Kerri Wachter

Approximately only 75% of patients diagnosed with idiopathic Parkinson's disease (PD) actually prove to have the disease at autopsy. Common alternative diagnoses include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). Clinically differentiating parkinsonian syndromes has proved particularly difficult early in the course of the disease.

“There are a lot of different parkinsonian disorders that look like classical Parkinson's disease, but they have a different prognosis. The typical therapeutic strategies, like deep-brain stimulation and even dopamine agonist drugs, don't work for these patients,” said Dr. David Eidelberg of the neurosciences research center of the North Shore-Long Island Jewish Health System in Manhasset, New York. “The prognosis [for the parkinson variant disorders] is uniformly bad. If you have PSP or MSA, for example, not only is your prognosis unfortunately not as good, but surgical treatments are not as effective either,” said Dr. Eidelberg.

A number of studies using [18F]-fluorodeoxyglucose (FDG) positron emission tomography have described characteristic glucose metabolism patterns in patients with PD, MSA, PSP, and CBD. Dr. Eidelberg and his colleague Dr. Thomas Eckert have demonstrated the utility of such imaging as an adjunct to clinical evaluation in differentiating parkinsonian syndromes early in the disease process (Neuroimage 2005;26:912–21).

For this 65-year-old patient and others for whom the clinical diagnosis is uncertain, FDG PET can provide additional information with which to differentiate PD and variant syndromes. Patients at the neurosciences research center are required to fast overnight, and antiparkinsonian medications are withheld at least 12 hours before scanning. Scanning yields 35 two-dimensional image planes with an axial field view of 14.5 cm and a transaxial resolution of 4.2 mm in all directions.

For routine visual reading by experts familiar with typical uptake patterns for the different syndromes, the scans are reconstructed, corrected for attenuation, and smoothed for each subject. Images are displayed as a series of 35 transaxial slices.

Dr. Eidelberg, Dr. Eckert, and their colleagues have developed a computer-supported tool that allows nonexperts to read FDG PET scans. The technique uses statistical parametric mapping for all image processing and analyses. Images are spatially normalized and then a smoothing filter is applied to the images. Template statistical maps have been developed to aid in PET scan interpretation. Any voxels showing increased or decreased metabolism in the patient groups (PD, MSA, PSP, or CBD), compared with a group of healthy controls are overlaid onto T1 magnetic resonance template images. These templates are used to assist in the differential diagnosis of single scans.

Individual patient scans can then be compared statistically with a reference group of healthy control subjects. All voxels showing increased or decreased glucose metabolism above a statistical threshold, compared with that of the control group, also are overlaid into the T1 MRI maps. The hallmark of glucose metabolism in PD patients is increased metabolism in the putamen and globus pallidus and is present bilaterally without regard to the affected side, as seen in this patient's scan. Increased metabolism also is observed in the ventral thalamus, the motor cortex, and the cerebellum. Abnormal reductions in glucose metabolism are present bilaterally in the parietal and occipital association areas and in the dorsolateral prefrontal cortex.

MSA metabolism is characterized by marked bilateral reductions in the putamen and in the cerebellum (see image). Increased metabolism is seen in the frontal and superior parietal and cortical areas and in the thalamus. Hypometabolism is seen in the brainstem.

The distinguishing features of PSP metabolism are the presence of metabolic decrements in midline frontal regions and in the brainstem (see image). Decreased metabolism is also noted bilaterally in the caudate nucleus. Increased metabolism is seen bilaterally in the cortical motor areas, the parietal cortex, and the thalamus.

Glucose metabolism in CBD is characterized by a distinctive asymmetrical cortical activation (relative hypometabolism contralateral to the most affected side) and asymmetrical basal ganglia metabolism (relative hypometabolism contralateral to the most affected side). Hypometabolism is also seen in the paraventricular areas, the brain stem, and the midline frontal areas (see image).

Dr. Eckert, Dr. Eidelberg, and their colleagues used this computer-assisted technique to aid in the differential diagnosis of parkinsonism in a group of 135 patients for whom the clinical diagnosis was uncertain at the time of referral for imaging. The technique was compared with the final clinical diagnosis, which is the preferred diagnostic method.

The computer-assisted reading technique produced the correct diagnosis in 92% of all subjects—98% for early PD. A sensitivity of 100% and a specificity of 86% were obtained in identifying early PD patients (duration of symptoms less than 5 years), as compared with normal controls. A sensitivity of 96% and a specificity of 91% were achieved for PD patients, compared with patients with presumed atypical parkinsonism. This patient was diagnosed with early PD and was started on dopaminergic medication for 6 months after imaging. Symptoms markedly improved.

FDG-PET of PD case shows increased metabolism in the putamen and globus pallidus (red/yellow). MSA shows reduction (blue) in the putamen and cerebellum. In PSP, reduction occurs in frontal regions, brain stem, caudate nucleus. Courtesy Dr. Thomas Eckert/Dr. David Eidelberg

Approximately only 75% of patients diagnosed with idiopathic Parkinson's disease (PD) actually prove to have the disease at autopsy. Common alternative diagnoses include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). Clinically differentiating parkinsonian syndromes has proved particularly difficult early in the course of the disease.

“There are a lot of different parkinsonian disorders that look like classical Parkinson's disease, but they have a different prognosis. The typical therapeutic strategies, like deep-brain stimulation and even dopamine agonist drugs, don't work for these patients,” said Dr. David Eidelberg of the neurosciences research center of the North Shore-Long Island Jewish Health System in Manhasset, New York. “The prognosis [for the parkinson variant disorders] is uniformly bad. If you have PSP or MSA, for example, not only is your prognosis unfortunately not as good, but surgical treatments are not as effective either,” said Dr. Eidelberg.

A number of studies using [18F]-fluorodeoxyglucose (FDG) positron emission tomography have described characteristic glucose metabolism patterns in patients with PD, MSA, PSP, and CBD. Dr. Eidelberg and his colleague Dr. Thomas Eckert have demonstrated the utility of such imaging as an adjunct to clinical evaluation in differentiating parkinsonian syndromes early in the disease process (Neuroimage 2005;26:912–21).

For this 65-year-old patient and others for whom the clinical diagnosis is uncertain, FDG PET can provide additional information with which to differentiate PD and variant syndromes. Patients at the neurosciences research center are required to fast overnight, and antiparkinsonian medications are withheld at least 12 hours before scanning. Scanning yields 35 two-dimensional image planes with an axial field view of 14.5 cm and a transaxial resolution of 4.2 mm in all directions.

For routine visual reading by experts familiar with typical uptake patterns for the different syndromes, the scans are reconstructed, corrected for attenuation, and smoothed for each subject. Images are displayed as a series of 35 transaxial slices.

Dr. Eidelberg, Dr. Eckert, and their colleagues have developed a computer-supported tool that allows nonexperts to read FDG PET scans. The technique uses statistical parametric mapping for all image processing and analyses. Images are spatially normalized and then a smoothing filter is applied to the images. Template statistical maps have been developed to aid in PET scan interpretation. Any voxels showing increased or decreased metabolism in the patient groups (PD, MSA, PSP, or CBD), compared with a group of healthy controls are overlaid onto T1 magnetic resonance template images. These templates are used to assist in the differential diagnosis of single scans.

Individual patient scans can then be compared statistically with a reference group of healthy control subjects. All voxels showing increased or decreased glucose metabolism above a statistical threshold, compared with that of the control group, also are overlaid into the T1 MRI maps. The hallmark of glucose metabolism in PD patients is increased metabolism in the putamen and globus pallidus and is present bilaterally without regard to the affected side, as seen in this patient's scan. Increased metabolism also is observed in the ventral thalamus, the motor cortex, and the cerebellum. Abnormal reductions in glucose metabolism are present bilaterally in the parietal and occipital association areas and in the dorsolateral prefrontal cortex.

MSA metabolism is characterized by marked bilateral reductions in the putamen and in the cerebellum (see image). Increased metabolism is seen in the frontal and superior parietal and cortical areas and in the thalamus. Hypometabolism is seen in the brainstem.

The distinguishing features of PSP metabolism are the presence of metabolic decrements in midline frontal regions and in the brainstem (see image). Decreased metabolism is also noted bilaterally in the caudate nucleus. Increased metabolism is seen bilaterally in the cortical motor areas, the parietal cortex, and the thalamus.

Glucose metabolism in CBD is characterized by a distinctive asymmetrical cortical activation (relative hypometabolism contralateral to the most affected side) and asymmetrical basal ganglia metabolism (relative hypometabolism contralateral to the most affected side). Hypometabolism is also seen in the paraventricular areas, the brain stem, and the midline frontal areas (see image).

Dr. Eckert, Dr. Eidelberg, and their colleagues used this computer-assisted technique to aid in the differential diagnosis of parkinsonism in a group of 135 patients for whom the clinical diagnosis was uncertain at the time of referral for imaging. The technique was compared with the final clinical diagnosis, which is the preferred diagnostic method.

The computer-assisted reading technique produced the correct diagnosis in 92% of all subjects—98% for early PD. A sensitivity of 100% and a specificity of 86% were obtained in identifying early PD patients (duration of symptoms less than 5 years), as compared with normal controls. A sensitivity of 96% and a specificity of 91% were achieved for PD patients, compared with patients with presumed atypical parkinsonism. This patient was diagnosed with early PD and was started on dopaminergic medication for 6 months after imaging. Symptoms markedly improved.

FDG-PET of PD case shows increased metabolism in the putamen and globus pallidus (red/yellow). MSA shows reduction (blue) in the putamen and cerebellum. In PSP, reduction occurs in frontal regions, brain stem, caudate nucleus. Courtesy Dr. Thomas Eckert/Dr. David Eidelberg

Approximately only 75% of patients diagnosed with idiopathic Parkinson's disease (PD) actually prove to have the disease at autopsy. Common alternative diagnoses include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). Clinically differentiating parkinsonian syndromes has proved particularly difficult early in the course of the disease.

“There are a lot of different parkinsonian disorders that look like classical Parkinson's disease, but they have a different prognosis. The typical therapeutic strategies, like deep-brain stimulation and even dopamine agonist drugs, don't work for these patients,” said Dr. David Eidelberg of the neurosciences research center of the North Shore-Long Island Jewish Health System in Manhasset, New York. “The prognosis [for the parkinson variant disorders] is uniformly bad. If you have PSP or MSA, for example, not only is your prognosis unfortunately not as good, but surgical treatments are not as effective either,” said Dr. Eidelberg.

A number of studies using [18F]-fluorodeoxyglucose (FDG) positron emission tomography have described characteristic glucose metabolism patterns in patients with PD, MSA, PSP, and CBD. Dr. Eidelberg and his colleague Dr. Thomas Eckert have demonstrated the utility of such imaging as an adjunct to clinical evaluation in differentiating parkinsonian syndromes early in the disease process (Neuroimage 2005;26:912–21).

For this 65-year-old patient and others for whom the clinical diagnosis is uncertain, FDG PET can provide additional information with which to differentiate PD and variant syndromes. Patients at the neurosciences research center are required to fast overnight, and antiparkinsonian medications are withheld at least 12 hours before scanning. Scanning yields 35 two-dimensional image planes with an axial field view of 14.5 cm and a transaxial resolution of 4.2 mm in all directions.

For routine visual reading by experts familiar with typical uptake patterns for the different syndromes, the scans are reconstructed, corrected for attenuation, and smoothed for each subject. Images are displayed as a series of 35 transaxial slices.

Dr. Eidelberg, Dr. Eckert, and their colleagues have developed a computer-supported tool that allows nonexperts to read FDG PET scans. The technique uses statistical parametric mapping for all image processing and analyses. Images are spatially normalized and then a smoothing filter is applied to the images. Template statistical maps have been developed to aid in PET scan interpretation. Any voxels showing increased or decreased metabolism in the patient groups (PD, MSA, PSP, or CBD), compared with a group of healthy controls are overlaid onto T1 magnetic resonance template images. These templates are used to assist in the differential diagnosis of single scans.

Individual patient scans can then be compared statistically with a reference group of healthy control subjects. All voxels showing increased or decreased glucose metabolism above a statistical threshold, compared with that of the control group, also are overlaid into the T1 MRI maps. The hallmark of glucose metabolism in PD patients is increased metabolism in the putamen and globus pallidus and is present bilaterally without regard to the affected side, as seen in this patient's scan. Increased metabolism also is observed in the ventral thalamus, the motor cortex, and the cerebellum. Abnormal reductions in glucose metabolism are present bilaterally in the parietal and occipital association areas and in the dorsolateral prefrontal cortex.

MSA metabolism is characterized by marked bilateral reductions in the putamen and in the cerebellum (see image). Increased metabolism is seen in the frontal and superior parietal and cortical areas and in the thalamus. Hypometabolism is seen in the brainstem.

The distinguishing features of PSP metabolism are the presence of metabolic decrements in midline frontal regions and in the brainstem (see image). Decreased metabolism is also noted bilaterally in the caudate nucleus. Increased metabolism is seen bilaterally in the cortical motor areas, the parietal cortex, and the thalamus.

Glucose metabolism in CBD is characterized by a distinctive asymmetrical cortical activation (relative hypometabolism contralateral to the most affected side) and asymmetrical basal ganglia metabolism (relative hypometabolism contralateral to the most affected side). Hypometabolism is also seen in the paraventricular areas, the brain stem, and the midline frontal areas (see image).

Dr. Eckert, Dr. Eidelberg, and their colleagues used this computer-assisted technique to aid in the differential diagnosis of parkinsonism in a group of 135 patients for whom the clinical diagnosis was uncertain at the time of referral for imaging. The technique was compared with the final clinical diagnosis, which is the preferred diagnostic method.

The computer-assisted reading technique produced the correct diagnosis in 92% of all subjects—98% for early PD. A sensitivity of 100% and a specificity of 86% were obtained in identifying early PD patients (duration of symptoms less than 5 years), as compared with normal controls. A sensitivity of 96% and a specificity of 91% were achieved for PD patients, compared with patients with presumed atypical parkinsonism. This patient was diagnosed with early PD and was started on dopaminergic medication for 6 months after imaging. Symptoms markedly improved.

FDG-PET of PD case shows increased metabolism in the putamen and globus pallidus (red/yellow). MSA shows reduction (blue) in the putamen and cerebellum. In PSP, reduction occurs in frontal regions, brain stem, caudate nucleus. Courtesy Dr. Thomas Eckert/Dr. David Eidelberg

NASHVILLE, TENN. — Trabecular bone loss in both men and women may begin much earlier than previously thought, Dr. B. Lawrence Riggs reported at the annual meeting of the American Society for Bone and Mineral Research.

With his colleagues, Dr. Riggs of the Mayo Clinic College of Medicine in Rochester, Minn., used high-resolution peripheral quantitative CT (pQCT) to assess cortical and trabecular bone loss in 375 women and 325 men aged 21–97 years.

A total of 97 women were excluded from the analysis because they were receiving hormone replacement therapy, selective estrogen receptor modulators, or bisphosphonate therapy. Measurements of cortical and trabecular volumetric bone mineral density at the distal radius and the distal tibia were made at two to four consecutive annual visits.

In women, trabecular “bone loss appears to begin in young adulthood, probably in the third decade, and continues throughout life, with the suggestion of a menopausal acceleration at the distal radius,” said Dr. Riggs. Cortical bone loss does not really begin until menopause.

Premenopausal women lost an average of 0.67% of trabecular bone per year at the distal radius, compared with postmenopausal women, who lost 1% of trabecular bone per year. At the distal tibia, premenopausal women lost 0.53% trabecular bone per year, compared with 0.61% trabecular bone loss for postmenopausal women.

Cortical bone loss at the proximal radius was 0.11% per year for premenopausal women, compared with 0.60% for postmenopausal women. Cortical bone loss at the proximal tibia was 0.08% per year for premenopausal women and 0.57% per year for postmenopausal women.

In men “there really is no [cortical] bone loss until the age of 70,” said Dr. Riggs. Studies have shown that sex steroids begin to decline in men around this age. “Now with respect to trabecular bone loss in men, as in women, we do in fact see substantial trabecular bone loss … with more bone loss in young men than subsequently [thought],” said Dr. Riggs. This perhaps relates to changes in microstructure, he speculated.

Trabecular bone loss at the distal radius was 0.66% per year for men younger than age 50, compared with 0.53% for men aged 50 and older. Trabecular bone loss at the distal tibia was 0.68% per year for men younger than age 50 and 0.24% per year for men aged 50 and older.

Cortical bone loss at the proximal radius was 0.08% per year for men younger than 50 years, compared with 0.38% for men aged 50 and older. Cortical bone loss at the proximal tibia was 0.8% per year for men younger than 50 years and 0.22% per year for men aged 50 and older.

The early trabecular bone loss described accounts for a substantial proportion of total bone loss. “Consequently, determining the causation should be an important priority for future osteoporosis research,” said Dr. Riggs.

“The onset of substantial trabecular bone loss in both sexes soon after the conclusion of puberty and at a time when sex steroid levels are, by definition, normal indicates the current paradigms for the pathogenesis of osteoporosis are incomplete,” he said.

NASHVILLE, TENN. — Trabecular bone loss in both men and women may begin much earlier than previously thought, Dr. B. Lawrence Riggs reported at the annual meeting of the American Society for Bone and Mineral Research.

With his colleagues, Dr. Riggs of the Mayo Clinic College of Medicine in Rochester, Minn., used high-resolution peripheral quantitative CT (pQCT) to assess cortical and trabecular bone loss in 375 women and 325 men aged 21–97 years.

A total of 97 women were excluded from the analysis because they were receiving hormone replacement therapy, selective estrogen receptor modulators, or bisphosphonate therapy. Measurements of cortical and trabecular volumetric bone mineral density at the distal radius and the distal tibia were made at two to four consecutive annual visits.

In women, trabecular “bone loss appears to begin in young adulthood, probably in the third decade, and continues throughout life, with the suggestion of a menopausal acceleration at the distal radius,” said Dr. Riggs. Cortical bone loss does not really begin until menopause.

Premenopausal women lost an average of 0.67% of trabecular bone per year at the distal radius, compared with postmenopausal women, who lost 1% of trabecular bone per year. At the distal tibia, premenopausal women lost 0.53% trabecular bone per year, compared with 0.61% trabecular bone loss for postmenopausal women.

Cortical bone loss at the proximal radius was 0.11% per year for premenopausal women, compared with 0.60% for postmenopausal women. Cortical bone loss at the proximal tibia was 0.08% per year for premenopausal women and 0.57% per year for postmenopausal women.

In men “there really is no [cortical] bone loss until the age of 70,” said Dr. Riggs. Studies have shown that sex steroids begin to decline in men around this age. “Now with respect to trabecular bone loss in men, as in women, we do in fact see substantial trabecular bone loss … with more bone loss in young men than subsequently [thought],” said Dr. Riggs. This perhaps relates to changes in microstructure, he speculated.

Trabecular bone loss at the distal radius was 0.66% per year for men younger than age 50, compared with 0.53% for men aged 50 and older. Trabecular bone loss at the distal tibia was 0.68% per year for men younger than age 50 and 0.24% per year for men aged 50 and older.

Cortical bone loss at the proximal radius was 0.08% per year for men younger than 50 years, compared with 0.38% for men aged 50 and older. Cortical bone loss at the proximal tibia was 0.8% per year for men younger than 50 years and 0.22% per year for men aged 50 and older.

The early trabecular bone loss described accounts for a substantial proportion of total bone loss. “Consequently, determining the causation should be an important priority for future osteoporosis research,” said Dr. Riggs.

“The onset of substantial trabecular bone loss in both sexes soon after the conclusion of puberty and at a time when sex steroid levels are, by definition, normal indicates the current paradigms for the pathogenesis of osteoporosis are incomplete,” he said.

NASHVILLE, TENN. — Trabecular bone loss in both men and women may begin much earlier than previously thought, Dr. B. Lawrence Riggs reported at the annual meeting of the American Society for Bone and Mineral Research.

With his colleagues, Dr. Riggs of the Mayo Clinic College of Medicine in Rochester, Minn., used high-resolution peripheral quantitative CT (pQCT) to assess cortical and trabecular bone loss in 375 women and 325 men aged 21–97 years.

A total of 97 women were excluded from the analysis because they were receiving hormone replacement therapy, selective estrogen receptor modulators, or bisphosphonate therapy. Measurements of cortical and trabecular volumetric bone mineral density at the distal radius and the distal tibia were made at two to four consecutive annual visits.

In women, trabecular “bone loss appears to begin in young adulthood, probably in the third decade, and continues throughout life, with the suggestion of a menopausal acceleration at the distal radius,” said Dr. Riggs. Cortical bone loss does not really begin until menopause.

Premenopausal women lost an average of 0.67% of trabecular bone per year at the distal radius, compared with postmenopausal women, who lost 1% of trabecular bone per year. At the distal tibia, premenopausal women lost 0.53% trabecular bone per year, compared with 0.61% trabecular bone loss for postmenopausal women.

Cortical bone loss at the proximal radius was 0.11% per year for premenopausal women, compared with 0.60% for postmenopausal women. Cortical bone loss at the proximal tibia was 0.08% per year for premenopausal women and 0.57% per year for postmenopausal women.

In men “there really is no [cortical] bone loss until the age of 70,” said Dr. Riggs. Studies have shown that sex steroids begin to decline in men around this age. “Now with respect to trabecular bone loss in men, as in women, we do in fact see substantial trabecular bone loss … with more bone loss in young men than subsequently [thought],” said Dr. Riggs. This perhaps relates to changes in microstructure, he speculated.

Trabecular bone loss at the distal radius was 0.66% per year for men younger than age 50, compared with 0.53% for men aged 50 and older. Trabecular bone loss at the distal tibia was 0.68% per year for men younger than age 50 and 0.24% per year for men aged 50 and older.

Cortical bone loss at the proximal radius was 0.08% per year for men younger than 50 years, compared with 0.38% for men aged 50 and older. Cortical bone loss at the proximal tibia was 0.8% per year for men younger than 50 years and 0.22% per year for men aged 50 and older.

The early trabecular bone loss described accounts for a substantial proportion of total bone loss. “Consequently, determining the causation should be an important priority for future osteoporosis research,” said Dr. Riggs.

“The onset of substantial trabecular bone loss in both sexes soon after the conclusion of puberty and at a time when sex steroid levels are, by definition, normal indicates the current paradigms for the pathogenesis of osteoporosis are incomplete,” he said.

The First Years has recalled six liquid-filled teethers for infants age 3 months and older due to possible bacterial contamination.

The liquid inside the teethers may contain Pseudomonas aeruginosa and Pseudomonas putida, which can cause serious illness in children if the teether is punctured and the liquid is ingested. No illnesses have been reported to date in connection with this problem.

The six teethers affected include: Disney Days of Hunny Soft Cool Ring Teether (style #Y1447), Disney Soft Cool Ring Teether (style #Y1470), Disney Soft Cool Ring Teether (style #Y1490), The First Years Cool Animal Teether/Fish, Zebra, and Dinosaur designs (style #Y1473), The First Years Floating Friends Teether (style #Y1474), and Sesame Beginnings Chill & Chew Teether (style #Y3095).

The teethers were sold nationwide by major retailers and grocery, drug, and specialty stores from July 2005 to January 2006. Consumers are advised to stop using the recalled products immediately and can contact The First Years by visiting www.thefirstyears.com

The First Years has recalled six liquid-filled teethers for infants age 3 months and older due to possible bacterial contamination.

The liquid inside the teethers may contain Pseudomonas aeruginosa and Pseudomonas putida, which can cause serious illness in children if the teether is punctured and the liquid is ingested. No illnesses have been reported to date in connection with this problem.

The six teethers affected include: Disney Days of Hunny Soft Cool Ring Teether (style #Y1447), Disney Soft Cool Ring Teether (style #Y1470), Disney Soft Cool Ring Teether (style #Y1490), The First Years Cool Animal Teether/Fish, Zebra, and Dinosaur designs (style #Y1473), The First Years Floating Friends Teether (style #Y1474), and Sesame Beginnings Chill & Chew Teether (style #Y3095).

The teethers were sold nationwide by major retailers and grocery, drug, and specialty stores from July 2005 to January 2006. Consumers are advised to stop using the recalled products immediately and can contact The First Years by visiting www.thefirstyears.com

The First Years has recalled six liquid-filled teethers for infants age 3 months and older due to possible bacterial contamination.

The liquid inside the teethers may contain Pseudomonas aeruginosa and Pseudomonas putida, which can cause serious illness in children if the teether is punctured and the liquid is ingested. No illnesses have been reported to date in connection with this problem.

The six teethers affected include: Disney Days of Hunny Soft Cool Ring Teether (style #Y1447), Disney Soft Cool Ring Teether (style #Y1470), Disney Soft Cool Ring Teether (style #Y1490), The First Years Cool Animal Teether/Fish, Zebra, and Dinosaur designs (style #Y1473), The First Years Floating Friends Teether (style #Y1474), and Sesame Beginnings Chill & Chew Teether (style #Y3095).

The teethers were sold nationwide by major retailers and grocery, drug, and specialty stores from July 2005 to January 2006. Consumers are advised to stop using the recalled products immediately and can contact The First Years by visiting www.thefirstyears.com

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002. Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA). Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) is growing. (See box.) Unlike health care-acquired MRSA, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology. Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

They estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30).

“What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees. Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission. “So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

Community-Acquired MRSA Emerging in San Francisco

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting from health care-acquired strains to community-acquired strains, at least in San Francisco, Dr. Henry F. Chambers III said at the meeting.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those figures are based on efforts to collect every unique MRSA isolate over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005. At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated. Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group. Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant. “The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” he said. The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002. Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA). Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) is growing. (See box.) Unlike health care-acquired MRSA, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology. Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

They estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30).

“What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees. Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission. “So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

Community-Acquired MRSA Emerging in San Francisco

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting from health care-acquired strains to community-acquired strains, at least in San Francisco, Dr. Henry F. Chambers III said at the meeting.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those figures are based on efforts to collect every unique MRSA isolate over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005. At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated. Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group. Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant. “The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” he said. The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002. Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA). Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) is growing. (See box.) Unlike health care-acquired MRSA, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology. Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

They estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30).

“What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees. Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission. “So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

Community-Acquired MRSA Emerging in San Francisco

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting from health care-acquired strains to community-acquired strains, at least in San Francisco, Dr. Henry F. Chambers III said at the meeting.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those figures are based on efforts to collect every unique MRSA isolate over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005. At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated. Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group. Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant. “The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” he said. The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

PORTO, PORTUGAL – Cerebral amyloid angiopathy appears to disproportionately affect the occipital region, according to findings presented at the Fourth International Congress on Vascular Dementia.

In a study involving the postmortem neuropathologic evaluation of brains from 113 subjects (61% women), the incidence and severity of cerebral amyloid angiopathy (CAA) was highest in the occipital region, followed by the frontal, hippocampal, and frontobasal areas. The occipital region was significantly more frequently and more severely affected than the other regions, said Dr. Johannes Attems, of the Otto Wagner Hospital in Vienna.

Cerebral amyloid angiopathy (CAA) is defined by the deposition of amyloid-β peptide in cerebral vessels and has been associated with Alzheimer's disease (AD). Despite the association with AD, CAA has been shown to be an independent risk factor for cognitive decline.

Dr. Attems and his colleagues looked at the topographical distribution of CAA in the vessels of the brain, as well as the relationship between CAA and AD. In all, 63 patients had a clinical diagnosis of dementia and 50 were nondemented. Dementia was assessed retrospectively from hospital charts based on ICD-10 criteria of a Mini-Mental State Examination score less than 20. Subjects ranged in age from 54 to 102 years at the time of death.

Neuropathologic assessment of AD was performed using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria, Braak stages, and National Institute on Aging/Reagan Institute (NIA-Reagan) criteria. In this cohort, 43 subjects had high-grade AD pathology, 16 had medium-grade AD pathology, 37 had low-grade AD pathology, and had no AD pathology.

Sections were immunostained with modified Bielschowsky silver stain and a commercially available monoclonal human amyloid-β antibody for the detection of amyloid-β in cerebral vessels. The severity of amyloid-β deposition in vessels–and CAA–was semiquantitatively assessed in the frontal, frontobasal, hippocampal, and occipital regions. The researchers used a 5-point scoring system. A grade of 0 signified no amyloid-β was present, while grade 4 signified severe amyloid-β deposition.

Within a region, scores were totaled separately for meningeal and cortical vessels. These values were totaled for a regional score. A mean overall score was then calculated using the regional values. In order to better estimate the relative contribution of the separate regional scores, the overall score was subtracted from each regional score to yield relative scores.

CAA was present in 77 cases. In these subjects, “Independent of the region, meningeal vessels were always affected more frequently and more severely than cortical vessels,” said Dr. Attems. However the differences between meningeal and cortical vessels were only statistically significant in the occipital region.

“CAA prevalence was significantly higher in cases with high-grade AD pathology, compared with cases with no to medium pathology,” said Dr. Attems. Overall CAA severity increased with increasing AD pathology. This was true in all of the regions, though only the relative contribution of CAA in the occipital region increases significantly with increasing AD pathology.

“This means that–at least statistically–increasing AD pathology shifts the topographic distribution of CAA even more towards the occipital cortex,” he said.

Interestingly, of the brains with no AD pathology, 24% had evidence of CAA. Conversely, 24% of brains with AD pathology showed no evidence of CAA. “We have cases with severe CAA but without any AD pathology and on the other hand, case with high AD pathology completely lacking CAA,” said Dr. Attems. This suggests that neuritic AD pathology and CAA might represent different entities.

Demented subjects more frequently showed signs of CAA and CAA total scores were greater than in nondemented patients. This finding suggests a significant association between CAA and dementia, said Dr. Attems. However, after controlling for clinical criteria the association was no longer statistically significant.

“The combination of AD pathology and CAA might synergistically contribute to the development of clinical dementia,” said Dr. Attems.

Interestingly, among patients with a CAA total score greater than 0, there was no difference in the prevalence of CAA between cases with high versus low AD pathology. Also the CAA total score did not increase with increasing AD pathology in this subgroup.

Immunostaining of tissue with cerebral amyloid angiopathy using modified Bielschowsky silver stain shows severe thickening of the cortical vessel walls. Courtesy Dr. Johannes Attems

PORTO, PORTUGAL – Cerebral amyloid angiopathy appears to disproportionately affect the occipital region, according to findings presented at the Fourth International Congress on Vascular Dementia.

In a study involving the postmortem neuropathologic evaluation of brains from 113 subjects (61% women), the incidence and severity of cerebral amyloid angiopathy (CAA) was highest in the occipital region, followed by the frontal, hippocampal, and frontobasal areas. The occipital region was significantly more frequently and more severely affected than the other regions, said Dr. Johannes Attems, of the Otto Wagner Hospital in Vienna.

Cerebral amyloid angiopathy (CAA) is defined by the deposition of amyloid-β peptide in cerebral vessels and has been associated with Alzheimer's disease (AD). Despite the association with AD, CAA has been shown to be an independent risk factor for cognitive decline.

Dr. Attems and his colleagues looked at the topographical distribution of CAA in the vessels of the brain, as well as the relationship between CAA and AD. In all, 63 patients had a clinical diagnosis of dementia and 50 were nondemented. Dementia was assessed retrospectively from hospital charts based on ICD-10 criteria of a Mini-Mental State Examination score less than 20. Subjects ranged in age from 54 to 102 years at the time of death.

Neuropathologic assessment of AD was performed using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria, Braak stages, and National Institute on Aging/Reagan Institute (NIA-Reagan) criteria. In this cohort, 43 subjects had high-grade AD pathology, 16 had medium-grade AD pathology, 37 had low-grade AD pathology, and had no AD pathology.

Sections were immunostained with modified Bielschowsky silver stain and a commercially available monoclonal human amyloid-β antibody for the detection of amyloid-β in cerebral vessels. The severity of amyloid-β deposition in vessels–and CAA–was semiquantitatively assessed in the frontal, frontobasal, hippocampal, and occipital regions. The researchers used a 5-point scoring system. A grade of 0 signified no amyloid-β was present, while grade 4 signified severe amyloid-β deposition.

Within a region, scores were totaled separately for meningeal and cortical vessels. These values were totaled for a regional score. A mean overall score was then calculated using the regional values. In order to better estimate the relative contribution of the separate regional scores, the overall score was subtracted from each regional score to yield relative scores.

CAA was present in 77 cases. In these subjects, “Independent of the region, meningeal vessels were always affected more frequently and more severely than cortical vessels,” said Dr. Attems. However the differences between meningeal and cortical vessels were only statistically significant in the occipital region.

“CAA prevalence was significantly higher in cases with high-grade AD pathology, compared with cases with no to medium pathology,” said Dr. Attems. Overall CAA severity increased with increasing AD pathology. This was true in all of the regions, though only the relative contribution of CAA in the occipital region increases significantly with increasing AD pathology.

“This means that–at least statistically–increasing AD pathology shifts the topographic distribution of CAA even more towards the occipital cortex,” he said.

Interestingly, of the brains with no AD pathology, 24% had evidence of CAA. Conversely, 24% of brains with AD pathology showed no evidence of CAA. “We have cases with severe CAA but without any AD pathology and on the other hand, case with high AD pathology completely lacking CAA,” said Dr. Attems. This suggests that neuritic AD pathology and CAA might represent different entities.

Demented subjects more frequently showed signs of CAA and CAA total scores were greater than in nondemented patients. This finding suggests a significant association between CAA and dementia, said Dr. Attems. However, after controlling for clinical criteria the association was no longer statistically significant.

“The combination of AD pathology and CAA might synergistically contribute to the development of clinical dementia,” said Dr. Attems.

Interestingly, among patients with a CAA total score greater than 0, there was no difference in the prevalence of CAA between cases with high versus low AD pathology. Also the CAA total score did not increase with increasing AD pathology in this subgroup.

Immunostaining of tissue with cerebral amyloid angiopathy using modified Bielschowsky silver stain shows severe thickening of the cortical vessel walls. Courtesy Dr. Johannes Attems

PORTO, PORTUGAL – Cerebral amyloid angiopathy appears to disproportionately affect the occipital region, according to findings presented at the Fourth International Congress on Vascular Dementia.

In a study involving the postmortem neuropathologic evaluation of brains from 113 subjects (61% women), the incidence and severity of cerebral amyloid angiopathy (CAA) was highest in the occipital region, followed by the frontal, hippocampal, and frontobasal areas. The occipital region was significantly more frequently and more severely affected than the other regions, said Dr. Johannes Attems, of the Otto Wagner Hospital in Vienna.

Cerebral amyloid angiopathy (CAA) is defined by the deposition of amyloid-β peptide in cerebral vessels and has been associated with Alzheimer's disease (AD). Despite the association with AD, CAA has been shown to be an independent risk factor for cognitive decline.

Dr. Attems and his colleagues looked at the topographical distribution of CAA in the vessels of the brain, as well as the relationship between CAA and AD. In all, 63 patients had a clinical diagnosis of dementia and 50 were nondemented. Dementia was assessed retrospectively from hospital charts based on ICD-10 criteria of a Mini-Mental State Examination score less than 20. Subjects ranged in age from 54 to 102 years at the time of death.

Neuropathologic assessment of AD was performed using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria, Braak stages, and National Institute on Aging/Reagan Institute (NIA-Reagan) criteria. In this cohort, 43 subjects had high-grade AD pathology, 16 had medium-grade AD pathology, 37 had low-grade AD pathology, and had no AD pathology.

Sections were immunostained with modified Bielschowsky silver stain and a commercially available monoclonal human amyloid-β antibody for the detection of amyloid-β in cerebral vessels. The severity of amyloid-β deposition in vessels–and CAA–was semiquantitatively assessed in the frontal, frontobasal, hippocampal, and occipital regions. The researchers used a 5-point scoring system. A grade of 0 signified no amyloid-β was present, while grade 4 signified severe amyloid-β deposition.

Within a region, scores were totaled separately for meningeal and cortical vessels. These values were totaled for a regional score. A mean overall score was then calculated using the regional values. In order to better estimate the relative contribution of the separate regional scores, the overall score was subtracted from each regional score to yield relative scores.

CAA was present in 77 cases. In these subjects, “Independent of the region, meningeal vessels were always affected more frequently and more severely than cortical vessels,” said Dr. Attems. However the differences between meningeal and cortical vessels were only statistically significant in the occipital region.

“CAA prevalence was significantly higher in cases with high-grade AD pathology, compared with cases with no to medium pathology,” said Dr. Attems. Overall CAA severity increased with increasing AD pathology. This was true in all of the regions, though only the relative contribution of CAA in the occipital region increases significantly with increasing AD pathology.

“This means that–at least statistically–increasing AD pathology shifts the topographic distribution of CAA even more towards the occipital cortex,” he said.

Interestingly, of the brains with no AD pathology, 24% had evidence of CAA. Conversely, 24% of brains with AD pathology showed no evidence of CAA. “We have cases with severe CAA but without any AD pathology and on the other hand, case with high AD pathology completely lacking CAA,” said Dr. Attems. This suggests that neuritic AD pathology and CAA might represent different entities.

Demented subjects more frequently showed signs of CAA and CAA total scores were greater than in nondemented patients. This finding suggests a significant association between CAA and dementia, said Dr. Attems. However, after controlling for clinical criteria the association was no longer statistically significant.

“The combination of AD pathology and CAA might synergistically contribute to the development of clinical dementia,” said Dr. Attems.

Interestingly, among patients with a CAA total score greater than 0, there was no difference in the prevalence of CAA between cases with high versus low AD pathology. Also the CAA total score did not increase with increasing AD pathology in this subgroup.

Immunostaining of tissue with cerebral amyloid angiopathy using modified Bielschowsky silver stain shows severe thickening of the cortical vessel walls. Courtesy Dr. Johannes Attems

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002.

Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA).

Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) continues to grow. (See box at right.) Unlike MRSA acquired in health care facilities, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology.

Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

The investigators estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30). “What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees.

Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission.

“So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended these steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

MRSA Burden in San Francisco Hospitals Shifts to Community-Onset Phenotypes

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting recently from health care-acquired strains to community-acquired strains in San Francisco, Dr. Henry F. Chambers III told attendees at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those numbers are based on efforts to collect every MRSA isolate that is unique over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005.

At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated.

Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group.

Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant.

“The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” Dr. Chambers said.

The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002.

Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA).

Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) continues to grow. (See box at right.) Unlike MRSA acquired in health care facilities, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology.

Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

The investigators estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30). “What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees.

Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission.

“So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended these steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

MRSA Burden in San Francisco Hospitals Shifts to Community-Onset Phenotypes

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting recently from health care-acquired strains to community-acquired strains in San Francisco, Dr. Henry F. Chambers III told attendees at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those numbers are based on efforts to collect every MRSA isolate that is unique over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005.

At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated.

Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group.

Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant.

“The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” Dr. Chambers said.

The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

WASHINGTON — As many as 2.3 million people in the United States carry methicillin-resistant Staphylococcus aureus, Dr. Daniel B. Jernigan reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The estimate comes from a recent study in which nasal swab samples were collected from 9,622 people (at least 1 year of age) as part of the National Health and Nutrition Examination Survey in 2001–2002.

Roughly one-third (32%) were nasally colonized with S. aureus and 0.8% were nasally colonized with methicillin-resistant S. aureus (MRSA).

Based on those numbers, the population prevalence of all strains of S. aureus is 89.4 million (J. Infect. Dis. 2006;193:172–9).

“MRSA colonization was associated with being over the age of 60 and also with being female,” said Dr. Jernigan, a medical epidemiologist with the National Center for Infectious Diseases.

Concern about community-acquired MRSA (CA-MRSA) continues to grow. (See box at right.) Unlike MRSA acquired in health care facilities, CA-MRSA affects healthy individuals, is not associated with traditional risk factors for health care-acquired MRSA, and varies in prevalence by race, age, and geography. In particular, there is an elevated prevalence of MRSA among African Americans and among children.

Population surveillance of bacterial infections in the United States is performed through the Active Bacterial Core surveillance program, which is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network.

According to this program, CA-MRSA incidence in the United States ranged from 18 to 26 cases per 100,000 people per year in 2001–2002 (N. Engl. J. Med. 2005;352:1436–44). “I believe that is a conservative estimate,” Dr. Jernigan said at the meeting sponsored by the American Society for Microbiology.

Overall confirmed or probable CA-MRSA cases accounted for 17% of all MRSA infections in three large cities.

“The majority of infections due to these community-associated cases are skin and soft tissue infections—about 77%,” he said.

In an unpublished analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers at the National Center for Health Statistics identified skin conditions likely to be caused by S. aureus infection based on ICD-9 codes.

The investigators estimated that 4,000 outpatient visits per 100,000 people per year are due to such skin and soft tissue infections.

In another study, researchers in California cultured each culturable pus lesion in a Los Angeles area emergency department during 1 month (Emerg. Infect. Dis. 2005;11:928–30). “What they found was that 59% of culturable pus seen in the emergency department was due to MRSA, and of those the majority was community-associated MRSA strains,” Dr. Jernigan said.

CA-MRSA outbreaks have been reported among athletes, inmates, soldiers, children in schools and day-care centers, Native Americans/Alaskan Natives, men who have sex with other men, and Hurricane Katrina evacuees.

Transmission factors that have been associated with outbreaks of CA-MRSA include crowding, frequent skin-to-skin contact, compromised skin, contaminated surfaces, shared items, uncleanliness, and antimicrobial use.

Two recent unpublished studies from the CDC's Epidemic Intelligence Service have documented CA-MRSA transmission among people getting tattoos from unlicensed tattooists and among crystal meth smokers, although not among IV drug users, Dr. Jernigan said.

The CDC's CA-MRSA prevention strategy includes steps to prevent infection, effectively diagnose and treat infections, use antimicrobials wisely, and prevent transmission.

“So rather than just a focused area on judicious antimicrobial use, we think—for this particular pathogen, which has colonize status, infective status, susceptible status, and possibly the environment as sources of infection—that you have to have a multipronged approach,” he said.

Experts at a CDC-sponsored meeting on CA-MRSA recommended these clinical steps for combating CA-MRSA:

▸ Increase awareness about CA-MRSA.

▸ Use local data to develop treatment strategies.

▸ Collect diagnostic specimens.

▸ Provide adequate follow-up.

▸ Target treatment with alternative antibiotics.

The experts also recommended these steps to better control outbreaks of CA-MRSA:

▸ Enhance surveillance during an outbreak by looking for skin infections.

▸ Target empiric therapy to the outbreak strains.

▸ Provide education about wound care and wound containment.

▸ Promote enhanced personal hygiene and encourage limiting shared use of items.

▸ Consider excluding patients from certain activities that involve skin-to-skin contact, such as athletic events.

▸ Achieve and maintain a clean environment.

MRSA Burden in San Francisco Hospitals Shifts to Community-Onset Phenotypes

The burden of methicillin-resistant Staphylococcus aureus disease appears to be shifting recently from health care-acquired strains to community-acquired strains in San Francisco, Dr. Henry F. Chambers III told attendees at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The burden of MRSA disease at three hospitals in San Francisco has shifted toward community onset. “About 50%–60% of MRSA disease in San Francisco is now community-acquired,” said Dr. Chambers, chief of the division of infectious diseases at San Francisco General Hospital.

Those numbers are based on efforts to collect every MRSA isolate that is unique over a 1-year period in every hospital in San Francisco. A total of nine hospitals (90%) participated from 2004 to 2005.

At San Francisco General Hospital alone, more than 1,000 unique isolates were collected in that time.

“There is one MRSA isolate for every 250 persons per year in San Francisco at the current time—now, that's a lot of burden of MRSA disease,” Dr. Chambers said.

He also presented data from the Integrated Soft Tissue Infection Service clinic, which performs as many as 2,000 incision and drainage procedures and other surgical procedures in the outpatient setting. For many years, the drug of choice there has been cephalexin.

To evaluate the role of antimicrobials in skin and soft tissue infections in patients who were treated with incision and drainage, Dr. Chambers and his colleagues conducted a randomized, double-blind, placebo-controlled trial.

Patients at the clinic were enrolled if they were 18 years of age or older and had an abscess requiring incision and drainage that was severe enough that the treating physician thought antibiotics were indicated.

Patients were fairly young, with an average age of 26 years in the group that received cephalexin and 30 years in the placebo group.

Roughly two-thirds of each group had abscesses that went down to subcutaneous tissue.

The predominant isolate identified was S. aureus alone, found in 69% of those in the cephalexin group and 67% of those in the placebo group. Of the S. aureus isolates, 88% and 90% were MRSA in the cephalexin and placebo groups, respectively.

“You could see the typical pattern of resistance for a community-onset phenotype,” Dr. Chambers said.

The cure rate was 87% in the cephalexin group and 92% in the placebo group, a difference that was not statistically significant.

“The cure rates for the placebo suggest that incision and drainage is sufficient for treatment of skin and soft tissue infections with abscess,” Dr. Chambers said.

The results of this trial are consistent with the findings of several other studies.

“If we can define patients who do not need antibiotic therapy and actually live with that and act as though they don't need antibiotic therapy, we'll be a whole lot better off with this problem [of drug resistance] in general,” Dr. Chambers said.

Liver Toxicity Reported With Ketek

The Food and Drug Administration is recommending that physicians monitor patients taking telithromycin (Ketek) for signs and symptoms of liver problems in response to reports of liver toxicity in three patients taking the drug.

Telithromycin is the first of the ketolide class of antibiotics to be approved, and is indicated for adults for the treatment of serious bacterial infections, such as community-acquired pneumonia, acute bacterial sinusitis, and acute exacerbation of chronic bronchitis. The drug is marketed by Aventis Pharmaceuticals Inc.

All three patients developed jaundice and abnormal liver function. One patient recovered, one required a transplant, and one died. The patients previously had been healthy and were not using other prescription drugs.

Examination of the livers of two of the patients revealed massive tissue death. The cases were reported online as an early-release article in the Annals of Internal Medicine (

www.acponline.org/journals/annals/hepatotoxicity.htm

The FDA recommends that telithromycin should be stopped in patients who develop signs or symptoms of liver problems. Patients who have been prescribed the drug and who are not experiencing side effects such as jaundice should continue taking their medicine as prescribed. Patients who notice any yellowing of their eyes or skin, or other problems such as blurry vision, should call their health care provider immediately.

Telithromycin should be used only for infections caused by a susceptible microorganism. These include Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. The FDA is continuing to investigate the issue of liver problems in association with the use of telithromycin in order to determine if labeling changes or other actions are warranted.

Infections Prolong Hospitalization

Elderly patients who developed surgical site infections after undergoing orthopedic surgery had significantly longer hospital stays, Dr. Jeanne Lee wrote in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Surgical site infection was a significant independent predictor of prolonged hospital stay according to both bivariate and multivariate analyses in the outcomes study, conducted by Dr. Lee and her colleagues at Duke University in Durham, N.C.

The study was conducted in eight hospitals between 1991 and 2002. The most common procedures were hip arthroplasty in 74 patients (22%), fracture repair in 55 patients (16%), and knee arthroplasty in 40 patients (12%). Staphylococcus aureus was the dominant pathogen, associated with 95 infections (56%), and 55% of these pathogens were methicillin resistant.

The mean length of stay was 13 days among 169 infected patients, compared with 4 days among 171 uninfected controls. The patient's mean age was 75 years; 66% were women, and 83% were white.

Other predictors of prolonged hospital stay included an inability to bathe independently, undergoing procedures of longer duration, postoperative glucose greater than 200 mg/dL, and having procedures on the same day as hospitalization.

Severe Diabetic Skin Infections

Diabetic patients with severe skin infections had greater improvement when treated with meropenem than with imipenem-cilastatin, Dr. John M. Embil reported in a poster presented at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Skin and skin-structure infections are a perpetual problem for diabetic patients, and may require surgical intervention if left untreated, wrote Dr. Embil of the University of Manitoba, Winnipeg, Canada.

The international, randomized, double-blind study included 1,037 hospitalized patients with complicated skin infections, 398 of whom were diabetic.

The clinical cure rate was 86% among the 204 diabetic patients who received a 500-mg intravenous dose of meropenem every 8 hours, compared with 72% among the 194 diabetic patients who received the same dosing regimen of imipenem-cilastatin. The cure rate among the nondiabetic patients treated with meropenem (87%) was similar to the rate in those treated with imipenem-cilastatin (89%).

Overall, meropenem was associated with slightly higher cure rates for all groups of pathogens—aerobic gram-negative, aerobic gram-positive, anaerobic, and polymicrobial—compared with imipenem-cilastatin, but the differences were not statistically significant. More than 40% of the pathogens were gram-negative aerobic or anaerobic organisms, and 29% of the Staphylococcus aureus isolates showed methicillin resistance. A similar spectrum of pathogens appeared in both diabetic and nondiabetic patients.

Liver Toxicity Reported With Ketek

The Food and Drug Administration is recommending that physicians monitor patients taking telithromycin (Ketek) for signs and symptoms of liver problems in response to reports of liver toxicity in three patients taking the drug.

Telithromycin is the first of the ketolide class of antibiotics to be approved, and is indicated for adults for the treatment of serious bacterial infections, such as community-acquired pneumonia, acute bacterial sinusitis, and acute exacerbation of chronic bronchitis. The drug is marketed by Aventis Pharmaceuticals Inc.

All three patients developed jaundice and abnormal liver function. One patient recovered, one required a transplant, and one died. The patients previously had been healthy and were not using other prescription drugs.

Examination of the livers of two of the patients revealed massive tissue death. The cases were reported online as an early-release article in the Annals of Internal Medicine (

www.acponline.org/journals/annals/hepatotoxicity.htm

The FDA recommends that telithromycin should be stopped in patients who develop signs or symptoms of liver problems. Patients who have been prescribed the drug and who are not experiencing side effects such as jaundice should continue taking their medicine as prescribed. Patients who notice any yellowing of their eyes or skin, or other problems such as blurry vision, should call their health care provider immediately.

Telithromycin should be used only for infections caused by a susceptible microorganism. These include Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. The FDA is continuing to investigate the issue of liver problems in association with the use of telithromycin in order to determine if labeling changes or other actions are warranted.

Infections Prolong Hospitalization

Elderly patients who developed surgical site infections after undergoing orthopedic surgery had significantly longer hospital stays, Dr. Jeanne Lee wrote in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Surgical site infection was a significant independent predictor of prolonged hospital stay according to both bivariate and multivariate analyses in the outcomes study, conducted by Dr. Lee and her colleagues at Duke University in Durham, N.C.

The study was conducted in eight hospitals between 1991 and 2002. The most common procedures were hip arthroplasty in 74 patients (22%), fracture repair in 55 patients (16%), and knee arthroplasty in 40 patients (12%). Staphylococcus aureus was the dominant pathogen, associated with 95 infections (56%), and 55% of these pathogens were methicillin resistant.

The mean length of stay was 13 days among 169 infected patients, compared with 4 days among 171 uninfected controls. The patient's mean age was 75 years; 66% were women, and 83% were white.

Other predictors of prolonged hospital stay included an inability to bathe independently, undergoing procedures of longer duration, postoperative glucose greater than 200 mg/dL, and having procedures on the same day as hospitalization.

Severe Diabetic Skin Infections

Diabetic patients with severe skin infections had greater improvement when treated with meropenem than with imipenem-cilastatin, Dr. John M. Embil reported in a poster presented at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Skin and skin-structure infections are a perpetual problem for diabetic patients, and may require surgical intervention if left untreated, wrote Dr. Embil of the University of Manitoba, Winnipeg, Canada.

The international, randomized, double-blind study included 1,037 hospitalized patients with complicated skin infections, 398 of whom were diabetic.

The clinical cure rate was 86% among the 204 diabetic patients who received a 500-mg intravenous dose of meropenem every 8 hours, compared with 72% among the 194 diabetic patients who received the same dosing regimen of imipenem-cilastatin. The cure rate among the nondiabetic patients treated with meropenem (87%) was similar to the rate in those treated with imipenem-cilastatin (89%).

Overall, meropenem was associated with slightly higher cure rates for all groups of pathogens—aerobic gram-negative, aerobic gram-positive, anaerobic, and polymicrobial—compared with imipenem-cilastatin, but the differences were not statistically significant. More than 40% of the pathogens were gram-negative aerobic or anaerobic organisms, and 29% of the Staphylococcus aureus isolates showed methicillin resistance. A similar spectrum of pathogens appeared in both diabetic and nondiabetic patients.

Liver Toxicity Reported With Ketek

The Food and Drug Administration is recommending that physicians monitor patients taking telithromycin (Ketek) for signs and symptoms of liver problems in response to reports of liver toxicity in three patients taking the drug.

Telithromycin is the first of the ketolide class of antibiotics to be approved, and is indicated for adults for the treatment of serious bacterial infections, such as community-acquired pneumonia, acute bacterial sinusitis, and acute exacerbation of chronic bronchitis. The drug is marketed by Aventis Pharmaceuticals Inc.

All three patients developed jaundice and abnormal liver function. One patient recovered, one required a transplant, and one died. The patients previously had been healthy and were not using other prescription drugs.

Examination of the livers of two of the patients revealed massive tissue death. The cases were reported online as an early-release article in the Annals of Internal Medicine (

www.acponline.org/journals/annals/hepatotoxicity.htm

The FDA recommends that telithromycin should be stopped in patients who develop signs or symptoms of liver problems. Patients who have been prescribed the drug and who are not experiencing side effects such as jaundice should continue taking their medicine as prescribed. Patients who notice any yellowing of their eyes or skin, or other problems such as blurry vision, should call their health care provider immediately.

Telithromycin should be used only for infections caused by a susceptible microorganism. These include Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. The FDA is continuing to investigate the issue of liver problems in association with the use of telithromycin in order to determine if labeling changes or other actions are warranted.

Infections Prolong Hospitalization

Elderly patients who developed surgical site infections after undergoing orthopedic surgery had significantly longer hospital stays, Dr. Jeanne Lee wrote in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Surgical site infection was a significant independent predictor of prolonged hospital stay according to both bivariate and multivariate analyses in the outcomes study, conducted by Dr. Lee and her colleagues at Duke University in Durham, N.C.

The study was conducted in eight hospitals between 1991 and 2002. The most common procedures were hip arthroplasty in 74 patients (22%), fracture repair in 55 patients (16%), and knee arthroplasty in 40 patients (12%). Staphylococcus aureus was the dominant pathogen, associated with 95 infections (56%), and 55% of these pathogens were methicillin resistant.

The mean length of stay was 13 days among 169 infected patients, compared with 4 days among 171 uninfected controls. The patient's mean age was 75 years; 66% were women, and 83% were white.

Other predictors of prolonged hospital stay included an inability to bathe independently, undergoing procedures of longer duration, postoperative glucose greater than 200 mg/dL, and having procedures on the same day as hospitalization.

Severe Diabetic Skin Infections

Diabetic patients with severe skin infections had greater improvement when treated with meropenem than with imipenem-cilastatin, Dr. John M. Embil reported in a poster presented at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Skin and skin-structure infections are a perpetual problem for diabetic patients, and may require surgical intervention if left untreated, wrote Dr. Embil of the University of Manitoba, Winnipeg, Canada.

The international, randomized, double-blind study included 1,037 hospitalized patients with complicated skin infections, 398 of whom were diabetic.

The clinical cure rate was 86% among the 204 diabetic patients who received a 500-mg intravenous dose of meropenem every 8 hours, compared with 72% among the 194 diabetic patients who received the same dosing regimen of imipenem-cilastatin. The cure rate among the nondiabetic patients treated with meropenem (87%) was similar to the rate in those treated with imipenem-cilastatin (89%).

Overall, meropenem was associated with slightly higher cure rates for all groups of pathogens—aerobic gram-negative, aerobic gram-positive, anaerobic, and polymicrobial—compared with imipenem-cilastatin, but the differences were not statistically significant. More than 40% of the pathogens were gram-negative aerobic or anaerobic organisms, and 29% of the Staphylococcus aureus isolates showed methicillin resistance. A similar spectrum of pathogens appeared in both diabetic and nondiabetic patients.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. Nasal swabs were collected from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA. “On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“I think the household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst. … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. Nasal swabs were collected from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA. “On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“I think the household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst. … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. Nasal swabs were collected from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA. “On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“I think the household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst. … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. They collected nasal swabs from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA.

“On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“The household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, which was sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

It's also important to consider pets in the household if a patient has an otherwise unexplained MRSA infection or recurrent, persistent infections. “Infection control measures are the key” to prevent household transmission of MRSA between pets and people, Dr. Weese said. Animals appear to eradicate MRSA colonizations on their own in most situations, he noted.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. They collected nasal swabs from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA.

“On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“The household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, which was sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

It's also important to consider pets in the household if a patient has an otherwise unexplained MRSA infection or recurrent, persistent infections. “Infection control measures are the key” to prevent household transmission of MRSA between pets and people, Dr. Weese said. Animals appear to eradicate MRSA colonizations on their own in most situations, he noted.

WASHINGTON — As if there weren't already enough reasons to be worried about methicillin-resistant Staphylococcus aureus, the troublesome organism is now turning up in the pet population and appears to be able to move readily between animals and humans, a veterinary expert said at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“Methicillin-resistant Staphylococcus aureus, and Staph aureus in general, really hasn't been considered to be zoonotic, but now we're seeing that it can be transmitted between animals and people in both directions. As community-associated MRSA becomes more of a problem in people, it creates more potential exposure of pets,” said J. Scott Weese, D.V.M., a professor of large animal medicine at the University of Guelph in Ontario, Canada.

Methicillin-resistant Staphylococcus aureus (MRSA) appears to be endemic at a low level in the horse population worldwide, and it can be transmitted between horses and people fairly readily. During an equine outbreak in Ontario between 2000 and 2002, MRSA was isolated from 79 horses and 29 horse personnel. In addition, there were 13 clinical infections in horses and 1 clinical infection in a veterinarian.

“So there was fairly clear interspecies transmission,” Dr. Weese said. In fact, the outbreak was traced back to one individual.

To determine what was going on in the larger equine community, Dr. Weese and his colleagues performed a study using a convenience-based sample of 972 horses and 107 horse personnel in Ontario and New York. They collected nasal swabs from horses and humans. Approximately 5% of horses—all of them on farms with previous MRSA exposures—and 13% of personnel were colonized with MRSA.

“On every farm that had a colonized horse, there was at least one person who was colonized with an indistinguishable strain,” Dr. Weese said.

“The household pet issue is a more concerning issue because of the degree of contact that we have with our pets in most situations,” he said.

In the past year or two, there have been reports of a few hundred clinically infected pets in the United Kingdom. The numbers are lower in North America, but this may be attributable to lower rates of diagnosis and reporting. “We definitely do see them in North America.”

However, the prevalence of colonization in pets in the general population appears to be very low. “Most of the reports of household MRSA report strains that are typical of the common human strains in the area,” he said. The USA 100 strain is predominant in the United States and Canada.

Dr. Weese presented a few cases of transmission of MRSA between pets and humans that he has investigated. “These are not the worst of the worst … They are representative of a lot of situations that we've investigated,” he said.

In one case in Washington, two kittens were brought to a veterinary clinic with chronic rhinitis. MRSA was isolated from cultures taken from both kittens. A technician at the clinic who had worked with the kittens was colonized as well. The kittens' owners, as well as the other cat in the household, were also colonized. Upon investigation, the researchers learned that the kittens had been adopted from a rescue facility, and the head of the rescue facility was colonized, too. The isolates collected in the course of the investigation were indistinguishable.

The MRSA originated at the rescue facility and “one or more of the kittens brought it into the house, transmitted it to both owners and the other cat and one person at the veterinary clinic,” Dr. Weese said at the meeting, which was sponsored by the American Society for Microbiology.

In another case a few years ago, a dog was presented to a primary care veterinary clinic in New York for a postoperative infection related to a surgery performed at another facility the previous week. The culture was positive for a very aggressive strain of MRSA. The dog had necrotizing fasciitis and osteomyelitis and had to be euthanized. During the investigation, another dog developed a serious postoperative infection. This dog was admitted for surgery after the first dog had been euthanized, so there had been no chance for direct contact.

Two personnel were found to be colonized, one of whom had been observed poking at the incision line of the second dog. The investigators determined that the first dog had acquired MRSA at the facility where surgery was performed, and had transmitted the organism to the owner and two personnel at the second facility, who then infected the other dog.

Dr. Weese and his colleagues are currently investigating the possibility of transmission from people to therapy dogs making visits to hospitals. Dogs are screened for MRSA at enrollment and are periodically rechecked. The study is ongoing, and to date, one dog has been documented to have acquired MRSA during visitation with a colonized individual. “The concern is that if the dog is colonized and seeing other patients in the hospital … what's the risk for transmission,” he said.

When it comes to MRSA and potential transmission, different species have different issues, Dr. Weese said. With horses, there is concern about nasal/facial contamination, fecal contamination, and the greater potential for international movement.

With household pets—dogs, cats, and hamsters, among others—the degree, duration, and intensity of contact is the primary concern. “There's a lot of high-level contact within the household, creating the chance for transmission,” he said.

As a general rule, physicians “need to know what's going on in the household with pets,” he said. Find out if there are pets and how many, and if the pets are healthy. It's important to reinforce the importance of hand hygiene for people with pets, especially if the pet is sick.

It's also important to consider pets in the household if a patient has an otherwise unexplained MRSA infection or recurrent, persistent infections. “Infection control measures are the key” to prevent household transmission of MRSA between pets and people, Dr. Weese said. Animals appear to eradicate MRSA colonizations on their own in most situations, he noted.

Without the information provided by imaging, the differential diagnosis of cerebral venous thrombosis is fairly broad, said Dr. Andrew D. Perron, residency program director in the department of emergency medicine at Maine Medical Center in Portland.

The patient may have ongoing seizures (nonconvulsive status) with a variety of etiologies possible—infectious, tumor, metabolic, or toxic, Dr. Perron said in an interview.

Cerebral venous thrombosis (CVT) disproportionately affects women. Mortality in untreated cases is reported to range from 14% to 48%. The outcome overall is good, particularly with IV heparin therapy, he said.

The MRI shown on the left is from a 22-year-old female graduate student who was taken to the emergency department by her roommate. She had had a headache for 5 days, and over the last 18 hours she had been somnolent with episodes of vomiting. Her right leg began twitching rhythmically and continuously about an hour before her admission to the ED. She had suffered no trauma, recent illness, or previous episodes.

On physical examination the patient was somnolent but aroused to pain, opening her eyes to regard the examiner. She made nonsensical but fluent verbalizations. Her right leg and right abdominal muscles were rhythmically twitching. She could move her arms and legs, but she clearly moved her left extremities more than her right. Bilateral papilledema was present on examination, Dr. Perron said.

The woman had a history of irregular, heavy menses, and she had recently started taking oral contraceptives to regulate her cycle.

When considered together, the recent history of headache, vomiting, twitching of the right leg, impaired movement of extremities on her right side, verbal difficulties, and papilledema strongly suggested CVT. Initial imaging of CVT can be difficult, and the diagnosis may not always be evident on contrast/noncontrast CT, Dr. Perron said. CT can be useful for ruling out other conditions such as neoplasm and in evaluating coexistent lesions, such as subdural empyema.

Evidence of infarction may not correspond to arterial distribution on CT. And in the absence of a hemorrhagic component, evidence of an infarct may be delayed by 48–72 hours. The empty delta sign, pathognomonic of sagittal sinus thrombosis, can be seen sometimes on contrast CT. It appears as an enhancement of the collateral veins in the superior sagittal sinus walls surrounding a nonenhanced thrombus in the sinus. But the empty delta sign is frequently absent, and early division of the superior sagittal sinus can give a false delta sign.

This patient was given an initial dose of phenytoin to manage the rhythmic leg twitching. Due to the strong suspicion of CVT, she was heparinized and admitted to the intensive care unit.

She underwent MRI and MR venography (MRV). MRI shows the pattern of an infarct when it does not follow the distribution of an expected arterial occlusion. It may show the absence of flow void in the normal venous channels. MRV provides excellent visualization of the dural venous sinuses and larger cerebral veins, Dr. Perron said.

In this case, both MRI and MRV revealed thrombosis of the superior saggital sinus and also the left transverse sinus. In addition, other findings were consistent with left parietal venous infarction. The woman had no further seizure activity on phenytoin. She was started on warfarin. The weakness on the right resolved, and she was discharged on phenytoin and warfarin.

CVT is an uncommon cause of cerebral infarction, relative to arterial disease, Dr. Perron said. The top five causes of CVT are oral contraceptive use, thrombophilia, pregnancy and puerperium, infection, and hematologic causes (polycythemia, thrombocythemia, and anemia).

In this T2-weighted axial MRI, evidence of infarct can clearly be seen. The 22-year-old woman had thrombosis of the superior saggital sinus and the left transverse sinus. Courtesy Dr. Andrew D. Perron

Without the information provided by imaging, the differential diagnosis of cerebral venous thrombosis is fairly broad, said Dr. Andrew D. Perron, residency program director in the department of emergency medicine at Maine Medical Center in Portland.

The patient may have ongoing seizures (nonconvulsive status) with a variety of etiologies possible—infectious, tumor, metabolic, or toxic, Dr. Perron said in an interview.

Cerebral venous thrombosis (CVT) disproportionately affects women. Mortality in untreated cases is reported to range from 14% to 48%. The outcome overall is good, particularly with IV heparin therapy, he said.

The MRI shown on the left is from a 22-year-old female graduate student who was taken to the emergency department by her roommate. She had had a headache for 5 days, and over the last 18 hours she had been somnolent with episodes of vomiting. Her right leg began twitching rhythmically and continuously about an hour before her admission to the ED. She had suffered no trauma, recent illness, or previous episodes.

On physical examination the patient was somnolent but aroused to pain, opening her eyes to regard the examiner. She made nonsensical but fluent verbalizations. Her right leg and right abdominal muscles were rhythmically twitching. She could move her arms and legs, but she clearly moved her left extremities more than her right. Bilateral papilledema was present on examination, Dr. Perron said.

The woman had a history of irregular, heavy menses, and she had recently started taking oral contraceptives to regulate her cycle.

When considered together, the recent history of headache, vomiting, twitching of the right leg, impaired movement of extremities on her right side, verbal difficulties, and papilledema strongly suggested CVT. Initial imaging of CVT can be difficult, and the diagnosis may not always be evident on contrast/noncontrast CT, Dr. Perron said. CT can be useful for ruling out other conditions such as neoplasm and in evaluating coexistent lesions, such as subdural empyema.

Evidence of infarction may not correspond to arterial distribution on CT. And in the absence of a hemorrhagic component, evidence of an infarct may be delayed by 48–72 hours. The empty delta sign, pathognomonic of sagittal sinus thrombosis, can be seen sometimes on contrast CT. It appears as an enhancement of the collateral veins in the superior sagittal sinus walls surrounding a nonenhanced thrombus in the sinus. But the empty delta sign is frequently absent, and early division of the superior sagittal sinus can give a false delta sign.

This patient was given an initial dose of phenytoin to manage the rhythmic leg twitching. Due to the strong suspicion of CVT, she was heparinized and admitted to the intensive care unit.

She underwent MRI and MR venography (MRV). MRI shows the pattern of an infarct when it does not follow the distribution of an expected arterial occlusion. It may show the absence of flow void in the normal venous channels. MRV provides excellent visualization of the dural venous sinuses and larger cerebral veins, Dr. Perron said.

In this case, both MRI and MRV revealed thrombosis of the superior saggital sinus and also the left transverse sinus. In addition, other findings were consistent with left parietal venous infarction. The woman had no further seizure activity on phenytoin. She was started on warfarin. The weakness on the right resolved, and she was discharged on phenytoin and warfarin.

CVT is an uncommon cause of cerebral infarction, relative to arterial disease, Dr. Perron said. The top five causes of CVT are oral contraceptive use, thrombophilia, pregnancy and puerperium, infection, and hematologic causes (polycythemia, thrombocythemia, and anemia).

In this T2-weighted axial MRI, evidence of infarct can clearly be seen. The 22-year-old woman had thrombosis of the superior saggital sinus and the left transverse sinus. Courtesy Dr. Andrew D. Perron

Without the information provided by imaging, the differential diagnosis of cerebral venous thrombosis is fairly broad, said Dr. Andrew D. Perron, residency program director in the department of emergency medicine at Maine Medical Center in Portland.

The patient may have ongoing seizures (nonconvulsive status) with a variety of etiologies possible—infectious, tumor, metabolic, or toxic, Dr. Perron said in an interview.

Cerebral venous thrombosis (CVT) disproportionately affects women. Mortality in untreated cases is reported to range from 14% to 48%. The outcome overall is good, particularly with IV heparin therapy, he said.

The MRI shown on the left is from a 22-year-old female graduate student who was taken to the emergency department by her roommate. She had had a headache for 5 days, and over the last 18 hours she had been somnolent with episodes of vomiting. Her right leg began twitching rhythmically and continuously about an hour before her admission to the ED. She had suffered no trauma, recent illness, or previous episodes.

On physical examination the patient was somnolent but aroused to pain, opening her eyes to regard the examiner. She made nonsensical but fluent verbalizations. Her right leg and right abdominal muscles were rhythmically twitching. She could move her arms and legs, but she clearly moved her left extremities more than her right. Bilateral papilledema was present on examination, Dr. Perron said.

The woman had a history of irregular, heavy menses, and she had recently started taking oral contraceptives to regulate her cycle.

When considered together, the recent history of headache, vomiting, twitching of the right leg, impaired movement of extremities on her right side, verbal difficulties, and papilledema strongly suggested CVT. Initial imaging of CVT can be difficult, and the diagnosis may not always be evident on contrast/noncontrast CT, Dr. Perron said. CT can be useful for ruling out other conditions such as neoplasm and in evaluating coexistent lesions, such as subdural empyema.

Evidence of infarction may not correspond to arterial distribution on CT. And in the absence of a hemorrhagic component, evidence of an infarct may be delayed by 48–72 hours. The empty delta sign, pathognomonic of sagittal sinus thrombosis, can be seen sometimes on contrast CT. It appears as an enhancement of the collateral veins in the superior sagittal sinus walls surrounding a nonenhanced thrombus in the sinus. But the empty delta sign is frequently absent, and early division of the superior sagittal sinus can give a false delta sign.

This patient was given an initial dose of phenytoin to manage the rhythmic leg twitching. Due to the strong suspicion of CVT, she was heparinized and admitted to the intensive care unit.

She underwent MRI and MR venography (MRV). MRI shows the pattern of an infarct when it does not follow the distribution of an expected arterial occlusion. It may show the absence of flow void in the normal venous channels. MRV provides excellent visualization of the dural venous sinuses and larger cerebral veins, Dr. Perron said.

In this case, both MRI and MRV revealed thrombosis of the superior saggital sinus and also the left transverse sinus. In addition, other findings were consistent with left parietal venous infarction. The woman had no further seizure activity on phenytoin. She was started on warfarin. The weakness on the right resolved, and she was discharged on phenytoin and warfarin.

CVT is an uncommon cause of cerebral infarction, relative to arterial disease, Dr. Perron said. The top five causes of CVT are oral contraceptive use, thrombophilia, pregnancy and puerperium, infection, and hematologic causes (polycythemia, thrombocythemia, and anemia).

In this T2-weighted axial MRI, evidence of infarct can clearly be seen. The 22-year-old woman had thrombosis of the superior saggital sinus and the left transverse sinus. Courtesy Dr. Andrew D. Perron