Surveillance of schistosomiasis in rivers and lakes area in Jiaxing, Zhejiang,2008-2011

Objective To understand the epidemic pattern of schistosomiasis in Xiuzhou district in Jiaxing, Zhejiang province and provide evidence for the development of prevention and control strategy of schistosomiasis and effect evaluation in rivers and lakes area in Zhejiang. Methods According to Zhejiang provincial schistosomiasis surveillance protocol, the surveillance of schistosomiasis was carried out in Xiuzhou from 2008 to 2011 to understand the snail distribution and information about local residents and floating population as well as sick cattle. Results Snail distribution was surveyed in an area of 261 050 ㎡. Remerging snail spots were found in 2009. The density of alive snails was 0.44/box, and alive snail rate was 100%. The boxes in which snails were found repeatedly accounted for 8.82% and no infected snail was found. The average positive rate of indirect hemagglutination (IHA) in local residents was 2.27%, the yearly differences had statistical significance (2=34.079, P0.005). One imported acute case of schistosomiasis was detected in 2009. Conclusion Snails were re-found and imported infection source existed in Xiuzhou during 2008-2011. It is critical to strengthen the surveillance of snail distribution and schistosomiasis in floating population to consolidate the gain already made in schistosomiasis prevention and control.