江苏省江滩地区感染性钉螺动态观察

DYNAMIC OF INFECTED SNAILS IN MARSHLAND AREAS OF JIANGSU PROVINCE

目的 掌握江苏省江滩地区感染性钉螺 (以下简称阳性钉螺 )的现状分布和消长规律 ,为控制成批急性血吸虫感染 (以下简称急感 )的发生提供科学依据。方法 以县 (市、区 )为单位 ,随机抽检 5 - 10个有螺滩 ,每滩采样 5 - 10个点 ,每点捕捉钉螺 5 0 - 10 0只 ,然后由专业人员采用解剖镜检法检测钉螺的自然感染情况 ,同时对查出的阳性钉螺滩块及螺点即时进行药物杀灭。结果 5年共检测沿江有螺滩 467个 (条块 ) ,捕捉钉螺 1692 0 0只 ,检出阳性螺滩 (条块 ) 10 2个和阳性钉螺 43 3只 ,覆盖于 12个县 (市、区 ) ,已占全省沿江县 (市、区 )的 75 .0 % ( 12 /16)。结论 经连续 5年的观察 ,江滩阳性钉螺面积和阳性钉螺的螺口数呈逐年增长态势 ,存在着发生成批急感的潜在威胁。因此 ,加强江滩和通江河道的治理 。

Objective To understand the distribution and fluctuation tendency of infected Oncomelania snails in marshland areas of Jiangsu Province in order to provide the scientific basis for acute schistosomiasis control. Methods In each county(city, district) 5-10 marshland areas with snails were sampled randomly, and of which 5-10 sites were selected. Fifty to one hundred snails were collected in each site and dissected by professionals to determine the natural infection rate. At the same time, the mollusiciding actions were carried out in the schistosome-positive snail sites and beaches. Results In 5 years, a total of 467 beaches have been checked and 102 positive beaches were find out and the snails detected. The positive rate of beaches was 21.84%(102/467). A total of 169200 snails were dissected , and of which 433 were positive snails. The natural infection rate was 0.2559%(433/169200). The infested areas and the number of positive snails in 2002 were 2.71 and 18.33 times of those in 1998 in Jiangsu Province. Conclusion In the continuous 5 years observation, the tendency of the population of positive snails and the infested areas were significantly growing, and there is a apotential threat for the acute infections. So, the keys of the following work should be controlling snails seriously in the marshlands and the rivers in connection with the Yangtze River, increasing the mollusiciding cover rate and improving the quality in the positive beaches, and surveying and treating the cattle time by time.