Shen Ji-chuan, Lin Jun-fen, Gao Jie, Yao Wen-ting, Wen Dong, Liu Guang-tao, Han Jian-kang, Ma Hui-lai, Zhang Li-jie, Zhu Bao-ping
Chinese Field Epidemiology Training Program, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2011 Aug;32(8):800-3.
To study a local hospital reported acute gastroenteritis in a boarding school on its source of infection, mode of transmission and risk factors of the infection.
A suspected case was defined as who had developed diarrhea (≥ 3 times/day) or vomiting among teachers or students of the school, during April 19 - 30, 2010. A confirmed case was from a probable case plus tested positive for norovirus in stool specimens by using RT-PCR. Stool specimens of cases and environmental specimens were collected for laboratory diagnosis. In a case-control study, we compared exposures to sources of bottled water, consumption of bottled water, and hygienic habits of 220 probable or confirmed cases from April 21 - 23 in the peak of the outbreak, together with another 220 controls, with frequency-matched by school grade.
20.3% of the 1536 students but none of the teachers developed the disease. 98.6% of the cases (n = 217) and 85.5% (n = 188) of the controls had drunk bottled water in the classroom (OR(M-H) = 12.3, 95%CI: 3.7 - 40.9). 47.9% (n = 104) of the cases and 41.5% (n = 78) of the controls had drunk unboiled bottled water in classroom (OR(M-H) = 3.8, 95%CI: 1.5 - 9.6). 47.9% (n = 104) of the cases and 48.4% (n = 91) of the controls had drunk bottled mixed water (boiled and unboiled) in the classroom (OR(M-H) = 2.8, 95%CI: 1.1 - 7.0). Stool specimens from 3 cases and one bottle of uncovered bottled water in classroom showed positive of having norovirus genotype II. Coliforms was cultured much higher rates than standard deviations in the bottled water. The factory making the bottled water was not licensed or having strict disinfection facilities.
Bottled spring water contaminated by norovirus was responsible for this outbreak.
研究一所寄宿学校报告的急性肠胃炎的感染源、传播方式及感染的危险因素。
疑似病例定义为2010年4月19日至30日期间该校教师或学生中出现腹泻（≥3次/天）或呕吐的人。确诊病例为疑似病例且粪便标本经逆转录聚合酶链反应检测诺如病毒呈阳性。收集病例的粪便标本和环境标本进行实验室诊断。在一项病例对照研究中，我们比较了2010年4月21日至23日疫情高峰期220例疑似或确诊病例与另外220例对照在瓶装水水源暴露情况、瓶装水饮用情况及卫生习惯，按学校年级进行频率匹配。
1536名学生中有20.3%患病，教师无人患病。98.6%的病例（n = 217）和85.5%的对照（n = 188）在教室饮用过瓶装水（比值比（M-H）= 12.3，95%可信区间：3.7 - 40.9）。47.9%的病例（n = 104）和41.5%的对照（n = 78）在教室饮用过未煮沸的瓶装水（比值比（M-H）= 3.8，95%可信区间：1.5 - 9.6）。47.9%的病例（n = 104）和48.4%的对照（n = 91）在教室饮用过瓶装混合水（煮沸和未煮沸）（比值比（M-H）= 2.8，95%可信区间：1.1 - 7.0）。3例病例的粪便标本及教室中一瓶未开封的瓶装水检测出诺如病毒Ⅱ型呈阳性。瓶装水中大肠菌群培养率远高于标准差。生产瓶装水的工厂无许可证且无严格的消毒设施。
此次疫情由被诺如病毒污染的瓶装泉水所致。
