一起学校水污染引起的其他感染性腹泻暴发疫情调查

Investigation of an outbreak of other infectious diarrhea caused by water pollution in a school

目的调查郑州市某高校一起腹泻暴发疫情的原因,查明传播途径及危险因素,为有效进行疫情防控提供科学依据。方法2022年10月,对饮水、食堂、学生宿舍等开展卫生学调查,采集病例和厨师肛拭子、留样食品、饮用水和环境等样本进行诺如病毒、致泻性大肠杆菌等肠道病原检测,采用描述流行病学方法分析疫情流行特征和相关因素。结果2022年10月5日—11日,疫情共报告病例171例,罹患率为0.86%(171/19860)。临床症状主要为腹泻(97.66%)和呕吐(43.86%)。病例均为学生,男女比例为0.69∶1,无宿舍聚集性。实验室检测发现26份病例肛拭子、7份学生宿舍环境样本诺如病毒、致泻性大肠杆菌等肠道病原阳性,23份水样卫生学指标严重超标,阳性样本除4份病例样本外均来自1号直饮水站供水区域。结论这是一起因直饮水站供水系统污染引起的,以诺如病毒和致泻大肠杆菌混合感染为主的一起其他感染性腹泻疫情,应加强对学校饮用水的管理及监督,确保学生用水安全。

Objective To investigate the reason of an outbreak of diarrhea in a university in Zhengzhou,and identify the transmission route and risk factors so as to provide scientific basis for effective epidemic prevention and control.Methods In October 2022,hygienic investigation was carried out in drinking water,canteens and student dormitories.Samples of cases and cooks′anal swabs,food,drinking water and environment were collected for detection of intestinal pathogens such as norovirus,diarrheal Escherichia coli and so on.Descriptive epidemiological methods were used to analyze the epidemiological characteristics and related factors of the outbreak.Results From October 5 to 11,2022,a total of 171 cases were reported in this outbreak,with an attack rate of 0.86%(171/19860).The main clinical symptoms were diarrhea(97.66%)and vomiting(43.86%).All cases were students with a male to female ratio of 0.69∶1,and there was no dormitory clustering.Laboratory tests found that26 samples of anal swabs and 7 samples of student dormitory environment were positive for intestinal pathogens such as norovirus and diarrheal Escherichia coli.;the hygienic index of 23 water samples exceeded the standard seriously,and the positive samples were all from the water supply area of No.1 direct drinking water station except for four samples from cases.Conclusions This is an outbreak of other infectious diarrhea caused by the contamination of the water supply system of the direct drinking water station,mainly featuring a mixed infection of norovirus and diarrheal E.coli.The management and supervision of drinking water in schools should be strengthened to ensure the safety of water for students.