一起游学团诺如病毒感染性腹泻暴发疫情的流行病学调查

Epidemiological survey of diarrhea outbreak caused by norovirus in a study tour

目的 探索游学团诺如病毒胃肠炎暴发疫情流行病学特征,采取针对性管控措施,避免疫情扩散及类似事件的再次发生。方法 依照病例定义开展病例搜索,利用问卷星开展个案调查及病例对照研究,采集呕吐物、肛拭子及食品等样本进行实时荧光定量PCR检测确定病原。结果 该起疫情共发现135例疑似病例,发病时间集中,临床表现以恶心、呕吐、腹痛、腹泻为主。27份标本(20份人员生物样本,3份水样本及4份环境涂抹样)诺如病毒核酸检测阳性。所有患者均有2020年11月17日午餐在某酒店共同聚餐史,共同就餐点餐饮店有3名从业人员肛拭子诺如病毒核酸阳性,使用被污染的露天井水清洗菜品及餐具可能是导致本次诺如病毒感染性腹泻暴发疫情的主要原因。结论 本次事件是一起因共同饮食暴露由诺如病毒引起的感染性腹泻暴发疫情。

Objective To explore the epidemiological characteristics of norovirus gastroenteritis outbreak in a study group,and take targeted control measures to avoid the spread of the epidemic and the recurrence of similar events.Methods We carried out case search according to the case definition, carried out case investigation and case-control study by using questionnaire stars, and collected vomitus, anal swabs and food samples for real-time fluorescent quantitative PCR detection to determine the pathogen.Results A total of 135 suspected cases were found in the epidemic and the onset time was concentrated, while the clinical manifestations were mainly nausea, vomiting, abdominal pain and diarrhea. 27 samples(20 samples of human biological samples, 3 water samples and 4 environmental smear samples) tested positive for nucleic acid of norovirus. All the suspected cases had a comma experience of eating together in a restaurant for lunch on November 17, and the norovirus nucleic acid test results of three employees in the restaurant were positive. Using contaminated outdoor well water to clean dishes and tableware may be the main cause of the diarrhea outbreak caused by norovirus.Conclusion This incident is an outbreak of infectious diarrhea caused by norovirus due to common dietary exposure.