上海市流动人口对血吸虫病传播的潜在危险性研究

Potential Risks for Transmission of Schistosomiasis Caused by Mobile Population in Shanghai

目的掌握流动人口对上海市血吸虫病传播可能造成的潜在危险性。方法2004年在上海市城郊结合部流动人口较多的闵行区和浦东新区,根据整群随机抽样原则两区各抽取3乡(镇)、每乡(镇)各抽取1行政村作为调查点,居住满1个月以上、≥1周岁的外来流动人口为调查对象,进行问卷调查和间接红细胞凝集试验(IHA)。IHA阳性者再以尼龙绢集卵孵化法进行粪检。结果共调查流动人口2931人,其中男性1575人(占53.74%),女性1356人(占46.26%)。血清学检测阳性率为4.71%(138/2931)。来自血吸虫病流行省的流动人口共1938人(占66.12%),其中血清学检测阳性率为5.99%,显著高于来自传播阻断省的2.60%(χ2=10.28,P<0.01)和非流行省的1.68%(χ2=12.86,P<0.01)。对138例血清学检测阳性者进行集卵法粪检,均为阴性。根据2004年全国未控制和控制血吸虫病的地区人群感染和发病情况,推算上海市来自未控制地区和控制地区的流动人口中血清学检测阳性数约为15055例(分别为13356和1699例),发病人数约为2423例(分别为2168和255例),其中来自安徽省的流动人口的血清学检测阳性数及发病人数均占首位。结论流动人口为上海市血吸虫病潜在流行的主要隐患因素。

Objective To understand the potential risk for schistosomiasis transmission caused by introduction of infection source from mobile population in Shanghai. Methods Field investigation was conducted in the suburb of Shanghai City by screening the mobile population living in Shanghai for more than I month and over I years old in a procedure of interviewing, serum indirect hemagglutination （IHA） test, and then fecal examination to detect the eggs with nylon sedimentation approach for those IHA positives. Results Among 2 931 mobile people investigated, 1 575 were male （53.74%） and 1 356 were female（46.26%）; 138 out of 2 931 were positive in IHA test （4.71%）. 1 938 （66.12%） out of 2 931 came from Schistosoma japonicum-endemic provinces and its positive rate in mobile population （5.99%） was significantly higher than those from the transmission-intemlpted provinces （2.6%） （χ^2=10.28, P〈0.01）, and those from non-endemic provinces （1.68%） （χ^2=12.86, P〈0.01）. The 138 IHA positives all showed negative in fecal examination. In accordance with the serum positive rate and egg-infection rate in the national reporting system in 2004, it was estimated that there would be about 13 356 and 1 699 potential serum positive cases respectively from endemic area and transmission controlled area, and about 2 168 and 255 egg-positive cases from the two kind areas respectively, majority of the cases were from Anhui Province. Conclusion Schistosomiasis transmission risks potentially exist in Shanghai suburb due to the introduction of infected mobile people from other endemic provinces, and a surveillance system and quick response are needed for the possible re-emergence of the disease.