Outbreaks of norovirus infections in Zhejiang province during 2004-2014 / 中华临床感染病杂志

ABSTRACT

Objective To review the epidemiologic features of norovirus infection outbreaks in Zhejiang province during 2004-2014.Methods Epidemiological data of norovirus infection outbreaks in Zhejiang province from January 2004 to February 2014 were collected from the Emergency Public Reporting System in Zhejiang Provincial CDC.The distribution of time,area,population,route of transmission and genotype of norovirus were analyzed.Results There were 16 outbreaks of norovirus infections with 2 037 cases during 2004-2014 in Zhejiang province.Eleven outbreaks occurred during February and April,and 13 outbreaks occurred in schools.The outbreaks in schools mainly involved students aged 15-20 years,while other outbreaks took place mainly in the young and middle-aged population.The sex ratio of male to female was 1.05 ∶ 1.Among 16 outbreaks,10 were induced by norovirus G Ⅱ infections,3 were induced by norovirus G Ⅰ infections and 3 were induced by norovirus G Ⅰ and G Ⅱ infections.Fourteen outbreaks were caused by water pollution.Conclusion Outbreak of norovirus infection usually occurs in schools during winter and spring in Zhejiang province,and the epidemic of disease is mainly associated with polluted water.