一起学校诺如病毒感染暴发疫情的调查

Investigation on an outbreak of school norovirus infection

目的调查一起中学胃肠炎暴发疫情,明确病原和传播途径。方法于2017年2月13—21日搜索LC中学783名学生中的病例并采用现场流行病学调查、个案调查法了解学校发病情况和可疑传播途径,采集饮用水、食物和肛拭子等样本进行病原体检测。结果该校发现病例63例,罹患率为8.05%。63例患者临床症状以呕吐(87.30%)、恶心(76.19%)、腹痛(74.60%)为主。1号宿舍楼罹患率高于其余宿舍楼(χ^2=10.75,P<0.05),住校生罹患率高于走读生(χ^2=5.38,P<0.05),患者肛拭子及学校自备水中均检出GⅡ型诺如病毒核酸阳性,食物中未检出。结论本次疫情由GⅡ型诺如病毒感染引起,可能通过污染的自备水传播。

Objective To investigate an outbreak of gastroenteritis in a middle school, so as to find the patho-genic factors and transmission routes. Methods The cases among 783 students in LC school during February 13th and February 21st 2017 were searched to investigate the incidence and suspected transmission route by field epidemio-logical investigation and case investigation. Drinking water, food and anal swabs were collected and detected. Results A total of 63 cases were reposed in the school with the incidence rate of 8.05%. The main clinical symptoms were vom-iting (87.30%), nausea (76.19%), and abdominal pain (74.60%). The No. 1 dormitory had a higher incidence rate than the rest ones (χ^2=10.75, P<0.05). The residential students had a higher incidence rate than day students (χ^2=5.38, P<0.05). Anal swabs from patients and school self-contained water were positive for GⅡ-type norovirus. No vi-rus was detected in food. Conclusions This outbreak is caused by GⅡ norovirus infection. The possible source of in-fection is self-provided water pollution.