ABSTRACT
Objective To understand the distribution and characteristics of historical Oncomelania hupensis snail environ-ments in Baoshan District,Shanghai City,so as to provide the reference for adjusting and formulating the monitoring program of the snail situation in the future.Methods A retrospective survey and a field survey were conducted to collect the information of historical O.hupensis snail environments and set up the database.The distribution and characteristics of them were analyzed.Re-sults There were 53 historical O.hupensis snail environments which distributed in three towns,and the accumulative area was 1 635 530 m2in Baoshan District,Shanghai City.Class Ⅰ,Ⅱ,Ⅲ and Ⅳ accounted for 73.58％,5.66％,16.98％and 3.77％re-spectively.The complete transformation(Class Ⅰ and Class Ⅱ)was done in 42 places which covered the area of 1 622 043 m2,in which Class Ⅰ environments and Class Ⅱ environments accounted for 79.25％and 99.18％of the total,respectively.Conclu-sions There has been a great change in the historical O.hupensis snail environments in Baoshan District,Shanghai City.The information of the field investigation should be enriched and updated at different times to guide the investigation of O.hupensis snails in the future.
ABSTRACT
Objective To understand the distribution and characteristics of historical Oncomelania hupensis snail environ-ments and wetland environments in Wuxi City since 1952 so as to provide the evidence for formulating the monitoring strategy after the schistosomiasis transmission was interrupted. Methods A cross-sectional survey was conducted to collect the informa-tion of historical O. hupensis snail environments and wetland environments. Google Earth was used to present and analyze the distribution and characteristics of them. Results There were 2 124 historical O. hupensis snail environments in Wuxi City and the accumulative area was 2 995.7 hm2. In 2013 there were 61 surveillance sites of wetland with the area of 32.8 hm2 totally 1 695 snails were caught and no O. hupensis snails were found. Conclusion The historical O. hupensis snail environments were distributed widely and covered a large area in Wuxi City. The surveillance should be focused on the key environments and wetland.