一起网络订餐引起的食源性疾病暴发事件的流行病学调查及分子溯源

Epidemiological investigation and molecular phylogenetic study of an outbreak of foodborne disease caused by online food ordering

目的对发生在本省的一起网络订餐引起的食源性疾病暴发事件开展流行病学调查,分析事件的流行病学特点,查找原因食品、致病因子和污染来源。方法通过描述性流行病方法分析病例的临床特征和流行病学特点,通过食品卫生学调查和实验室检测查找原因食品、致病因子、污染来源和污染原因。采用脉冲场凝胶电泳(PFGE)技术对不同来源的沙门菌进行溯源分析。结果此次事件共发现24例病例,病例主要临床表现为腹泻(100%)、发热(100%)、腹痛(96%),恶心(58%),呕吐(29%)。发病潜伏期中值为23 h(12.5～54 h)。所有病例均食用过某外卖生产单位加工制作的蛋苞饭。剩余食品及原料、病例及从业人员肛拭子标本、环境标本中均检出肠炎沙门菌,不同来源标本中分离到的沙门菌阳性菌株经PFGE分子分型分析具有同源性。结论结合病例临床表现、流行病学资料和实验室检测结果,证实此次事件为一起肠炎沙门菌食源性疾病暴发事件,原因食品为某外卖生产单位加工制作的蛋苞饭。

Objective To investigate the epidemiological characteristics,causative foods,pathogenic factors and source of contamination in an outbreak of foodborne disease caused by online food ordering in Shanxi Province,through an epidemiological survey.Methods Descriptive epidemiological approach was used to analyze the clinical features and epidemiological characteristics of the patients.Food hygiene investigations and laboratory tests were used to identify the causative foods,pathogenic factors,source and cause of contamination.Pulsed field gel electrophoresis(PFGE)was used for molecular phylogenetic study of Salmonella strains from different sources.Results A total of 24 cases were identified in the incident.The clinical manifestations were chiefly diarrhea(100%),fever(100%),abdomi-nal pain(96%),nausea(58%),and vomiting(29%).The median incubation period was 23 h(12.5-54 h).All victims had consumed take-away omelet rice processed by a preparation unit.Salmonella enteritidis was detected in the re-maining foods,raw materials,patients and processing staffs′anal swabs and environmental specimens.The Salmonella positive strains in samples isolated from different source were homologous by PFGE phylogenetic study.Conclusion The clinical manifestations,epidemiological data and laboratory findings confirmed that the incident was a food-borne outbreak of S.enteritidis caused by the take-away omelet rice processed by a processing unit.