Remote sensing for predicting potential habitats ofudOncomelania hupensis in Hongze, Baima and Gaoyouudlakes in Jiangsu province, China

摘要

Political and health sector reforms, along with demographic, environmental and socio-economic transformationsudin the face of global warming, could cause the re-emergence of schistosomiasis in areas where transmission hasudbeen successfully interrupted and its emergence in previously non-endemic areas in China. In the present study, we usedudgeographic information systems and remote sensing techniques to predict potential habitats of Oncomelania hupensis,udthe intermediate host snail of Schistosoma japonicum. Focussing on the Hongze, Baima and Gaoyou lakes in Jiangsuudprovince in eastern China, we developed a model using the normalized difference vegetation index, a tasseled-cap transformedudwetness index, and flooding areas to predict snail habitats at a small scale. Data were extracted from twoudLandsat images, one taken during a typical dry year and the other obtained three years later during a flooding event.udAn area of approximately 163.6 km2 was predicted as potential O. hupensis habitats around the three lakes, whichudaccounts for 4.3% of the estimated snail habitats in China. In turn, these predicted snail habitats are risk areas forudtransmission of schistosomiasis, and hence illustrate the scale of the possible impact of climate change and other ecologicaludtransformations. The generated risk map can be used by health policy makers to guide mitigation policies targettingudthe possible spread of O. hupensis, and with the aim of containing the transmission of S. japonicum.