Laboratory studies on host-parasite relationship of Bithynia snails and the liver fluke, Opisthorchis viverrini.

The infection rate of Bithynia snails to Opisthorchis viverrini eggs was studied in relation to exposure intensity, age and species of host. It was found that 50 miracidial eggs per snail yielded the highest percentage of living surviving positive snails. Bithynia funiculata and Bithynia siamensis siamensis were highly susceptible to O. viverrini, about four to seven times higher than Bithynia siamensis goniomphalos. Young snails, 1-3 months old, appeared more susceptible than old snails.