Relationship between schistosomiasis prevalence and snail status during the period from 1990 to 2002 in the areas of ¡°breaking dikes or opening sluice for waterstore¡± in Dongting Lake

    SAI Xiaoª²Yong1, CAI Kaiª²Ping2, XU Deª²Zhong1,YAN Yongª²Ping1, ZHANG Zhiª²Ying1, LI Yueª²Sheng2, ZHOU Xiaoª²Nong3

    1Department of Epidemiology, School of Prevention Medicine,Fourth Military Medical University, Xi¬ðan 710033, China, 2Hunan Institute of Antiª²epidemic of Schistosomiasis,Yueyang 414000, China, 3Institute of Parasitic Diseases, Chinese Center for Diseases Control & Prevention, Shanghai 200032, China

    ¡¾Abstract¡¿ AIM: To analyze the relationship between schistosomiasis prevalence and snail status during the period from 1990 to 2002 in the areas of ¡°breaking dikes or opening sluice for waterstore¡± in Dongting Lake,to afford reference to the work of schistosomiasis prevention. METHODS: The schistosomiasis prevalence and snail density during the period from 1990 to 2002 in the areas of ¡°breaking dikes or opening sluice for waterstore¡±, and in the controlled area were compared by statistical methods. The relationship between schistosomiasis prevalence, snail density and snail area was analyzed. RESULTS: Snail density in the areas of ¡°breaking dikes or opening sluice for waterstore¡± increased significantly (P<0.05) after 1998 and that in the controlled area also increased (P>0.05).Schistosomiasis prevalence in the areas of ¡°breaking dikes or opening sluice for waterstore¡± increased significantly (P<0.01) after 1998 and that in the controlled area decreased (P<0.05). The chart showed schistosomiasis prevalence in thoroughlyª²abandoned area increased significantly (P <0.05), that in partially abandoned area increased unsignificantly (P>0.05) and that in the controlled area even reduced.Schistosomiasis prevalence was correlated positively with the snail area (P<0.01, r=0.788) and the snail density (P<0.05, r=0.764). CONCLUSION: Schistosomiasis prevalence during the period from 1990 to 2002 in the areas of ¡°breaking dikes or opening sluice for waterstore¡± in Dongting Lake was correlated positively with the snail area and the snail density ;The policy of ¡°breaking dikes or opening sluice for waterstore¡± made schistosomiasis prevalence more complicated. ......