北京市恙虫病病例流行病学特征及实际感染病例数估计

目的分析北京市2008--2012年恙虫病的流行病学特征，并开展社区居民血清流行病学调查，利用血清流行病学调查结果估计北京市主要疫区——平谷区社区居民恙虫病感染水平及实际感染病例数。方法采用SPSS16．0软件分析恙虫病病例流行病学特征，利用AreGIS9．3软件展示病例的时空分布特征。在平谷区随机抽取常住人口170人，利用间接免疫荧光试验测定人群恙虫病抗体水平，根据结果推算平谷区实际感染人数。结果截至2012年，北京市累计报告198例恙虫病临床诊断病例，患者职业主要为农民（73．1％），平均年龄（52±12）岁，男女性别比1．04：1（101：97），98．99％的病例现住址均为平谷区，此外昌平区和延庆区县各出现1例城区病例。近几年平谷区疫区范围迅速扩大，仅周边个别乡镇无病例报告。估计平谷区常住人口恙虫病抗体阳性率为14．12％，据此估计平谷区约有41142人曾感染恙虫病。结论北京市恙虫病疫情呈上升态势，人群感染水平较高，应通过多种形式在当地农村开展健康教育。此外，有必要开展社区干预研究，并根据成本效益分析结果，选择适合的干预方法。

Epidemiological characteristics of scrub typhus and estimation of the real case number in Beijing

Objective ] To analyze the epidemiological characteristics of scrub typhus in Beijing from 2008-2012, carry out the sero- epidemiological survey among community residents, and estimate the infection status and real case number of scrub typhus in Pinggu District （ main epidemic area of Beijing） by using the results of seroepidemiological survey. Methods] The epidemiologieal charac- teristics of scrub typhus were analyzed by SPSS 16.0, and the space-time distribution features were described by AreGIS 9.3. 170 permanent residents were randomly collected in Pinggu District. The antibody level of scrub typhus in this population was tested by the indirect immunofluoreseence test, to estimate the real case number in Pinggu District. Results ] A total of 198 cases of scrub typhus were reported in Beijing at the end of 2012. 73.1% of cases were peasants, the average age was （52 ＋ 12） year-old, and the ratio of male-to-female was 1.04：1 C 101：97 ）. 98.99% of patients have lived in Pinggu District, and each one case was reported in Changping District and Yanqing District respectively. The epidemic area in Pinggu District has expanding rapidly in recent years, while only a few towns had no case of scrub typhus. It was estimated that the positive rate of antibody against scrub typhus among permanent residents in Pinggu District was 14. 12%, and approximately 41 142 residents had been infected with scrub typhus. Conclusion ] The incidence of scrub typhus has increased gradually in Beijing, and the infection rate of residents is high, so it is urgent to take the health education in rural area by various ways. Moreover, it is important to carry out intervention study in community, and choose the appropriate intervention method based on the results of cost-benefit analysis.