南水北调东线工程运西线运行后对血吸虫病传播影响的监测

Influence of schistosomiasis transmission after operation of the western route of South to North Water Diversion Project

目的了解南水北调东线工程运西线运行后对血吸虫病传播的影响,完善血吸虫病监测预警体系,提高监测预警及疫情处置能力水平。方法采取查阅资料、现场勘察法了解南水北调东线工程运西线建设和运行、历史有螺环境分布与改造、水文气候和湿地分布情况;采取系统抽样结合环境抽样法对运西线内的重点环境开展钉螺监测;采用网捞法和稻草帘诱螺法开展钉螺扩散监测。采用胶体染料试纸条法对境内生产作业人员进行血吸虫病监测,阳性者采用Kato-katz法(1粪3检)进行血吸虫病原学检查。结果 2013—2020年南水北调东线工程金湖站累计调水12次,累计调水量319 100 hm3,平均每年调水53.88 d;洪泽站累计调水11次,累计调水量329 404 hm3,平均每年调水52.63 d。运西线末次有螺年份为1995年。2018-2020年累计钉螺调查环境46块,调查面积2 262.24 hm2,未发现钉螺。累计打捞漂浮物1 600 kg,投放稻草帘480块,清污机检测漂浮物996 kg,均未发现钉螺。开展血清学查病5 650人,阳性126人,阳性率2.23%;渔船民血检阳性率(2.63%)高于养(种)殖人员(0.88%)和工程施工人员(0.92%),差异均有统计学意义(P<0.01)。粪检122人,未发现血吸虫阳性者。南水北调运西线输水河道的金宝航道及其支流为河道湿地,面积185.8 hm2;淮河入江水道区域均为湿地保护区,面积7 147.61 hm2。结论南水北调东线工程运西线自2013年运行以来,未增加血吸虫病的传播风险,但该区域内的自然环境和生态环境符合钉螺的孳生条件,经济发展模式和生产生活方式等具有输入钉螺和传染源的风险,应长期、连续地开展钉螺和血吸虫病监测。

Objective To understand the impact of the operation of the western route of the East Route of South toNorth Water Diversion on the transmission of schistosomiasis,we will improve the surveillance and early warning system for schistosomiasis,and improve the ability of monitoring,early warning and epidemic situation disposal.Methods The construction and operation of Yunxi line of the East Route of South to North Water Diversion Project,the distribution and transformation of historical snail environment,the hydrological climate and the distribution of wetland were understood by means of consulting data and field investigation;Systematic sampling combined with environmental sampling was adopted to monitor Oncomelania hupensis in the key environment of Yunxi line;The methods of net fishing and straw curtain were used to monitor the spread of Oncomelania hupensis.The colloidal dye test strip method was used to monitor schistosomiasis in domestic production workers.Kato Katz method (1 stool and 3 tests) was used to detect the pathogen of schistosomiasis.ResultsFrom 2013 to 2020,Jinhu station of the East Route Project of South to north water diversion has transferred water for12 times,with a cumulative water transfer volume of 319 100 hm3,with an average annual water diversion of 53.88 d;Hongze station has transferred water 11 times in total,with 329 404 hm3of water transferred,with an average of 52.63 d per year.The last year with snails was in 1995.From 2018 to 2020,a total of 46 snails fields were investigated,with an area of 2 262.24 hm2,and no snails were found.A total of 1 600 kg of floating objects were salvaged,480 straw curtains were put in,and 996 kg of floating objects were detected by the cleaning machine,and no snails were found.Among 5 650 cases of serological examination of the disease,126 were positive,the positive rate was 2.23%;The positive rate of blood test in fishing boat people(2.63%) was higher than that in breeding personnel (0.88%),and engineering construction personnel (0.92%).The difference was statistically significant (P<0.01).No schistosome was found in 122 stool samples.The Jinbao channel and its tributaries of the west route of the South to North Water Transfer Project are River wetland,with an area of 185.8 hm2,and the Huaihe River channel area is a wetland reserve,with an area of 7 147.61 hm2.Conclusion Since its operation in 2013,the risk of schistosomiasis transmission has not been increased.However,the natural environment and ecological environment in the region meet the breeding conditions of Oncomelania hupensis,and the economic development mode and production and lifestyle have the risk of importing snails and infectious sources,long term and continuous surveillance of Oncomelania and schistosomiasis should be carried out.