目的 调查分析一起农村自来水水污染事件的原因,为突发水污染事件处置提供参考。方法 采用回顾性研究方法对BY镇居民进行感染性腹泻流行病学调查,对BY镇自来水厂开展环境卫生学调查,采用细菌培养、RT-PCR方法对患者肛拭子、粪便及BY镇自来水厂水源水、出厂水以及末梢水等相关水样进行肠道病原检测。结果 2020年8月17—28日,BY镇累计出现感染性腹泻患者598例,其中128例患者进行了病原检查,107例患者生物样本检测出志贺菌,阳性率83.59%。病例主要集中在8月19—23日,20日达到峰值,临床以腹痛、腹泻、发热症状为主。各年龄段均有发病,以14岁以下儿童居多(占55.9%)。病例地区分布与某水厂供水范围一致,BY镇各村均有病例出现,BY街道罹患率最高(5.0%)。水源水检测为IV类水质,达不到饮用水水源标准,水厂清水池中培养出志贺菌。结论 本次事件是由志贺菌污染生活饮用水导致的暴发疫情。

Objective To investigate and analyze the causes of a drinking water pollution incident in a township,so as to provide reference for the disposal of sudden water pollution incident. Methods A retrospective study was conducted to investigate the epidemiology of infectious diarrhea among residents of BY Town,and an environmental hygiene investigation was carried out on the waterworks of BY Town.Bacterial culture and RT-PCR methods were used to detect intestinal pathogens in patients' anal swabs,feces,and related water samples such as the raw water,treated water,and peripheral water of BY town's waterworks. Results From August 17 to 28,2020,BY Town experienced a total of 598 cases of infectious diarrhea,of which 128 patients were tested for pathogens.Shigella was detected in 107 patients with a positive rate of 83.59%.The cases were mainly concentrated in August 19 to 23,and peaked on August 20.The clinical symptoms were mainly abdominal pain,diarrhea and fever.Most of them were under 14 years old (accounting for 55.9%).The distribution of the cases was consistent with the water supply scope of a waterworks.Cases were found in all villages of BY Town,with the highest incidence in BY street (accounting for 5.0%).The water quality of the raw water was detected as class IV,which did not meet the drinking water source standard.Shigella was cultivated in the clean water pool of the waterworks. Conclusion This incident is an outbreak of the epidemic caused by Shigella contamination of drinking water.