建坝蓄水对湖区血吸虫病传播的影响

目的　阐明建坝蓄水后钉螺消亡规律及其对血吸虫病传播的影响。　方法　选择江西省进贤县军山湖为调查点,收集其建坝前洲滩钉螺分布高程与血吸虫病疫情资料;抄录1995～2001年坝内外逐日水位记录,测算不同高程有螺洲滩全年及4～6月份水淹天数,分析钉螺消亡与水位变化的相关性;在一个历史疫情资料较为完整的寺背村开展现况调查,确认当前血吸虫病流行态势。　结果　军山湖沿岸曾有3乡6村流行血吸虫病,但有螺面积仅1394030m2(2090亩),钉螺集中分布在16.6～17.2m高程范围内。建坝前居民血吸虫病平均感染率为12.5%,建坝后坝内水位波幅显著缩小,最低水位抬高至16.0～16.8m。在此水情条件下,2年后未再检获活螺,居民血吸虫病感染率相应剧降。寺背村现况调查未发现患者、病牛和钉螺。　结论　军山湖建坝蓄水2年后阻断了血吸虫病传播。

Impact of a Reservoir Project on Schistosomiasis Transmission in Lake Region

Objective To determine the impact of a project of building dike for storing water on schistosomiasis transmission in Junshan Lake. Methods Junshan Lake in Jinxian County of Jiangxi Province was selected as survey {pilot}. Data on snail distribution and historical prevalence of schistosomiasis before building dike were collected. The water {level} inside and outside of the dike was recorded from 1995 to 2002, and the relationship between the water level and snail population at the inside of the dike was analyzed. Survey was made in a natural endemic village to confirm the {current} {endemicity} of schistosomiasis. Results In the selected area of Junshan lake, schistosomiasis was prevalent in 6 villages of 3 townships, with a snail area of 1 394 030 m+2 (2 090 Chinese Mu). Snails distributed mainly in the marshland at an {elevation} of 16^6-17^2 m, and the average infection rate of schistosomiasis in the residents was 12^5% in 1958 before the dike project. In 1960, two years after the dike was built, no living snails were found on the marshland, and the infection rate of schistosomiasis in the residents reduced remarkably. Curently, no schistosomiasis cases were found in human being and cattle in the surveyed village. Conclusion The reservoir project had helped the elimination of snails and interrupted schistosomiasis transmission.