Exorchis sp. in the catfish Silurus asotus and Oncomelania hupensis in marshlands of Poyang Lake, China: A potential biological control tool for Schistosoma japonicum.

Oncomelania hupensis is the obligate intermediate host of Schistosoma japonicum, highlighting the medical importance of interrupting this unique and long-standing parasite-host interaction in controlling schistosomiasis transmission. It has been reported that a catfish trematode Exorchis sp. could have the potential to function as an effective anti-schistosomal agent in the snail host. However, the feasibility of this eco-friendly biological control strategy should be comprehensively investigated and evaluated in endemic areas for schistosomiasis. In this study, a field survey was conducted from 2012 to 2016 in the marshlands of Poyang Lake, which is one of the highly endemic regions for schistosomiasis in China. Results showed that more than half of Silurus asotus (65.79%) were infected with Exorchis sp., and the average intensity of infection was 14.21 per fish. And the average infection rate of Exorchis sp. in O. hupensis is 1.11%. These findings indicated that there are abundant biological resources for the implementation of this biology control strategy in the marshlands of Poyang Lake. The data presented here provide solid evidences for the practical application of this biological control strategy, thereby contributing to achieving the goals of the elimination of schistosomiasis.