一起不明致病因子引起食源性疾患的调查报告

Investigation report on one case of food poisoning caused by unknown pathogenic factor

目的调查北京市平谷区某小学一起食源性疾患的感染病源和发病的危险因素。方法进行现场卫生学和流行病学调查,采集样本进行实验室检测。结果流行曲线提示为点源暴发模式,病人的症状、体征与发病潜伏期及发病季节与蜡样芽胞杆菌引起的食源性疾患相似。经回顾性队列研究显示,学校食堂晚餐的粉条豆腐包子的相对危险度较高,为可疑食品(R^2=5.21,95%CI:1.69~16.08),其他食物与发病无统计学关联。晚餐粉条豆腐包子蜡样芽胞杆菌为7.0×10~4cfu/g,绿豆汤蜡样芽胞杆菌为4.5×10~4cfu/ml。结论本次事件是不明致病因子污染晚餐粉条豆腐包子引起学生集体发病的食源性疾患。考虑蜡样芽孢杆菌致病的可能性大。

Objective Through the epidemiological investigation of food poisoning in Pinggu XX primary school, to discuss the etiology of epidemic and prevalence factors. Methods Used on - site hygienic investigation and epidemiological investigation, collected samples to conduct laboratory test. Results Time distribution showed point - source outbreak. The clinical manifesta- tion, asymptomatic, incubation period and season accorded with the disease caused by bacillus cereus. Retrospective cohort study showed that the relative risk of steamed vermicelli tofu stuffed bun is in high level（R2 = 5. 21, 95% CI： 1.69 -16. 08）, and there is no statistical correlation between other food and this case. The bacillus cereus＇ s count in steamed vermicelli tofu stuffed bun was 7.0 × 104 cfu/g while mung bean soup was 4. 5 × 104 cfu/ml. Conclusion The conclusion was determined as an unknown cause case of food poisoning due to the steamed vermicelli tofu stuffed bun. Bacillus cereus is the suspicious pathogenic factor.