Estimating the burden of acute gastroenteritis, foodborne disease, and pathogens commonly transmitted by food: an international review.

The burden of foodborne disease is not well defined in many countries or regions or on a global level. The World Health Organization (WHO), in conjunction with other national public health agencies, is coordinating a number of international activities designed to assist countries in the strengthening of disease surveillance and to determine the burden of acute gastroenteritis. These data can then be used to estimate the following situations: (1) the burden associated with acute gastroenteritis of foodborne origin, (2) the burden caused by specific pathogens commonly transmitted by food, and (3) the burden caused by specific foods or food groups. Many of the scientists collaborating with the WHO on these activities have been involved in quantifying the burden of acute gastroenteritis on a national basis. This article reviews these key national studies and the international efforts that are providing the necessary information and technical resources to derive national, regional, and global burden of disease estimates.

Prevalence of diarrhoea in the community in Australia, Canada, Ireland, and the United States.

BACKGROUND: Studies in several countries have estimated the prevalence of diarrhoea in the community. However, the use of different study designs and varying case definitions has made international comparisons difficult. METHODS: Similar cross-sectional telephone surveys were conducted in Australia, Canada, Ireland (including Northern Ireland), and the United States over 12 month periods between 2000 and 2002. Each survey asked about diarrhoea in the four weeks before the interview. For this comparative analysis, uniform definitions were used. RESULTS: Questionnaires were completed for 6087 respondents in Australia, 3496 in Canada, 9903 in Ireland, and 14,647 in the United States. In the four weeks prior to interview, at least one episode of diarrhoea was reported by 7.6% of respondents in Canada, 7.6% in the United States, 6.4% in Australia, and 3.4% in Ireland. The prevalence of diarrhoea was consistently higher in females. In all countries, the prevalence of diarrhoea was highest in children <5 years and lowest in persons > or =65 years of age. When diarrhoea and vomiting was considered, the prevalence was almost identical in the four studies (range: 2.0-2.6%). Despite different health care structures, a similar proportion of respondents sought medical care (approximately one in five). Antibiotic usage for the treatment of diarrhoea was reported by 8.3% of respondents in the United States, 5.6% in Ireland, 3.8% in Canada, and 3.6% in Australia. CONCLUSIONS: Diarrhoea is a common illness among persons in the community in Australia, Canada, Ireland, and the United States. With similar methodologies and a standard case definition, age and sex patterns and health care seeking behaviour were remarkably consistent between countries.

Guillain-Barré syndrome following influenza vaccination.

CONTEXT: An unexplained increase in the risk of Guillain-Barre syndrome (GBS) occurred among recipients of the swine influenza vaccine in 1976-1977. Guillain-Barre syndrome remains the most frequent neurological condition reported after influenza vaccination to the Vaccine Adverse Events Reporting System (VAERS) since its inception in 1990. OBJECTIVE: To evaluate trends of reports to VAERS of GBS following influenza vaccination in adults. DESIGN, SETTING, AND PARTICIPANTS: VAERS is the US national spontaneous reporting system for adverse events following vaccination. Reports of GBS in persons 18 years or older following influenza vaccination were evaluated for each influenza season from July 1, 1990, through June 30, 2003. The number of people vaccinated was estimated from the National Health Interview Survey and US census data. Beginning in 1994, active follow-up was conducted to verify GBS diagnosis and obtain other clinical details. MAIN OUTCOME MEASURE: Reporting rates of GBS following influenza vaccination over time. RESULTS: From July 1990 through June 2003, VAERS received 501 reports of GBS following influenza vaccination in adults. The median onset interval (13 days) was longer than that of non-GBS reports of adverse events after influenza vaccine (1 day) (P<.001). The annual reporting rate decreased 4-fold from a high of 0.17 per 100,000 vaccinees in 1993-1994 to 0.04 in 2002-2003 (P<.001). A GBS diagnosis was confirmed in 82% of reports. Preceding illness within 4 weeks of vaccination was identified in 24% of reported cases. CONCLUSIONS: From 1990 to 2003, VAERS reporting rates of GBS after influenza vaccination decreased. The long onset interval and low prevalence of other preexisting illnesses are consistent with a possible causal association between GBS and influenza vaccine. These findings require additional research, which can lead to a fuller understanding of the causes of GBS and its possible relationship with influenza vaccine.

Factors associated with seeking medical care and submitting a stool sample in estimating the burden of foodborne illness.

Laboratory-based surveillance is a foundation for public health and is essential for determining the incidence of most foodborne diseases caused by bacterial pathogens; however, reported cases represent a subset of infections in the community. To identify the factors associated with seeking medical care and submitting a stool specimen among persons with acute diarrheal illness, we used multivariate logistic regression to analyze data from two 12- month population-based telephone surveys conducted in the Foodborne Diseases Active Surveillance Network (FoodNet) from 2000 to 2003. Of 31,082 persons interviewed, 5% reported an acute diarrheal illness in the four weeks prior to the interview; of these, 20% sought medical care. On multivariate analysis, among persons with an acute diarrheal illness, factors associated with seeking medical care included: male sex; age <5 or >or=65 years; household income <25,000 dollars; having health insurance; diarrhea duration >or=3 days; having bloody diarrhea, fever, vomiting, sore throat, or cough. Of those seeking medical care, 19% provided a stool sample. Bloody diarrhea (odds ratio [OR] 3.35; 95% confidence interval [CI] 1.18-9.51) and diarrhea duration >or=3 days (OR 3.81; 95% CI: 1.50-9.69) were the most important factors associated with submission of a stool specimen. Cases of acute diarrheal illness ascertained through laboratory-based public health surveillance are likely to differ systematically from unreported cases and likely over-represent those with bloody diarrhea and longer diarrhea duration.