Bacterial Enteric Pathogens in Uncooked Foods in Thai Markets

In developing countries, the morbidity and mortality rates of gastrointestinal tract infections from food borne bacteria have been difficult to establish. Most studies have only been able to gather data prospectively from isolated geographic sources, rather than from large point-source epidemics. This study investigates the types of bacterial enteric pathogens found in food that was collected in a community in Western Thailand, where sporadic cases of hemolytic uremia syndrome and cholera have been reported. Samples of six different uncooked foods were collected from markets in two villages and in the hills in an area near Bangkok and were tested at a district hospital laboratory within 2 hours of collection. From the 820 food samples collected, enteric pathogens were isolated from approximately 12%. These included nontyphoidal salmonella; Vibrio parahemolyticus; attaching and effacing Escherichia coli of nonenteropathogenic E. coli serogroups; Campylobacter jejuni; enterotoxigenic E. coli; Shigella; and V. cholerae. Travelers in developing countries should be made aware by diarrheal disease programs that food obtained in markets may contain bacterial enteric pathogens and, therefore, the hygienic preparation of such foods is important in the prevention of gastrointestinal disease.