Hospitalizations and deaths due to Salmonella infections, FoodNet, 1996-1999.

Nontyphoidal Salmonella causes a higher proportion of food-related deaths annually than any other bacterial pathogen in the United States. We reviewed 4 years (1996-1999) of population-based active surveillance data on laboratory-confirmed Salmonella infections from the Emerging Infections Program's Foodborne Diseases Active Surveillance Network (FoodNet), to determine the rates of hospitalization and death associated with Salmonella infection. Overall, 22% of infected persons were hospitalized, with the highest rate (47%) among persons aged >60 years. Fifty-eight deaths occurred, for an estimated annual incidence of 0.08 deaths/100,000 population. These deaths accounted for 38% of all deaths reported through FoodNet from 1996 through 1999, and they occurred primarily among adults with serious underlying disease. Although Salmonella infection was seldom listed as a cause of death on hospital charts and death certificates, our chart review suggests that Salmonella infection contributed to these deaths.

Burden of self-reported acute diarrheal illness in FoodNet surveillance areas, 1998-1999.

To assess trends in the burden of acute diarrheal illness, the Foodborne Diseases Active Surveillance Network (FoodNet) conducted a population-based telephone survey during 1998-1999, using a random-digit-dialing, single-stage Genesys-ID sampling method. During the 12-month study period, 12,755 persons were interviewed; after the exclusion of persons with chronic diarrheal illnesses, 12,075 persons were included in the analysis; 6% (n=645) reported having experienced an acute diarrheal illness at some point during the 4 weeks preceding the interview (annualized rate, 0.72 episodes per person-year). Rates of diarrheal illness were highest among children aged <5 years (1.1 episodes per person-year) and were lowest in persons aged > or =65 years (0.32 episodes per person-year). Twenty-one percent of persons with acute diarrheal illness sought medical care as a result of their illness. Diarrheal illness imposes a considerable burden on the US population and health care system.

Limitations to successful investigation and reporting of foodborne outbreaks: an analysis of foodborne disease outbreaks in FoodNet catchment areas, 1998-1999.

To better understand factors associated with confirming the etiologic organism and identifying the food vehicle responsible for foodborne-disease outbreaks, we examined data from outbreaks reported in 1998 and 1999 through active surveillance by Foodborne Disease Active Surveillance Network (FoodNet) surveillance areas in 7 states. In 71% of these outbreaks, no confirmed etiology was identified, and in 46%, no suspected food vehicle was identified. Outbreaks involving > or =10 cases were significantly more likely to have their etiology identified than were smaller outbreaks. In two-thirds of outbreaks in which an etiology was not confirmed, no stool specimens were collected for laboratory testing; in 55% of these outbreaks, neither clinical specimens nor food samples were tested. If the etiology of and factors contributing to foodborne-disease outbreaks are to be understood, adequate resources must be available to allow specimens to be collected and tested and epidemiologic investigations to be conducted appropriately.

Consumer attitudes and use of antibiotics.

Recent antibiotic use is a risk factor for infection or colonization with resistant bacterial pathogens. Demand for antibiotics can be affected by consumers' knowledge, attitudes, and practices. In 1998-1999, the Foodborne Diseases Active Surveillance Network (FoodNet( conducted a population-based, random-digit dialing telephone survey, including questions regarding respondents' knowledge, attitudes, and practices of antibiotic use. Twelve percent had recently taken antibiotics; 27% believed that taking antibiotics when they had a cold made them better more quickly, 32% believed that taking antibiotics when they had a cold prevented more serious illness, and 48% expected a prescription for antibiotics when they were ill enough from a cold to seek medical attention. These misguided beliefs and expectations were associated with a lack of awareness of the dangers of antibiotic use; 58% of patients were not aware of the possible health dangers. National educational efforts are needed to address these issues if patient demand for antibiotics is to be reduced.