Abstract: Objective To understand the change trend of Oncomelania hupensis snails in the bottomland areas of Qian Liang Lake district in Eastern Dongting Lake area so as to provide the evidence for formulating a schistosomiasis control strategy. Meth? ods The monitoring data of snails of Qianliang Lake district from 1988 to 2011 were collected retrospectively and analyzed by us? ing the method of the trend Chi ? square test. The correlations among the snail density indicators were analyzed. Results From 1988 to 2011，the area of snails surveyed did not change and was 433.2 hm2 . The monitoring data showed that the change trend of the density of living snails and the schistosome infection rates of snails were not obvious（P > 0.05），but the mortality of snails showed a falling trend（P＜0.05）；There were positive correlations between the average density of infected snails and the mortality of snails（r = 0.640，P < 0.05），the infection rate of snails（r = 0.639，P < 0.05），and the average density of living snails（r = 0.646，P < 0.05），respectively. There was no correlation among other snail indicators. In 1999，only 7 snails were found，of them，only one snail was alive. The alive snails were not found after 2000. Conclusion In the bottomland areas of Qianliang Lake district，the change trend of the density of alive snails were not obvious from 1988 to 1998，but the number of snails underwent a sharp drop in 1999 and snails have been not found till now.

Key words: Oncomelania hupensis；Natural growth and decline；Surveillance；Schistosomiasis；Marshland；Qianliang Lake district

摘要： 目的 目的 了解东洞庭湖钱粮湖地区垸外钉螺自然消长的变化情况， 为制定血吸虫病防治策略提供参考依据。方 方 法 法 回顾性收集1988-2011年间钱粮湖地区垸外的查螺资料， 逐年比较螺情指标的变化趋势， 并对这些螺情指标进行相关 性分析。结果 结果 1988-2011年垸外洲滩每年查螺面积未变化， 均为433.2 hm2 。1988-1998年活螺平均密度、 钉螺感染率变 化趋势不明显 （P > 0.05）， 但钉螺死亡率有下降趋势 （P < 0.05）； 感染性钉螺密度与钉螺死亡率（R = 0.640， P < 0.05）、 钉螺 感染率 （R = 0.639， P < 0.05） 和活螺平均密度 （R = 0.646， P < 0.05） 呈正相关， 未发现其它螺情指标之间存在明显的相关关 系； 1999年查螺仅发现7只钉螺， 其中1只活螺， 无感染性钉螺；2000-2011每年均未查到活螺。结论 结论 钱粮湖垸外洲滩 1988-1998年活螺平均密度变化不明显， 1999年后钉螺数量骤减， 直至目前仍维持无螺状态。

关键词: 钉螺； 自然消长； 监测； 血吸虫病； 洲滩； 钱粮湖地区