies have found that BCG vaccination might provide nonspecific or off-target immune protection against an array of other pathogens.
“In small studies conducted in Africa, those younger than 5 were protected not only against tuberculosis but also against other respiratory diseases,” Dr. Croda affirmed. “However, these are small studies, and for now, there is no recommendation for using BCG vaccination to prevent other respiratory infections.”
A long-awaited, critical study on the impact of the BCG vaccine on COVID-19, in which Brazilian researchers participated, will be published in the New England Journal of Medicine.
New vaccines needed
The BCG vaccine is one of the oldest vaccines, but there are still several crucial unanswered questions about its use.
Previously published studies that examined the protective effect of BCG vaccination only considered low-burden settings and the historical literature before 1950. These studies need updating, but doing so has not been a simple task. To answer their questions, individual-level participant data for a prespecified list of variables, including the characteristics of the exposed participant (contact), the index case, and the environment, were requested from authors of all eligible studies.
Much of the data used in the published research were found through discussions with authors and experts in the field, as well as through data deposited in data storage repositories, conference abstracts, dissertations, and even direct requests to the authors. “The Pan-American Health Organization helped with this data collection and contacting some authors,” said Dr. Croda.
With the new data, the authors confirmed that infant BCG vaccination, although important to young children who are at high risk for tuberculosis, does not prevent adult-type cavitary tuberculosis and is therefore insufficient to impede the tuberculosis epidemic. “Novel vaccines are urgently needed,” they concluded.
“We need to develop novel, more effective vaccines, which, when administered during infancy, would ensure lifelong protection,” Dr. Croda added.
Dr. Croda and Dr. Ballalai reported no relevant financial relationships.
This article was translated from the Medscape Portuguese edition. A version of this article appeared on Medscape.com.
Bacillus Calmette-Guérin (BCG) vaccines are given to more than 100 million children every year, but there is considerable debate regarding the effectiveness of BCG vaccination in preventing tuberculosis and death, particularly among older children and adults.
The most extensive study ever conducted on the efficacy of the BCG vaccine for protection against tuberculosis, stratified by age and history of previous tuberculosis, was published in September 2022 in The Lancet Global Health. The study, which comprises a systematic review and meta-analysis, analyzed individual-level data from 26 case-contact cohort studies published over the past 20 years. The studies included data from 70,000 participants. The primary outcome was a composite of prevalent (diagnosed at or within 90 days of baseline) and incident (diagnosed more than 90 days after baseline) tuberculosis in contacts exposed to tuberculosis. Secondary outcomes were pulmonary tuberculosis, extrapulmonary tuberculosis, and mortality.
Participants were characterized as having been exposed to tuberculosis if they were reported to have been a close contact (either living in the same household or having substantial interaction outside the household) of a person with microbiologically or radiologically diagnosed pulmonary tuberculosis. Previous tuberculosis was defined as a positive interferon-gamma (IFN-gamma) release assay or tuberculin skin test, also known as PPD or Mantoux test.
Most studies included in the analysis were conducted in the past 10 years in countries with a high tuberculosis burden. Those countries included India, South Africa, China, Vietnam, Indonesia, Uganda, the Gambia, and Brazil.
Primary outcomes
The study’s main findings included the following:
- The overall effectiveness of BCG vaccination against all forms of tuberculosis was 18% (adjusted odds ratio, 0.82; 95% CI, 0.74-0.91).
- Stratified by age, BCG vaccination only significantly protected against all tuberculosis in children younger than 5 years (aOR, 0.63; 95% CI, 0.49-0.81).
- There was no protective effect among those whose previous tests for tuberculosis were negative unless they were younger than 5 years (aOR, 0.54; 95% CI, 0.32-0.90).
- Among contacts who had a positive tuberculin skin test or IFN-gamma release assay, BCG vaccination significantly protected against tuberculosis among all participants (aOR, 0.81; 95% CI, 0.69-0.96), participants younger than 5 years (aOR, 0.68; 95% CI, 0.47-0.97), and participants aged 5-9 years (aOR, 0.62; 95% CI, 0.38-0.99).
- BCG vaccination was protective against pulmonary tuberculosis (19% effectiveness), but this effect was only seen in children younger than 3 years (42% effectiveness) when stratified by age.
- Protection against all tuberculosis and pulmonary tuberculosis was greater among female participants than male participants.
“This is a definitive BCG protection study because it involves a significant number of individuals evaluated using this meta-analysis. Protection is clearly lost with age. From as early as age 5, no protective effect can be observed. Protection, including against pulmonary tuberculosis, can be observed up to 3 years of age,” stated study author Julio Croda, MD, PhD, chair of the Brazilian Society of Tropical Medicine.
Dr. Croda emphasized that the findings from their study indicate that BCG vaccine protects against pulmonary tuberculosis and that those results differ from results of some previous studies.
“Every physician believes the BCG vaccine protects against serious forms of tuberculosis up to age 5. That fact is not surprising at all,” Dr. Croda remarked. “However, the fact that it protects against pulmonary tuberculosis, especially in children younger than 3, was surprising. In medical practice, we did not believe in this protection.”
Currently, 1.2% of new tuberculosis cases in Brazil occur among those younger than 5. Nevertheless, these cases represent 40.1% of new diagnoses recorded among those younger than 15, highlighting the importance of protection for this age group. An increase in extrapulmonary tuberculosis cases was recently observed in patients younger than 5.
Isabella Ballalai, MD, PhD, is deputy chair of the Brazilian Society of Immunizations. Although she did not participate in this study, she commented on its findings. “All publications are welcome; they help us think,” she explained. She emphasized that the BCG vaccine is not optimal. “There are studies indicating 80% efficacy and others indicating 0%. So, what we can look at is decades of effectiveness in practice.”
Dr. Ballalai explained that the BCG vaccine could keep severe forms of tuberculosis, meningitis, and miliary tuberculosis at bay. She shared her experience of caring for several patients with tuberculous meningitis shortly after she had graduated. “Today, thanks to the BCG vaccine, we don’t see it anymore.” However, she pointed out that the vaccine›s efficacy and effectiveness against pulmonary tuberculosis are low and that pulmonary tuberculosis remains the most significant problem among adults.
Dr. Ballalai also emphasized a few shortcomings of the study. “One is the definition of ‘vaccinated’ and ‘unvaccinated,’ which was based on the presence or absence of a mark on the arm. Today, we know that the absence of a mark does not indicate that the child has not been vaccinated, nor that the vaccine has not been effective. Therefore, several vaccinated participants may have been included amongst the unvaccinated participants.”
The authors emphasized that the definition of “vaccinated” and “unvaccinated” was based on a scar and on vaccination records, and they recognized that participants who did not have a scar on their arm could have been misclassified. Regardless, it is still considered a sensitive indicator. “Few vaccinated children from various settings do not show a scar years after vaccine administration,” they stated in their article.
Adults unprotected
Dr. Ballalai also shared her concerns regarding the lack of protection for older individuals. “We know those older than 60 are at greater risk for complications of tuberculosis. Individuals in this age group naturally have a lower immunity, and they usually have comorbidities. From this study, I can only conclude what was already expected: that adults who received a BCG vaccine as infants are not clear of pulmonary tuberculosis.”
Dr. Croda agreed that it was already evident that the BCG vaccine administered at birth did not provide protection for adults. “In the past, even with 80%-90% vaccine coverage, there were numerous tuberculosis cases in adults in Brazil.”
Are boosters needed?
The authors concluded that immunoprotection needs to be boosted in older populations, as vaccination at birth is ineffective for adolescents and adults. They have also discussed whether children older than 10 years and adults could benefit from a booster shot.
Dr. Croda emphasized that there is no indication for this, because there are no data regarding protection with a booster dose during adulthood. However, he cited a study conducted in South Africa in which the BCG vaccine was compared with another vaccine, and another study, which is being conducted in India, is assessing whether a BCG booster offers protection against pulmonary tuberculosis. “There are few studies. Perhaps the revaccination of more vulnerable groups could be of interest, but additional studies are needed first.”
Dr. Croda intends to assess revaccination in those deprived of liberty, in which the incidence of tuberculosis is very high. From 2015 to 2021, many new cases were recorded in this population in Brazil. The number rose from 5,860 to 6,773 during that period.
“However, BCG revaccination carries a significant risk of patients presenting with serious adverse events,” Dr. Ballalai pointed out. He noted that several years ago, to extend protection, Brazil adopted a booster program for persons aged 10 years or older, but the program was discontinued owing to the numerous adverse events reported and the absence of evidence of benefit from increased protection against tuberculosis.
“The adult groups at greater risk for severe tuberculosis manifestations normally presented with an underlying disease, particularly in immunocompromised patient groups. The [administration of the] BCG [vaccine] is contraindicated for those who are immunocompromised. And, for the older population, we do not have data on [vaccine] safety,” she emphasized.
Nonspecific immune protection
One of the study’s secondary outcomes regarded mortality. Four studies in the meta-analysis followed up tuberculosis contacts for death. In these studies, which evaluated 20,000 participants, BCG vaccination was shown to be significantly protective against death for participants younger than 15 years.
However, the authors urged caution in interpreting these data. They emphasized that they were unable to identify specific mechanisms by which BCG vaccination might have reduced mortality, and there are possible study biases that could have led to an overestimation of mortality benefit. Moreover, given the observational nature of the included studies, vaccinated children might have had higher socioeconomic status and greater access to health care, and they may have been more likely to have received other vaccinations, compared with children who did not receive BCG vaccines.
Nevertheless, previous experimental and observational studies have found that BCG vaccination might provide nonspecific or off-target immune protection against an array of other pathogens.
“In small studies conducted in Africa, those younger than 5 were protected not only against tuberculosis but also against other respiratory diseases,” Dr. Croda affirmed. “However, these are small studies, and for now, there is no recommendation for using BCG vaccination to prevent other respiratory infections.”
A long-awaited, critical study on the impact of the BCG vaccine on COVID-19, in which Brazilian researchers participated, will be published in the New England Journal of Medicine.
New vaccines needed
The BCG vaccine is one of the oldest vaccines, but there are still several crucial unanswered questions about its use.
Previously published studies that examined the protective effect of BCG vaccination only considered low-burden settings and the historical literature before 1950. These studies need updating, but doing so has not been a simple task. To answer their questions, individual-level participant data for a prespecified list of variables, including the characteristics of the exposed participant (contact), the index case, and the environment, were requested from authors of all eligible studies.
Much of the data used in the published research were found through discussions with authors and experts in the field, as well as through data deposited in data storage repositories, conference abstracts, dissertations, and even direct requests to the authors. “The Pan-American Health Organization helped with this data collection and contacting some authors,” said Dr. Croda.
With the new data, the authors confirmed that infant BCG vaccination, although important to young children who are at high risk for tuberculosis, does not prevent adult-type cavitary tuberculosis and is therefore insufficient to impede the tuberculosis epidemic. “Novel vaccines are urgently needed,” they concluded.
“We need to develop novel, more effective vaccines, which, when administered during infancy, would ensure lifelong protection,” Dr. Croda added.
Dr. Croda and Dr. Ballalai reported no relevant financial relationships.
This article was translated from the Medscape Portuguese edition. A version of this article appeared on Medscape.com.
Bacillus Calmette-Guérin (BCG) vaccines are given to more than 100 million children every year, but there is considerable debate regarding the effectiveness of BCG vaccination in preventing tuberculosis and death, particularly among older children and adults.
The most extensive study ever conducted on the efficacy of the BCG vaccine for protection against tuberculosis, stratified by age and history of previous tuberculosis, was published in September 2022 in The Lancet Global Health. The study, which comprises a systematic review and meta-analysis, analyzed individual-level data from 26 case-contact cohort studies published over the past 20 years. The studies included data from 70,000 participants. The primary outcome was a composite of prevalent (diagnosed at or within 90 days of baseline) and incident (diagnosed more than 90 days after baseline) tuberculosis in contacts exposed to tuberculosis. Secondary outcomes were pulmonary tuberculosis, extrapulmonary tuberculosis, and mortality.
Participants were characterized as having been exposed to tuberculosis if they were reported to have been a close contact (either living in the same household or having substantial interaction outside the household) of a person with microbiologically or radiologically diagnosed pulmonary tuberculosis. Previous tuberculosis was defined as a positive interferon-gamma (IFN-gamma) release assay or tuberculin skin test, also known as PPD or Mantoux test.
Most studies included in the analysis were conducted in the past 10 years in countries with a high tuberculosis burden. Those countries included India, South Africa, China, Vietnam, Indonesia, Uganda, the Gambia, and Brazil.
Primary outcomes
The study’s main findings included the following:
- The overall effectiveness of BCG vaccination against all forms of tuberculosis was 18% (adjusted odds ratio, 0.82; 95% CI, 0.74-0.91).
- Stratified by age, BCG vaccination only significantly protected against all tuberculosis in children younger than 5 years (aOR, 0.63; 95% CI, 0.49-0.81).
- There was no protective effect among those whose previous tests for tuberculosis were negative unless they were younger than 5 years (aOR, 0.54; 95% CI, 0.32-0.90).
- Among contacts who had a positive tuberculin skin test or IFN-gamma release assay, BCG vaccination significantly protected against tuberculosis among all participants (aOR, 0.81; 95% CI, 0.69-0.96), participants younger than 5 years (aOR, 0.68; 95% CI, 0.47-0.97), and participants aged 5-9 years (aOR, 0.62; 95% CI, 0.38-0.99).
- BCG vaccination was protective against pulmonary tuberculosis (19% effectiveness), but this effect was only seen in children younger than 3 years (42% effectiveness) when stratified by age.
- Protection against all tuberculosis and pulmonary tuberculosis was greater among female participants than male participants.
“This is a definitive BCG protection study because it involves a significant number of individuals evaluated using this meta-analysis. Protection is clearly lost with age. From as early as age 5, no protective effect can be observed. Protection, including against pulmonary tuberculosis, can be observed up to 3 years of age,” stated study author Julio Croda, MD, PhD, chair of the Brazilian Society of Tropical Medicine.
Dr. Croda emphasized that the findings from their study indicate that BCG vaccine protects against pulmonary tuberculosis and that those results differ from results of some previous studies.
“Every physician believes the BCG vaccine protects against serious forms of tuberculosis up to age 5. That fact is not surprising at all,” Dr. Croda remarked. “However, the fact that it protects against pulmonary tuberculosis, especially in children younger than 3, was surprising. In medical practice, we did not believe in this protection.”
Currently, 1.2% of new tuberculosis cases in Brazil occur among those younger than 5. Nevertheless, these cases represent 40.1% of new diagnoses recorded among those younger than 15, highlighting the importance of protection for this age group. An increase in extrapulmonary tuberculosis cases was recently observed in patients younger than 5.
Isabella Ballalai, MD, PhD, is deputy chair of the Brazilian Society of Immunizations. Although she did not participate in this study, she commented on its findings. “All publications are welcome; they help us think,” she explained. She emphasized that the BCG vaccine is not optimal. “There are studies indicating 80% efficacy and others indicating 0%. So, what we can look at is decades of effectiveness in practice.”
Dr. Ballalai explained that the BCG vaccine could keep severe forms of tuberculosis, meningitis, and miliary tuberculosis at bay. She shared her experience of caring for several patients with tuberculous meningitis shortly after she had graduated. “Today, thanks to the BCG vaccine, we don’t see it anymore.” However, she pointed out that the vaccine›s efficacy and effectiveness against pulmonary tuberculosis are low and that pulmonary tuberculosis remains the most significant problem among adults.
Dr. Ballalai also emphasized a few shortcomings of the study. “One is the definition of ‘vaccinated’ and ‘unvaccinated,’ which was based on the presence or absence of a mark on the arm. Today, we know that the absence of a mark does not indicate that the child has not been vaccinated, nor that the vaccine has not been effective. Therefore, several vaccinated participants may have been included amongst the unvaccinated participants.”
The authors emphasized that the definition of “vaccinated” and “unvaccinated” was based on a scar and on vaccination records, and they recognized that participants who did not have a scar on their arm could have been misclassified. Regardless, it is still considered a sensitive indicator. “Few vaccinated children from various settings do not show a scar years after vaccine administration,” they stated in their article.
Adults unprotected
Dr. Ballalai also shared her concerns regarding the lack of protection for older individuals. “We know those older than 60 are at greater risk for complications of tuberculosis. Individuals in this age group naturally have a lower immunity, and they usually have comorbidities. From this study, I can only conclude what was already expected: that adults who received a BCG vaccine as infants are not clear of pulmonary tuberculosis.”
Dr. Croda agreed that it was already evident that the BCG vaccine administered at birth did not provide protection for adults. “In the past, even with 80%-90% vaccine coverage, there were numerous tuberculosis cases in adults in Brazil.”
Are boosters needed?
The authors concluded that immunoprotection needs to be boosted in older populations, as vaccination at birth is ineffective for adolescents and adults. They have also discussed whether children older than 10 years and adults could benefit from a booster shot.
Dr. Croda emphasized that there is no indication for this, because there are no data regarding protection with a booster dose during adulthood. However, he cited a study conducted in South Africa in which the BCG vaccine was compared with another vaccine, and another study, which is being conducted in India, is assessing whether a BCG booster offers protection against pulmonary tuberculosis. “There are few studies. Perhaps the revaccination of more vulnerable groups could be of interest, but additional studies are needed first.”
Dr. Croda intends to assess revaccination in those deprived of liberty, in which the incidence of tuberculosis is very high. From 2015 to 2021, many new cases were recorded in this population in Brazil. The number rose from 5,860 to 6,773 during that period.
“However, BCG revaccination carries a significant risk of patients presenting with serious adverse events,” Dr. Ballalai pointed out. He noted that several years ago, to extend protection, Brazil adopted a booster program for persons aged 10 years or older, but the program was discontinued owing to the numerous adverse events reported and the absence of evidence of benefit from increased protection against tuberculosis.
“The adult groups at greater risk for severe tuberculosis manifestations normally presented with an underlying disease, particularly in immunocompromised patient groups. The [administration of the] BCG [vaccine] is contraindicated for those who are immunocompromised. And, for the older population, we do not have data on [vaccine] safety,” she emphasized.
Nonspecific immune protection
One of the study’s secondary outcomes regarded mortality. Four studies in the meta-analysis followed up tuberculosis contacts for death. In these studies, which evaluated 20,000 participants, BCG vaccination was shown to be significantly protective against death for participants younger than 15 years.
However, the authors urged caution in interpreting these data. They emphasized that they were unable to identify specific mechanisms by which BCG vaccination might have reduced mortality, and there are possible study biases that could have led to an overestimation of mortality benefit. Moreover, given the observational nature of the included studies, vaccinated children might have had higher socioeconomic status and greater access to health care, and they may have been more likely to have received other vaccinations, compared with children who did not receive BCG vaccines.
Nevertheless, previous experimental and observational studies have found that BCG vaccination might provide nonspecific or off-target immune protection against an array of other pathogens.
“In small studies conducted in Africa, those younger than 5 were protected not only against tuberculosis but also against other respiratory diseases,” Dr. Croda affirmed. “However, these are small studies, and for now, there is no recommendation for using BCG vaccination to prevent other respiratory infections.”
A long-awaited, critical study on the impact of the BCG vaccine on COVID-19, in which Brazilian researchers participated, will be published in the New England Journal of Medicine.
New vaccines needed
The BCG vaccine is one of the oldest vaccines, but there are still several crucial unanswered questions about its use.
Previously published studies that examined the protective effect of BCG vaccination only considered low-burden settings and the historical literature before 1950. These studies need updating, but doing so has not been a simple task. To answer their questions, individual-level participant data for a prespecified list of variables, including the characteristics of the exposed participant (contact), the index case, and the environment, were requested from authors of all eligible studies.
Much of the data used in the published research were found through discussions with authors and experts in the field, as well as through data deposited in data storage repositories, conference abstracts, dissertations, and even direct requests to the authors. “The Pan-American Health Organization helped with this data collection and contacting some authors,” said Dr. Croda.
With the new data, the authors confirmed that infant BCG vaccination, although important to young children who are at high risk for tuberculosis, does not prevent adult-type cavitary tuberculosis and is therefore insufficient to impede the tuberculosis epidemic. “Novel vaccines are urgently needed,” they concluded.
“We need to develop novel, more effective vaccines, which, when administered during infancy, would ensure lifelong protection,” Dr. Croda added.
Dr. Croda and Dr. Ballalai reported no relevant financial relationships.
This article was translated from the Medscape Portuguese edition. A version of this article appeared on Medscape.com.
FROM THE LANCET GLOBAL HEALTH
What is the genetic influence on the severity of COVID-19?
A striking characteristic of COVID-19 is that the severity of clinical outcomes is remarkably variable. Establishing a prognosis for individuals infected with COVID-19 remains a challenge.
Since the start of the COVID-19 pandemic, the heterogeneity of individuals who progress toward severe disease or death, along with the fact that individuals directly exposed to the virus do not necessarily become sick, supports the hypothesis that genetic risk or protective factors are at play.
In an interview with this news organization, Mayana Zatz, PhD, head professor of genetics and coordinator of the Human Genome and Stem Cell Study Center at the University of São Paulo, explained: “The first case that caught my eye was the case of my neighbors, a couple. He presented COVID-19 symptoms, but his wife, who took care of him, had absolutely no symptoms. I thought that it was strange, but we received 3,000 emails from people saying, ‘This happened to me, too.’”
Reports in the media about seven pairs of monozygotic (MZ) twins who died from COVID-19 within days of one another in Brazil also stood out, said the researcher.
, as well as their pathology. Dr. Zatz’s team analyzed the case of a 31-year-old Brazilian MZ twin brother pair who presented simultaneously with severe COVID-19 and the need for oxygen support, despite their age and good health conditions. Curiously, they were admitted and intubated on the same day, but neither of the twins knew about the other’s situation; they found out only when they were extubated.
The study was carried out at the USP with the collaboration of the State University of São Paulo. The authors mapped the genetic profile (by sequencing the genome responsible for coding proteins, or whole-exome sequencing) and the immune cell profile to evaluate innate and adaptive immunity.
The MZ twin brothers shared the same two rare genetic mutations, which may be associated with their increased risk of developing severe COVID-19. However, since these variants were not studied at the protein or functional level, their pathogenicity has yet to be determined. The twins also had [human leukocyte antigen (HLA)] alleles associated with severe COVID-19, which are important candidates for the mechanisms of innate and adaptive immunity and susceptibility to COVID-19 infection and manifestation.
But one particular oddity stood out to the researchers: One of the brothers required longer hospitalization, and only he reported symptoms of long COVID.
In the authors’ eyes, even though the patients shared genetic mutations potentially associated with the risk of developing severe COVID-19, the differences in clinical progression emphasize that, beyond genetic risk factors, continuous exposure to pathogens over a lifetime and other environmental factors mean that each individual’s immune response is unique, even in twins.
“There is no doubt that genetics contribute to the severity of COVID-19, and environmental factors sometimes give us the opportunity to study the disease, too. Such [is the case with] MZ twins who have genetic similarities, even with changes that take place over a lifetime,” José Eduardo Krieger, MD, PhD, professor of molecular medicine at the University of São Paulo Medical School (FMUSP), told this news organization. “Examining MZ twins is a strategy that may help, but, with n = 2, luck really needs to be on your side to get straight to the problem. You need to combine [these findings] with other studies to solve this conundrum,” said Dr. Krieger, who did not take part in the research.
Large cohorts
Genomic and computer resources allow for the study of large sets of data from thousands of individuals. In each of those sets of data, the signal offered by thousands of markers distributed throughout the genome can be studied. This is the possibility offered by various genomic studies of large cohorts of patients with different clinical manifestations.
“Researchers examine thousands of genetic variants throughout the genome from a large sample of individuals and have the chance, for example, to identify genetic variants that are more prevalent in patients who have presented with severe disease than in those who presented with milder disease,” said Dr. Krieger. “These associations highlight a chromosome region in which one or more genes explain, at least in part, the differences observed.”
Genomewide association studies have identified some genetic variants that indicate severity of COVID-19, with potential impact on the virus entering the cell, the immune response, or the development of cytokine storms.
One of these studies, COVID-19 Host Genetics Initiative (COVID-19 HGI), is an international, open-science collaboration for sharing scientific methods and resources with research groups across the world, with the goal of robustly mapping the host genetic determinants of SARS-CoV-2 infection and the severity of the resulting COVID-19 disease. At the start of 2021, the COVID-19 HGI combined genetic data from 49,562 cases and 2 million controls from 46 studies in 19 countries. A total of 853 samples from the BRACOVID study were included in the meta-analysis. The endeavor enabled the identification of 13 genomewide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19.
The BRACOVID study, in which Dr. Krieger participates, aims to identify host genetic factors that determine the severity of COVID-19. It is currently the largest project of its kind in Latin America. An article provides the analysis of the first 5,233 participants in the BRACOVID study, who were recruited in São Paulo. Of these participants, 3,533 had been infected with COVID-19 and hospitalized at either the Heart Institute or the Central Institute of the FMUSP General Hospital. The remaining 1,700 made up the control group, which included health care professionals and members of the general population. The controls were recruited through serology assays or PCR tests for SARS-CoV-2.
The researchers discovered a region of chromosome 1 that could play a role in modulating immune response and that could lead to an increase in the likelihood of hospitalization across a wide range of COVID-19 risk factors. This region of chromosome 1 was observed only in Brazilians with a strong European ancestry; however, this finding had not been mentioned in previous studies, suggesting that it could harbor a risk allele specific to the Brazilian population.
The study also confirmed most, but not all, of the regions recorded in the literature, which may be significant in identifying factors determining severity that are specific to a given population.
Including information from the BRACOVID study, other studies have enhanced the knowledge on affected organs. Combined data from 14,000 patients from nine countries evaluated a region of a single chromosome and found that carriers of a certain allele had a higher probability of experiencing various COVID-19 complications, such as severe respiratory failure, venous thromboembolism, and liver damage. The risk was even higher for individuals aged 60 years and over.
Discordant couples
Smaller sample sizes of underrepresented populations also provide relevant data for genomic studies. Dr. Zatz’s team carried out genomic studies on smaller groups, comparing serodiscordant couples (where one was infected and symptomatic while the partner remained asymptomatic and seronegative despite sharing the same bedroom during the infection). Their research found genetic variants related to immune response that were associated with susceptibility to infection and progression to severe COVID-19.
The team also went on to study a group of patients older than 90 years who recovered from COVID-19 with mild symptoms or who remained asymptomatic following a positive test for SARS-CoV-2. They compared these patients with a sample of elderly patients from the same city (São Paulo), sampled before the current pandemic. The researchers identified a genetic variant related to mucin production. “In individuals with mild COVID-19, the degradation of these mucins would be more efficient,” said Dr. Zatz. It is possible for this variant to interfere not only with the production of mucus, but also in its composition, as there is an exchange of amino acids in the protein.
“We continued the study by comparing the extremes, i.e., those in their 90s with mild COVID-19 and younger patients with severe COVID-19, including several who died,” said Dr. Zatz.
More personalized medicine
The specialists agreed that a genetic test to predict COVID-19 severity is still a long way away. The genetic component is too little understood to enable the evaluation of individual risk. It has been possible to identify several important areas but, as Dr. Krieger pointed out, a variant identified in a certain chromosome interval may not be just one gene. There may be various candidate genes, or there may be a regulatory sequence for a distant gene. Furthermore, there are regions with genes that make sense as moderators of COVID-19 severity, because they regulate an inflammatory or immunologic reaction, but evidence is still lacking.
Reaching the molecular mechanism would, in future, allow a medicine to be chosen for a given patient, as already happens with other diseases. It also could enable the discovery of new medicines following as-yet-unexplored lines of research. Dr. Zatz also considers the possibility of genetic therapy.
Even with the knowledge of human genetics, one part of the equation is missing: viral genetics. “Many of the individuals who were resistant to the Delta variant were later affected by Omicron,” she pointed out.
Significance of Brazil
“We have an infinite amount of genomic data worldwide, but the vast majority originates from White Americans of European origin,” said Dr. Krieger. Moreover, genomic associations of COVID-19 severity discovered in the Chinese population were not significant in the European population. Besides underscoring the importance of collaborating with international studies, this situation supports scientists’ interest in carrying out genetic studies within Brazil, he added.
“In the genomic study of the Brazilian population, we found 2 million variants that were not present in the European populations,” said Dr. Zatz.
Dr. Krieger mentioned a technical advantage that Brazil has. “Having been colonized by different ethnic groups and mixed many generations ago, Brazil has a population with a unique genetic structure; the recombinations are different. When preparing the samples, the regions break differently.” This factor could help to separate, in a candidate region, the gene that is significant from those that might not be.
In general, severe COVID-19 would be a complex phenomenon involving several genes and interactions with environmental factors. The Brazilian studies tried to find a factor that was unique to Brazil, but the significance of the differences remained unclear. “We found some signs that were specific to our population,” concluded Dr. Krieger. “But the reason that more people in Brazil died as a result of COVID-19 was not genetic,” he added.
Dr. Zatz and Dr. Krieger reported no conflicts of interest. This article was translated from the Medscape Portuguese edition.
A version of this article first appeared on Medscape.com.
A striking characteristic of COVID-19 is that the severity of clinical outcomes is remarkably variable. Establishing a prognosis for individuals infected with COVID-19 remains a challenge.
Since the start of the COVID-19 pandemic, the heterogeneity of individuals who progress toward severe disease or death, along with the fact that individuals directly exposed to the virus do not necessarily become sick, supports the hypothesis that genetic risk or protective factors are at play.
In an interview with this news organization, Mayana Zatz, PhD, head professor of genetics and coordinator of the Human Genome and Stem Cell Study Center at the University of São Paulo, explained: “The first case that caught my eye was the case of my neighbors, a couple. He presented COVID-19 symptoms, but his wife, who took care of him, had absolutely no symptoms. I thought that it was strange, but we received 3,000 emails from people saying, ‘This happened to me, too.’”
Reports in the media about seven pairs of monozygotic (MZ) twins who died from COVID-19 within days of one another in Brazil also stood out, said the researcher.
, as well as their pathology. Dr. Zatz’s team analyzed the case of a 31-year-old Brazilian MZ twin brother pair who presented simultaneously with severe COVID-19 and the need for oxygen support, despite their age and good health conditions. Curiously, they were admitted and intubated on the same day, but neither of the twins knew about the other’s situation; they found out only when they were extubated.
The study was carried out at the USP with the collaboration of the State University of São Paulo. The authors mapped the genetic profile (by sequencing the genome responsible for coding proteins, or whole-exome sequencing) and the immune cell profile to evaluate innate and adaptive immunity.
The MZ twin brothers shared the same two rare genetic mutations, which may be associated with their increased risk of developing severe COVID-19. However, since these variants were not studied at the protein or functional level, their pathogenicity has yet to be determined. The twins also had [human leukocyte antigen (HLA)] alleles associated with severe COVID-19, which are important candidates for the mechanisms of innate and adaptive immunity and susceptibility to COVID-19 infection and manifestation.
But one particular oddity stood out to the researchers: One of the brothers required longer hospitalization, and only he reported symptoms of long COVID.
In the authors’ eyes, even though the patients shared genetic mutations potentially associated with the risk of developing severe COVID-19, the differences in clinical progression emphasize that, beyond genetic risk factors, continuous exposure to pathogens over a lifetime and other environmental factors mean that each individual’s immune response is unique, even in twins.
“There is no doubt that genetics contribute to the severity of COVID-19, and environmental factors sometimes give us the opportunity to study the disease, too. Such [is the case with] MZ twins who have genetic similarities, even with changes that take place over a lifetime,” José Eduardo Krieger, MD, PhD, professor of molecular medicine at the University of São Paulo Medical School (FMUSP), told this news organization. “Examining MZ twins is a strategy that may help, but, with n = 2, luck really needs to be on your side to get straight to the problem. You need to combine [these findings] with other studies to solve this conundrum,” said Dr. Krieger, who did not take part in the research.
Large cohorts
Genomic and computer resources allow for the study of large sets of data from thousands of individuals. In each of those sets of data, the signal offered by thousands of markers distributed throughout the genome can be studied. This is the possibility offered by various genomic studies of large cohorts of patients with different clinical manifestations.
“Researchers examine thousands of genetic variants throughout the genome from a large sample of individuals and have the chance, for example, to identify genetic variants that are more prevalent in patients who have presented with severe disease than in those who presented with milder disease,” said Dr. Krieger. “These associations highlight a chromosome region in which one or more genes explain, at least in part, the differences observed.”
Genomewide association studies have identified some genetic variants that indicate severity of COVID-19, with potential impact on the virus entering the cell, the immune response, or the development of cytokine storms.
One of these studies, COVID-19 Host Genetics Initiative (COVID-19 HGI), is an international, open-science collaboration for sharing scientific methods and resources with research groups across the world, with the goal of robustly mapping the host genetic determinants of SARS-CoV-2 infection and the severity of the resulting COVID-19 disease. At the start of 2021, the COVID-19 HGI combined genetic data from 49,562 cases and 2 million controls from 46 studies in 19 countries. A total of 853 samples from the BRACOVID study were included in the meta-analysis. The endeavor enabled the identification of 13 genomewide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19.
The BRACOVID study, in which Dr. Krieger participates, aims to identify host genetic factors that determine the severity of COVID-19. It is currently the largest project of its kind in Latin America. An article provides the analysis of the first 5,233 participants in the BRACOVID study, who were recruited in São Paulo. Of these participants, 3,533 had been infected with COVID-19 and hospitalized at either the Heart Institute or the Central Institute of the FMUSP General Hospital. The remaining 1,700 made up the control group, which included health care professionals and members of the general population. The controls were recruited through serology assays or PCR tests for SARS-CoV-2.
The researchers discovered a region of chromosome 1 that could play a role in modulating immune response and that could lead to an increase in the likelihood of hospitalization across a wide range of COVID-19 risk factors. This region of chromosome 1 was observed only in Brazilians with a strong European ancestry; however, this finding had not been mentioned in previous studies, suggesting that it could harbor a risk allele specific to the Brazilian population.
The study also confirmed most, but not all, of the regions recorded in the literature, which may be significant in identifying factors determining severity that are specific to a given population.
Including information from the BRACOVID study, other studies have enhanced the knowledge on affected organs. Combined data from 14,000 patients from nine countries evaluated a region of a single chromosome and found that carriers of a certain allele had a higher probability of experiencing various COVID-19 complications, such as severe respiratory failure, venous thromboembolism, and liver damage. The risk was even higher for individuals aged 60 years and over.
Discordant couples
Smaller sample sizes of underrepresented populations also provide relevant data for genomic studies. Dr. Zatz’s team carried out genomic studies on smaller groups, comparing serodiscordant couples (where one was infected and symptomatic while the partner remained asymptomatic and seronegative despite sharing the same bedroom during the infection). Their research found genetic variants related to immune response that were associated with susceptibility to infection and progression to severe COVID-19.
The team also went on to study a group of patients older than 90 years who recovered from COVID-19 with mild symptoms or who remained asymptomatic following a positive test for SARS-CoV-2. They compared these patients with a sample of elderly patients from the same city (São Paulo), sampled before the current pandemic. The researchers identified a genetic variant related to mucin production. “In individuals with mild COVID-19, the degradation of these mucins would be more efficient,” said Dr. Zatz. It is possible for this variant to interfere not only with the production of mucus, but also in its composition, as there is an exchange of amino acids in the protein.
“We continued the study by comparing the extremes, i.e., those in their 90s with mild COVID-19 and younger patients with severe COVID-19, including several who died,” said Dr. Zatz.
More personalized medicine
The specialists agreed that a genetic test to predict COVID-19 severity is still a long way away. The genetic component is too little understood to enable the evaluation of individual risk. It has been possible to identify several important areas but, as Dr. Krieger pointed out, a variant identified in a certain chromosome interval may not be just one gene. There may be various candidate genes, or there may be a regulatory sequence for a distant gene. Furthermore, there are regions with genes that make sense as moderators of COVID-19 severity, because they regulate an inflammatory or immunologic reaction, but evidence is still lacking.
Reaching the molecular mechanism would, in future, allow a medicine to be chosen for a given patient, as already happens with other diseases. It also could enable the discovery of new medicines following as-yet-unexplored lines of research. Dr. Zatz also considers the possibility of genetic therapy.
Even with the knowledge of human genetics, one part of the equation is missing: viral genetics. “Many of the individuals who were resistant to the Delta variant were later affected by Omicron,” she pointed out.
Significance of Brazil
“We have an infinite amount of genomic data worldwide, but the vast majority originates from White Americans of European origin,” said Dr. Krieger. Moreover, genomic associations of COVID-19 severity discovered in the Chinese population were not significant in the European population. Besides underscoring the importance of collaborating with international studies, this situation supports scientists’ interest in carrying out genetic studies within Brazil, he added.
“In the genomic study of the Brazilian population, we found 2 million variants that were not present in the European populations,” said Dr. Zatz.
Dr. Krieger mentioned a technical advantage that Brazil has. “Having been colonized by different ethnic groups and mixed many generations ago, Brazil has a population with a unique genetic structure; the recombinations are different. When preparing the samples, the regions break differently.” This factor could help to separate, in a candidate region, the gene that is significant from those that might not be.
In general, severe COVID-19 would be a complex phenomenon involving several genes and interactions with environmental factors. The Brazilian studies tried to find a factor that was unique to Brazil, but the significance of the differences remained unclear. “We found some signs that were specific to our population,” concluded Dr. Krieger. “But the reason that more people in Brazil died as a result of COVID-19 was not genetic,” he added.
Dr. Zatz and Dr. Krieger reported no conflicts of interest. This article was translated from the Medscape Portuguese edition.
A version of this article first appeared on Medscape.com.
A striking characteristic of COVID-19 is that the severity of clinical outcomes is remarkably variable. Establishing a prognosis for individuals infected with COVID-19 remains a challenge.
Since the start of the COVID-19 pandemic, the heterogeneity of individuals who progress toward severe disease or death, along with the fact that individuals directly exposed to the virus do not necessarily become sick, supports the hypothesis that genetic risk or protective factors are at play.
In an interview with this news organization, Mayana Zatz, PhD, head professor of genetics and coordinator of the Human Genome and Stem Cell Study Center at the University of São Paulo, explained: “The first case that caught my eye was the case of my neighbors, a couple. He presented COVID-19 symptoms, but his wife, who took care of him, had absolutely no symptoms. I thought that it was strange, but we received 3,000 emails from people saying, ‘This happened to me, too.’”
Reports in the media about seven pairs of monozygotic (MZ) twins who died from COVID-19 within days of one another in Brazil also stood out, said the researcher.
, as well as their pathology. Dr. Zatz’s team analyzed the case of a 31-year-old Brazilian MZ twin brother pair who presented simultaneously with severe COVID-19 and the need for oxygen support, despite their age and good health conditions. Curiously, they were admitted and intubated on the same day, but neither of the twins knew about the other’s situation; they found out only when they were extubated.
The study was carried out at the USP with the collaboration of the State University of São Paulo. The authors mapped the genetic profile (by sequencing the genome responsible for coding proteins, or whole-exome sequencing) and the immune cell profile to evaluate innate and adaptive immunity.
The MZ twin brothers shared the same two rare genetic mutations, which may be associated with their increased risk of developing severe COVID-19. However, since these variants were not studied at the protein or functional level, their pathogenicity has yet to be determined. The twins also had [human leukocyte antigen (HLA)] alleles associated with severe COVID-19, which are important candidates for the mechanisms of innate and adaptive immunity and susceptibility to COVID-19 infection and manifestation.
But one particular oddity stood out to the researchers: One of the brothers required longer hospitalization, and only he reported symptoms of long COVID.
In the authors’ eyes, even though the patients shared genetic mutations potentially associated with the risk of developing severe COVID-19, the differences in clinical progression emphasize that, beyond genetic risk factors, continuous exposure to pathogens over a lifetime and other environmental factors mean that each individual’s immune response is unique, even in twins.
“There is no doubt that genetics contribute to the severity of COVID-19, and environmental factors sometimes give us the opportunity to study the disease, too. Such [is the case with] MZ twins who have genetic similarities, even with changes that take place over a lifetime,” José Eduardo Krieger, MD, PhD, professor of molecular medicine at the University of São Paulo Medical School (FMUSP), told this news organization. “Examining MZ twins is a strategy that may help, but, with n = 2, luck really needs to be on your side to get straight to the problem. You need to combine [these findings] with other studies to solve this conundrum,” said Dr. Krieger, who did not take part in the research.
Large cohorts
Genomic and computer resources allow for the study of large sets of data from thousands of individuals. In each of those sets of data, the signal offered by thousands of markers distributed throughout the genome can be studied. This is the possibility offered by various genomic studies of large cohorts of patients with different clinical manifestations.
“Researchers examine thousands of genetic variants throughout the genome from a large sample of individuals and have the chance, for example, to identify genetic variants that are more prevalent in patients who have presented with severe disease than in those who presented with milder disease,” said Dr. Krieger. “These associations highlight a chromosome region in which one or more genes explain, at least in part, the differences observed.”
Genomewide association studies have identified some genetic variants that indicate severity of COVID-19, with potential impact on the virus entering the cell, the immune response, or the development of cytokine storms.
One of these studies, COVID-19 Host Genetics Initiative (COVID-19 HGI), is an international, open-science collaboration for sharing scientific methods and resources with research groups across the world, with the goal of robustly mapping the host genetic determinants of SARS-CoV-2 infection and the severity of the resulting COVID-19 disease. At the start of 2021, the COVID-19 HGI combined genetic data from 49,562 cases and 2 million controls from 46 studies in 19 countries. A total of 853 samples from the BRACOVID study were included in the meta-analysis. The endeavor enabled the identification of 13 genomewide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19.
The BRACOVID study, in which Dr. Krieger participates, aims to identify host genetic factors that determine the severity of COVID-19. It is currently the largest project of its kind in Latin America. An article provides the analysis of the first 5,233 participants in the BRACOVID study, who were recruited in São Paulo. Of these participants, 3,533 had been infected with COVID-19 and hospitalized at either the Heart Institute or the Central Institute of the FMUSP General Hospital. The remaining 1,700 made up the control group, which included health care professionals and members of the general population. The controls were recruited through serology assays or PCR tests for SARS-CoV-2.
The researchers discovered a region of chromosome 1 that could play a role in modulating immune response and that could lead to an increase in the likelihood of hospitalization across a wide range of COVID-19 risk factors. This region of chromosome 1 was observed only in Brazilians with a strong European ancestry; however, this finding had not been mentioned in previous studies, suggesting that it could harbor a risk allele specific to the Brazilian population.
The study also confirmed most, but not all, of the regions recorded in the literature, which may be significant in identifying factors determining severity that are specific to a given population.
Including information from the BRACOVID study, other studies have enhanced the knowledge on affected organs. Combined data from 14,000 patients from nine countries evaluated a region of a single chromosome and found that carriers of a certain allele had a higher probability of experiencing various COVID-19 complications, such as severe respiratory failure, venous thromboembolism, and liver damage. The risk was even higher for individuals aged 60 years and over.
Discordant couples
Smaller sample sizes of underrepresented populations also provide relevant data for genomic studies. Dr. Zatz’s team carried out genomic studies on smaller groups, comparing serodiscordant couples (where one was infected and symptomatic while the partner remained asymptomatic and seronegative despite sharing the same bedroom during the infection). Their research found genetic variants related to immune response that were associated with susceptibility to infection and progression to severe COVID-19.
The team also went on to study a group of patients older than 90 years who recovered from COVID-19 with mild symptoms or who remained asymptomatic following a positive test for SARS-CoV-2. They compared these patients with a sample of elderly patients from the same city (São Paulo), sampled before the current pandemic. The researchers identified a genetic variant related to mucin production. “In individuals with mild COVID-19, the degradation of these mucins would be more efficient,” said Dr. Zatz. It is possible for this variant to interfere not only with the production of mucus, but also in its composition, as there is an exchange of amino acids in the protein.
“We continued the study by comparing the extremes, i.e., those in their 90s with mild COVID-19 and younger patients with severe COVID-19, including several who died,” said Dr. Zatz.
More personalized medicine
The specialists agreed that a genetic test to predict COVID-19 severity is still a long way away. The genetic component is too little understood to enable the evaluation of individual risk. It has been possible to identify several important areas but, as Dr. Krieger pointed out, a variant identified in a certain chromosome interval may not be just one gene. There may be various candidate genes, or there may be a regulatory sequence for a distant gene. Furthermore, there are regions with genes that make sense as moderators of COVID-19 severity, because they regulate an inflammatory or immunologic reaction, but evidence is still lacking.
Reaching the molecular mechanism would, in future, allow a medicine to be chosen for a given patient, as already happens with other diseases. It also could enable the discovery of new medicines following as-yet-unexplored lines of research. Dr. Zatz also considers the possibility of genetic therapy.
Even with the knowledge of human genetics, one part of the equation is missing: viral genetics. “Many of the individuals who were resistant to the Delta variant were later affected by Omicron,” she pointed out.
Significance of Brazil
“We have an infinite amount of genomic data worldwide, but the vast majority originates from White Americans of European origin,” said Dr. Krieger. Moreover, genomic associations of COVID-19 severity discovered in the Chinese population were not significant in the European population. Besides underscoring the importance of collaborating with international studies, this situation supports scientists’ interest in carrying out genetic studies within Brazil, he added.
“In the genomic study of the Brazilian population, we found 2 million variants that were not present in the European populations,” said Dr. Zatz.
Dr. Krieger mentioned a technical advantage that Brazil has. “Having been colonized by different ethnic groups and mixed many generations ago, Brazil has a population with a unique genetic structure; the recombinations are different. When preparing the samples, the regions break differently.” This factor could help to separate, in a candidate region, the gene that is significant from those that might not be.
In general, severe COVID-19 would be a complex phenomenon involving several genes and interactions with environmental factors. The Brazilian studies tried to find a factor that was unique to Brazil, but the significance of the differences remained unclear. “We found some signs that were specific to our population,” concluded Dr. Krieger. “But the reason that more people in Brazil died as a result of COVID-19 was not genetic,” he added.
Dr. Zatz and Dr. Krieger reported no conflicts of interest. This article was translated from the Medscape Portuguese edition.
A version of this article first appeared on Medscape.com.
What role does the uterine microbiome play in fertility?
Until the second half of the 20th century, it was believed that the uterine cavity was sterile. Since then, technological advances have provided insight into the nature of the microbiome throughout the female reproductive tract. The role of these microorganisms on the fertility of women of reproductive age has been the subject of research. Is there an “optimal microbiome” for fertility? Can changing the microbiome of the uterine cavity affect fertility? There is still no definitive scientific response to these questions.
Several studies describe the healthy state of the uterine microbiota in women of reproductive age, with most of these studies reporting dominance of Lactobacillus species. However, by contrast, some studies did not observe Lactobacillus predominance inside the uterine cavity in cases of healthy uterine microbiomes. The presence of other microorganisms, such as Gardnerella vaginalis, was associated with reduced success in patients attempting in vitro fertilization (IVF) treatment, such as, for example, embryo implantation failure and miscarriage.
It is also possible that a physiologic endometrial microbiome could be considered healthy despite a minor presence of pathogenic bacteria. Importantly, responses from the host also modulate many aspects of human conception. These shifts correlate with parameters such as age, hormonal changes, ethnicity, sexual activity, and intrauterine devices.
Carlos Simón, MD, PhD, is a gynecologist and obstetrician and professor at the University of Valencia in Valencia, Spain; Harvard University, Cambridge, Mass.; and Baylor College of Medicine, Houston. He was in São Paulo at the time of the XXVI Brazilian Congress of Assisted Reproduction and agreed to be interviewed by Medscape Portuguese Edition. Dr. Simón, who is Spanish and is an international reference in uterine microbiome studies, created an endometrial receptivity analysis (ERA).
“What we know is that the human uterus has its own microbiome. Thanks to next-generation sequencing (NGS), we can detect microbial DNA. We’re talking about a microbiome that, if changed, affects [embryo] implantation. We have identified that Lactobacilli are the good [microorganisms], but if there are Streptococci, Gardnerella, or other bacteria, the implantation [of the embryo] is affected.”
In 2018, Dr. Simón’s team published a pilot study assessing the microbiome of 30 patients during fertilization treatment. It was observed that, when there is a change in the microbiome, the implantation rate drops to half and the miscarriage rate doubles.
Following this study, also in 2018, the team published a multicenter, prospective, observational study. A 16S ribosomal RNA (16S rRNA) gene sequencing technique was used to analyze endometrial fluid and biopsy samples before embryo transfer in a cohort of 342 infertile patients asymptomatic for infection. Participants underwent fertilization procedures in 13 centers on three continents.
A dysbiotic endometrial microbiota profile composed of Atopobium, Bifidobacterium, Chryseobacterium, Gardnerella, Haemophilus, Klebsiella, Neisseria, Staphylococcus, and Streptococcus was associated with unsuccessful outcomes. In contrast, Lactobacillus was consistently enriched in patients with live birth outcomes. The authors concluded that endometrial microbiota composition before embryo transfer is a useful biomarker to predict reproductive outcome.
“You see a microbial signature in patients who become pregnant, another in those who do not become pregnant, and yet another in those who miscarry,” Dr. Simón summarized. “By knowing this signature, the microbiome can be analyzed and treated so that it is stabilized before the embryo is transferred.”
What should be done?
Endometrial microbiome profiles do not use microbial cultures. They are obtained by NGS of the endometrial sample. This is because the 16S rRNA gene, which can be found in bacteria, presents hypervariable regions that serve as markers to identify the bacteria present.
If a microbiome is found to be somewhat unhealthy, it is theoretically possible to change its composition, increasing the chances of successful assisted reproduction. The administration of antibiotics and vaginal probiotics are two treatment approaches.
According to Dr. Simón, treatment is specific to the bacterium (metronidazole, and, if that fails, rifampicin for Gardnerella, amoxicillin and clavulanic acid for Streptococci). Once the pathogenic bacterium has been treated, the probiotics can be administered. “If all is well, we can then go ahead with the procedure,” he explained.
Dr. Simón pointed out that, with respect to treatment, knowledge is still limited and primarily based on case reports. “You look for issues in the microbiome when the patient experiences reproductive failure and there are no other causes,” he emphasized. “Microbiology plays a role in reproduction, affecting the human uterus. It’s good to know about it to improve reproductive outcomes. When there are repeated [embryo] implantation failures, we suggest an endometrial biopsy to identify the implantation window and determine whether the uterine microbiome is healthy or not. And if there are any abnormalities in the microbiome, they can be treated.”
There are still many open questions, such as how long the “good microbiome” lasts after antibiotic therapy. “We suggest checking the microbiome after [antibiotic] treatment and before implanting the embryo,” said Dr. Simón.
Although there is no consensus on how the endometrial microbiota relate to reproductive outcomes, the analysis and change in microbiome are already being offered in clinical practice as a way to increase the chances of conception. Márcia Riboldi, PhD, a genetics specialist serving as Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses, provides an idea of the market for such analyses in Brazil. “We perform approximately 500 analyses per month,” she said, adding that most patients have a history of [embryo] implantation failure or miscarriage.
Matheus Roque, MD, PhD, an IVF specialist, shared two IVF case reports from the Mater Prime Human Reproduction Clinic in the southern region of the city of São Paulo. He emphasized that the decision to perform a microbiome analysis was made only after repeated implantation failure.
“With the outcomes the doctors started to see, the paradigm started to shift,” said Dr. Riboldi. “Why wait for the patient to have [an embryo] transfer failure? Let’s study the endometrium, check the ideal moment for the transfer, see whether it’s receptive or not, if there’s any disease and if there are Lactobacilli,” she proposed. “We need medical training and awareness, and we need to use them appropriately. We have the tests. Doctors need to learn about them and know when and how to use them.” The microbiome analysis costs approximately BRL 2,000, plus expenses for the medical procedure.
Is it too early?
Caio Parente Barbosa, MD, PhD, is an obstetrician/gynecologist specializing in human reproduction, as well as the director general and founder of the Fertile Idea Institute for Reproductive Health. He shared a few of his experiences in an interview with this news organization. “I would say it is still too early to confirm that [the microbiome analysis] produces effective outcomes.”
Dr. Barbosa, who is also provost of graduate studies, research, and innovation of the ABC School of Medicine, Santo André, Brazil, emphasized there is still little global experience with these analyses. “There are doubts worldwide regarding whether these analyses produce effective outcomes. Scientific studies are entirely controversial.”
He stated that some professionals recommend the microbiome analysis for “patients who don’t know what else to do,” but also recognized that there is already a demand for patients who don’t fit this category, who research the analyses on social networks and YouTube. “But it is the smallest of demands. Patients are not as worried about this yet.”
Dr. Barbosa recognized that the idea of an increasingly tailored treatment plan is inevitable. He believes that the study and treatment of the microbiome will become more critical in the future, but he thinks it still “does not offer any value.”
Dr. Barbosa emphasized that the financial side of things must also be considered. “If we add all these tests when investigating a patient’s issues, the treatment becomes ridiculously expensive.” He pointed out that health care professionals need to be careful to perform minimal testing. “We have already added some tests, such as the karyotype test, to the minimal testing for all patients.”
Dr. Simón responded to this criticism, stating: “The cost of repeating cycles is always greater than that of being thorough and knowing what’s going on. Nothing is certain, but if my daughter or wife needed it, I would like to have as much information as possible to make this decision.”
Dr. Barbosa and Dr. Simón reported no relevant financial relationships. Dr. Riboldi is Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses.
This article was translated from the Medscape Portuguese edition and appeared on Medscape.com.
Until the second half of the 20th century, it was believed that the uterine cavity was sterile. Since then, technological advances have provided insight into the nature of the microbiome throughout the female reproductive tract. The role of these microorganisms on the fertility of women of reproductive age has been the subject of research. Is there an “optimal microbiome” for fertility? Can changing the microbiome of the uterine cavity affect fertility? There is still no definitive scientific response to these questions.
Several studies describe the healthy state of the uterine microbiota in women of reproductive age, with most of these studies reporting dominance of Lactobacillus species. However, by contrast, some studies did not observe Lactobacillus predominance inside the uterine cavity in cases of healthy uterine microbiomes. The presence of other microorganisms, such as Gardnerella vaginalis, was associated with reduced success in patients attempting in vitro fertilization (IVF) treatment, such as, for example, embryo implantation failure and miscarriage.
It is also possible that a physiologic endometrial microbiome could be considered healthy despite a minor presence of pathogenic bacteria. Importantly, responses from the host also modulate many aspects of human conception. These shifts correlate with parameters such as age, hormonal changes, ethnicity, sexual activity, and intrauterine devices.
Carlos Simón, MD, PhD, is a gynecologist and obstetrician and professor at the University of Valencia in Valencia, Spain; Harvard University, Cambridge, Mass.; and Baylor College of Medicine, Houston. He was in São Paulo at the time of the XXVI Brazilian Congress of Assisted Reproduction and agreed to be interviewed by Medscape Portuguese Edition. Dr. Simón, who is Spanish and is an international reference in uterine microbiome studies, created an endometrial receptivity analysis (ERA).
“What we know is that the human uterus has its own microbiome. Thanks to next-generation sequencing (NGS), we can detect microbial DNA. We’re talking about a microbiome that, if changed, affects [embryo] implantation. We have identified that Lactobacilli are the good [microorganisms], but if there are Streptococci, Gardnerella, or other bacteria, the implantation [of the embryo] is affected.”
In 2018, Dr. Simón’s team published a pilot study assessing the microbiome of 30 patients during fertilization treatment. It was observed that, when there is a change in the microbiome, the implantation rate drops to half and the miscarriage rate doubles.
Following this study, also in 2018, the team published a multicenter, prospective, observational study. A 16S ribosomal RNA (16S rRNA) gene sequencing technique was used to analyze endometrial fluid and biopsy samples before embryo transfer in a cohort of 342 infertile patients asymptomatic for infection. Participants underwent fertilization procedures in 13 centers on three continents.
A dysbiotic endometrial microbiota profile composed of Atopobium, Bifidobacterium, Chryseobacterium, Gardnerella, Haemophilus, Klebsiella, Neisseria, Staphylococcus, and Streptococcus was associated with unsuccessful outcomes. In contrast, Lactobacillus was consistently enriched in patients with live birth outcomes. The authors concluded that endometrial microbiota composition before embryo transfer is a useful biomarker to predict reproductive outcome.
“You see a microbial signature in patients who become pregnant, another in those who do not become pregnant, and yet another in those who miscarry,” Dr. Simón summarized. “By knowing this signature, the microbiome can be analyzed and treated so that it is stabilized before the embryo is transferred.”
What should be done?
Endometrial microbiome profiles do not use microbial cultures. They are obtained by NGS of the endometrial sample. This is because the 16S rRNA gene, which can be found in bacteria, presents hypervariable regions that serve as markers to identify the bacteria present.
If a microbiome is found to be somewhat unhealthy, it is theoretically possible to change its composition, increasing the chances of successful assisted reproduction. The administration of antibiotics and vaginal probiotics are two treatment approaches.
According to Dr. Simón, treatment is specific to the bacterium (metronidazole, and, if that fails, rifampicin for Gardnerella, amoxicillin and clavulanic acid for Streptococci). Once the pathogenic bacterium has been treated, the probiotics can be administered. “If all is well, we can then go ahead with the procedure,” he explained.
Dr. Simón pointed out that, with respect to treatment, knowledge is still limited and primarily based on case reports. “You look for issues in the microbiome when the patient experiences reproductive failure and there are no other causes,” he emphasized. “Microbiology plays a role in reproduction, affecting the human uterus. It’s good to know about it to improve reproductive outcomes. When there are repeated [embryo] implantation failures, we suggest an endometrial biopsy to identify the implantation window and determine whether the uterine microbiome is healthy or not. And if there are any abnormalities in the microbiome, they can be treated.”
There are still many open questions, such as how long the “good microbiome” lasts after antibiotic therapy. “We suggest checking the microbiome after [antibiotic] treatment and before implanting the embryo,” said Dr. Simón.
Although there is no consensus on how the endometrial microbiota relate to reproductive outcomes, the analysis and change in microbiome are already being offered in clinical practice as a way to increase the chances of conception. Márcia Riboldi, PhD, a genetics specialist serving as Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses, provides an idea of the market for such analyses in Brazil. “We perform approximately 500 analyses per month,” she said, adding that most patients have a history of [embryo] implantation failure or miscarriage.
Matheus Roque, MD, PhD, an IVF specialist, shared two IVF case reports from the Mater Prime Human Reproduction Clinic in the southern region of the city of São Paulo. He emphasized that the decision to perform a microbiome analysis was made only after repeated implantation failure.
“With the outcomes the doctors started to see, the paradigm started to shift,” said Dr. Riboldi. “Why wait for the patient to have [an embryo] transfer failure? Let’s study the endometrium, check the ideal moment for the transfer, see whether it’s receptive or not, if there’s any disease and if there are Lactobacilli,” she proposed. “We need medical training and awareness, and we need to use them appropriately. We have the tests. Doctors need to learn about them and know when and how to use them.” The microbiome analysis costs approximately BRL 2,000, plus expenses for the medical procedure.
Is it too early?
Caio Parente Barbosa, MD, PhD, is an obstetrician/gynecologist specializing in human reproduction, as well as the director general and founder of the Fertile Idea Institute for Reproductive Health. He shared a few of his experiences in an interview with this news organization. “I would say it is still too early to confirm that [the microbiome analysis] produces effective outcomes.”
Dr. Barbosa, who is also provost of graduate studies, research, and innovation of the ABC School of Medicine, Santo André, Brazil, emphasized there is still little global experience with these analyses. “There are doubts worldwide regarding whether these analyses produce effective outcomes. Scientific studies are entirely controversial.”
He stated that some professionals recommend the microbiome analysis for “patients who don’t know what else to do,” but also recognized that there is already a demand for patients who don’t fit this category, who research the analyses on social networks and YouTube. “But it is the smallest of demands. Patients are not as worried about this yet.”
Dr. Barbosa recognized that the idea of an increasingly tailored treatment plan is inevitable. He believes that the study and treatment of the microbiome will become more critical in the future, but he thinks it still “does not offer any value.”
Dr. Barbosa emphasized that the financial side of things must also be considered. “If we add all these tests when investigating a patient’s issues, the treatment becomes ridiculously expensive.” He pointed out that health care professionals need to be careful to perform minimal testing. “We have already added some tests, such as the karyotype test, to the minimal testing for all patients.”
Dr. Simón responded to this criticism, stating: “The cost of repeating cycles is always greater than that of being thorough and knowing what’s going on. Nothing is certain, but if my daughter or wife needed it, I would like to have as much information as possible to make this decision.”
Dr. Barbosa and Dr. Simón reported no relevant financial relationships. Dr. Riboldi is Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses.
This article was translated from the Medscape Portuguese edition and appeared on Medscape.com.
Until the second half of the 20th century, it was believed that the uterine cavity was sterile. Since then, technological advances have provided insight into the nature of the microbiome throughout the female reproductive tract. The role of these microorganisms on the fertility of women of reproductive age has been the subject of research. Is there an “optimal microbiome” for fertility? Can changing the microbiome of the uterine cavity affect fertility? There is still no definitive scientific response to these questions.
Several studies describe the healthy state of the uterine microbiota in women of reproductive age, with most of these studies reporting dominance of Lactobacillus species. However, by contrast, some studies did not observe Lactobacillus predominance inside the uterine cavity in cases of healthy uterine microbiomes. The presence of other microorganisms, such as Gardnerella vaginalis, was associated with reduced success in patients attempting in vitro fertilization (IVF) treatment, such as, for example, embryo implantation failure and miscarriage.
It is also possible that a physiologic endometrial microbiome could be considered healthy despite a minor presence of pathogenic bacteria. Importantly, responses from the host also modulate many aspects of human conception. These shifts correlate with parameters such as age, hormonal changes, ethnicity, sexual activity, and intrauterine devices.
Carlos Simón, MD, PhD, is a gynecologist and obstetrician and professor at the University of Valencia in Valencia, Spain; Harvard University, Cambridge, Mass.; and Baylor College of Medicine, Houston. He was in São Paulo at the time of the XXVI Brazilian Congress of Assisted Reproduction and agreed to be interviewed by Medscape Portuguese Edition. Dr. Simón, who is Spanish and is an international reference in uterine microbiome studies, created an endometrial receptivity analysis (ERA).
“What we know is that the human uterus has its own microbiome. Thanks to next-generation sequencing (NGS), we can detect microbial DNA. We’re talking about a microbiome that, if changed, affects [embryo] implantation. We have identified that Lactobacilli are the good [microorganisms], but if there are Streptococci, Gardnerella, or other bacteria, the implantation [of the embryo] is affected.”
In 2018, Dr. Simón’s team published a pilot study assessing the microbiome of 30 patients during fertilization treatment. It was observed that, when there is a change in the microbiome, the implantation rate drops to half and the miscarriage rate doubles.
Following this study, also in 2018, the team published a multicenter, prospective, observational study. A 16S ribosomal RNA (16S rRNA) gene sequencing technique was used to analyze endometrial fluid and biopsy samples before embryo transfer in a cohort of 342 infertile patients asymptomatic for infection. Participants underwent fertilization procedures in 13 centers on three continents.
A dysbiotic endometrial microbiota profile composed of Atopobium, Bifidobacterium, Chryseobacterium, Gardnerella, Haemophilus, Klebsiella, Neisseria, Staphylococcus, and Streptococcus was associated with unsuccessful outcomes. In contrast, Lactobacillus was consistently enriched in patients with live birth outcomes. The authors concluded that endometrial microbiota composition before embryo transfer is a useful biomarker to predict reproductive outcome.
“You see a microbial signature in patients who become pregnant, another in those who do not become pregnant, and yet another in those who miscarry,” Dr. Simón summarized. “By knowing this signature, the microbiome can be analyzed and treated so that it is stabilized before the embryo is transferred.”
What should be done?
Endometrial microbiome profiles do not use microbial cultures. They are obtained by NGS of the endometrial sample. This is because the 16S rRNA gene, which can be found in bacteria, presents hypervariable regions that serve as markers to identify the bacteria present.
If a microbiome is found to be somewhat unhealthy, it is theoretically possible to change its composition, increasing the chances of successful assisted reproduction. The administration of antibiotics and vaginal probiotics are two treatment approaches.
According to Dr. Simón, treatment is specific to the bacterium (metronidazole, and, if that fails, rifampicin for Gardnerella, amoxicillin and clavulanic acid for Streptococci). Once the pathogenic bacterium has been treated, the probiotics can be administered. “If all is well, we can then go ahead with the procedure,” he explained.
Dr. Simón pointed out that, with respect to treatment, knowledge is still limited and primarily based on case reports. “You look for issues in the microbiome when the patient experiences reproductive failure and there are no other causes,” he emphasized. “Microbiology plays a role in reproduction, affecting the human uterus. It’s good to know about it to improve reproductive outcomes. When there are repeated [embryo] implantation failures, we suggest an endometrial biopsy to identify the implantation window and determine whether the uterine microbiome is healthy or not. And if there are any abnormalities in the microbiome, they can be treated.”
There are still many open questions, such as how long the “good microbiome” lasts after antibiotic therapy. “We suggest checking the microbiome after [antibiotic] treatment and before implanting the embryo,” said Dr. Simón.
Although there is no consensus on how the endometrial microbiota relate to reproductive outcomes, the analysis and change in microbiome are already being offered in clinical practice as a way to increase the chances of conception. Márcia Riboldi, PhD, a genetics specialist serving as Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses, provides an idea of the market for such analyses in Brazil. “We perform approximately 500 analyses per month,” she said, adding that most patients have a history of [embryo] implantation failure or miscarriage.
Matheus Roque, MD, PhD, an IVF specialist, shared two IVF case reports from the Mater Prime Human Reproduction Clinic in the southern region of the city of São Paulo. He emphasized that the decision to perform a microbiome analysis was made only after repeated implantation failure.
“With the outcomes the doctors started to see, the paradigm started to shift,” said Dr. Riboldi. “Why wait for the patient to have [an embryo] transfer failure? Let’s study the endometrium, check the ideal moment for the transfer, see whether it’s receptive or not, if there’s any disease and if there are Lactobacilli,” she proposed. “We need medical training and awareness, and we need to use them appropriately. We have the tests. Doctors need to learn about them and know when and how to use them.” The microbiome analysis costs approximately BRL 2,000, plus expenses for the medical procedure.
Is it too early?
Caio Parente Barbosa, MD, PhD, is an obstetrician/gynecologist specializing in human reproduction, as well as the director general and founder of the Fertile Idea Institute for Reproductive Health. He shared a few of his experiences in an interview with this news organization. “I would say it is still too early to confirm that [the microbiome analysis] produces effective outcomes.”
Dr. Barbosa, who is also provost of graduate studies, research, and innovation of the ABC School of Medicine, Santo André, Brazil, emphasized there is still little global experience with these analyses. “There are doubts worldwide regarding whether these analyses produce effective outcomes. Scientific studies are entirely controversial.”
He stated that some professionals recommend the microbiome analysis for “patients who don’t know what else to do,” but also recognized that there is already a demand for patients who don’t fit this category, who research the analyses on social networks and YouTube. “But it is the smallest of demands. Patients are not as worried about this yet.”
Dr. Barbosa recognized that the idea of an increasingly tailored treatment plan is inevitable. He believes that the study and treatment of the microbiome will become more critical in the future, but he thinks it still “does not offer any value.”
Dr. Barbosa emphasized that the financial side of things must also be considered. “If we add all these tests when investigating a patient’s issues, the treatment becomes ridiculously expensive.” He pointed out that health care professionals need to be careful to perform minimal testing. “We have already added some tests, such as the karyotype test, to the minimal testing for all patients.”
Dr. Simón responded to this criticism, stating: “The cost of repeating cycles is always greater than that of being thorough and knowing what’s going on. Nothing is certain, but if my daughter or wife needed it, I would like to have as much information as possible to make this decision.”
Dr. Barbosa and Dr. Simón reported no relevant financial relationships. Dr. Riboldi is Country Manager for Igenomix Brasil and Argentina, the company that offers the analyses.
This article was translated from the Medscape Portuguese edition and appeared on Medscape.com.
Long COVID-19 in children and adolescents: What do we know?
Among scientists, the existence of long COVID-19 in children and adolescents has been the subject of debate.
Published by a Mexican multidisciplinary group in Scientific Reports, the first study is a systematic review and meta-analysis. It identified mood symptoms as the most prevalent clinical manifestations of long COVID-19 in children and adolescents. These symptoms included sadness, tension, anger, depression, and anxiety (16.50%); fatigue (9.66%); and sleep disorders (8.42%).
The second study, LongCOVIDKidsDK, was conducted in Denmark. It compared 11,000 children younger than 14 years who had tested positive for COVID-19 with 33,000 children who had no history of COVID-19. The study was published in The Lancet Child and Adolescent Health.
Definitions are changing
In their meta-analysis, the researchers estimated the prevalence and counted signs and symptoms of long COVID-19, as defined by the United Kingdom’s National Institute for Health and Care Excellence. Long COVID-19 was defined as the presence of one or more symptoms more than 4 weeks after SARS-CoV-2 infection. For search terms, the researchers used “COVID-19,” “COVID,” “SARSCOV-2,” “coronavirus,” “long COVID,” “postCOVID,” “PASC,” “long-haulers,” “prolonged,” “post-acute,” “persistent,” “convalescent,” “sequelae,” and “postviral.”
Of the 8,373 citations returned by the search as of Feb. 10, 2022, 21 prospective studies, 2 of them on preprint servers, met the authors’ selection criteria. Those studies included a total of 80,071 children and adolescents younger than 18 years.
In the meta-analysis, the prevalence of long COVID-19 among children and adolescents was reported to be 25.24% (95% confidence interval, 18.17-33.02; I2, 99.61%), regardless of whether the case had been asymptomatic, mild, moderate, severe, or serious. For patients who had been hospitalized, the prevalence was 29.19% (95% CI, 17.83-41.98; I2, 80.84%).
These numbers, while striking, are not the focus of the study, according to first author Sandra Lopez-Leon, MD, PhD, associate professor of pharmacoepidemiology at Rutgers University, New Brunswick, N.J. “It’s important that we don’t focus on that 25%,” she said in an interview. “It’s a disease that we’re learning about, we’re at a time when the definitions are still changing, and, depending on when it is measured, a different number will be given. The message we want to give is that long COVID-19 exists, it’s happening in children and adolescents, and patients need this recognition. And also to show that it can affect the whole body.”
The study showed that the children and adolescents who presented with SARS-CoV-2 infection were at higher risk of subsequent long dyspnea, anosmia/ageusia, or fever, compared with control persons.
In total, in the studies that were included, more than 40 long-term clinical manifestations associated with COVID-19 in the pediatric population were identified.
The most common symptoms among children aged 0-3 years were mood swings, skin rashes, and stomachaches. In 4- to 11-year-olds, the most common symptoms were mood swings, trouble remembering or concentrating, and skin rashes. In 12- to 14-year-olds, they were fatigue, mood swings, and trouble remembering or concentrating. These data are based on parent responses.
The list of signs and symptoms also includes headache, respiratory symptoms, cognitive symptoms (such as decreased concentration, learning difficulties, confusion, and memory loss), loss of appetite, and smell disorder (hyposmia, anosmia, hyperosmia, parosmia, and phantom smell).
In the studies, the prevalence of the following symptoms was less than 5%: hyperhidrosis, chest pain, dizziness, cough, myalgia/arthralgia, changes in body weight, taste disorder, otalgia (tinnitus, ear pain, vertigo), ophthalmologic symptoms (conjunctivitis, dry eye, blurred vision, photophobia, pain), dermatologic symptoms (dry skin, itchy skin, rashes, hives, hair loss), urinary symptoms, abdominal pain, throat pain, chest tightness, variations in heart rate, palpitations, constipation, dysphonia, fever, diarrhea, vomiting/nausea, menstrual changes, neurological abnormalities, speech disorders, and dysphagia.
The authors made it clear that the frequency and severity of these symptoms can fluctuate from one patient to another.
“The meta-analysis is important because it brings together 21 studies selected from more than 8,000 articles – and in them, a large number of children – to study the most common manifestations of long COVID-19,” Gabriela Ensinck, MD, head of the infectious diseases department at the Víctor J. Vilela Children’s Hospital in Rosario, Argentina, told this news organization. Dr. Ensinck did not participate in the study. “The important thing here is that long COVID-19 exists in pediatrics. And that it is a prolongation of signs or symptoms over time, a time for which there is no single definition.”
“It’s a snapshot of all the symptoms that can remain after COVID-19,” Dr. Lopez-Leon explained. “The meta-analysis seeks to see if there’s an association between having had COVID-19 and having the symptoms, but at no time does it speak of causality.”
The prevalence of symptoms largely depends on the time since the onset of acute COVID-19. Most symptoms improve over time. In the studies that were included in the meta-analysis, the follow-up time varied between 1 and 13 months. It is important to understand what symptoms are associated with each period after the onset of infection, the authors said.
Danish parent survey
The Danish study LongCOVIDKidsDK followed the World Health Organization criteria for long COVID-19 and included children and adolescents aged 0-14 years who received a diagnosis of COVID-19 and who experienced symptoms that lasted at least 2 months.
Between July 20, 2021, and Sept. 15, 2021, a questionnaire was sent to 38,152 case patients and 147,212 control persons. Of this group, 10,997 (28.8%) case patients and 33,016 (22.4%) control persons answered the survey.
Children who had been diagnosed with SARS-CoV-2 infection were more likely to experience long-lasting symptoms than children who had never been diagnosed. Approximately one-third of children with a positive SARS-CoV-2 test experienced symptoms that were not present before infection. Children who experienced long-lasting symptoms included 40% of children diagnosed with COVID-19 and 27% of control persons aged 0-3 years, 38% of case patients and 34% of control persons aged 4-11 years, and 46% of case patients and 41% of control persons aged 12-14 years.
Interestingly, those diagnosed with COVID-19 reported fewer psychological and social problems than those in the control group. Among the oldest (aged 12-14 years), quality of life scores were higher and anxiety scores were lower for those who had tested positive for SARS-CoV-2.
More information needed
Given the diversity of symptoms in the meta-analysis and the LongCOVIDKidsDK study, a multidisciplinary approach is imperative. Dr. Lopez-Leon suggests that there is a need to raise awareness among parents, clinicians, researchers, and the health system about the conditions that can occur after COVID-19. Clinicians must better understand the sequelae to provide targeted care and treatment. The authors of the Danish study recommend establishing clinics for long COVID-19 with multispecialty care.
Maren J. Heilskov Rytter, PhD, associate professor of clinical medicine at the University of Copenhagen, wrote an editorial in The Lancet Child and Adolescent Health about the Danish study. Until it is clarified whether SARS-CoV-2 does indeed cause persistent symptoms, she wrote, “it seems excessive and premature to establish specific multidisciplinary clinics for children with long COVID-19.”
Dr. Rytter highlighted the difficulty of interpreting LongCOVIDKidsDK data, owing to recall bias, the failure to exclude other causes of symptoms in the cases analyzed, and the number of symptoms in the control persons. In addition, the data analyzed in Denmark are of limited clinical relevance, she said, given a greater presence of mild symptoms and, paradoxically, a higher quality of life.
She concluded, “In the majority of children with nonspecific symptoms after COVID-19, the symptoms presented are more likely to have been caused by something other than COVID-19, and if they are related to COVID-19, they are likely to go away over time.”
Dr. Ensinck, who is coauthor of the Argentine Ministry of Health’s guide for long COVID-19 monitoring for children and adolescents and who represented the Infectious Diseases Committee of the Argentine Society of Pediatrics, highlighted another aspect of the problem. “What should be taken into account in these data is to see how much the confinement contributed. Children are the ones who suffered the most in the period in which schools were closed; they could not meet their peers, they had sick relatives, they felt fear. … all this must be taken into account.”
There is as yet no agreement on how to define and diagnose long COVID-19 in adults, a population that has been studied more closely. Part of the problem is that long COVID-19 has been linked to more than 200 symptoms, which can range in severity from inconvenient to debilitating, can last for months or years, and can recur, sometimes months after apparent recovery. Thus, there are still disparate answers to basic questions about the syndrome’s frequency and its effects on vaccination, reinfection, and the latest variant of SARS-CoV-2.
This article has been translated from the Medscape Spanish edition. A version appeared on Medscape.com.
Among scientists, the existence of long COVID-19 in children and adolescents has been the subject of debate.
Published by a Mexican multidisciplinary group in Scientific Reports, the first study is a systematic review and meta-analysis. It identified mood symptoms as the most prevalent clinical manifestations of long COVID-19 in children and adolescents. These symptoms included sadness, tension, anger, depression, and anxiety (16.50%); fatigue (9.66%); and sleep disorders (8.42%).
The second study, LongCOVIDKidsDK, was conducted in Denmark. It compared 11,000 children younger than 14 years who had tested positive for COVID-19 with 33,000 children who had no history of COVID-19. The study was published in The Lancet Child and Adolescent Health.
Definitions are changing
In their meta-analysis, the researchers estimated the prevalence and counted signs and symptoms of long COVID-19, as defined by the United Kingdom’s National Institute for Health and Care Excellence. Long COVID-19 was defined as the presence of one or more symptoms more than 4 weeks after SARS-CoV-2 infection. For search terms, the researchers used “COVID-19,” “COVID,” “SARSCOV-2,” “coronavirus,” “long COVID,” “postCOVID,” “PASC,” “long-haulers,” “prolonged,” “post-acute,” “persistent,” “convalescent,” “sequelae,” and “postviral.”
Of the 8,373 citations returned by the search as of Feb. 10, 2022, 21 prospective studies, 2 of them on preprint servers, met the authors’ selection criteria. Those studies included a total of 80,071 children and adolescents younger than 18 years.
In the meta-analysis, the prevalence of long COVID-19 among children and adolescents was reported to be 25.24% (95% confidence interval, 18.17-33.02; I2, 99.61%), regardless of whether the case had been asymptomatic, mild, moderate, severe, or serious. For patients who had been hospitalized, the prevalence was 29.19% (95% CI, 17.83-41.98; I2, 80.84%).
These numbers, while striking, are not the focus of the study, according to first author Sandra Lopez-Leon, MD, PhD, associate professor of pharmacoepidemiology at Rutgers University, New Brunswick, N.J. “It’s important that we don’t focus on that 25%,” she said in an interview. “It’s a disease that we’re learning about, we’re at a time when the definitions are still changing, and, depending on when it is measured, a different number will be given. The message we want to give is that long COVID-19 exists, it’s happening in children and adolescents, and patients need this recognition. And also to show that it can affect the whole body.”
The study showed that the children and adolescents who presented with SARS-CoV-2 infection were at higher risk of subsequent long dyspnea, anosmia/ageusia, or fever, compared with control persons.
In total, in the studies that were included, more than 40 long-term clinical manifestations associated with COVID-19 in the pediatric population were identified.
The most common symptoms among children aged 0-3 years were mood swings, skin rashes, and stomachaches. In 4- to 11-year-olds, the most common symptoms were mood swings, trouble remembering or concentrating, and skin rashes. In 12- to 14-year-olds, they were fatigue, mood swings, and trouble remembering or concentrating. These data are based on parent responses.
The list of signs and symptoms also includes headache, respiratory symptoms, cognitive symptoms (such as decreased concentration, learning difficulties, confusion, and memory loss), loss of appetite, and smell disorder (hyposmia, anosmia, hyperosmia, parosmia, and phantom smell).
In the studies, the prevalence of the following symptoms was less than 5%: hyperhidrosis, chest pain, dizziness, cough, myalgia/arthralgia, changes in body weight, taste disorder, otalgia (tinnitus, ear pain, vertigo), ophthalmologic symptoms (conjunctivitis, dry eye, blurred vision, photophobia, pain), dermatologic symptoms (dry skin, itchy skin, rashes, hives, hair loss), urinary symptoms, abdominal pain, throat pain, chest tightness, variations in heart rate, palpitations, constipation, dysphonia, fever, diarrhea, vomiting/nausea, menstrual changes, neurological abnormalities, speech disorders, and dysphagia.
The authors made it clear that the frequency and severity of these symptoms can fluctuate from one patient to another.
“The meta-analysis is important because it brings together 21 studies selected from more than 8,000 articles – and in them, a large number of children – to study the most common manifestations of long COVID-19,” Gabriela Ensinck, MD, head of the infectious diseases department at the Víctor J. Vilela Children’s Hospital in Rosario, Argentina, told this news organization. Dr. Ensinck did not participate in the study. “The important thing here is that long COVID-19 exists in pediatrics. And that it is a prolongation of signs or symptoms over time, a time for which there is no single definition.”
“It’s a snapshot of all the symptoms that can remain after COVID-19,” Dr. Lopez-Leon explained. “The meta-analysis seeks to see if there’s an association between having had COVID-19 and having the symptoms, but at no time does it speak of causality.”
The prevalence of symptoms largely depends on the time since the onset of acute COVID-19. Most symptoms improve over time. In the studies that were included in the meta-analysis, the follow-up time varied between 1 and 13 months. It is important to understand what symptoms are associated with each period after the onset of infection, the authors said.
Danish parent survey
The Danish study LongCOVIDKidsDK followed the World Health Organization criteria for long COVID-19 and included children and adolescents aged 0-14 years who received a diagnosis of COVID-19 and who experienced symptoms that lasted at least 2 months.
Between July 20, 2021, and Sept. 15, 2021, a questionnaire was sent to 38,152 case patients and 147,212 control persons. Of this group, 10,997 (28.8%) case patients and 33,016 (22.4%) control persons answered the survey.
Children who had been diagnosed with SARS-CoV-2 infection were more likely to experience long-lasting symptoms than children who had never been diagnosed. Approximately one-third of children with a positive SARS-CoV-2 test experienced symptoms that were not present before infection. Children who experienced long-lasting symptoms included 40% of children diagnosed with COVID-19 and 27% of control persons aged 0-3 years, 38% of case patients and 34% of control persons aged 4-11 years, and 46% of case patients and 41% of control persons aged 12-14 years.
Interestingly, those diagnosed with COVID-19 reported fewer psychological and social problems than those in the control group. Among the oldest (aged 12-14 years), quality of life scores were higher and anxiety scores were lower for those who had tested positive for SARS-CoV-2.
More information needed
Given the diversity of symptoms in the meta-analysis and the LongCOVIDKidsDK study, a multidisciplinary approach is imperative. Dr. Lopez-Leon suggests that there is a need to raise awareness among parents, clinicians, researchers, and the health system about the conditions that can occur after COVID-19. Clinicians must better understand the sequelae to provide targeted care and treatment. The authors of the Danish study recommend establishing clinics for long COVID-19 with multispecialty care.
Maren J. Heilskov Rytter, PhD, associate professor of clinical medicine at the University of Copenhagen, wrote an editorial in The Lancet Child and Adolescent Health about the Danish study. Until it is clarified whether SARS-CoV-2 does indeed cause persistent symptoms, she wrote, “it seems excessive and premature to establish specific multidisciplinary clinics for children with long COVID-19.”
Dr. Rytter highlighted the difficulty of interpreting LongCOVIDKidsDK data, owing to recall bias, the failure to exclude other causes of symptoms in the cases analyzed, and the number of symptoms in the control persons. In addition, the data analyzed in Denmark are of limited clinical relevance, she said, given a greater presence of mild symptoms and, paradoxically, a higher quality of life.
She concluded, “In the majority of children with nonspecific symptoms after COVID-19, the symptoms presented are more likely to have been caused by something other than COVID-19, and if they are related to COVID-19, they are likely to go away over time.”
Dr. Ensinck, who is coauthor of the Argentine Ministry of Health’s guide for long COVID-19 monitoring for children and adolescents and who represented the Infectious Diseases Committee of the Argentine Society of Pediatrics, highlighted another aspect of the problem. “What should be taken into account in these data is to see how much the confinement contributed. Children are the ones who suffered the most in the period in which schools were closed; they could not meet their peers, they had sick relatives, they felt fear. … all this must be taken into account.”
There is as yet no agreement on how to define and diagnose long COVID-19 in adults, a population that has been studied more closely. Part of the problem is that long COVID-19 has been linked to more than 200 symptoms, which can range in severity from inconvenient to debilitating, can last for months or years, and can recur, sometimes months after apparent recovery. Thus, there are still disparate answers to basic questions about the syndrome’s frequency and its effects on vaccination, reinfection, and the latest variant of SARS-CoV-2.
This article has been translated from the Medscape Spanish edition. A version appeared on Medscape.com.
Among scientists, the existence of long COVID-19 in children and adolescents has been the subject of debate.
Published by a Mexican multidisciplinary group in Scientific Reports, the first study is a systematic review and meta-analysis. It identified mood symptoms as the most prevalent clinical manifestations of long COVID-19 in children and adolescents. These symptoms included sadness, tension, anger, depression, and anxiety (16.50%); fatigue (9.66%); and sleep disorders (8.42%).
The second study, LongCOVIDKidsDK, was conducted in Denmark. It compared 11,000 children younger than 14 years who had tested positive for COVID-19 with 33,000 children who had no history of COVID-19. The study was published in The Lancet Child and Adolescent Health.
Definitions are changing
In their meta-analysis, the researchers estimated the prevalence and counted signs and symptoms of long COVID-19, as defined by the United Kingdom’s National Institute for Health and Care Excellence. Long COVID-19 was defined as the presence of one or more symptoms more than 4 weeks after SARS-CoV-2 infection. For search terms, the researchers used “COVID-19,” “COVID,” “SARSCOV-2,” “coronavirus,” “long COVID,” “postCOVID,” “PASC,” “long-haulers,” “prolonged,” “post-acute,” “persistent,” “convalescent,” “sequelae,” and “postviral.”
Of the 8,373 citations returned by the search as of Feb. 10, 2022, 21 prospective studies, 2 of them on preprint servers, met the authors’ selection criteria. Those studies included a total of 80,071 children and adolescents younger than 18 years.
In the meta-analysis, the prevalence of long COVID-19 among children and adolescents was reported to be 25.24% (95% confidence interval, 18.17-33.02; I2, 99.61%), regardless of whether the case had been asymptomatic, mild, moderate, severe, or serious. For patients who had been hospitalized, the prevalence was 29.19% (95% CI, 17.83-41.98; I2, 80.84%).
These numbers, while striking, are not the focus of the study, according to first author Sandra Lopez-Leon, MD, PhD, associate professor of pharmacoepidemiology at Rutgers University, New Brunswick, N.J. “It’s important that we don’t focus on that 25%,” she said in an interview. “It’s a disease that we’re learning about, we’re at a time when the definitions are still changing, and, depending on when it is measured, a different number will be given. The message we want to give is that long COVID-19 exists, it’s happening in children and adolescents, and patients need this recognition. And also to show that it can affect the whole body.”
The study showed that the children and adolescents who presented with SARS-CoV-2 infection were at higher risk of subsequent long dyspnea, anosmia/ageusia, or fever, compared with control persons.
In total, in the studies that were included, more than 40 long-term clinical manifestations associated with COVID-19 in the pediatric population were identified.
The most common symptoms among children aged 0-3 years were mood swings, skin rashes, and stomachaches. In 4- to 11-year-olds, the most common symptoms were mood swings, trouble remembering or concentrating, and skin rashes. In 12- to 14-year-olds, they were fatigue, mood swings, and trouble remembering or concentrating. These data are based on parent responses.
The list of signs and symptoms also includes headache, respiratory symptoms, cognitive symptoms (such as decreased concentration, learning difficulties, confusion, and memory loss), loss of appetite, and smell disorder (hyposmia, anosmia, hyperosmia, parosmia, and phantom smell).
In the studies, the prevalence of the following symptoms was less than 5%: hyperhidrosis, chest pain, dizziness, cough, myalgia/arthralgia, changes in body weight, taste disorder, otalgia (tinnitus, ear pain, vertigo), ophthalmologic symptoms (conjunctivitis, dry eye, blurred vision, photophobia, pain), dermatologic symptoms (dry skin, itchy skin, rashes, hives, hair loss), urinary symptoms, abdominal pain, throat pain, chest tightness, variations in heart rate, palpitations, constipation, dysphonia, fever, diarrhea, vomiting/nausea, menstrual changes, neurological abnormalities, speech disorders, and dysphagia.
The authors made it clear that the frequency and severity of these symptoms can fluctuate from one patient to another.
“The meta-analysis is important because it brings together 21 studies selected from more than 8,000 articles – and in them, a large number of children – to study the most common manifestations of long COVID-19,” Gabriela Ensinck, MD, head of the infectious diseases department at the Víctor J. Vilela Children’s Hospital in Rosario, Argentina, told this news organization. Dr. Ensinck did not participate in the study. “The important thing here is that long COVID-19 exists in pediatrics. And that it is a prolongation of signs or symptoms over time, a time for which there is no single definition.”
“It’s a snapshot of all the symptoms that can remain after COVID-19,” Dr. Lopez-Leon explained. “The meta-analysis seeks to see if there’s an association between having had COVID-19 and having the symptoms, but at no time does it speak of causality.”
The prevalence of symptoms largely depends on the time since the onset of acute COVID-19. Most symptoms improve over time. In the studies that were included in the meta-analysis, the follow-up time varied between 1 and 13 months. It is important to understand what symptoms are associated with each period after the onset of infection, the authors said.
Danish parent survey
The Danish study LongCOVIDKidsDK followed the World Health Organization criteria for long COVID-19 and included children and adolescents aged 0-14 years who received a diagnosis of COVID-19 and who experienced symptoms that lasted at least 2 months.
Between July 20, 2021, and Sept. 15, 2021, a questionnaire was sent to 38,152 case patients and 147,212 control persons. Of this group, 10,997 (28.8%) case patients and 33,016 (22.4%) control persons answered the survey.
Children who had been diagnosed with SARS-CoV-2 infection were more likely to experience long-lasting symptoms than children who had never been diagnosed. Approximately one-third of children with a positive SARS-CoV-2 test experienced symptoms that were not present before infection. Children who experienced long-lasting symptoms included 40% of children diagnosed with COVID-19 and 27% of control persons aged 0-3 years, 38% of case patients and 34% of control persons aged 4-11 years, and 46% of case patients and 41% of control persons aged 12-14 years.
Interestingly, those diagnosed with COVID-19 reported fewer psychological and social problems than those in the control group. Among the oldest (aged 12-14 years), quality of life scores were higher and anxiety scores were lower for those who had tested positive for SARS-CoV-2.
More information needed
Given the diversity of symptoms in the meta-analysis and the LongCOVIDKidsDK study, a multidisciplinary approach is imperative. Dr. Lopez-Leon suggests that there is a need to raise awareness among parents, clinicians, researchers, and the health system about the conditions that can occur after COVID-19. Clinicians must better understand the sequelae to provide targeted care and treatment. The authors of the Danish study recommend establishing clinics for long COVID-19 with multispecialty care.
Maren J. Heilskov Rytter, PhD, associate professor of clinical medicine at the University of Copenhagen, wrote an editorial in The Lancet Child and Adolescent Health about the Danish study. Until it is clarified whether SARS-CoV-2 does indeed cause persistent symptoms, she wrote, “it seems excessive and premature to establish specific multidisciplinary clinics for children with long COVID-19.”
Dr. Rytter highlighted the difficulty of interpreting LongCOVIDKidsDK data, owing to recall bias, the failure to exclude other causes of symptoms in the cases analyzed, and the number of symptoms in the control persons. In addition, the data analyzed in Denmark are of limited clinical relevance, she said, given a greater presence of mild symptoms and, paradoxically, a higher quality of life.
She concluded, “In the majority of children with nonspecific symptoms after COVID-19, the symptoms presented are more likely to have been caused by something other than COVID-19, and if they are related to COVID-19, they are likely to go away over time.”
Dr. Ensinck, who is coauthor of the Argentine Ministry of Health’s guide for long COVID-19 monitoring for children and adolescents and who represented the Infectious Diseases Committee of the Argentine Society of Pediatrics, highlighted another aspect of the problem. “What should be taken into account in these data is to see how much the confinement contributed. Children are the ones who suffered the most in the period in which schools were closed; they could not meet their peers, they had sick relatives, they felt fear. … all this must be taken into account.”
There is as yet no agreement on how to define and diagnose long COVID-19 in adults, a population that has been studied more closely. Part of the problem is that long COVID-19 has been linked to more than 200 symptoms, which can range in severity from inconvenient to debilitating, can last for months or years, and can recur, sometimes months after apparent recovery. Thus, there are still disparate answers to basic questions about the syndrome’s frequency and its effects on vaccination, reinfection, and the latest variant of SARS-CoV-2.
This article has been translated from the Medscape Spanish edition. A version appeared on Medscape.com.
FROM SCIENTIFIC REPORTS AND THE LANCET CHILD AND ADOLESCENT HEALTH
Brazilian researchers tracking reinfection by new virus variant
Just as Brazil surpassed 200,000 deaths from COVID-19 on Jan. 7, news from Bahia added another layer of concern: A platform case report in a preprint detailed the first case of reinfection in that state, apparently caused by a new strain, one having the E484K mutation.
That variant, now called Brazil P.1, has migrated to the United States. The Minnesota Department of Health announced on Jan. 25 the nation’s first known COVID-19 case associated with it.
The mutation is located in the protein gene of the virus’ spike, which forms the crown structure of coronaviruses and is responsible for the virus’ binding to human cells. The E484K mutation is now the focus because it’s associated with mutations that escape the immune system’s neutralizing antibodies.
“This mutation is at the center of worldwide concern, and it is the first time that it has appeared in a reinfection,” the study’s first author, Bruno Solano de Freitas Souza, MD, a researcher at the Salvador regional unit of Instituto D’Or of Teaching and Research, based at Hospital São Rafael, Salvador, Brazil, explained in an interview.
“We will wait for the sample from Bahia to confirm the case from the perspective of the Ministry of Health’s surveillance network,” said Fernando Motta, PhD, deputy head of the Laboratory for Respiratory Virus and Measles at the Oswaldo Cruz Institute in Rio de Janeiro, which acts as a national reference center for respiratory viruses with the Brazilian Ministry of Health (MS) and as a reference for the World Health Organization.
A case of reinfection
The case patient that led to the alarm was a 45-year-old woman who is a health care executive. She had no comorbidities. The team had been following health care professionals and patients who had tested positive on reverse transcription–polymerase chain reaction (RT-PCR) testing more than once to understand whether they represented cases of prolonged viral persistence or new infections.
The woman had symptoms of viral infection on two occasions (May 26 and Oct. 26). On both occasions, results of RT-PCR testing for SARS-CoV-2 on nasopharyngeal samples were positive. In the first episode, the patient had diarrhea, myalgia, asthenia, and odynophagia for about 7 days. She returned to activities 21 days later. In the second episode, she had more severe symptoms that lasted longer, but she still did not require hospitalization.
“It was the first confirmed case of reinfection in Bahia, and in the second episode, we observed a mutation that could have an impact on the ability of antibodies to neutralize the virus,” Dr. Souza said. “The research continues with the investigation of cases in which the patient has a positive SARS-CoV-2 RT-PCR more than once in an interval greater than 45 days, to have a higher level of evidence.”
He stressed that “it is very important to reinforce measures to control the pandemic, social distance, use of masks, and speed up vaccination to be able to control the circulation of the virus, while monitoring the evolution of it.”
On alert for more cases
A person who twice tests positive for SARS-CoV-2 on real-time RT-PCR is suspected of having been reinfected, provided 90 or more days have elapsed between the two episodes, regardless of the condition observed. To confirm the suspected case, the samples must be sent to reference laboratories according to a plan established by the Ministry of Health in Brazil.
A health professional living in the Brazilian city of Natal represented the first confirmed case of reinfection by the new coronavirus in Brazil. That case was announced on Dec. 10, 2020.
“We communicated this case of reinfection to the MS in early December 2020. And the second sample already had the E484K mutation on the spike, as in the case of Bahia,” said Dr. Motta.
The first step in differentiating reinfection from persistence is to observe differences in the genotyping of the virus. For the technique to be successful, Dr. Souza said, researchers need a large amount of viral genetic material, which usually cannot be obtained.
“That is why there are many more suspected than confirmed cases,” Dr. Souza explained. He admitted that, although there are few cases, “it is increasingly clear that reinfection is a reality.”
Markers of mutations
What worried the researchers most was not only the possibility of reinfection but also the fact that preliminary analyses showed a specific mutation.
“The E484K mutation is present in a group of variants identified in South Africa that have been associated with increased infectivity and has been observed in a strain recently described in Brazil,” Dr. Souza said.
Mutations are expected, appear spontaneously, and in most cases have no effects on transmission or clinical outcome – they are simply used as markers and are useful for contact tracing or studying transmission routes. But some mutations can last because they provide an advantage for the pathogen, even if only momentary. In the case of SARS-CoV-2, mutations in the protein spike gene (S) are relevant because they may give clues to that advantage – as well as to changes in infectivity, transmission potential, antibodies, and response to vaccines.
A variant of the virus that has eight changes that affect the protein S gene – and several others in different genes – is behind the increase in the number of cases in London and southeastern England. Researchers from the University of São Paulo identified one of the factors that made this new variant – classified as B.1.1.7 – more infectious.
With bioinformatics tools, they found that the protein S gene in the new viral strain has a stronger molecular interaction with the ACE2 receptor, which is on the surface of human cells and to which the virus binds, making infection possible. The variant has already spread to the rest of the world, and the first two cases have been confirmed in Brazil by the Adolf Lutz Institute.
The alert for a new variant in Africa – similar to B.1.1.7 in the United Kingdom in that it carries nine changes in protein S at position 501 – was made by the Brazilian virologist Tulio de Oliveira, PhD.
“We found that this strain seems to be spreading much faster,” Dr. Oliveira, who is with the University of KwaZulu Natal, told the journal Science. His work first alerted British scientists to the importance of the position N501Y.
“The new variants just described in the United Kingdom and South Africa are slightly more transmissible and have already been identified in cases imported into Brazil,” Dr. Motta said. “Unfortunately, we believe it is only a matter of time before it becomes indigenous.”
The viral family grows
Viruses such as SARS-CoV-2 are classified into strains on the basis of small differences in their genetic material. Since Dec. 26, 2020, in addition to the British and South African variants, it appears the Carioca lineage also is a player.
In a preprint article, researchers analyzed the evolution of the epidemic in Rio de Janeiro from April 2020 until just before the new increase in incidence in December. They compared the complete sequences of the viral genome of 180 patients from different municipalities. The study, which is being jointly conducted by members of the Federal University of Rio de Janeiro and the National Laboratory for Scientific Computing, identified a new variant of SARS-CoV-2 that has five unique mutations (from one of the predominant strains). Concern arose because, in addition to those five genetic changes, many of the samples had a sixth – the well-known E484K mutation.
“The three lines – the U.K., South Africa, and Brazil – were almost synchronous publications, but there is no clear evidence that they have any kind of common ancestry,” Carolina M. Voloch, PhD, the article’s first author and a biologist and researcher at the Molecular Virology Laboratory and associate professor in the department of genetics at the Federal University of Rio de Janeiro, said in an interview.
Dr. Voloch’s research focuses on the use of bioinformatics tools to study the molecular, phylogenetic, and genomic evolution of viruses.
“The emergence of new strains is common for viruses,” she said. “It can be happening anywhere in the world at any time.”
She stressed that identifying when mutations emerge will help to define the new Brazilian lineage. Researchers are working to determine whether the neutralizing antibodies of patients who have been infected with other strains respond to this Rio de Janeiro strain.
“We hope to soon be sharing these results,” Dr. Voloch said.
The article’s authors estimated that the new strain likely appeared in early July. They say more analysis is needed to predict whether the changes have a major effect on viral infectivity, the host’s immune response, or the severity of the disease. Asked about the lineage that caused the reinfection in Bahia, Dr. Voloch said she hadn’t yet contacted the authors to conduct a joint analysis but added that the data disclosed in the preprint would not represent the same variant.
“There are only two of the five mutations that characterize the Rio de Janeiro lineage. However, it has the E484K mutation that is present in more than 94% of the samples of the new variant of Rio,” she said.
She added that there’s a possibility of reinfection by the lineage that’s circulating in Rio de Janeiro and in other states, as well as countries such as the United States, the United Kingdom, and Japan.
“The Carioca virus is being exported to the rest of the world,” Dr. Voloch said.
Virus’ diversity still unknown
Researchers now know that SARS-CoV-2 probably circulated silently in Brazil as early as February 2020 and reached all the nation’s regions before air travel was restricted. Since the first half of 2020, there have been two predominant strains.
“More than a dozen strains have been identified in Brazil, but more important than counting strains to identify the speed with which they arise – which is directly associated with the rate of infection, which is very high in the country,” said Dr. Motta.
The so-called variant of Rio de Janeiro, he said, has also been detected in other states in four regions of Brazil. The key to documenting variants is to get a more representative sample with genomes from other parts of the country.
As of Jan. 10, a total of 347,000 complete genome sequences had been shared globally through open databases since SARS-CoV-2 was first identified, but the contribution of countries is uneven. Although the cost and complexity of genetic sequencing has dropped significantly over time, effective sequencing programs still require substantial investments in personnel, equipment, reagents, and bioinformatics infrastructure.
According to Dr. Voloch, it will only be possible to combat the new coronavirus by knowing its diversity and understanding how it evolves. The Fiocruz Genomic Network has made an infographic available so researchers can track the strains circulating in Brazil. It›s the result of collaboration between researchers from Fiocruz and the GISAID Initiative, an international partnership that promotes rapid data sharing.
As of Jan. 5, researchers in Brazil had studied 1,897 genomes – not nearly enough.
“In Brazil, there is little testing and even less sequencing,” lamented Dr. Souza.
“In the U.K., 1 in 600 cases is sequenced. In Brazil it is less than 1 in 10 million cases,” Dr. Voloch added.
So far, no decisive factors for public health, such as greater virulence or greater transmissibility, have been identified in any of the strains established in Brazil. The million-dollar question is whether the emergence of new strains could have an impact on the effectiveness of vaccines being administered today.
“In one way or another, the vaccine is our best bet ever, even if in the future we identify escapist mutants and have to modify it,” Dr. Motta said. “It is what we do annually with influenza.”
Dr. Voloch, Dr. Motta, and Dr. Souza disclosed no relevant financial relationships.
A version of this article first appeared on the Portuguese edition of Medscape.com.
Just as Brazil surpassed 200,000 deaths from COVID-19 on Jan. 7, news from Bahia added another layer of concern: A platform case report in a preprint detailed the first case of reinfection in that state, apparently caused by a new strain, one having the E484K mutation.
That variant, now called Brazil P.1, has migrated to the United States. The Minnesota Department of Health announced on Jan. 25 the nation’s first known COVID-19 case associated with it.
The mutation is located in the protein gene of the virus’ spike, which forms the crown structure of coronaviruses and is responsible for the virus’ binding to human cells. The E484K mutation is now the focus because it’s associated with mutations that escape the immune system’s neutralizing antibodies.
“This mutation is at the center of worldwide concern, and it is the first time that it has appeared in a reinfection,” the study’s first author, Bruno Solano de Freitas Souza, MD, a researcher at the Salvador regional unit of Instituto D’Or of Teaching and Research, based at Hospital São Rafael, Salvador, Brazil, explained in an interview.
“We will wait for the sample from Bahia to confirm the case from the perspective of the Ministry of Health’s surveillance network,” said Fernando Motta, PhD, deputy head of the Laboratory for Respiratory Virus and Measles at the Oswaldo Cruz Institute in Rio de Janeiro, which acts as a national reference center for respiratory viruses with the Brazilian Ministry of Health (MS) and as a reference for the World Health Organization.
A case of reinfection
The case patient that led to the alarm was a 45-year-old woman who is a health care executive. She had no comorbidities. The team had been following health care professionals and patients who had tested positive on reverse transcription–polymerase chain reaction (RT-PCR) testing more than once to understand whether they represented cases of prolonged viral persistence or new infections.
The woman had symptoms of viral infection on two occasions (May 26 and Oct. 26). On both occasions, results of RT-PCR testing for SARS-CoV-2 on nasopharyngeal samples were positive. In the first episode, the patient had diarrhea, myalgia, asthenia, and odynophagia for about 7 days. She returned to activities 21 days later. In the second episode, she had more severe symptoms that lasted longer, but she still did not require hospitalization.
“It was the first confirmed case of reinfection in Bahia, and in the second episode, we observed a mutation that could have an impact on the ability of antibodies to neutralize the virus,” Dr. Souza said. “The research continues with the investigation of cases in which the patient has a positive SARS-CoV-2 RT-PCR more than once in an interval greater than 45 days, to have a higher level of evidence.”
He stressed that “it is very important to reinforce measures to control the pandemic, social distance, use of masks, and speed up vaccination to be able to control the circulation of the virus, while monitoring the evolution of it.”
On alert for more cases
A person who twice tests positive for SARS-CoV-2 on real-time RT-PCR is suspected of having been reinfected, provided 90 or more days have elapsed between the two episodes, regardless of the condition observed. To confirm the suspected case, the samples must be sent to reference laboratories according to a plan established by the Ministry of Health in Brazil.
A health professional living in the Brazilian city of Natal represented the first confirmed case of reinfection by the new coronavirus in Brazil. That case was announced on Dec. 10, 2020.
“We communicated this case of reinfection to the MS in early December 2020. And the second sample already had the E484K mutation on the spike, as in the case of Bahia,” said Dr. Motta.
The first step in differentiating reinfection from persistence is to observe differences in the genotyping of the virus. For the technique to be successful, Dr. Souza said, researchers need a large amount of viral genetic material, which usually cannot be obtained.
“That is why there are many more suspected than confirmed cases,” Dr. Souza explained. He admitted that, although there are few cases, “it is increasingly clear that reinfection is a reality.”
Markers of mutations
What worried the researchers most was not only the possibility of reinfection but also the fact that preliminary analyses showed a specific mutation.
“The E484K mutation is present in a group of variants identified in South Africa that have been associated with increased infectivity and has been observed in a strain recently described in Brazil,” Dr. Souza said.
Mutations are expected, appear spontaneously, and in most cases have no effects on transmission or clinical outcome – they are simply used as markers and are useful for contact tracing or studying transmission routes. But some mutations can last because they provide an advantage for the pathogen, even if only momentary. In the case of SARS-CoV-2, mutations in the protein spike gene (S) are relevant because they may give clues to that advantage – as well as to changes in infectivity, transmission potential, antibodies, and response to vaccines.
A variant of the virus that has eight changes that affect the protein S gene – and several others in different genes – is behind the increase in the number of cases in London and southeastern England. Researchers from the University of São Paulo identified one of the factors that made this new variant – classified as B.1.1.7 – more infectious.
With bioinformatics tools, they found that the protein S gene in the new viral strain has a stronger molecular interaction with the ACE2 receptor, which is on the surface of human cells and to which the virus binds, making infection possible. The variant has already spread to the rest of the world, and the first two cases have been confirmed in Brazil by the Adolf Lutz Institute.
The alert for a new variant in Africa – similar to B.1.1.7 in the United Kingdom in that it carries nine changes in protein S at position 501 – was made by the Brazilian virologist Tulio de Oliveira, PhD.
“We found that this strain seems to be spreading much faster,” Dr. Oliveira, who is with the University of KwaZulu Natal, told the journal Science. His work first alerted British scientists to the importance of the position N501Y.
“The new variants just described in the United Kingdom and South Africa are slightly more transmissible and have already been identified in cases imported into Brazil,” Dr. Motta said. “Unfortunately, we believe it is only a matter of time before it becomes indigenous.”
The viral family grows
Viruses such as SARS-CoV-2 are classified into strains on the basis of small differences in their genetic material. Since Dec. 26, 2020, in addition to the British and South African variants, it appears the Carioca lineage also is a player.
In a preprint article, researchers analyzed the evolution of the epidemic in Rio de Janeiro from April 2020 until just before the new increase in incidence in December. They compared the complete sequences of the viral genome of 180 patients from different municipalities. The study, which is being jointly conducted by members of the Federal University of Rio de Janeiro and the National Laboratory for Scientific Computing, identified a new variant of SARS-CoV-2 that has five unique mutations (from one of the predominant strains). Concern arose because, in addition to those five genetic changes, many of the samples had a sixth – the well-known E484K mutation.
“The three lines – the U.K., South Africa, and Brazil – were almost synchronous publications, but there is no clear evidence that they have any kind of common ancestry,” Carolina M. Voloch, PhD, the article’s first author and a biologist and researcher at the Molecular Virology Laboratory and associate professor in the department of genetics at the Federal University of Rio de Janeiro, said in an interview.
Dr. Voloch’s research focuses on the use of bioinformatics tools to study the molecular, phylogenetic, and genomic evolution of viruses.
“The emergence of new strains is common for viruses,” she said. “It can be happening anywhere in the world at any time.”
She stressed that identifying when mutations emerge will help to define the new Brazilian lineage. Researchers are working to determine whether the neutralizing antibodies of patients who have been infected with other strains respond to this Rio de Janeiro strain.
“We hope to soon be sharing these results,” Dr. Voloch said.
The article’s authors estimated that the new strain likely appeared in early July. They say more analysis is needed to predict whether the changes have a major effect on viral infectivity, the host’s immune response, or the severity of the disease. Asked about the lineage that caused the reinfection in Bahia, Dr. Voloch said she hadn’t yet contacted the authors to conduct a joint analysis but added that the data disclosed in the preprint would not represent the same variant.
“There are only two of the five mutations that characterize the Rio de Janeiro lineage. However, it has the E484K mutation that is present in more than 94% of the samples of the new variant of Rio,” she said.
She added that there’s a possibility of reinfection by the lineage that’s circulating in Rio de Janeiro and in other states, as well as countries such as the United States, the United Kingdom, and Japan.
“The Carioca virus is being exported to the rest of the world,” Dr. Voloch said.
Virus’ diversity still unknown
Researchers now know that SARS-CoV-2 probably circulated silently in Brazil as early as February 2020 and reached all the nation’s regions before air travel was restricted. Since the first half of 2020, there have been two predominant strains.
“More than a dozen strains have been identified in Brazil, but more important than counting strains to identify the speed with which they arise – which is directly associated with the rate of infection, which is very high in the country,” said Dr. Motta.
The so-called variant of Rio de Janeiro, he said, has also been detected in other states in four regions of Brazil. The key to documenting variants is to get a more representative sample with genomes from other parts of the country.
As of Jan. 10, a total of 347,000 complete genome sequences had been shared globally through open databases since SARS-CoV-2 was first identified, but the contribution of countries is uneven. Although the cost and complexity of genetic sequencing has dropped significantly over time, effective sequencing programs still require substantial investments in personnel, equipment, reagents, and bioinformatics infrastructure.
According to Dr. Voloch, it will only be possible to combat the new coronavirus by knowing its diversity and understanding how it evolves. The Fiocruz Genomic Network has made an infographic available so researchers can track the strains circulating in Brazil. It›s the result of collaboration between researchers from Fiocruz and the GISAID Initiative, an international partnership that promotes rapid data sharing.
As of Jan. 5, researchers in Brazil had studied 1,897 genomes – not nearly enough.
“In Brazil, there is little testing and even less sequencing,” lamented Dr. Souza.
“In the U.K., 1 in 600 cases is sequenced. In Brazil it is less than 1 in 10 million cases,” Dr. Voloch added.
So far, no decisive factors for public health, such as greater virulence or greater transmissibility, have been identified in any of the strains established in Brazil. The million-dollar question is whether the emergence of new strains could have an impact on the effectiveness of vaccines being administered today.
“In one way or another, the vaccine is our best bet ever, even if in the future we identify escapist mutants and have to modify it,” Dr. Motta said. “It is what we do annually with influenza.”
Dr. Voloch, Dr. Motta, and Dr. Souza disclosed no relevant financial relationships.
A version of this article first appeared on the Portuguese edition of Medscape.com.
Just as Brazil surpassed 200,000 deaths from COVID-19 on Jan. 7, news from Bahia added another layer of concern: A platform case report in a preprint detailed the first case of reinfection in that state, apparently caused by a new strain, one having the E484K mutation.
That variant, now called Brazil P.1, has migrated to the United States. The Minnesota Department of Health announced on Jan. 25 the nation’s first known COVID-19 case associated with it.
The mutation is located in the protein gene of the virus’ spike, which forms the crown structure of coronaviruses and is responsible for the virus’ binding to human cells. The E484K mutation is now the focus because it’s associated with mutations that escape the immune system’s neutralizing antibodies.
“This mutation is at the center of worldwide concern, and it is the first time that it has appeared in a reinfection,” the study’s first author, Bruno Solano de Freitas Souza, MD, a researcher at the Salvador regional unit of Instituto D’Or of Teaching and Research, based at Hospital São Rafael, Salvador, Brazil, explained in an interview.
“We will wait for the sample from Bahia to confirm the case from the perspective of the Ministry of Health’s surveillance network,” said Fernando Motta, PhD, deputy head of the Laboratory for Respiratory Virus and Measles at the Oswaldo Cruz Institute in Rio de Janeiro, which acts as a national reference center for respiratory viruses with the Brazilian Ministry of Health (MS) and as a reference for the World Health Organization.
A case of reinfection
The case patient that led to the alarm was a 45-year-old woman who is a health care executive. She had no comorbidities. The team had been following health care professionals and patients who had tested positive on reverse transcription–polymerase chain reaction (RT-PCR) testing more than once to understand whether they represented cases of prolonged viral persistence or new infections.
The woman had symptoms of viral infection on two occasions (May 26 and Oct. 26). On both occasions, results of RT-PCR testing for SARS-CoV-2 on nasopharyngeal samples were positive. In the first episode, the patient had diarrhea, myalgia, asthenia, and odynophagia for about 7 days. She returned to activities 21 days later. In the second episode, she had more severe symptoms that lasted longer, but she still did not require hospitalization.
“It was the first confirmed case of reinfection in Bahia, and in the second episode, we observed a mutation that could have an impact on the ability of antibodies to neutralize the virus,” Dr. Souza said. “The research continues with the investigation of cases in which the patient has a positive SARS-CoV-2 RT-PCR more than once in an interval greater than 45 days, to have a higher level of evidence.”
He stressed that “it is very important to reinforce measures to control the pandemic, social distance, use of masks, and speed up vaccination to be able to control the circulation of the virus, while monitoring the evolution of it.”
On alert for more cases
A person who twice tests positive for SARS-CoV-2 on real-time RT-PCR is suspected of having been reinfected, provided 90 or more days have elapsed between the two episodes, regardless of the condition observed. To confirm the suspected case, the samples must be sent to reference laboratories according to a plan established by the Ministry of Health in Brazil.
A health professional living in the Brazilian city of Natal represented the first confirmed case of reinfection by the new coronavirus in Brazil. That case was announced on Dec. 10, 2020.
“We communicated this case of reinfection to the MS in early December 2020. And the second sample already had the E484K mutation on the spike, as in the case of Bahia,” said Dr. Motta.
The first step in differentiating reinfection from persistence is to observe differences in the genotyping of the virus. For the technique to be successful, Dr. Souza said, researchers need a large amount of viral genetic material, which usually cannot be obtained.
“That is why there are many more suspected than confirmed cases,” Dr. Souza explained. He admitted that, although there are few cases, “it is increasingly clear that reinfection is a reality.”
Markers of mutations
What worried the researchers most was not only the possibility of reinfection but also the fact that preliminary analyses showed a specific mutation.
“The E484K mutation is present in a group of variants identified in South Africa that have been associated with increased infectivity and has been observed in a strain recently described in Brazil,” Dr. Souza said.
Mutations are expected, appear spontaneously, and in most cases have no effects on transmission or clinical outcome – they are simply used as markers and are useful for contact tracing or studying transmission routes. But some mutations can last because they provide an advantage for the pathogen, even if only momentary. In the case of SARS-CoV-2, mutations in the protein spike gene (S) are relevant because they may give clues to that advantage – as well as to changes in infectivity, transmission potential, antibodies, and response to vaccines.
A variant of the virus that has eight changes that affect the protein S gene – and several others in different genes – is behind the increase in the number of cases in London and southeastern England. Researchers from the University of São Paulo identified one of the factors that made this new variant – classified as B.1.1.7 – more infectious.
With bioinformatics tools, they found that the protein S gene in the new viral strain has a stronger molecular interaction with the ACE2 receptor, which is on the surface of human cells and to which the virus binds, making infection possible. The variant has already spread to the rest of the world, and the first two cases have been confirmed in Brazil by the Adolf Lutz Institute.
The alert for a new variant in Africa – similar to B.1.1.7 in the United Kingdom in that it carries nine changes in protein S at position 501 – was made by the Brazilian virologist Tulio de Oliveira, PhD.
“We found that this strain seems to be spreading much faster,” Dr. Oliveira, who is with the University of KwaZulu Natal, told the journal Science. His work first alerted British scientists to the importance of the position N501Y.
“The new variants just described in the United Kingdom and South Africa are slightly more transmissible and have already been identified in cases imported into Brazil,” Dr. Motta said. “Unfortunately, we believe it is only a matter of time before it becomes indigenous.”
The viral family grows
Viruses such as SARS-CoV-2 are classified into strains on the basis of small differences in their genetic material. Since Dec. 26, 2020, in addition to the British and South African variants, it appears the Carioca lineage also is a player.
In a preprint article, researchers analyzed the evolution of the epidemic in Rio de Janeiro from April 2020 until just before the new increase in incidence in December. They compared the complete sequences of the viral genome of 180 patients from different municipalities. The study, which is being jointly conducted by members of the Federal University of Rio de Janeiro and the National Laboratory for Scientific Computing, identified a new variant of SARS-CoV-2 that has five unique mutations (from one of the predominant strains). Concern arose because, in addition to those five genetic changes, many of the samples had a sixth – the well-known E484K mutation.
“The three lines – the U.K., South Africa, and Brazil – were almost synchronous publications, but there is no clear evidence that they have any kind of common ancestry,” Carolina M. Voloch, PhD, the article’s first author and a biologist and researcher at the Molecular Virology Laboratory and associate professor in the department of genetics at the Federal University of Rio de Janeiro, said in an interview.
Dr. Voloch’s research focuses on the use of bioinformatics tools to study the molecular, phylogenetic, and genomic evolution of viruses.
“The emergence of new strains is common for viruses,” she said. “It can be happening anywhere in the world at any time.”
She stressed that identifying when mutations emerge will help to define the new Brazilian lineage. Researchers are working to determine whether the neutralizing antibodies of patients who have been infected with other strains respond to this Rio de Janeiro strain.
“We hope to soon be sharing these results,” Dr. Voloch said.
The article’s authors estimated that the new strain likely appeared in early July. They say more analysis is needed to predict whether the changes have a major effect on viral infectivity, the host’s immune response, or the severity of the disease. Asked about the lineage that caused the reinfection in Bahia, Dr. Voloch said she hadn’t yet contacted the authors to conduct a joint analysis but added that the data disclosed in the preprint would not represent the same variant.
“There are only two of the five mutations that characterize the Rio de Janeiro lineage. However, it has the E484K mutation that is present in more than 94% of the samples of the new variant of Rio,” she said.
She added that there’s a possibility of reinfection by the lineage that’s circulating in Rio de Janeiro and in other states, as well as countries such as the United States, the United Kingdom, and Japan.
“The Carioca virus is being exported to the rest of the world,” Dr. Voloch said.
Virus’ diversity still unknown
Researchers now know that SARS-CoV-2 probably circulated silently in Brazil as early as February 2020 and reached all the nation’s regions before air travel was restricted. Since the first half of 2020, there have been two predominant strains.
“More than a dozen strains have been identified in Brazil, but more important than counting strains to identify the speed with which they arise – which is directly associated with the rate of infection, which is very high in the country,” said Dr. Motta.
The so-called variant of Rio de Janeiro, he said, has also been detected in other states in four regions of Brazil. The key to documenting variants is to get a more representative sample with genomes from other parts of the country.
As of Jan. 10, a total of 347,000 complete genome sequences had been shared globally through open databases since SARS-CoV-2 was first identified, but the contribution of countries is uneven. Although the cost and complexity of genetic sequencing has dropped significantly over time, effective sequencing programs still require substantial investments in personnel, equipment, reagents, and bioinformatics infrastructure.
According to Dr. Voloch, it will only be possible to combat the new coronavirus by knowing its diversity and understanding how it evolves. The Fiocruz Genomic Network has made an infographic available so researchers can track the strains circulating in Brazil. It›s the result of collaboration between researchers from Fiocruz and the GISAID Initiative, an international partnership that promotes rapid data sharing.
As of Jan. 5, researchers in Brazil had studied 1,897 genomes – not nearly enough.
“In Brazil, there is little testing and even less sequencing,” lamented Dr. Souza.
“In the U.K., 1 in 600 cases is sequenced. In Brazil it is less than 1 in 10 million cases,” Dr. Voloch added.
So far, no decisive factors for public health, such as greater virulence or greater transmissibility, have been identified in any of the strains established in Brazil. The million-dollar question is whether the emergence of new strains could have an impact on the effectiveness of vaccines being administered today.
“In one way or another, the vaccine is our best bet ever, even if in the future we identify escapist mutants and have to modify it,” Dr. Motta said. “It is what we do annually with influenza.”
Dr. Voloch, Dr. Motta, and Dr. Souza disclosed no relevant financial relationships.
A version of this article first appeared on the Portuguese edition of Medscape.com.