昆明市滇池旅游度假区某寄宿高中一起诺如病毒暴发调查

目的查明昆明市滇池旅游度假区某寄宿高中1起聚集性呕吐事件的原因,制定有效的预防和控制措施。方法采用现场流行病学和实验室检测方法,对该高中学生出现呕吐暴发疫情进行危险因素分析。结果现场排查51人,符合病例定义者23人,其中1人为厨房员工,主要症状以呕吐并伴有腹泻为主,占48%(11/23),病例在班级及宿舍分布较散,罹患率1.83%(23/1257),仅在14岁组和15岁组有女性病例,首末例病例发病间隔5天,流行曲线提示为同源连续暴露。采集7份标本,检测3份为GⅡ型诺如病毒核酸阳性,阳性率42.86%(3/7)。结论本次疫情为诺如病毒感染引起的呕吐腹泻事件,发病期间,昆明市区内气温急剧下降,学生未做好防寒保暖措施,通过密切接触和近距离接触呕吐物,造成疫情的扩散。

Investigation on a norovirus infection outbreak in one boarding senior high school in Dianchi Scenic Region in Kunming City

Objective To investigate the reason for an aggregation diarrhea outbreak caused by norovirus infection in a boarding senior high school, so as to provide the evidence for formulating effective prevention and control measures. Methods The field epidemiological investigation and laboratory detection were performed among the cases in this school. Results A total of 51 cases were investigated on the spot, 23 cases fitted the case definitions, one of whom was the canteen employee. The main symptoms were vomiting and diarrhea, accounting for 48% (11/23). The distribution of the cases in classes and dormitories was scattered and the incidence rate was 1.83% (23/1 257). Only in the 14-year-old and 15-year-old groups there were female patients. The interval between the first and the last cases was 5 days, and the epidemic curve was supposed to be homologous continuously exposed. Three norovirus samples were positive for GⅡ norovirus nucleic acid among seven samples, constituting 42. 86% (3/7). Conclusion This is a case of vomiting and diarrhea caused by norovirus infection. During the outbreak, the temperature in Kunming City dropped sharply, and the students failed to take measures to prevent cold and keep warm. The intimate contact and close contact with vomitus might be the risk factors of this outbreak.