[Surveillance of schistosomiasis in Xixi National Wetland Park, 2012-2014].

Objective: To understand the endemic dynamic and situation of schistosomiasis in the Xixi National Wetland Park.
Methods: The surveillances of Oncomelania hupensis snail situation and the schistosome infection status of the permanent residents and floating population in the Xixi National Wetland were conducted annually from 2012 to 2014 according to the Surveillance Programs of Schistosomiasis in Surveillance Sites of Zhejiang Province.
Results: From 2012 to 2014, accumulatively 12.31 hm2 of area, 4965 m2 of vegetation and 75,379 alien plants were surveyed in the Xixi National Wetland Park, and no Oncomelania snails were found. The seropositive rates in the permanent residents and floating population were 0.71% (5/706) and 1.36% (25/1 834), respectively, and 1 imported chronic schistosomiasis case was found in 2014. Totally 3 006 floating personnel were involved in the investigation of infection status and awareness on knowledge of schistosomiasis control in 2013, the sero-positive rate was 0.63% (19/3 006), and the rates of those from endemic and non-endemic areas were 1.00% (15/1 503) and 0.27% (4/1 503), respectively, and the difference was statistically significant ( χ2 = 6.41, P < 0.05). The results of the fecal examinations among the seropositive cases were all negative. The awareness rates on the Regulation of Schistosomiasis Control and Prevention as well as related knowledge about Oncomelania snails were low. The indoor survival experiment of Oncomelania snails showed the survival rates of Oncomelania snails were 58.33% and 1.25% after observing for 3 and 6 months respectively.
Conclusions: The Xixi National Wetland Park is suitable for Oncomelania snails to inhabit and breed. The imported cases in floating population pose a serious threat to the endemic situation of schistosomiasis in local. In the future, the surveillance on snails and floating population as well as the health education should be strengthened.