Investigation of A Norovirus Outbreak in A Training Institute-New Taipei City, 2016

Investigation of A Norovirus Outbreak in A Training Institute-New Taipei City, 2016

On April 27, 2016, the Department of Health of New Taipei City (DHNTC) was notified of diarrhea clusters in a training institute since late March. On April 29, the Taipei regional center of Centers for Disease Control along with DHNTC conducted an investigation, including a cohort study among 250 trainees with semi-structural questionnaires. The laboratory results indicated norovirus was the etiological pathogen. Besides, the water specimens from well water (water source), tap water from one toilet/hand wash sink and warm water from one drinking fountain were positive for norovirus, the genotype was the same as those from ill trainees. After refining the case definition, we found the risk of illness was significantly associated with consuming warm water from unspecific drinking fountain (RR 3.12, p ＜ 0.05). On May 19, we conducted a second survey in order to find out the association between the specific drinking fountain and illness but none reached statistical significance. After all, we assumed contaminated well water most likely caused the outbreak, and norovirus might be transmitted by contacting or accidentally drinking the contaminated water. This investigation provides a reference to prevent diarrhea outbreak in similar institutions.