Noncommunicable Disease Looks Different in the "Bottom Billion"

BOSTON – Unhealthy lifestyle habits are largely responsible for heart disease, diabetes, cancer, and lung disease in much of the world, but among the poorest people, much of the noncommunicable disease burden stems from infections and other endemic environmental factors.

Photo credit: Ilvy Njiokiktjien

Recognition of such fundamental differences in the etiology of noncommunicable diseases (NCDs) – and the endemic causes of those diseases among the world’s poorest billion people – is needed as the United Nations forges ahead with plans to address NCDs on a global scale. That was the conclusion drawn by stakeholders at a meeting aimed at decreasing the burden of noncommunicable diseases in the so-called "bottom billion" – the world’s population living on less than one dollar a day.

"The term ‘endemic’ is significant because it places the emphasis on the diseases that are already there in these populations, in addition to the epidemics of emerging NCDs. We’re expanding the notion of what ‘noncommunicable disease’ is," Dr. Gene Bukhman said at the meeting, which was sponsored by Partners In Health, an international nonprofit organization that provides direct health care services to people living in poverty around the world.

Over the last two decades, people and organizations have been clamoring for the inclusion of NCDs on the global health agenda. That movement has been newly energized by the United Nation’s announcement last May that it will hold a General Assembly High-level Meeting on NCDs in September. It will be only the second such disease-related meeting that the UN has ever held. The first such meeting in 2001 focused on HIV/AIDS, and is credited with galvanizing global attention and fund-raising efforts for that cause.

Participants at the Partners In Health meeting are working to ensure that the upcoming UN meeting doesn’t overlook the needs of the poorest people in the world.

The primary focus of the upcoming UN meeting will be on "noncommunicable disease" as defined by the World Health Organization in its 2008-2013 NCD action plan: cardiovascular diseases, diabetes, cancers, and chronic respiratory diseases related to the four shared risk factors – tobacco use, physical inactivity, unhealthy diets, and the harmful use of alcohol. Together, these conditions account for approximately 60% of all global deaths, of which 80% occur in low- and middle-income countries, according to WHO.

That "four-by-four" model, however, doesn’t encompass the breadth of chronic conditions seen in the poorest countries, where infection, malnutrition, environmental toxins, and lack of access to care contribute much more to the NCD burden than do lifestyle factors. Taken together, "endemic NCDs" account for nearly 25% of disease among the world’s poorest billion, said Dr. Bukhman, a cardiologist who serves as director of the Harvard Medical School Program in Non-Communicable Disease and Social Change, Boston, and also as the cardiology director for Partners In Health, working in Rwanda.

Infectious origins of many NCDs in poor countries highlight the "false dichotomy" view of NCDs as separate from infectious disease and that scarce resources need be divided between the two camps. "If we pit one set of interventions against another, we’re not going to get very far," said Dr. Paul Farmer, director of Partners In Health.

Neglected Tropical Diseases. Neglected tropical diseases (NTDs) are a prime example of the blurred line between NCDs and infectious disease. The NTDs are not communicable from person to person, and they cause chronic illness that is not typically fatal in the short term but which can severely debilitate and reduce productive capacity, according to Dr. Peter Hotez, Distinguished Research Professor and Walter G. Ross Professor and Chair of the Department of Microbiology, Immunology, and Tropical Medicine at George Washington University, Washington.

Affecting approximately 1.4 billion people worldwide, the NTDs include chronic parasitic infections such as ascariasis, trichuriasis, hookworm, and schistosomiasis. Some of the NTDs cause NCDs, including cardiomyopathy due to Chagas disease, cor pulmonale from schistosomiasis, asthma due to toxocariasis, and inflammatory bowel disease from trichuriasis, said Dr. Hotez, who also serves as president of the Sabin Vaccine Institute, a nonprofit research and advocacy organization that is currently conducting trials on vaccines against hookworm, schistosomiasis, Chagas disease, and malaria.

Together, the NTD global burden in terms of disability-associated life-years is 56.6 million, greater than that of malaria (46.5 million) or tuberculosis (34.7 million), and two-thirds that of HIV/AIDS (84.5 million), Dr. Hotez and his associated reported (N. Engl. J. Med. 2007;357:1018-27).

Cardiovascular Diseases. The spectrum of cardiovascular diseases due to endemic causes in Africa represents another "neglected" set of conditions, according to Dr. Ana Mocumbi, a cardiologist and researcher at the Maputo Heart Institute in Mozambique.

Although Africa is seeing a rise in lifestyle-associated atherosclerosis and other conditions common in the developed world, there are also large numbers of people suffering from chronic heart conditions with infectious origins, including rheumatic heart disease arising from streptococcal infection, endomyocardial fibrosis, and tuberculous pericarditis.

Together, these conditions "can be considered neglected diseases because, despite considerable numbers of people, they have not been the subject of systematic research or structured control programs and did not benefit from translation of knowledge obtained in other areas of human knowledge," Dr. Mocumbi said.

Dr. Mocumbi was an investigator for a survey using clinical and echocardiographic screening in 2,370 children aged 6-17 years who were randomly selected from six primary schools in Mozambique. The prevalence of rheumatic heart disease was about 30 per 1,000, a rate far higher than had been previously found in studies that only used echocardiography for cases suspected from clinical screening (New Engl. J. Med. 2007;357:470-6).

Another echocardiographic screening study for which Dr. Mocumbi was the lead investigator assessed a random sample of 1,063 individuals of all ages selected by clustering in a rural area of Mozambique with about 76,000 inhabitants, and found an endomyocardial fibrosis prevalence of 20%. The highest prevalence, 28%, was among children and adolescents aged 10-19 years (New Engl. J. Med. 2008;359:43-9).

That was the only epidemiologic study ever done on endomyocardial fibrosis, a restrictive cardiomyopathy that primarily affects children from sub-Saharan Africa. Its exact etiology and pathogenesis are unknown, although autoimmunity and infectious triggers are believed to play a role. Endomyocardial fibrosis "places a high burden on a community, where children and young adults are disabled," Dr. Mocumbi commented.

Chronic Respiratory Disease. Chronic respiratory disease is another NCD area for which the picture is different among the bottom billion. While smoking is by far the most common cause of chronic obstructive pulmonary disease (COPD) in developed countries, emerging evidence suggests that other environmental factors may play a greater role in poor countries, where an estimated 25%-45% of COPD patients have never smoked, said Dr. Sundeep Salvi, director of the Chest Research Foundation, Pune, India.

About 3 billion people, half the world’s population, are exposed to smoke from biomass fuel, compared with 1.01 billion people who smoke tobacco, suggesting that exposure to biomass smoke might be the biggest risk factor for COPD globally, Dr. Salvi said (Lancet 2009;374:733-43).

A recently published meta-analysis of 25 studies identified significant associations between exposure to solid biomass fuels such as wood, dung, and charcoal and acute respiratory infection in children (pooled odds ratio 3.53), chronic bronchitis in women (OR 2.52), and chronic pulmonary disease in women (OR 2.40). No associations were seen with asthma (Thorax 2011;66:232-9).

Other NCDs include sickle cell anemia, diabetes (including that associated with malnutrition rather than obesity), mental illness, diseases requiring surgery, cervical cancer, epilepsy, and anemia, which is often a result of infectious diseases such as malaria and bacteremia in the developing world rather than iron deficiency.

A ‘Diagonal’ Approach. Experts at the meeting agreed that integrated approaches are necessary to address endemic NCDs, most of which are relatively uncommon individually, but together account for a large burden of disease among the bottom billion.

Dr. Julio Frenk, dean of Harvard’s School of Public Health, advocated in favor of taking a so-called "diagonal approach" as an alternative to the narrow, disease-specific "vertical approach" to care as has been used to address HIV/AIDS, malaria, and tuberculosis. A diagonal approach is also preferred, he said, to taking a broad, and often ineffectual, "horizontal" approach that generally aims at strengthening health systems.

"Global health in the 21st century should integrate vertical and horizontal programs, because we now know that, through what [Dr.] Jaime Sepulveda has called the ‘diagonal approach,’ we can use explicit intervention priorities to strengthen the overall structure and function of health systems," Dr. Frenk said.

Such an approach is now being used by Partners In Health in Rwanda, an effort that began in 2005 with the Rwandan government’s request for support for rural health services. Also financed in part by the Clinton Foundation, the project provides building and renovations, supplementation of operational budgets, and staff training to three rural districts serving more than 750,000 in 2010.

The approach to chronic care in these regions follows a model similar to the way health systems were progressively decentralized to address HIV/AIDS in the 1990s: from tertiary referral centers to district hospitals, to local health centers, to community health workers. Under the model, primary care – typically delivered by nonphysician health care providers or trained laypeople – takes place at the community level, while increasingly specialized care takes place up the hierarchy of facilities, Dr. Bukhman explained.

District hospital leaders work closely with the staff of health centers, providing training, mentoring, and education, with the idea of reducing the need to transfer patients to referral centers. Each Partners In Health–supported district hospital in Rwanda has an advanced chronic care clinic for noninfectious diseases. Countries such as Rwanda that already have such integrated programs to address HIV/AIDS can more easily and less expensively integrate NCDs into their health systems, Dr. Bukhman noted.

Dr. Farmer, chair of the department of global health and social medicine at Harvard, stressed the need for "health systems strengthening" and for partnerships between governments, academia, nongovernmental organizations, private industry, and other stakeholders in order to tackle the complexity and heterogeneity of the endemic NCDs.

"It can’t be diabetes versus mental health or rheumatic heart disease versus cancer. It has to be a very collaborative effort that draws on partnerships and synergies. ... In building platforms for the delivering of care for chronic disease, we need to do many things at once."

Dr. Hotez disclosed that he has a patent on a hookworm vaccine, but no relationships with pharmaceutical companies. Dr. Mocumbi stated that she has no disclosures. Dr. Salvi disclosed that he has received fees from Merck Pharmaceuticals as an advisory board member and speaker. Partners In Health receives funding from corporate donors, including several pharmaceutical companies.

BOSTON – Unhealthy lifestyle habits are largely responsible for heart disease, diabetes, cancer, and lung disease in much of the world, but among the poorest people, much of the noncommunicable disease burden stems from infections and other endemic environmental factors.

Photo credit: Ilvy Njiokiktjien

Recognition of such fundamental differences in the etiology of noncommunicable diseases (NCDs) – and the endemic causes of those diseases among the world’s poorest billion people – is needed as the United Nations forges ahead with plans to address NCDs on a global scale. That was the conclusion drawn by stakeholders at a meeting aimed at decreasing the burden of noncommunicable diseases in the so-called "bottom billion" – the world’s population living on less than one dollar a day.

"The term ‘endemic’ is significant because it places the emphasis on the diseases that are already there in these populations, in addition to the epidemics of emerging NCDs. We’re expanding the notion of what ‘noncommunicable disease’ is," Dr. Gene Bukhman said at the meeting, which was sponsored by Partners In Health, an international nonprofit organization that provides direct health care services to people living in poverty around the world.

Over the last two decades, people and organizations have been clamoring for the inclusion of NCDs on the global health agenda. That movement has been newly energized by the United Nation’s announcement last May that it will hold a General Assembly High-level Meeting on NCDs in September. It will be only the second such disease-related meeting that the UN has ever held. The first such meeting in 2001 focused on HIV/AIDS, and is credited with galvanizing global attention and fund-raising efforts for that cause.

Participants at the Partners In Health meeting are working to ensure that the upcoming UN meeting doesn’t overlook the needs of the poorest people in the world.

The primary focus of the upcoming UN meeting will be on "noncommunicable disease" as defined by the World Health Organization in its 2008-2013 NCD action plan: cardiovascular diseases, diabetes, cancers, and chronic respiratory diseases related to the four shared risk factors – tobacco use, physical inactivity, unhealthy diets, and the harmful use of alcohol. Together, these conditions account for approximately 60% of all global deaths, of which 80% occur in low- and middle-income countries, according to WHO.

That "four-by-four" model, however, doesn’t encompass the breadth of chronic conditions seen in the poorest countries, where infection, malnutrition, environmental toxins, and lack of access to care contribute much more to the NCD burden than do lifestyle factors. Taken together, "endemic NCDs" account for nearly 25% of disease among the world’s poorest billion, said Dr. Bukhman, a cardiologist who serves as director of the Harvard Medical School Program in Non-Communicable Disease and Social Change, Boston, and also as the cardiology director for Partners In Health, working in Rwanda.

Infectious origins of many NCDs in poor countries highlight the "false dichotomy" view of NCDs as separate from infectious disease and that scarce resources need be divided between the two camps. "If we pit one set of interventions against another, we’re not going to get very far," said Dr. Paul Farmer, director of Partners In Health.

Neglected Tropical Diseases. Neglected tropical diseases (NTDs) are a prime example of the blurred line between NCDs and infectious disease. The NTDs are not communicable from person to person, and they cause chronic illness that is not typically fatal in the short term but which can severely debilitate and reduce productive capacity, according to Dr. Peter Hotez, Distinguished Research Professor and Walter G. Ross Professor and Chair of the Department of Microbiology, Immunology, and Tropical Medicine at George Washington University, Washington.

Affecting approximately 1.4 billion people worldwide, the NTDs include chronic parasitic infections such as ascariasis, trichuriasis, hookworm, and schistosomiasis. Some of the NTDs cause NCDs, including cardiomyopathy due to Chagas disease, cor pulmonale from schistosomiasis, asthma due to toxocariasis, and inflammatory bowel disease from trichuriasis, said Dr. Hotez, who also serves as president of the Sabin Vaccine Institute, a nonprofit research and advocacy organization that is currently conducting trials on vaccines against hookworm, schistosomiasis, Chagas disease, and malaria.

Together, the NTD global burden in terms of disability-associated life-years is 56.6 million, greater than that of malaria (46.5 million) or tuberculosis (34.7 million), and two-thirds that of HIV/AIDS (84.5 million), Dr. Hotez and his associated reported (N. Engl. J. Med. 2007;357:1018-27).

Cardiovascular Diseases. The spectrum of cardiovascular diseases due to endemic causes in Africa represents another "neglected" set of conditions, according to Dr. Ana Mocumbi, a cardiologist and researcher at the Maputo Heart Institute in Mozambique.

Although Africa is seeing a rise in lifestyle-associated atherosclerosis and other conditions common in the developed world, there are also large numbers of people suffering from chronic heart conditions with infectious origins, including rheumatic heart disease arising from streptococcal infection, endomyocardial fibrosis, and tuberculous pericarditis.

Together, these conditions "can be considered neglected diseases because, despite considerable numbers of people, they have not been the subject of systematic research or structured control programs and did not benefit from translation of knowledge obtained in other areas of human knowledge," Dr. Mocumbi said.

Dr. Mocumbi was an investigator for a survey using clinical and echocardiographic screening in 2,370 children aged 6-17 years who were randomly selected from six primary schools in Mozambique. The prevalence of rheumatic heart disease was about 30 per 1,000, a rate far higher than had been previously found in studies that only used echocardiography for cases suspected from clinical screening (New Engl. J. Med. 2007;357:470-6).

Another echocardiographic screening study for which Dr. Mocumbi was the lead investigator assessed a random sample of 1,063 individuals of all ages selected by clustering in a rural area of Mozambique with about 76,000 inhabitants, and found an endomyocardial fibrosis prevalence of 20%. The highest prevalence, 28%, was among children and adolescents aged 10-19 years (New Engl. J. Med. 2008;359:43-9).

That was the only epidemiologic study ever done on endomyocardial fibrosis, a restrictive cardiomyopathy that primarily affects children from sub-Saharan Africa. Its exact etiology and pathogenesis are unknown, although autoimmunity and infectious triggers are believed to play a role. Endomyocardial fibrosis "places a high burden on a community, where children and young adults are disabled," Dr. Mocumbi commented.

Chronic Respiratory Disease. Chronic respiratory disease is another NCD area for which the picture is different among the bottom billion. While smoking is by far the most common cause of chronic obstructive pulmonary disease (COPD) in developed countries, emerging evidence suggests that other environmental factors may play a greater role in poor countries, where an estimated 25%-45% of COPD patients have never smoked, said Dr. Sundeep Salvi, director of the Chest Research Foundation, Pune, India.

About 3 billion people, half the world’s population, are exposed to smoke from biomass fuel, compared with 1.01 billion people who smoke tobacco, suggesting that exposure to biomass smoke might be the biggest risk factor for COPD globally, Dr. Salvi said (Lancet 2009;374:733-43).

A recently published meta-analysis of 25 studies identified significant associations between exposure to solid biomass fuels such as wood, dung, and charcoal and acute respiratory infection in children (pooled odds ratio 3.53), chronic bronchitis in women (OR 2.52), and chronic pulmonary disease in women (OR 2.40). No associations were seen with asthma (Thorax 2011;66:232-9).

Other NCDs include sickle cell anemia, diabetes (including that associated with malnutrition rather than obesity), mental illness, diseases requiring surgery, cervical cancer, epilepsy, and anemia, which is often a result of infectious diseases such as malaria and bacteremia in the developing world rather than iron deficiency.

A ‘Diagonal’ Approach. Experts at the meeting agreed that integrated approaches are necessary to address endemic NCDs, most of which are relatively uncommon individually, but together account for a large burden of disease among the bottom billion.

Dr. Julio Frenk, dean of Harvard’s School of Public Health, advocated in favor of taking a so-called "diagonal approach" as an alternative to the narrow, disease-specific "vertical approach" to care as has been used to address HIV/AIDS, malaria, and tuberculosis. A diagonal approach is also preferred, he said, to taking a broad, and often ineffectual, "horizontal" approach that generally aims at strengthening health systems.

"Global health in the 21st century should integrate vertical and horizontal programs, because we now know that, through what [Dr.] Jaime Sepulveda has called the ‘diagonal approach,’ we can use explicit intervention priorities to strengthen the overall structure and function of health systems," Dr. Frenk said.

Such an approach is now being used by Partners In Health in Rwanda, an effort that began in 2005 with the Rwandan government’s request for support for rural health services. Also financed in part by the Clinton Foundation, the project provides building and renovations, supplementation of operational budgets, and staff training to three rural districts serving more than 750,000 in 2010.

The approach to chronic care in these regions follows a model similar to the way health systems were progressively decentralized to address HIV/AIDS in the 1990s: from tertiary referral centers to district hospitals, to local health centers, to community health workers. Under the model, primary care – typically delivered by nonphysician health care providers or trained laypeople – takes place at the community level, while increasingly specialized care takes place up the hierarchy of facilities, Dr. Bukhman explained.

District hospital leaders work closely with the staff of health centers, providing training, mentoring, and education, with the idea of reducing the need to transfer patients to referral centers. Each Partners In Health–supported district hospital in Rwanda has an advanced chronic care clinic for noninfectious diseases. Countries such as Rwanda that already have such integrated programs to address HIV/AIDS can more easily and less expensively integrate NCDs into their health systems, Dr. Bukhman noted.

Dr. Farmer, chair of the department of global health and social medicine at Harvard, stressed the need for "health systems strengthening" and for partnerships between governments, academia, nongovernmental organizations, private industry, and other stakeholders in order to tackle the complexity and heterogeneity of the endemic NCDs.

"It can’t be diabetes versus mental health or rheumatic heart disease versus cancer. It has to be a very collaborative effort that draws on partnerships and synergies. ... In building platforms for the delivering of care for chronic disease, we need to do many things at once."

Dr. Hotez disclosed that he has a patent on a hookworm vaccine, but no relationships with pharmaceutical companies. Dr. Mocumbi stated that she has no disclosures. Dr. Salvi disclosed that he has received fees from Merck Pharmaceuticals as an advisory board member and speaker. Partners In Health receives funding from corporate donors, including several pharmaceutical companies.

BOSTON – Unhealthy lifestyle habits are largely responsible for heart disease, diabetes, cancer, and lung disease in much of the world, but among the poorest people, much of the noncommunicable disease burden stems from infections and other endemic environmental factors.

Photo credit: Ilvy Njiokiktjien

Recognition of such fundamental differences in the etiology of noncommunicable diseases (NCDs) – and the endemic causes of those diseases among the world’s poorest billion people – is needed as the United Nations forges ahead with plans to address NCDs on a global scale. That was the conclusion drawn by stakeholders at a meeting aimed at decreasing the burden of noncommunicable diseases in the so-called "bottom billion" – the world’s population living on less than one dollar a day.

"The term ‘endemic’ is significant because it places the emphasis on the diseases that are already there in these populations, in addition to the epidemics of emerging NCDs. We’re expanding the notion of what ‘noncommunicable disease’ is," Dr. Gene Bukhman said at the meeting, which was sponsored by Partners In Health, an international nonprofit organization that provides direct health care services to people living in poverty around the world.

Over the last two decades, people and organizations have been clamoring for the inclusion of NCDs on the global health agenda. That movement has been newly energized by the United Nation’s announcement last May that it will hold a General Assembly High-level Meeting on NCDs in September. It will be only the second such disease-related meeting that the UN has ever held. The first such meeting in 2001 focused on HIV/AIDS, and is credited with galvanizing global attention and fund-raising efforts for that cause.

Participants at the Partners In Health meeting are working to ensure that the upcoming UN meeting doesn’t overlook the needs of the poorest people in the world.

The primary focus of the upcoming UN meeting will be on "noncommunicable disease" as defined by the World Health Organization in its 2008-2013 NCD action plan: cardiovascular diseases, diabetes, cancers, and chronic respiratory diseases related to the four shared risk factors – tobacco use, physical inactivity, unhealthy diets, and the harmful use of alcohol. Together, these conditions account for approximately 60% of all global deaths, of which 80% occur in low- and middle-income countries, according to WHO.

That "four-by-four" model, however, doesn’t encompass the breadth of chronic conditions seen in the poorest countries, where infection, malnutrition, environmental toxins, and lack of access to care contribute much more to the NCD burden than do lifestyle factors. Taken together, "endemic NCDs" account for nearly 25% of disease among the world’s poorest billion, said Dr. Bukhman, a cardiologist who serves as director of the Harvard Medical School Program in Non-Communicable Disease and Social Change, Boston, and also as the cardiology director for Partners In Health, working in Rwanda.

Infectious origins of many NCDs in poor countries highlight the "false dichotomy" view of NCDs as separate from infectious disease and that scarce resources need be divided between the two camps. "If we pit one set of interventions against another, we’re not going to get very far," said Dr. Paul Farmer, director of Partners In Health.

Neglected Tropical Diseases. Neglected tropical diseases (NTDs) are a prime example of the blurred line between NCDs and infectious disease. The NTDs are not communicable from person to person, and they cause chronic illness that is not typically fatal in the short term but which can severely debilitate and reduce productive capacity, according to Dr. Peter Hotez, Distinguished Research Professor and Walter G. Ross Professor and Chair of the Department of Microbiology, Immunology, and Tropical Medicine at George Washington University, Washington.

Affecting approximately 1.4 billion people worldwide, the NTDs include chronic parasitic infections such as ascariasis, trichuriasis, hookworm, and schistosomiasis. Some of the NTDs cause NCDs, including cardiomyopathy due to Chagas disease, cor pulmonale from schistosomiasis, asthma due to toxocariasis, and inflammatory bowel disease from trichuriasis, said Dr. Hotez, who also serves as president of the Sabin Vaccine Institute, a nonprofit research and advocacy organization that is currently conducting trials on vaccines against hookworm, schistosomiasis, Chagas disease, and malaria.

Together, the NTD global burden in terms of disability-associated life-years is 56.6 million, greater than that of malaria (46.5 million) or tuberculosis (34.7 million), and two-thirds that of HIV/AIDS (84.5 million), Dr. Hotez and his associated reported (N. Engl. J. Med. 2007;357:1018-27).

Cardiovascular Diseases. The spectrum of cardiovascular diseases due to endemic causes in Africa represents another "neglected" set of conditions, according to Dr. Ana Mocumbi, a cardiologist and researcher at the Maputo Heart Institute in Mozambique.

Although Africa is seeing a rise in lifestyle-associated atherosclerosis and other conditions common in the developed world, there are also large numbers of people suffering from chronic heart conditions with infectious origins, including rheumatic heart disease arising from streptococcal infection, endomyocardial fibrosis, and tuberculous pericarditis.

Together, these conditions "can be considered neglected diseases because, despite considerable numbers of people, they have not been the subject of systematic research or structured control programs and did not benefit from translation of knowledge obtained in other areas of human knowledge," Dr. Mocumbi said.

Dr. Mocumbi was an investigator for a survey using clinical and echocardiographic screening in 2,370 children aged 6-17 years who were randomly selected from six primary schools in Mozambique. The prevalence of rheumatic heart disease was about 30 per 1,000, a rate far higher than had been previously found in studies that only used echocardiography for cases suspected from clinical screening (New Engl. J. Med. 2007;357:470-6).

Another echocardiographic screening study for which Dr. Mocumbi was the lead investigator assessed a random sample of 1,063 individuals of all ages selected by clustering in a rural area of Mozambique with about 76,000 inhabitants, and found an endomyocardial fibrosis prevalence of 20%. The highest prevalence, 28%, was among children and adolescents aged 10-19 years (New Engl. J. Med. 2008;359:43-9).

That was the only epidemiologic study ever done on endomyocardial fibrosis, a restrictive cardiomyopathy that primarily affects children from sub-Saharan Africa. Its exact etiology and pathogenesis are unknown, although autoimmunity and infectious triggers are believed to play a role. Endomyocardial fibrosis "places a high burden on a community, where children and young adults are disabled," Dr. Mocumbi commented.

Chronic Respiratory Disease. Chronic respiratory disease is another NCD area for which the picture is different among the bottom billion. While smoking is by far the most common cause of chronic obstructive pulmonary disease (COPD) in developed countries, emerging evidence suggests that other environmental factors may play a greater role in poor countries, where an estimated 25%-45% of COPD patients have never smoked, said Dr. Sundeep Salvi, director of the Chest Research Foundation, Pune, India.

About 3 billion people, half the world’s population, are exposed to smoke from biomass fuel, compared with 1.01 billion people who smoke tobacco, suggesting that exposure to biomass smoke might be the biggest risk factor for COPD globally, Dr. Salvi said (Lancet 2009;374:733-43).

A recently published meta-analysis of 25 studies identified significant associations between exposure to solid biomass fuels such as wood, dung, and charcoal and acute respiratory infection in children (pooled odds ratio 3.53), chronic bronchitis in women (OR 2.52), and chronic pulmonary disease in women (OR 2.40). No associations were seen with asthma (Thorax 2011;66:232-9).

Other NCDs include sickle cell anemia, diabetes (including that associated with malnutrition rather than obesity), mental illness, diseases requiring surgery, cervical cancer, epilepsy, and anemia, which is often a result of infectious diseases such as malaria and bacteremia in the developing world rather than iron deficiency.

A ‘Diagonal’ Approach. Experts at the meeting agreed that integrated approaches are necessary to address endemic NCDs, most of which are relatively uncommon individually, but together account for a large burden of disease among the bottom billion.

Dr. Julio Frenk, dean of Harvard’s School of Public Health, advocated in favor of taking a so-called "diagonal approach" as an alternative to the narrow, disease-specific "vertical approach" to care as has been used to address HIV/AIDS, malaria, and tuberculosis. A diagonal approach is also preferred, he said, to taking a broad, and often ineffectual, "horizontal" approach that generally aims at strengthening health systems.

"Global health in the 21st century should integrate vertical and horizontal programs, because we now know that, through what [Dr.] Jaime Sepulveda has called the ‘diagonal approach,’ we can use explicit intervention priorities to strengthen the overall structure and function of health systems," Dr. Frenk said.

Such an approach is now being used by Partners In Health in Rwanda, an effort that began in 2005 with the Rwandan government’s request for support for rural health services. Also financed in part by the Clinton Foundation, the project provides building and renovations, supplementation of operational budgets, and staff training to three rural districts serving more than 750,000 in 2010.

The approach to chronic care in these regions follows a model similar to the way health systems were progressively decentralized to address HIV/AIDS in the 1990s: from tertiary referral centers to district hospitals, to local health centers, to community health workers. Under the model, primary care – typically delivered by nonphysician health care providers or trained laypeople – takes place at the community level, while increasingly specialized care takes place up the hierarchy of facilities, Dr. Bukhman explained.

District hospital leaders work closely with the staff of health centers, providing training, mentoring, and education, with the idea of reducing the need to transfer patients to referral centers. Each Partners In Health–supported district hospital in Rwanda has an advanced chronic care clinic for noninfectious diseases. Countries such as Rwanda that already have such integrated programs to address HIV/AIDS can more easily and less expensively integrate NCDs into their health systems, Dr. Bukhman noted.

Dr. Farmer, chair of the department of global health and social medicine at Harvard, stressed the need for "health systems strengthening" and for partnerships between governments, academia, nongovernmental organizations, private industry, and other stakeholders in order to tackle the complexity and heterogeneity of the endemic NCDs.

"It can’t be diabetes versus mental health or rheumatic heart disease versus cancer. It has to be a very collaborative effort that draws on partnerships and synergies. ... In building platforms for the delivering of care for chronic disease, we need to do many things at once."

Dr. Hotez disclosed that he has a patent on a hookworm vaccine, but no relationships with pharmaceutical companies. Dr. Mocumbi stated that she has no disclosures. Dr. Salvi disclosed that he has received fees from Merck Pharmaceuticals as an advisory board member and speaker. Partners In Health receives funding from corporate donors, including several pharmaceutical companies.