浙江省嘉兴市血吸虫病阻断传播18年疫情监测与结果评价

Evaluation of schistosomiasis surveillance after blocking of its transmission in Jiaxing,Zhejiang,1995-2012

目的对浙江省嘉兴市达到阻断血吸虫病传播标准后的监测方法进行评价。方法每年采用机械抽样结合环境抽样查螺法对历史有螺区实行普查、轮查和重点环境抽查,设监测点打捞漂浮物,采用自制细网兜捞刮法对来自外省市船只船体和停靠点查螺等输入性钉螺监测;采用血清学间接血凝试验(IHA)、环卵沉淀试验(COPT)、酶联免疫吸附试验(ELISA)等对当地遗漏传染源,外来输入性传染源和凝似患者进行筛检,阳性者粪检追查。结果在5个县(市、区)62个乡镇(次)67个村(次)查到417个有钉螺条块,面积793.2 km2,捕获并解剖钉螺781 649只,无感染性螺。血清学查病989 783人(次),阳性22 089人,阳性率2.23%,粪检追查到输入性病例4例,无本地病例。结论本地区血吸虫病疫情稳定,但存在残存钉螺和输入性病例,流行潜在因素存在。今后监测的重点是对未经环境改造的历史螺区,特别是20年内有螺环境的周围和城市化征迁土地后仍能孳生钉螺环境的查螺;对往返于未达到血吸虫病传播控制地区人员的病情监测。

Objective To evaluate the schistosomiasis surveillance after its transmission was blocked in Jiaxing and provide scientific evidence for the future prevention and control strategy. Methods Different kinds of snail survey were conducted every year by using mechanic-environmental screening method in previous epidemic areas; monitoring points were also set to capture floater, ships from other places were checked for any possible snail importation; potential patients, including the residents in previous epidemic areas, imported and suspected cases were examined by using indirect hemagglutination test, circumoval precipitin test and enzyme linked immunosorbentassay. Stool examination was conducted for the positive people. Results Totally 417 snail blocks were found in 67 villages in 5 counties, covering an area of 793.2 km2, no infection was found in 781 649 randomly captured snails. Among 989 783 serum samples from suspected patients, 22 089 were positive. Four imported patients were found by stool examination, and no local cases was found. Conclusion Schistosomiasis was under control in the past 18 years, but snails and imported cases stiU exist, which is the potential factor for re-transmission. The future surveillance emphasis should be put on the previous epidemic areas, especially those where snails till existed in the past 20 years and even after urbanization. The surveillance should be strengthened in people who often visit epidemic area.