Jeremy Sobel

An Outbreak of Gastroenteritis and Fever Due to Listeria monocytogenes in Milk

BACKGROUND After an outbreak of gastroenteritis and fever among persons who attended a picnic in Illinois, chocolate milk served at the picnic was found to be contaminated with Listeria monocytogenes. METHODS In investigating this outbreak, we interviewed the people who attended the picnic about what they ate and their symptoms. Surveillance for invasive listeriosis was initiated in the states that receive milk from the implicated dairy. Stool and milk samples were cultured for L. monocytogenes. Serum samples were tested for IgG antibody to listeriolysin O. RESULTS Forty-five persons had symptoms that met the case definition for illness due to L. monocytogenes, and cultures of stool from 11 persons yielded the organism. Illness in the week after the picnic was associated with the consumption of chocolate milk. The most common symptoms were diarrhea (present in 79 percent of the cases) and fever (72 percent). Four persons were hospitalized. The median incubation period for infection was 20 hours (range, 9 to 32), and persons who became ill had elevated levels of antibody to listeriolysin O. Isolates from stool specimens from patients who became ill after the picnic, from sterile sites in three additional patients identified by surveillance, from the implicated chocolate milk, and from a tank drain at the dairy were all serotype 1/2b and were indistinguishable on multilocus enzyme electrophoresis, ribotyping, and DNA macrorestriction analysis. CONCLUSIONS L. monocytogenes is a cause of gastroenteritis with fever, and sporadic cases of invasive listeriosis may be due to unrecognized outbreaks caused by contaminated food.

Multistate outbreak of listeriosis linked to Turkey deli meat and subsequent changes in US regulatory policy

BACKGROUND Listeriosis, a life-threatening foodborne illness caused by Listeria monocytogenes, affects approximately 2500 Americans annually. Between July and October 2002, an uncommon strain of L. monocytogenes caused an outbreak of listeriosis in 9 states. METHODS We conducted case finding, a case-control study, and traceback and microbiological investigations to determine the extent and source of the outbreak and to propose control measures. Case patients were infected with the outbreak strain of L. monocytogenes between July and November 2002 in 9 states, and control patients were infected with different L. monocytogenes strains. Outcome measures included food exposure associated with outbreak strain infection and source of the implicated food. RESULTS Fifty-four case patients were identified; 8 died, and 3 pregnant women had fetal deaths. The case-control study included 38 case patients and 53 control patients. Case patients consumed turkey deli meat much more frequently than did control patients (P = .008, by Wilcoxon rank-sum test). In the 4 weeks before illness, 55% of case patients had eaten deli turkey breast more than 1-2 times, compared with 28% of control patients (odds ratio, 4.5; 95% confidence interval, 1.3-17.1). Investigation of turkey deli meat eaten by case patients led to several turkey processing plants. The outbreak strain was found in the environment of 1 processing plant and in turkey products from a second. Together, the processing plants recalled > 30 million pounds of products. Following the outbreak, the US Department of Agricultures Food Safety and Inspection Service issued new regulations outlining a L. monocytogenes control and testing program for ready-to-eat meat and poultry processing plants. CONCLUSIONS Turkey deli meat was the source of a large multistate outbreak of listeriosis. Investigation of this outbreak helped guide policy changes designed to prevent future L. monocytogenes contamination of ready-to-eat meat and poultry products.

Foodborne Botulism in the United States, 1990–2000

Home-canned foods and Alaska Native foods are leading causes of U.S. foodborne botulism; botulism’s epidemic potential renders each case a public health emergency.

Outbreak of Listeriosis among Mexican Immigrants as a Result of Consumption of Illicitly Produced Mexican-Style Cheese

BACKGROUND In 2000, an outbreak of listeriosis among Hispanic persons was identified in Winston-Salem, North Carolina. The objectives of the present study were to identify the source of, strains associated with, and risk factors for Listeria monocytogenes infection for patients affected by the outbreak. METHODS Microbiological, case-control, and environmental investigations were conducted. Participants in the case-control study were case patients who became infected with L. monocytogenes between 1 October 2000 and 31 January 2001 and control subjects who were matched with case patients on the basis of ethnicity, sex, age, and pregnancy status. All participants were residents of Winston-Salem. RESULTS We identified 13 patients, all of whom were Hispanic, including 12 females who were 18-38 years of age. Eleven case patients were pregnant; infection with L. monocytogenes resulted in 5 stillbirths, 3 premature deliveries, and 3 infected newborns. Case patients were more likely than control subjects to have eaten the following foods: fresh, unlabeled, Mexican-style cheese sold by door-to-door vendors (matched odds ratio [MOR], 17.5; 95% confidence interval [CI], 2.0-152.5); queso fresco, a Mexican-style soft cheese (MOR, 7.3; 95% CI, 1.4-37.5); and hot dogs (MOR, 4.6; 95% CI, 1.1-19.4). L. monocytogenes isolates recovered from 10 female case patients, from cheese bought from a door-to-door vendor, from unlabeled cheese from 2 Hispanic markets, and from raw milk from a local dairy had indistinguishable patterns on pulsed-field gel electrophoresis. CONCLUSIONS This outbreak of listeriosis was caused by noncommercial, fresh, Mexican-style cheese made from contaminated raw milk traced to 1 local dairy. We recommend educating Hispanic women about food safety while they are pregnant, enforcing laws that regulate the sale of raw milk and dairy products made by unlicensed manufacturers, making listeriosis a reportable disease in all states, routinely interviewing case patients, and routinely subtyping clinical L. monocytogenes isolates.

Antimicrobial resistance incidence and risk factors among Helicobacter pylori-infected persons, United States.

Helicobacter pylori is the primary cause of peptic ulcer disease and an etiologic agent in the development of gastric cancer. H. pylori infection is curable with regimens of multiple antimicrobial agents, and antimicrobial resistance is a leading cause of treatment failure. The Helicobacter pylori Antimicrobial Resistance Monitoring Program (HARP) is a prospective, multicenter U.S. network that tracks national incidence rates of H. pylori antimicrobial resistance. Of 347 clinical H. pylori isolates collected from December 1998 through 2002, 101 (29.1%) were resistant to one antimicrobial agent, and 17 (5%) were resistant to two or more antimicrobial agents. Eighty-seven (25.1%) isolates were resistant to metronidazole, 45 (12.9%) to clarithromycin, and 3 (0.9%) to amoxicillin. On multivariate analysis, black race was the only significant risk factor (p < 0.01, hazard ratio 2.04) for infection with a resistant H. pylori strain. Formulating pretreatment screening strategies or providing alternative therapeutic regimens for high-risk populations may be important for future clinical practice.

Oral transmission of Chagas disease by consumption of açaí palm fruit, Brazil.

In 2006, a total of 178 cases of acute Chagas disease were reported from the Amazonian state of Pará, Brazil. Eleven occurred in Barcarena and were confirmed by visualization of parasites on blood smears. Using cohort and case–control studies, we implicated oral transmission by consumption of açaí palm fruit.

Inactivation of Bacillus anthracis Spores

After the intentional release of Bacillus anthracis through the U.S. Postal Service in the fall of 2001, many environments were contaminated with B. anthracis spores, and frequent inquiries were made regarding the science of destroying these spores. We conducted a survey of the literature that had potential application to the inactivation of B. anthracis spores. This article provides a tabular summary of the results.

Laboratory-confirmed shigellosis in the United States, 1989-2002: Epidemiologic trends and patterns

During 1989-2002, a total of 208,368 laboratory-confirmed Shigella infections were reported to the Centers for Disease Control and Prevention. Shigella sonnei accounted for 71.7%, Shigella flexneri accounted for 18.4%, Shigella boydii accounted for 1.6%, and Shigella dysenteriae accounted for 0.7% of infections; for 7.6%, no serogroup was reported. National incidence rates ranged from 7.6 cases per 100,000 persons in 1993 to 3.7 cases per 100,000 persons in 1999. Incidence rates for S. boydii, S. dysenteriae, and S. flexneri decreased over the 14-year period by 81%, 83%, and 64%, respectively; S. sonnei rates only decreased by 8%. The highest rates were reported from western states (10.0 cases per 100,000 persons) and among children 1-4 years of age (20.6 cases per 100,000 persons). The female-male S. sonnei incidence rate ratio among 20-39-year-old adults decreased from 2.3 during 1989-1999 to 1.4 during 2000-2002. Approximately 1% of isolates were from extraenteric sources; 0.25% were from blood. S. sonnei remains an important cause of diarrhea in the United States. Prevention efforts that target high-risk groups are needed.

Outbreak of Multidrug-Resistant Salmonella enterica Serotype Typhimurium Definitive Type 104 Infection Linked to Commercial Ground Beef, Northeastern United States, 2003–2004

BACKGROUND Multidrug-resistant Salmonella enterica serotype Typhimurium Definitive Type 104 (DT104) emerged in the 1990s and is associated with greater clinical severity than pansusceptible S. Typhimurium. Although infection with DT104 is common in the United States, it is rarely associated with outbreaks. From October to December 2003, a cluster of DT104 infections with indistinguishable pulsed-field gel electrophoresis patterns was identified in the northeastern United States. METHODS A case-control study that assessed exposures compared case patients to age- and geography-matched control subjects. Information on consumer purchasing and grocery store suppliers was used to trace the implicated food to its source. RESULTS We identified 58 case patients in 9 states by pulsed-field gel electrophoresis. Representative isolates were phage type DT104 and were resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R-type ACSSuT). Of 27 patients interviewed for the case-control study, 41% were hospitalized (median duration of hospitalization, 4 days). Compared with 71 healthy control subjects, case patients had more medical comorbidities (matched odds ratio, 4.3; 95% confidence interval, 1.5-12.7). Illness was associated with consuming store-bought ground beef prepared as hamburgers at home (matched odds ratio, 5.3; 95% confidence interval, 1.9-15.3) and with eating raw ground beef (P< or =.001). Seven case patients (27%), but no control subjects, ate raw ground beef. Product traceback linked cases to a single large ground beef manufacturer previously implicated in a multistate outbreak of highly drug-resistant Salmonella enterica Newport infections in 2002. CONCLUSIONS This first multistate outbreak of highly drug-resistant S. Typhimurium DT104 infection associated with ground beef highlights the need for enhanced animal health surveillance and infection control, prudent use of antimicrobials for animals, improved pathogen reduction during processing, and better product tracking and consumer education.

Reactive arthritis following culture-confirmed infections with bacterial enteric pathogens in Minnesota and Oregon: a population-based study

Objective: To describe the epidemiology and clinical spectrum of reactive arthritis (ReA) following culture-confirmed infection with bacterial enteric pathogens in a population-based study in the USA. Methods: We conducted telephone interviews of persons age >1 year with culture confirmed Campylobacter, Escherichia coli O157, Salmonella, Shigella and Yersinia infections reported to FoodNet (http://www.cdc.gov/FoodNet/) in Minnesota, USA and Oregon, USA between 2002 and 2004. Subjects with new onset joint pain, joint swelling, back pain, heel pain and morning stiffness lasting ⩾3 days within 8 weeks of culture (possible ReA) were invited to complete a detailed questionnaire and physical examination. Results: A total of 6379 culture-confirmed infections were reported; 70% completed screening interviews. Of these, 575 (13%) developed possible ReA; incidence was highest following Campylobacter (2.1/100 000) and Salmonella (1.4/100 000) infections. Risk was greater for females (relative risk (RR) 1.5, 95% CI, 1.3 to 1.7), adults (RR 2.5, 95% CI, 2.0 to 3.1) and subjects with severe acute illness (eg, fever, chills, headache, persistent diarrhoea). Risk was not associated with antibiotic use or human leukocyte antigen (HLA)-B27. A total of 54 (66%) of 82 subjects examined had confirmed ReA. Enthesitis was the most frequent finding; arthritis was less common. The estimated incidence of ReA following culture-confirmed Campylobacter, E coli O157, Salmonella, Shigella and Yersinia infections in Oregon was 0.6–3.1 cases/100 000. Conclusions: This is the first population-based study of ReA following infections due to bacterial enteric pathogens in the USA. These data will help determine the burden of illness due to these pathogens and inform clinicians about potential sequelae of these infections.