Escherichia coli O157:H7 causes 73,000 illnesses in the United States annually. We reviewed E. coli O157 outbreaks reported to Centers for Disease Control and Prevention (CDC) to better understand the epidemiology of E. coli O157. E. coli O157 outbreaks (>2 cases of E. coli O157 infection with a common epidemiologic exposure) reported to CDC from 1982 to 2002 were reviewed. In that period, 49 states reported 350 outbreaks, representing 8,598 cases, 1,493 (17%) hospitalizations, 354 (4%) hemolytic uremic syndrome cases, and 40 (0.5%) deaths. Transmission route for 183 (52%) was foodborne, 74 (21%) unknown, 50 (14%) person-to-person, 31 (9%) waterborne, 11 (3%) animal contact, and 1 (0.3%) laboratory-related. The food vehicle for 75 (41%) foodborne outbreaks was ground beef, and for 38 (21%) outbreaks, produce.

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Epidemiology of Escherichia coli O157:H7 outbreaks, United States, 1982-2002.

Fresh produce: a growing cause of outbreaks of foodborne illness in the United States, 1973 through 1997.

PulseNet, the national molecular subtyping network for foodborne disease surveillance, was established by the Centers for Disease Control and Prevention and several state health department laboratories to facilitate subtyping bacterial foodborne pathogens for epidemiologic purposes. PulseNet, which began in 1996 with 10 laboratories typing a single pathogen (Escherichia coli O157:H7), now includes 46 state and 2 local public health laboratories and the food safety laboratories of the U.S. Food and Drug Administration and the U.S. Department of Agriculture. Four foodborne pathogens (E. coli O157:H7; nontyphoidal Salmonella serotypes, Listeria monocytogenes and Shigella) are being subtyped, and other bacterial, viral, and parasitic organisms will be added soon.

PulseNet: the molecular subtyping network for foodborne bacterial disease surveillance, United States.

Context.— Differentiating individuals with early human immunodeficiency virus 1 (HIV-1) infection from those infected for longer periods is difficult but important for estimating HIV incidence and for purposes of clinical care and prevention. Objective.— To develop and validate a serologic testing algorithm in which HIV1‐positive persons with reactive test results on a sensitive HIV-1 enzyme immunoassay (EIA) but nonreactive results on a less sensitive (LS) EIA are identified as having early infection. Design.— Diagnostic test and testing strategy development, validation, and application. Specimens were tested with both a sensitive HIV-1 EIA (3A11 assay) and a less sensitive modification of the same EIA (3A11-LS assay). Settings and Participants.— For assay development: 104 persons seroconverting to HIV-1 comprising 38 plasma donors, 18 patients of a sexually transmitted disease clinic in Trinidad, and 48 participants in the San Francisco Men’s Health Study (SFMHS); 268 men without the acquired immunodeficiency syndrome (AIDS) in the SFMHS who had been infected for at least 2.5 years; and 207 persons with clinical AIDS; for testing strategy validation: 488 men in the SFMHS from 1985 through 1990 and 1 275 449 repeat blood donors at 3 American Red Cross blood centers from 1993 through 1995; and for HIV-1 incidence estimates: 2 717 910 first-time blood donors. We retrospectively identified persons eligible for a study of early infection. Main Outcome Measure.— Ability to identify early HIV infection. Results.— Estimated mean time to being 3A11 reactive/3A11-LS nonreactive was 129 days (95% confidence interval [CI], 109-149 days). Our testing strategy accurately diagnosed 95% of persons with early infection; however, 0.4% (1/268) of men with established infection and 2% (5/207) of persons with late-stage AIDS were misdiagnosed as having early HIV-1 infection. Average yearly incidence estimates in SFMHS subjects were 1.5% per year vs observed average incidence of 1.4 per 100 person-years. Incidence in repeat blood donors using the sensitive/less sensitive assay testing strategy was 2.95 per 100 000 per year (95% CI, 1.14-6.53/ 100 000) vs observed incidence of 2.60 per 100 000 person-years (95% CI, 1.494.21/100 000). Overall incidence in first-time blood donors was 7.18 per 100 000 per year (95% CI, 4.51-11.20/100 000) and did not change statistically significantly be

https://jamanetwork.com/journals/jama/articlepdf/187695/joc72285.pdf

New Testing Strategy to Detect Early HIV-1 Infection for Use in Incidence Estimates and for Clinical and Prevention Purposes

shot assessment of contamination at a particular location on a particular produce item at a particular time of year, they rarely provide information on the source of contamination. For these reasons, caution must be used when interpreting data from these types of studies, and overly broad conclusions should be avoided. Nevertheless, numerous pathogenic microorganisms have been isolated from a wide variety of fresh fruits and vegetables, sometimes at relatively high frequencies (Table I1-I7). Not all of the microorganisms listed in these tables have been linked to produce-associated illnesses. Under the right conditions, however, all of these microorganisms have the potential to cause produce-associated illness. Isolation rates are not consistent. Percentage of samples contaminated ranges from 0 to greater than 50%, depending upon the target pathogen and produce item. Data proScope An important consideration when addressing safety issues is the incidence of pathogens and outbreaks associated with particular food products. This chapter addresses outbreaks that have been associated with the consumption of fresh and fresh-cut produce. In addition, studies that investigate the incidence of pathogens and factors contributing to the survival and growth of pathogens are reviewed. Although they may not be exhaustive, the tables at the end of the chapter include highlights of incidence studies from industry and published literature sources (Tables I1-I7), outbreaks (Tables O1-O10), and growth/survival studies related to fresh produce (Tables G/S1 to G/S8).

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1541-4337.2003.tb00031.x

Outbreaks Associated with Fresh Produce: Incidence, Growth, and Survival of Pathogens in Fresh and Fresh-Cut Produce

In fall 1996, a small cluster of Escherichia coli O157:H7 infections was linked to unpasteurized apple juice. This study found that standard procedures at a plant that produces unpasteurized juices...

Balasubr Swaminathan

Papers

An outbreak of Escherichia coli O157:H7 infection from unpasteurized commercial apple juice.