岳阳市为湖沼型血吸虫病流行区。城区为东洞庭湖的一个湖汉群。50～60年代修筑了东风潮及南津港两大防洪围堤，防洪大堤长达24km，使大片洲滩成了训烷亚型。60年代初，钉螺面积为0．079亿m’，活螺平均密度33．9只／框（每框0．tim’，下同），钉螺感染率O44％，感染螺平均密度 Yueyang City is a swampy schistosomiasis endemic area. The city is a group of Donghu Lake Donghu Lake. In the 1950s and 1960s, two flood control embankments, the Dongfeng Tide and Nanjin Port, were built. The flood control embankment was up to 24km in length, making the Dachangpo Beach a traumatic subtype. In the early 1960s, the area of ​​snails was 0.079 billion m ’, the average density of live snails was 33.9 pieces / box (0.tim’ per frame, the same below), the infection rate of snails was O44%, the average density of infected snails