近几年,血吸虫病情和螺情有较大的回升,特别是长江中,下游相继发现了新的江滩螺区。鉴于上述情况,我们从1985年起,对江滩螺情进行监测。 监测方法 1 查螺时间与方法 每年5～9月,对江滩采取棋盘式系统抽样与环境抽样相结合的方法查螺。对1987年新发现螺区,取钉螺密度为45只/0.11m~2处深5cm的土层过筛查螺,并以同样密度地点连续3d作土表检螺。 2 螺口分析及附性率 根据方天起方法 In recent years, schistosomiasis and snail have a greater recovery, especially in the middle and lower reaches of the Yangtze River have found a new river beach spiral zone. In view of the above, we have been monitoring the river bank snail since 1985. Monitoring Method 1 Lo snoring time and method Each year from May to September, the river bank to take the checkerboard system sampling and environmental sampling method combined snail. The newly discovered snail area in 1987, take snail density 45 /0.11m ~ 2 deep 5cm soil screening snail, and the same density of continuous 3d for earthwork snail. 2 screw analysis and rate of attachment according to Fang Tianqi method