一起检出多种致病菌的食源性疾病暴发调查与病因探讨

An investigation and discussion on an outbreak caused by multiple foodborne pathogens

目的对一起食源性疾病暴发中检出多种致病菌的情况进行探讨分析,找出真正的致病菌,为研究类似的食源性疾病病因提供参考。方法利用标准化的食源性疾病暴发个案调查表收集信息,采用描述流行病学描述事件特征、分析流行病学探索危险食物,采集的样本按照GB 4789系列食品卫生微生物学检验标准进行可疑致病菌分离培养,分离出的副溶血性弧菌按照DNA指纹图谱分析方法进行基因分型。结果搜索到共同进餐者30例,失访5例,其中符合病例定义的17例,罹患率为56.67%(17/30);临床表现主要以腹泻(17/17)、腹痛(16/17)为主,腹痛以上腹部疼痛为主(10/16);发病潜伏期为11~25 h;回顾性队列研究未发现可疑食物。在病例肛拭子中检出9株副溶血性弧菌,8株奇异变形杆菌,1株沙门菌混合副溶血性弧菌,1株空肠弯曲菌;在从业人员肛拭子中检出1株奇异变形杆菌;在环境涂抹拭子中检出1株副溶血性弧菌,4株奇异变形杆菌;在食品样品中检出1株副溶血性弧菌,4株奇异变形杆菌。对从9例病例检测到的副溶血性弧菌进行脉冲场凝胶电泳分子分型,结果发现其遗传相似性达97%以上。结论综合现场流行病学调查和食品卫生学以及实验室检测结果分析,排除其他致病因子引起该起事件暴发的可能,认为这是一起由副溶血性弧菌引起的食源性疾病暴发事件。

Objective To investigate and analyze a food poisoning with multiple pathogens including Vibrio parahaemolyticus（ VP） and Proteus mirabilis. Methods Standardized questionnaire for food poisoning was used to collect information,descriptive epidemiology was used to detect the risk factors. The pathogens were isolated from the samples,enrichment was performed according to National Standard of Microbiological Examination of Food Hygiene,and the isolated VP were further identified by DNA fingerprint. Results Thirty diners were found and 5 lost,seventeen of which were consistent with case definition,and the incident rate was 56. 67%（ 17 /30）. Diarrhea,abdominal pain especially epigastralgia was the main clinical symptom. Incubation period of the cases was 11-25 hours. No risk factor was found by cohort study. Nineteen strains were isolated from patients,of which were VP（ 9）,Proteus mirabilis（ 8）,Salmonellae（ 1）and C. jejuni（ 1）. A strain of Proteus mirabilis was found in food handlers. A strain of VP and 4 strains of Proteus mirabilis were isolated from environmental swabs,the same situation was detected in food samples. Nine strains of VP isolated from patients were identified as the same genotype by molecular typing techniques,which genetic similarity reached more than97%. Conclusion Considering both the investigation of field epidemiology,food hygiene and experimental results,it was a foodborne disease outbreak caused by VP,and other pathogenic factors was excluded.