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.
Methods: The monitoring data of snails of Qianliang Lake district from 1988 to 2011 were collected retrospectively and analyzed by using the method of the trend Chi-square test. The correlations among the snail density indicators were analyzed.
Results: 1988 to 2011, the area of snails surveyed did not change and was 433.2 hm(2). 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.