Contributing Factor and Effectiveness of Control Strategy for Hilly-type Schistosomiasis Epidemic in Zhuzhou City

Objective To probe the contributing factors and effectiveness of control strategy for hilly-type schistosomiasis epidemic in Zhuzhou City,and provide a scientific basis for prevention of the disease from spreading. Methods To investigate the natural environment and find whether it is favorable for multiplication of snails;to assess the effectiveness of control strategy by snail and case survey which is frequently adopted in conventional method;to investigate the population,livestock and material in and out of the epidemic area. Results On the fair of epidemic area,16 alive snails were tracked within the living fish and shrimps;there was frequent entry of schistosomiasis patients and sick livestock into the epidemic area,and the positive rate of schistosomiasis in flowing population was 15.76%;the infection rate in residents had been lowered from(17.97%) in 1998 to 1.89% in 2005(U=26.06,P0.001).The infection rate in domestic animals lowered from 13.45% to(3.75%)(U=20.26,P0.05);the mean density of living snail reduced from 2.19/0.11m~2 to 0.12/0.11 m~2,with a decrease of 85.7% in infected snail rate.Conclusions Great achievement has been attained in schistosomiasis control in Zhuzhou City in recent years,yet there is still a distance from the standard of transmission intervention;the epidemic is likely to be spread around,since the natural environment and living habit of residents are quite similar between epidemic and non-epidemic area in Zhuzhou City.The contributing factors of epidemic are mostly due to snails stuck on materials during transportation.The contagious sources are likely to relate with patients and sick livestock entering in the area.