淮河入江水道上段血吸虫病监测预警方案研究

Study on surveillance and forecast scheme of schistosomiasis in upper section of Huaihe River outfall water way

目的了解淮河入江水道上段血吸虫病潜在流行因素,制定监测预警方案。方法 2014—2016年的每年4月份对淮河入江水道上段内的滩地、河道采取系统抽样结合环境抽样法开展钉螺调查;每年6—9月份在金湖站、洪泽站采用网捞法和稻草帘诱螺法开展钉螺扩散监测;对过往船只进行钉螺吸附调查。每年对淮河入江水道上段内的渔船民、施工、种植、养殖等人员采用胶体染料试纸条法(DDIA)进行血吸虫病监测,阳性者采用Kato-katz法(1粪3检)进行病原学检查。开展经济结构调查和相关因素调查。结果 2014—2016年共调查面积1 327.90 hm^2,未发现钉螺;累计打捞漂浮1 586 kg,投放稻草帘400块,调查船只129条,共检获海蛳等螺类17 585只,均未发现钉螺。累计DDIA查病2 441人次,阳性43人,阳性率1.76%。渔船民血检阳性率高于其他人群,差异有统计学意义(P<0.05);粪检33人,未发现血吸虫病人。淮河入江水道上段资源丰富,分布有油田、可种植的滩地、养殖的水面,畜牧业、航运业、旅游业发展良好。境内属亚热带湿润季风气候带,年平均气温14.9℃,年平均降水量1 023.2 mm,年平均日照时数2 072.5 h。属季节性行洪道,具有"冬陆夏水"的特征。结论淮河入江水道上段有潜在的血吸虫病流行因素,应做好与血吸虫病疫区相邻的重点环境钉螺监测和南水北调金湖站、洪泽站钉螺扩散监测,加强对渔船民等流动人口的病情监测,做好生态、自然环境的调查研究。

Objective To understand the potential epidemic factors of schistosomiasis outbreaks in the upper section of Huaihe River outfall water way and formulate a corresponding surveillance and forecast scheme. Methods The Oncomelania hupensis snail surveys were conducted by the mechanical sampling method combined with the environmental sampling method in the bottomland and river in the upper section of Huaihe River outfall water way in each April. The snails were collected by the scoop net and rice straw mats which were used to attraet snails in order to survey the snails from June to September in Jinhu Station and Hongze Station. An investigation of adsorption of the snails on the passing ships was also conducted. Every year, the fishermen, construction personnel, and planting and breeding personnel were screened for schistosomiasis with the dipstick dye immunoassay （DDIA）, and the fecal specimens from the DDIA positive individuals were tested by using the Kato-Katz technique （3 examinations for 1 fecal sample）. An investigation of economic structure and related factors was also carried out. Results From 2014 to 2016, the total area surveyed was 1 327.90 hm2, and no Oncomelania snails were found. A total of 1 586 kg of floating matter was collected, 400 mats of rice straw were placed, and 129 ships were surveyed. Totally 17 585 sea snails were found but no Oncomelania snails were found. In a total, 2 441 persons were surveyed with DDIA for schistosomiasis. Of those, there were 43 positives, with a rate of 1.76%. The positive rate of the fishermen was higher than that of the other peoples （P 〈 0.05）. Totally 33 people received stool examinations and no schistosomiasis case was found. There were rich resources in the upper section of Huaihe River outfall water way, including oil fields, planting beach, and cultured water surface. The animal husbandry, shipping industry and tourism were well developed. This area was within the sub-tropical humid monsoon climate zone, the annual average temperature was 14.9 ~C, average annual rainfall was 1 023.2 mm, and average annum sunshine time was 2 072.5 hours, and it belonged to the seasonal spillway, and its characteristics were ＂water in summer and land in winter＂. Conclusions There are potential risks of schistosomiasis transmission in the upper section of Huaihe River outfall water way, and therefore, we should strengthen the environmental monitoring of Oncomelania snails,especially in the Jinhu Station and Hongze Station. In addition, we should strengthen the monitoring of the floating population, fishermen and boatmen, and complete the investigation of ecological and natural environment.