Susceptibility of new Taiwan foci of Oncomelania hupensis to geographic strains of Schistosoma japonicum.

Six new recently identified Taiwan Oncomelania hupensis foci were exposed to miracidia from the Changhua Taiwan zoophilic and Indonesian and Philippine anthropophilic strains of Schistosoma japonicum. All new foci were found susceptible to infection in varying degrees. In general the new foci were more susceptible to the Changhua zoophilic strain of S. japonicum than the anthropophilic strains; 17% exposed to the zoophilic strain shed cercariae while 9% and 7%, respectively, of those exposed to the Indonesian and Philippine human strains demonstrated infection. These snails along with O.h. chiui on Taiwan could possibly serve as intermediate host for human oriental schistosomiasis if the parasite was accidentally introduced onto Taiwan.