An outbreak of food poisoning in Tamil Nadu associated with Yersinia enterocolitica.

An outbreak of food poisoning in a Tamil Nadu village, affecting 25 of 48 individuals who participated in a feast, was investigated. The risk of developing illness was associated with consumption of buttermilk (relative risk 3.8). None of the food items consumed during the feast was available for analysis. Toxin-producing Y. enterocolitica (serotype 3, biotype 4) was grown from 1 of 11 stool samples from affected individuals, as well as from a water sample from the source used to dilute the buttermilk. High titres of antibody of Yersinia were detected in 2 of 12 patients but in neither of the two groups of controls. Toxin production was noted in buttermilk incubated for 6 h with Y. enterocolitica. This is the first report from India of a food poisoning outbreak associated with this organism.