第1页参见附件(227KB，2页)。
【摘要】 目的 了解某中学甲肝爆发的原因，为有效开展学校传染病防治工作提供参考。方法 应用描述性流行病学方法分析病例的分布情况，提出初步病因假设，进行病例对照研究、访谈、现场观察和实验室检测，进一步验证假设。结果 甲肝病例发病时间为2006年11月2日-12月8日，爆发时间为11月13日-12月8日，发病高峰为11月28日。男生罹患率显著高于女生；学生年龄越小，罹患率越高；病例有班级和宿舍集聚性。病例对照研究结果显示，使用河水洗手显著增加学生发生甲肝的相对危险性，是仅使用自来水洗手学生的7.53倍，且使用河水洗手次数越多，危险性越高。混用喝水杯也显著增加发生甲肝的相对危险性。病例组与对照组的饮食和饮水差异均无统计学意义(P>0.05)。现场调查显示，该校取水口处于厕所排污口的下游，学校使用的河水被甲肝病毒污染。结论 此次疫情爆发主要是由于早期发病的学生污染了河水，其他学生使用被污染的河水洗手、刷牙、漱口和刷碗，从而引起学校甲肝爆发。密切接触以及甲肝免疫空白也是此次疫情发病数较多的原因之一。
【关键词】 肝炎，甲型；疾病爆发流行；流行病学因素；学生保健服务
【中图分类号】 R 179 G 478.2 R 512.6+1 【文献标识码】 A 【文章编号】 1000-9817(2007)12-1099-02
An Epidemiological Study on Hepatitis A Outbreak from Unsterilized River Water in a School/LI Qin*，HAN Jing-xiu，LI Zhi-feng，et al. * Chongqing Center for Disease Control and Prevention，Chongqing(400042)，China
【Abstract】 Objective To investigate the cause of the Hepatitis A outbreak in the school，and to provide reference for the prevention against school infectious diseases. Methods The distribution of the cases was analyzed by characteristic epidemiology，and propose the hypothesis for the cause of outbreak. The hypothesis was tested by case-control study，interview，field observation and laboratory test. Results The onset time of all the cases was from Nov.2 to Dec.8 in 2006.The germ of the outbreak was from Nov.3 to Dec.8. The peak of the onset time curve was in Nov.28. The attack rate in male(9.3%) was higher than female(5.0%) significantly，and the lower was the age，the higher was the attack rate. The cases clustered in class and in dormitory. The result of the case-control study indicated that the relative risk of washing hands using the river water was 7.35 times more than using tap water. The more was the frequency of washing hands using river water，the higher was the risk of Hepatitis A. The students' using others' cup also increased the risk of Hepatitis A. The drinks and the foods had no statistical difference between the cases and the controls. The result of interview indicated that the river water was downstream of the discharge site of the toilet in school ......
