Objective To explore how to control schistosomiasis at the presence of snails in lake marshland. Methods From March 1st to October 31st every year, 2000-2002- the measure of "marshland isolation and farming prohibition" was carried out. Local residents and cattle were examined and treated for schistosomiasis. Results The infections rate of schistosomiasis in surveillance spots decreased from 2.66% (1999) to 1.66% (2002). The infections rate was 0.57% (5/ 871 ) in the township. There were no acute schislosomiasis cases and new patients. The rate of schistosomiasis of cattle decreased from 4. 90% (1999) to 0. 14% . and there was no new calf under two years of age infected. The rale of infected snails decreased from 1. 450% to 0. 005% , and the density of positive snails from 0. 014 8 snail /0. 1 m2 to 0. 000 11 snail/0. 1 m2. Conclusion The measure, mainly including "marshland isolation and farming prohibition", can control schistosomiasis prevalence even at the presence of snails in lake marshland.

The endemic situation of schistosomiasis in Tangyin Village of Duchang County from 2000 to 2007 showed the infection rates of residents between 2003 and 2007 were all around 10%.In 2000.2002 and 2007,the infection rates of snails were 0.32%,O.45%and 0.38%,respectively,and the densities of infected snails were 0.016,0.004 No./0.1 m~2.and 0.004 No./0.1 m~2,respectively.It is suggested that the snail control and health education should be strengthened and the self-protection awareness of residents should improve for schistosomiasis control.