Role of the U.S. Food and Drug Administration in the regulatory management of human listeriosis in the United States.

From 1986 to 2006, the incidence of listeriosis in the United States dropped from approximately seven to three cases per million population, a reduction that most likely reflects the joint efforts of industry, government, consumers, and academia. Herein, we describe the U.S. Food and Drug Administration (FDA) strategy over the past three decades to combat listeriosis. Specifically, we discuss early actions taken to address outbreaks during the 1980s, policy decisions regarding the presence of Listeria monocytogenes in FDA-regulated foods, FDA compliance programs with L. monocytogenes components, enforcement actions to remove L. monocytogenes-contaminated products from the market (i.e., recalls) or to prevent entry of such products into the market (i.e., import detentions and refusals), research milestones, outreach and education efforts, and selected special projects. Evolving demographic trends in the United States may pose a challenge to further reduction of the incidence of listeriosis.

Listeria monocytogenes infection from foods prepared in a commercial establishment: a case-control study of potential sources of sporadic illness in the United States.

BACKGROUND: Listeria monocytogenes has been estimated to cause >2500 illnesses and 500 deaths annually in the United States. Efforts to reduce foodborne listeriosis have focused on foods frequently implicated in outbreaks. Potential sources for L. monocytogenes infection not associated with outbreaks remain poorly understood. METHODS: The Foodborne Diseases Active Surveillance Network conducts surveillance for culture-confirmed listeriosis at clinical laboratories in 9 states. After excluding outbreak-associated cases, we attempted to enroll eligible case patients with L. monocytogenes infection in a case-control study from 2000 through 2003. Control subjects were recruited through health care providers and were matched to case patients by state, age, and immunosuppression status. Data were collected about exposures occurring in the 4 weeks before specimen collection from the case patients. RESULTS: Of the 249 case patients with L. monocytogenes infection, only 12 (5%) had cases that were associated with outbreaks; 6 other patients were ineligible for other reasons. Of 231 eligible case patients, 169 (73%) were enrolled in the study. We classified 28 case patients as having pregnancy-associated cases. We enrolled 376 control subjects. In multivariable analysis, L. monocytogenes infection was associated with eating melons at a commercial establishment (odds ratio, 2.6; 95% confidence interval, 1.4-5.0) and eating hummus prepared in a commercial establishment (odds ratio, 5.7; 95% confidence interval, 1.7-19.1). CONCLUSIONS: Most cases of L. monocytogenes infection were not associated with outbreaks. Reducing the burden of foodborne listeriosis may require interventions directed at retail environments and at foods, such as melons and hummus, that are not commonly recognized as high risk. Because of the severity of listeriosis, pregnant women and other persons at risk may wish to avoid eating these newly implicated foods.

Sporadic campylobacter infection in infants: a population-based surveillance case-control study.

BACKGROUND: Campylobacter is an important cause of foodborne illness in infants (younger than 1 year of age), but little is known about the sources of infection in this age group. METHODS: Eight sites in the Foodborne Diseases Active Surveillance Network (FoodNet) participated in a 24-month population-based case-control study conducted in 2002-2004. Cases were infants with laboratory-confirmed Campylobacter infection ascertained through active laboratory surveillance, and controls were infants in the community. RESULTS: We enrolled 123 cases and 928 controls. Infants 0-6 months of age with Campylobacter infection were less likely to be breast-fed than controls [odds ratio (OR); 0.2; 95% confidence interval (CI), 0.1-0.6]. Risk factors for infants 0-6 months of age included drinking well water (OR 4.4; CI, 1.4-14) and riding in a shopping cart next to meat or poultry (OR 4.0; CI, 1.2-13.0). Risk factors for infants 7-11 months of age included visiting or living on a farm (OR 6.2; CI, 2.2-17), having a pet with diarrhea in the home (OR 7.6; CI, 2.1-28) and eating fruits and vegetables prepared in the home (OR 2.5, CI 1.2-4.9). Campylobacter infection was associated with travel outside the United States at all ages (OR 19.3; CI, 4.5-82.1). CONCLUSIONS: Several unique protective and risk factors were identified among infants, and these risk factors vary by age, suggesting that prevention measures be targeted accordingly. Breast-feeding was protective for the youngest infants and should continue to be encouraged.

Dietary supplements in a national survey: Prevalence of use and reports of adverse events.

OBJECTIVE: To examine information collected from the 2002 Health and Diet Survey regarding the use dietary supplements and self-reported health problems that the survey participants believed were related to dietary supplements. METHODS: The US Food and Drug Administration sponsors a Health and Diet Survey to track trends of consumer awareness, attitudes, and practices related to health and diet issues. By telephone, the 2002 Health and Diet Survey staff interviewed English-speaking noninstitutionalized adults aged 18 years or older in households in the 50 states and District of Columbia. Survey respondents were queried as to whether or not they had taken a dietary supplement during the past year and if they had experienced any health problem that they attributed to supplement use. RESULTS: Seventy-three percent of US noninstitutionalized adults aged 18 years or older who spoke English and resided in households with telephones used a dietary supplement in the previous 12 months and 4% of them had experienced an adverse event that they believed might be related to dietary supplement use. Eighty-five percent of supplement users reported taking multivitamins/multiminerals and 13.3% of adverse events reported were attributed to multivitamins/multiminerals. A higher proportion of supplement users with adverse events than users without adverse events were concurrently taking supplements and prescription drugs or were taking supplements instead of prescription drug to treat or prevent a health condition. CONCLUSIONS: This self-reported data describes the prevalence of supplement use and related adverse events. Multivitamins/multiminerals accounted for much of the supplements use and was attributed to a little more than 10% of the adverse events reported. Food and nutrition-professionals and other health care professionals should take special care to learn about their patients' use of these products.

A case-control study of the epidemiology of sporadic Salmonella infection in infants.

OBJECTIVE: Rates of Salmonella infection are highest in infants, but little is known about potential sources of infection in this high-risk population. We performed a case-control study to identify dietary and environmental risk factors for sporadic salmonellosis among infants. PATIENTS AND METHODS: In 2002-2004, the Foodborne Diseases Active Surveillance Network conducted a population-based, case-control study of sporadic salmonellosis among infants <1 year of age in 8 states. Cases were identified via active laboratory-based surveillance. Healthy controls were frequency matched by age and identified through birth registries or published birth announcements. We assessed diet and environmental exposures in the 5 days before illness onset or interview. Data were analyzed by using logistic regression adjusting for age. RESULTS: The study enrolled 442 subjects and 928 controls. Compared with healthy controls, infants with Salmonella infection were less likely to have been breastfed and more likely to have had exposure to reptiles, to have ridden in a shopping cart next to meat or poultry, or to have consumed concentrated liquid infant formula during the 5-day exposure period. Travel outside the United States was associated with illness in infants 3 to 6 and >6 months of age. Attending day care with a child with diarrhea was associated with salmonellosis in infants >6 months of age. CONCLUSIONS: We identified a number of modifiable protective and risk factors for salmonellosis in infants. Attention should be directed at developing effective preventive measures for this high-risk population.