An outbreak of Yersinia enterocolitica O : 8 infections associated with pasteurized milk

In October 1995, an outbreak of Yersinia enterocolitica O:8 infections occu rred in the Upper Valley of Vermont and New Hampshire. Ten patients were id entified, median age 9 years (range, 6 months-44 years). Three patients wer e hospitalized; 1 underwent an appendectomy. Consumption of bottled pasteur ized milk from a local dairy was associated with illness (matched odds rati o undefined; lower 95% confidence interval, 1,9), No deficiencies in pasteu rization procedures or equipment were detected. Y. enterocolitica O:8 was i solated from 1 raw-milk sample and from a fecal sample from 1 dairy pig. Th e route of contamination was not determined; this outbreak likely resulted from postpasteurization contamination of milk. Dairy pigs were the most lik ely source of contamination, Milli bottles were likely contaminated by rins ing with untreated well water prior to filling or by other environmental ro utes. Educating dairy owners about Y. enterocolitica and postpasteurization contamination is necessary to prevent further outbreaks.