三峡工程蓄水后鄱阳湖水情变化及其对血吸虫病流行的影响

The changes of hydrological regime in Poyang Lake after runs of Three Gorges Project and its impact on prevalence of schistosomiasis in the lake region

目的阐明三峡工程运行后,鄱阳湖区水文情势的新特点,及其对这一地区血吸虫病流行的影响。方法调查收集三峡工程蓄水信息、2002-2012年鄱阳湖都昌水文站日均水位资料和同期鄱阳湖区沿湖12个血吸虫病流行县(市、区)血吸虫病疫情及防治资料,分析在新的水情条件下疫情的动态与趋势。结果三峡工程蓄水运行后,湖区全年水位受到抑制,汛期高水位下降,春季水位低枯,秋季退水提前,枯水期水位下降快,水位更低枯。三峡蓄水后,鄱阳湖血吸虫病疫区人群感染率、耕牛感染率和钉螺密度分别下降了92.65%、76.37%和94.21%,血吸虫病流行水平呈现显著下降趋势。结论三峡工程蓄水运行后,鄱阳湖水文情势呈现以低枯水位为特点的常态性改变,并导致湖区洲滩的钉螺密度下降和血吸虫病流行程度减轻。此期间防治力度的显著加强亦是疫情得以控制在较低水平并得到稳定的重要原因。

Objective To clarify new features of hydrological regime in the Poyang Lake after runs of the Three Gorges Proj- ect and its impact on the prevalence of schistosomiasis in this region. Methods It is collected information of Three Gorges Proj- ect, average daily water level from 2002 to 2012 at Duchang hydrological station in Poyang Lake and the data of prevalence and control of schistosomiasis in 12 endemic counties along the lake. It was analyzed the trends of prevalence of schistosomiasis under the changed condition of hydrologic situation, Results Effects of impoundment of Three Gorges reservoir running on water level of Poyang Lake are mainly shown in ： Water levels of the lake are suppressed throughout the year which was characterized by high wa- ter level in flood season dropped, lower water level appeared in the spring, water withdrew earlier and quicker in the fall and to an even lower level in dry season. After impoundment of Three Gorges Project, infection rate of Schistosomajaponica in human and in bovine decreased by 92.65% and 76.37% respectively in endemic areas around the lake. The density of Oncomelania snails de- creased by 94.21%. Prevalent of schistosomiasis in this region showed a significant downward trend. Conclusions After runs of the Three Gorges Project, regularized changes hydrologic conditions has taken place in Poyang Lake which is characterized by low- er water level and thus might lead to lower density of Oncomelania snails on marshlands and reducing of prevalence of schistosomia- sis. Significant strengthening of schistosomiasis control efforts might also contributed to the stable and low level of prevalence of schistosomiasis in the region.