Zheng Hui-Zhen, Guo Ru-Ning, Li Jian-Sen, Zhang Zheng-Min, Li Hui
Institute of Epidemic Disease Prevention and Control, Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2009 Jul;43(7):628-31.
To investigate the etiology and source of an infectious diarrhea outbreak and control the epidemic.
Through the retrospective cohort study, we had surveyed all the residents who complained symptoms of diarrhea or vomiting since Nov. 20th,2007 from the five villages in the north of town Y, and collected hygiene information on the water supply system of the five villages, the environment information of three villages and hygiene information of some case-indexed families, and tested the etiological biomarker, including nucleoside acid of norovirus through Real-time PCR and nested PCR technologies.
From Nov. 24th to Dec. 3th in 2007, 435 diarrhea or vomiting cases were found in the north of Y town, where tap water A was supplied for daily use. The attack rate was 12.93%. The diarrhea cases were distributed among all country groups who has used tap water A and the attack rate was ranged from 5.21% (20/384) to 21.23% (100/471). Drinking the tap water A was significantly associated with an increased risk of infection (RR = 9.246, 95% CI: 6.25 -13.68). About 85.9% (262/ 305) of the cases were from Nov. 25th to 27th. An investigation of a country of S2 group showed that the incidence of different age groups was distributed as the following: 0 - year-old 20.0% (3/15); 10 - year-old 17.3% (9/52); 20 - year-old 15.2% (16/105); older than 60 year-old 23.3% (7/30). No statistical significance was identified between age and infection(chi2 = 1.15, P >0.05). Most of the patients were not serious and well prognostic, and no hospitalized or dead cases were reported. On site investigation and daily water quality monitoring showed that disinfection procedures were not strictly followed. The monitoring data also indicated the bacteriology index of tap water A was disqualified. The test of Salmonella, Shigella and Staphylococcus aureus were negative in two vomit and one stool samples from patients. Three specimens by Real-time PCR, and six by nested PCR were positive for norovirus among the three feces and three anal swabs samples. With the drinking water sterilization and health education, the epidemic had been controlled rapidly and effectively.
The epidemic was a diarrhea outbreak that might be caused by norovirus through drinking the contaminated tap water A.
调查一起感染性腹泻暴发的病因及源头并控制疫情。
通过回顾性队列研究，我们对自2007年11月20日以来Y镇北部五个村庄中所有出现腹泻或呕吐症状的居民进行了调查，收集了这五个村庄供水系统的卫生信息、三个村庄的环境信息以及部分病例索引家庭的卫生信息，并通过实时荧光定量聚合酶链反应（Real-time PCR）和巢式聚合酶链反应技术检测了包括诺如病毒核酸在内的病原生物标志物。
2007年11月24日至12月3日，在使用A自来水的Y镇北部发现435例腹泻或呕吐病例。罹患率为12.93%。腹泻病例分布于所有使用A自来水的农村组，罹患率在5.21%（20/384）至21.23%（100/471）之间。饮用A自来水与感染风险增加显著相关（相对危险度RR = 9.246，95%可信区间CI：6.25 - 13.68）。约85.9%（262/305）的病例发生在11月25日至27日。对S2组一个村庄的调查显示，不同年龄组的发病率分布如下：0岁组为20.0%（3/15）；10岁组为17.3%（9/52）；20岁组为15.2%（16/105）；60岁以上组为23.3%（7/30）。年龄与感染之间未发现统计学差异（卡方值chi2 = 1.15，P > 0.05）。大多数患者病情不严重，预后良好，未报告住院或死亡病例。现场调查和日常水质监测表明，消毒程序未得到严格遵守。监测数据还表明A自来水的细菌学指标不合格。患者的两份呕吐物和一份粪便样本中沙门氏菌、志贺氏菌和金黄色葡萄球菌检测均为阴性。在三份粪便和三份肛拭子样本中，实时荧光定量聚合酶链反应检测的三个样本以及巢式聚合酶链反应检测的六个样本诺如病毒呈阳性。通过饮用水消毒和健康教育，疫情迅速得到有效控制。
此次疫情是一起可能由饮用受污染的A自来水导致的诺如病毒引起的腹泻暴发。
