The viability of Schistosoma mansoni miracidia in host molluscs, obtained from two origins is examined: from eggs eliminated with feces of the definitive hosts and liver granuloma eggs. The effect of the origin of the miracidia on the number of cercariae and on the time of cercariae elimination was investigated. The prepatent period of cercariae elimination, snail survival after infection and the sex of the eliminated cercariae were also observed. The following results were obtained: a) snails infected with miracidia from liver granuloma eggs took longer to begin to eliminate cercariae; b) snail survival after infection was longer in the group infected with miracidia from liver granuloma eggs; c) the total number of cercariae produced by the snail group infected with miracidia from liver granuloma eggs was three times that of the group infected with miracidia from eggs eliminated with feces.
Schistosoma mansoni; Host-parasite relations; Biomphalaria glabrata; Mice
