A Foodborne Outbreak Associated with School Lunch Program in a School - New Taipei City, Taiwan, November 2016

On November 4, 2016, Taiwan CDC was notified of a foodborne outbreak in two schools whose lunch served by the same caterer and 361 of 1,686 students who consumed school lunch were ill. We conducted a case-control study among 9th grade students and teachers in School A and defined cases as people who ate lunch on November 1, 2, or 3 and developed diarrhea or abdominal pain within 72 hours after consuming. We performed univariate analysis to identify associated food items. Stools from ill students, food handlers, and food samples were collected to test for common foodborne pathogens. Food distribution process was reviewed. Fifty-four cases consumed lunch on November 3 were sick and median incubation period was 10 hours. Compared with 125 controls, consuming pork slices with mashed garlic (OR 17.58, 95% CI 1.04-297.80) and grapes (OR 2.13, 95% CI 1.06-4.31) were associated with illness, but only the former was served to both schools. Specimens of leftovers and stool from one food handler were tested positive for Bacillus cereus, but specimens from ill students were culture-negative. It took at least 2 hours from foods cooked before to be served. We recommend school caterer should review food distribution process to ensure food safety.