目的　探讨水库灌溉系统血吸虫病新流行区的形成因素与防制对策。方法　通过现场调查结合访问、座谈、查阅历史资料 ,了解钉螺和传染源来源情况。选择有代表性且疫情较重的 2个自然村 ,采取化疗消除传染源为主结合重点灭螺的综合防制对策。结果　历史上可能有未发现的少量钉螺存在 ,通过 6 0年代修建黄石水库 ,钉螺进入灌溉渠道大量扩散 ,在输入外来传染源后 ,导致了血吸虫病新流行区的形成和扩大。试区采取上述防制对策后 ,居民血吸虫感染率由 1998年的 12 .16 %下降到 2 0 0 0年的 0 .14% ,下降了 98.8% ;耕牛感染率由 15 .91%下降到 1.35 % ,下降了 91.2 % ;活螺密度由 9.12 %只 /框 (每框 0 .1m2 ,下同 ) ,下降到 0 .11只 /框 ,下降了 98.8% ;感染螺密度由0 .0 2 48只 /框 ,下降到 0。 1999年和 2 0 0 0年均未查到感染螺。结论　修建水库 ,如有钉螺进入灌溉系统 ,可以沿水系造成大面积扩散 ,加之传染源输入而形成新的血吸虫病流行区。采取以消除传染源为主结合重点灭螺的综合防制对策 ,短期内可以控制血吸虫病的流行和传播 Objective To discuss the formation factors and control strategies of the new endemic area of ​​schistosomiasis in the reservoir irrigation system. Methods Through on-the-spot investigation combined with interview, discussion, access to historical data to understand the source of snails and sources of infection. Select two representative villages and the epidemic of heavy natural villages, to eliminate the source of infection combined with the focus of snail control measures. As a result, a small number of snails were found in the history. Through the construction of the Huangshi Reservoir in the 1960s, snails entered the irrigation channels to proliferate in a large amount. After the imported sources of infection were introduced, they led to the formation and expansion of new endemic areas of schistosomiasis. After taking the above control measures, the infection rate of residents decreased from 12.16% in 1998 to 0.014% in 2000, down by 98.8%. The rate of cattle infection decreased from 15.91% to 1.35%, a decrease of 91.2%. The density of living snails decreased from 9.12% per box (0.lm2 per box, the same below) to 0.11 per box, down by 98.8% 48 / box, down to 0. No infection was detected in 1999 and 2000. Conclusion If reservoirs are built, if snails enter the irrigation system, they can spread along a large area along the water system. In addition, a new schistosomiasis endemic area is formed by input of infectious sources. To take to eliminate the source of infection combined with the key focus on snail control measures in the short term can control the spread of schistosomiasis and transmission