A hospital food-borne outbreak of diarrhea caused by Bacillus cereus: clinical, epidemiologic, and microbiologic studies.

An outbreak of diarrhea involving 28 patients occurred in two wards of a chronic disease hospital. The illness was characterized by abdominal cramps and watery diarrhea without vomiting or fever. An epidemiologic investigation suggested food-borne intoxication and incriminated turkey loaf served at the preceding evening meal as the source of the outbreak. Bacillus cereus was isolated both from the stool of all 14 symptomatic patients who were cultured and from turkey loaf. No other enteropathogens were found. The isolate of B. cereus was shown to elaborate an enterotoxin that caused fluid secretion in assays in the rabbit ileal loop and suckling mice and that also caused a positive response in the Y-1 adrenal cell assay. B. cereus is an enteropathogen that should be sought in outbreaks of food-related gastroenteritis. This organism affects the gastrointestinal tract probably by the elaboration of enterotoxins.