Estimating the burden of 2009 pandemic influenza A (H1N1) in the United States (April 2009-April 2010).

To calculate the burden of 2009 pandemic influenza A (pH1N1) in the United States, we extrapolated from the Centers for Disease Control and Prevention's Emerging Infections Program laboratory-confirmed hospitalizations across the entire United States, and then corrected for underreporting. From 12 April 2009 to 10 April 2010, we estimate that approximately 60.8 million cases (range: 43.3-89.3 million), 274,304 hospitalizations (195,086-402,719), and 12,469 deaths (8868-18,306) occurred in the United States due to pH1N1. Eighty-seven percent of deaths occurred in those under 65 years of age with children and working adults having risks of hospitalization and death 4 to 7 times and 8 to 12 times greater, respectively, than estimates of impact due to seasonal influenza covering the years 1976-2001. In our study, adults 65 years of age or older were found to have rates of hospitalization and death that were up to 75% and 81%, respectively, lower than seasonal influenza. These results confirm the necessity of a concerted public health response to pH1N1.

Prevalence of HIV in the US household population: the National Health and Nutrition Examination Surveys, 1988 to 2002.

To examine trends in HIV prevalence in the US household population, serum or urine samples from 2 National Health and Nutrition Examinations Surveys (NHANES) (1988-1994 and 1999-2002), were tested for HIV antibody. In the 1999 to 2002 survey, data on risk behaviors, CD4 T lymphocytes, and antiretroviral therapy (ART) were also available. In the 1988 to 1994 survey, there were 59 positive individuals of 11,203 tested. In NHANES 1999 to 2002, there were 32 positive individuals of 5926 tested. The prevalence of HIV infection among those aged 18 to 39 years in NHANES 1988 to 1994 was 0.38% (95% confidence interval [CI]: 0.22-0.68) as compared with 0.37% (95% CI: 0.17 to 0.80) in 1999 to 2002. Prevalence did not change significantly between surveys in any race and/or ethnic or gender group among 18- to 39-year-old participants. HIV prevalence was 3.58% (95% CI: 1.88 to 6.71) among non-Hispanic blacks in the 40- to 49-year-old age group in 1999 to 2002, but the age range available in NHANES 1988 to 1994 was 18 to 59 years and does not allow direct comparison of prevalence. Cocaine use and the presence of herpes simplex virus-2 antibody were the only significant risk factors for HIV infection for non-Hispanic blacks. Fifty-eight percent of infected individuals not reporting ART had CD4 T-lymphocyte counts < 200 cells/mm3 compared with 18.2% on therapy and 12.5% of participants newly informed of their HIV status.

Epidemic diarrhea due to enterotoxigenic Escherichia coli.

BACKGROUND: In June 1998, we investigated one of the largest foodborne outbreaks of enterotoxigenic Escherichia coli gastroenteritis reported in the United States. METHODS: We conducted cohort studies of 11 catered events to determine risk factors for illness. We used stool cultures, polymerase chain reaction, and serologic tests to determine the etiologic agent, and we conducted an environmental inspection to identify predisposing conditions and practices at the implicated establishment. RESULTS: During 5-7 June, the implicated delicatessen catered 539 events attended by >16,000 people. Our epidemiological study of 11 events included a total of 612 attendees. By applying the median prevalence of illness (20%) among events with ill attendees to the total number of events with any ill attendees, we estimate that at least 3300 persons may have developed gastroenteritis during this outbreak. Multiple food items (potato salad, macaroni salad, egg salad, and watermelon) were associated with illness, all of which required extensive handling during preparation. Enterotoxigenic Escherichia coli serotype O6:H16 producing heat-labile and heat-stable toxins was isolated from the stool specimens from 11 patients. Eight patients with positive stool culture results, 11 (58%) of 19 other symptomatic attendees, and 0 (0%) of 17 control subjects had elevated serum antibody titers to E. coli O6 lipopolysaccharide. The delicatessen had inadequate hand-washing supplies, inadequate protection against back siphonage of wastewater in the potable water system, a poorly draining kitchen sink, and improper food storage and transportation practices. CONCLUSIONS: In the United States, where enterotoxigenic Escherichia coli is an emerging cause of foodborne disease, enterotoxigenic Escherichia coli should be suspected in outbreaks of gastroenteritis when common bacterial or viral enteric pathogens are not identified.