浙江省慈溪市一起伤寒暴发的流行病学调查

目的 为了查明2014年浙江省慈溪市发生的一起伤寒暴发原因、传播方式、波及范围，提出针对性的预防措施开展本次调查。方法 对病例进行流行病学个案调查，并对其中76例进行1:1病例对照研究，比较病例组和对照组危险因素暴露情况。对现场调查资料应用描述性流行病学和卫生统计学方法进行分析。结果 本起疫情共发生伤寒91例，病例以成年人为主，本地户籍病例占90%以上，发病率为6.20/10万，流行曲线呈现双峰状，病例分布由中心城区逐渐向周边乡镇/街道扩散。病例对照研究显示，生食蚶子（OR=5.00，95%CI:1.57～21.62）是可疑危险因素，但卫生学调查提示蚶子来源环节污染可能性小。分层分析后发现使用被粪便污染的井水冲洗贝壳类海产品和经口使用被粪便污染的井水（OR=22.89，95%CI:2.73～503.40）是导致本次伤寒暴发的原因。采集井水样本检测结果显示受到粪便污染。结论 本次伤寒暴发为使用了受污染的井水所导致，建议所有菜市场禁用井水，卫生部门加强饮用水的卫生监督和管理，继续推动农村改水改厕。

Epidemiological investigation of an outbreak of typhoid fever in Cixi,Zhejiang

Objective To identify the cause,transmission route and affected areas of an outbreak of typhoid fever occurred in Cixi,Zhejiang province,during January-June,2014.Methods An epidemiological case survey and a 1 ∶ 1 case-control study involving 76 cases were conducted respectively.Results A total of 91 cases of typhoid fever were reported with the incidence of 6.20/100 000.Most cases were local adults (≥90％).The incidence curve showed double peaks.The cases were mainly distributed in urban area with the spread to surrounding area.The case control study indicated that the disease might be caused by eating raw blood clam (OR =5.00,95％ CI:1.57-21.62),but the hygiene investigation showed that this possibility was low.The stratification analysis showed that using contaminated well-water to wash sea foods was the main risk factor (OR =22.89,95％ CI:2.73-503.40).Conclusion Using contaminated well-water was possible risk factor for this outbreak.It is suggested not to use well-water in the all the markets.In addition,the supervision of water quality should be strengthened and the promotion of rural water project should be continued.