A foodborne gastroenteritis outbreak caused by Norovirus GII. 2

Abstract

Objective To investigate the suspected Norovirus outbreak in a primary school reported by a hospital on November 2nd, 2017. Investigations were conducted to confirm the causative agent and mode of transmission. Methods A case-control study was performed to test the hypothesis that the canteen food in the school was the suspected vehicle. Stool samples were collected from 14 suspected cases and 11 kitchen staffs to test Norovirus. Results A total of 159 cases were identified, all of which were students, and the attack rate was 11.5%(159/1 378). Signs and symptoms included vomiting(95.0%, 151/159), nausea(84.3%, 134/159) and abdominal pain(81.8%, 130/159). Resultsof the analysis revealed that consumption of fried chicken fillet offered on 1st Nov, 2017(OR=3.2, 95% CI: 1.41-7.22) was associated with illness. All 14 cases and 2 of 11 kitchen staffs were positive for Norovirus GⅡ. 2, and had 100% genetic homology. Conclusion This outbreak was caused by Norovirus GⅡ. 2 contaminated fried chicken fillet.

Keywords

• norovirus
• asymptomatic infection
• foodborne disease
• case-control
• outbreak