七里湖为沿江一较大湖泊,原呈冬陆夏水状,历史上为血吸虫病重疫区。1974年,东至县动用20万民工,耗资1526.3万元进行综合治理,1976年主体工程竣工,使400.4万m~2的湖区变为内陆,彻底改变了原来面貌。至1982年,改造工程基本完成,钉螺面积从治理前的3200万平方米降至292万平方米,减少了90.8％;原沿湖3个村的居民感染率从 Qili Lake is a large lake along the Yangtze River. It was originally a winter land and a summer water, historically a severe epidemic area of ​​schistosomiasis. In 1974, Dongzhi County mobilized 200,000 migrant workers for 15,263,000 yuan for comprehensive management. When the main project was completed in 1976, 4,042,000 m 2 of the lake area became inland, completely changing the original appearance. By 1982, the renovation project was basically completed. The area of ​​snails dropped from 32 million square meters before treatment to 292 million square meters, a decrease of 90.8%. The infection rate of residents in the three villages along the original lake from