2016-2019年南水北调东线工程高邮段血吸虫病监测

Surveillance of schistosomiasis in Gaoyou sections of Eastern Route of the South-to-North Water Diversion Project from 2016 to 2019

目的了解南水北调东线工程高邮段血吸虫病疫情现状。方法采用系统抽样结合环境抽样法对南水北调东线工程高邮段大运河、三阳河及毗邻的湖区进行钉螺监测调查;采用网捞法和稻草帘诱螺法对大运河和三阳河监测点进行水体钉螺监测;采用DDIA和IHA对相关监测区居民及家畜进行血吸虫病筛查,筛查阳性者采用粪便孵化法或Kato-Katz法进行病原学检测。结果2016-2019年大运河和三阳河河道累计调查钉螺面积309.66 hm 2,未发现钉螺;毗邻的湖区累计调查面积11402.74 hm 2,查出有螺面积27.55~77.51 hm 2。监测点打捞漂浮物125 kg,投放稻草帘160块,均未发现钉螺。人群查病31311人次,其中DDIA阳性226人次;病原学查病10736人次,未发现阳性。家畜调查1083头次,未发现病畜。结论南水北调东线工程高邮段未发现血吸虫病疫情和钉螺扩散,但开展血吸虫病和钉螺监测仍然十分必要。

Objective To understand the epidemic of schistosomiasis in Gaoyou sections of Eastern Route of the South-to-North Water Diversion Project.Methods The Oncomelania snails were monitored by means of systematic sampling combined with environmental sampling in the Grand Canal,Sanyang River and the adjacent lake areas.Net salvage and rice straw curtains were used to capture the snails for survey of their prevalence in the surveillance sites of the Grand Canal,Sanyang River.Dipstick dye immunoassay(DDIA)and indirect hemagglutination(IHA)were used to screen residents and livestock in the monitoring area.Both population and livestock with positive findings further underwent pathogen detection using stool hatching or Kato-Katz technique.Results The Oncomelania snails were not found in the Grand Canal and Sanyang River from 2016 to 2019.Investigation of a total area of 11402.74 hm 2 in the adjacent lake area revealed that areas with snails were between 27.55 hm 2 and 77.51 hm 2.Totally,125 kg floating debris was refloated and 160 pieces of rice straw curtains were placed in the surveillance sites,in which no snails were detected.Of the 31311 residents(person-time)underwent detection,positive for DDIA was found in 226,yet infection was free in the 10736 residents(person-time)received pathogen detection.No infection was seen in the 1083 livestock detected.Conclusion Although there is no spreading of the Oncomelania hupensis and schistosomiasis prevalence in Gaoyou sections of Eastern Route of the South-to-North Water Diversion Project,yet surveillance over the snails and schistosomiasis remains necessary in those areas.