Investigation of A Foodborne Outbreak in High School, Tainan City, Taiwan, 2017

Investigation of A Foodborne Outbreak in High School, Tainan City, Taiwan, 2017

In September 2017, Taiwan Centers for Disease Control was notified of a foodborne outbreak in a girls' senior high school in Tainan City. The outbreak caused 289 students developing diarrhea. We conducted a cohort study using questionnaires to clarify the magnitude of outbreak, infection source, and the etiologic agent. We identified 169 cases and the attack rate was 20%. The major symptoms included diarrhea and abdominal pain. The results indicated that many food items in dinners on September 4 and 5 were associated with the illness. We speculated that dinner food handlers, environment of kitchen or cafeteria might be the infection source. However, microbiological examination and epidemiological investigation did not identify possible etiologic agents. Many food handlers were tested positive for different foodborne pathogens such as norovirus, rotavirus, Staphylococcus aureus and Bacillus cereus. We also found violations of regulations regarding leftover retaining and sampling process. We recommended that food handlers should ensure their personal hygiene. Furthermore, school should follow the regulations for leftover retaining and sampling process.