Epidemic<i>Yersinia enterocolitica</i>Infection Due to Contaminated Chocolate Milk

TLDR

In 1976, a chocolate‑milk outbreak caused Yersinia enterocolitica infection, hospitalizing 36 children, 16 of whom required appendectomies. The contamination likely occurred when chocolate syrup was hand‑mixed with pasteurized milk at the dairy. Serotype 0:8 Yersinia enterocolitica was isolated from the milk and identified in 38 patients, with most showing high agglutinin titers and a strong association with chocolate milk consumed in school cafeterias.

Abstract

In September and October, 1976, an outbreak of illness due to chocolate milk contaminated with Yersinia enterocolitica resulted in hospitalization of 36 children, 16 of whom had appendectomies. Infection with Y. enterocolitica serotype 0:8 was demonstrated in 38 ill persons. Sixty-one per cent of the persons who were infected had a titer greater than 1:160 OH agglutinins to serotype 8 yersinia, whereas 48 per cent of the hospitalized children had a fourfold change in agglutinin titer. An epidemiologic investigation demonstrated that illness was associated with drinking of chocolate milk purchased in school cafeterias, and Y. enterocolitica 0:8 was subsequently isolated from the milk. The investigation suggested that the bacterium was introduced at the dairy during the mixing by hand of chocolate syrup with previously pasteurized milk.