Epidemiological characteristics of norovirus outbreak at schools in Hunan province during 2013-2016

Objective To investigate the epidemiological characteristics of norovirus (NoVs) outbreak at schools of Hunan province.Methods Descriptive epidemiological method was utilized to analyze the data of NoVs outbreak at schools in Hunan province during 2013-2016.Results During 2013 to 2016,17 NoVs outbreaks were reported in schools,with a total incidence rate of 5.64%,which occurred in autumn and winter.The outbreaks mainly occurred at primary schools and kindergartens (11/17,64.71%).The median report time was 2.00 d.The peak viral shedding occurred with a median period of 1.00 d after infection,and the median duration from infection to outbreak was 6.25 days.The main symptoms of NoVs outbreak included vomitting,diarrhea and abdominal pain.Genotype was given priority to with G Ⅱ (9,52.94%).Waterborne (5.53%) and food-borne (7.70%) contact were the main transmission mode,compared with that of person-to-person contact (3.83%)(x2=20.02,71.19,P<0.01).Rural schools was in higher risk of NoVs outbreak than urban schools(x2 =280.497,P<0.01).Conclusion Most of the Norovirus outbreaks at schools in Hunan province occurred in primary schools and kindergartens.Primary prevention measures should be taken to prevent norovirus outbreaks in school and childcare settings with priority placing upon rural areas.