Mapping the potential distribution of the schistosomiasis intermediate host Biomphalaria straminea in China

Biomphalaria straminea is native to Brazil but has established a population in Guangdong Province, China. Its potential of expanding and transmitting Schistosoma mansoni is of great concern. We seek to map S. mansoni transmission potential by predicting ecological dimensions and potential distributions of B. straminea using state-of-the-art ecological niche model approaches. Two environmental datasets were selected to fit individual and ensemble niche models, together with the evaluation of niche conservatism during B. straminea invasion in China. A small area is still occupied by the introduced population compared to that in Brazil. A vast space with suitable climate remains unfilled and might be available to B. straminea. Contrasting results of niche conservatism evaluation were attained based on the two environmental datasets. The coastal areas in southern China, together with south-western Yunnan and southern Hainan and Taiwan were consistent supported by multiple model approaches, showing high climate suitability for B. straminea. Attention should be paid to the possibility of S. mansoni epidemic in these identified areas, as high pressure due to propagation and future climate change may further complicate conditions. Our results call for rigorous monitoring and supervising along these areas in China.