一起疑似奇异变形杆菌引起的食源性疾病调查分析

Investigation and analysis of cases of foodborne disease caused by suspicious Proteus mirabilis

目的调查1起食源性疾病事件的发生原因,为预防类似事件发生提供参考依据。方法采用现场流行病学和病例对照研究方法,制定病例定义,开展病例搜索,结合病例临床、就餐史等信息查找可疑餐次,采集可疑食物、病例和环境等样本进行实验室检测。结果共发现20例病例,均为广东省珠海市某公司员工,罹患率为18.7%(20/107)。临床表现主要为腹痛(占100%,20/20)和腹泻(占95%,19/20)。流行曲线显示点源暴露模式。现场流行病学调查结果显示,9月6日中餐为可疑餐次(RR=8.63,95%CI:1.04~71.53),病例对照分析结果显示,9月6日中餐的脆皮鸭为可疑食物(OR=5.11,95%CI:1.50~17.37),剂量-反应关系结果显示进食脆皮鸭的量越多,发病的风险越高(P<0.05)。实验室从3份病例肛拭子和1份留样脆皮鸭中检出占优势、同生化型的奇异变形杆菌,检出率为10.8%(4/37)。结论在实验室未能开展PFGE等分子分型方法时,现场流行病学调查对于区分奇异变形杆菌的致腹泻菌株和肠道正常携带菌株仍有一定的指导意义。建议将奇异变形杆菌的病原学监测纳入食源性疾病监测的国家分子分型网络体系Pulse Net China。

Objective To investigate causes of cases of foodborne disease and provide reference evidence for preventing the occurrence and handling similar incidents. Methods A field epidemiological study method and a case-control study method were conducted. Case definitions were defined and case sear- ches were performed. Suspected meals were searched according to clinical case data and meal history infor- mation, and samples of suspicious foods, cases and environment were collected for laboratory testing. Results A total of 20 cases were found, all of whom were employees of a company in Zhuhai City, Guang- dong Province, with an attack rate of 18.7% （20/107）. Clinical manifestations included abdominal pain （100% , 20/20） and diarrhea （95% , 19/20）. Epidemic chart showed a point-source exposure patterns. The field epidemiologieal survey results showed that lunch food on September 6 was a suspicious meal （RR = 8.63, 95% CI： 1.04 -71.53）. The case-control analysis results showed that ＂crispy roasted duck＂ was a suspicious food （OR = 5.11, 95% CI： 1.50 - 17.37）. The results of dose-response relationship showed that the more the intake amount of crispy roasted duck, the higher the risk of onset （x2trend= 5.19 , P 〈 0. 05 ）. Dominant and isobiochemical Proteus mirabilis was detected from 3 cases and 1 preserved specimen of crispy roasted duck, with a detection rate of 10. 8% （4/37）. Conclusion When the pulsed field gel e- lectrophoresis and other molecular typing methods were unavailable for the laboratory, the field epidemio- logical investigation for the differentiation of Proteus mirabilis diarrhea strains and the normal intestinal tract carrier strains still has some guiding significance. It is recommended to include pathogen monitoring of Pro-teus mirabilis into PulseNet China, a national molecular classification network system for foodborne disease surveillance.