Detection of heat-labile enterotoxin-like activity in stools of patients with cholera and Escherichia coli diarrhea.

The Y1 adrenal cell tissue culture assay was used to detect heat-labile enterotoxin-like activity in the stools of 14 of 74 patients with diarrhea. A positive effect of the stool on the adrenal cells was heat-labile and neutralized by cholera antitoxin. Enterotoxin-like activity was detected in the stools of 10 of 30 patients with cholera and in those of 2 of 4 from whom heat-labile Escherichia coli were isolated. None of the stools from nine individuals with Vibrio parahaemolyticus, Salmonella, or Shigella infections were positive. Two of 31 individuals from whom no pathogens were isolated had detectable toxin-like activity in their stools. The Y1 adrenal cell assay provides a rapid method of diagnosing heat-labile enterotoxigenic diarrhea and could be an adjunct in epidemiological studies of gastroenteritis.