钉螺的扩散是当前血防工作中一个亟需解决的问题。我省大量调查研究的资料表明,钉螺不仅局部扩散严重,而且还有远距离的成群扩散,尤其是江、河、湖滩(俗称“三滩”)的芦苇地区,是钉螺扩散的源头,造成许多新淤洲滩形成有螺区,并使一些已经基本消灭血吸虫病的地区疫情回升。一、钉螺是怎样扩散的? 钉螺属腮螺类,水陆两栖,其扩散的方式很多,可归纳为主动扩散和被动扩散两类,但主要是借助其它力量被动扩散。 1.钉螺自身仰游水面随水扩散:洪水期,水下钉螺(尤其是幼螺)顺植物向上爬漂浮于水面,随水漂 The proliferation of snails is an urgent problem to be solved in the current blood-shelter work. Data from a large number of investigations and studies in our province show that the snails are not only locally diffused, but also have long-term spread in groups, especially the reed areas of rivers, lakes and beaches (commonly known as “three beaches”), As a result, many new silt beaches formed a snail zone and some areas that had basically eliminated schistosomiasis recovered. First, the snail is how to spread? Snail genus snail, amphibious, its proliferation of many ways can be summed up as active diffusion and passive diffusion of two types, but mainly by other means of passive diffusion. 1. Snail self-tour of the surface water with the proliferation of: flood period, the underwater snail (especially snail) Shun plant up floating in the water surface, with the water drift