西藏自治区尼玛县一起导致3例死亡病例的水痘暴发疫情分析

An outbreak of varicella with three deaths in a remote village in Nima, Tibet

目的查明此次水痘疫情暴发的传染来源、传播途径和感染危险因素，为有效防控疫情提供科学依据。方法本次暴发调查的病例定义为：2010年11月7日以来，尼玛县吉瓦乡四村当贡自然村的村民中，出现发热（腋下温度≥37．3℃或自述发热者）伴有皮疹者。应用调查问卷搜集病例信息，主要内容包括基本信息（年龄、性别、住址）、发病时间、临床症状、就诊情况、疾病史和疫苗接种史等。采用酶联免疫吸附法（ELISA）检测3份健康者血清和8份现症病例血清水痘IgM抗体。结果此次疫情共发现15例病例，罹患率为20．5％，其中成人发病10例，罹患率为17．9％。死亡病例3例，病死率为20．O％，均为成人病例且出现呼吸困难等并发症。3例死亡病例均有10年以上结核病史，其他病例无相关疾病史，所有病例均无水痘疫苗接种史。3份健康者血清水痘IgM抗体均为阴性，8份现症病例血清中7份为阳性。结论易感性积累、水痘疫苗覆盖率低可能是此次疫情暴发的原因，而结核病导致的机体免疫力低下、严重并发症以及未及时有效治疗可能是导致成年病例死亡的主要原因。

Objective To indentify the source of the outbreak, mode of transmission and risk factors for outbreak of varieella. Methods A probable case was one with fever and rash since November 7 in 2010. The cases were investigated on demographic information, dates of onset, clinical symptoms, history of disease and varicella vaccination. Enzyme-linked immunosorbent assay was implied to test the IgM antibody of the serum of three healthy people and eight new cases. Results We found 15 cases, and the attack rate was 20. 5%. 10 of them were adult cases, and the attack rate was 17.9%. There were 3 dealths, and they were all adult patients with the serious complications. The three dealths had the history of tuberculosis, but not in the others. All cases had no history of varicella vaccination. The IgM antibody of the serum of 3 healthy people were negative, and 7 of the 8 eight new cases were positive. Conclusion The accumulation of susceptibility, low level of coverage rate of varicella vaccination might be the reasons for the outbreak. Hypoimmunity caused by tuberculosis, serious complications and having no effective treatment should be the reasons for dealth in adult cases.