1起学校诺如病毒感染性腹泻暴发疫情的调查

Investigation and analysis on an outbreak of infectious diarrhea caused by norovirus in a school

目的通过对1起该学校诺如病毒感染性腹泻暴发疫情流行病学调查,查明疫情危险因素,提出有效的控制建议。方法对病例进行描述性流行病学分析,采用回顾性队列研究的方法,探查病例危险因素。结果截止3月12日累计报告病例21例,学生罹患率为42.00%(21/50),9份样品中均检出诺如病毒核酸阳性,病例阳性检出率为9/9。可疑危险因素为靠近大巴就坐(RR=2.91,95%CI:1.37～6.20)和分享食物(RR=2.06,95%CI:1.12～3.77)。结论该疫情为1起春游后暴发诺如病毒感染疫情,传播途径为人传人。

Objective To take an epidemiological investigation for norovirus infectious diarrhea in a school,so as to find out the risk factors and provide the effective measures to prevent and control the events. Methods Descriptive epidemiological analysis was carried out in the retrospective cohort study to explore risk factors. Results A total of 21 cases were reported ending 12 th March,and the attack rate among students was 42.00%(21/50).Norovirus nucleic acid was all positive of the total 9 samples.The suspicious risk factors were sitting close to the bus aisle(RR =2.91,95%CI :1.37-6.20)and sharing food(RR =2.06,95%CI :1.12-3.77). Conclusion The outbreak of infectious diarrhea caused by norovirus infection occurs after the spring outing.The risk factors of norovirus infection are sitting near the bus aisle and sharing food with cases Jiang or Yan.The route of transmission is human-to-human,which basically excludes the possibility through food or water.