Wild (W) and human (H) strains of Schistosoma mansoni were isolated in the lowland region of Maranhão State (northeastern Brazil). Snail progenies of Biomphalaria tenagophila collected from Paraiba do Sul River valley (Southeastern Brazil) were exposed to W miracidia, obtained from livers of wild rodents,and to H miracidia, from eggs in human stools. The date of elimination of cercariae, the quantity of eliminated larvae, the infection index of the moluscs and the mortality rate of the snails were recorded. This data suggest better adaptation of the W strain than of the H strain to B. tenagophila. These results were compared with published data of H and W strains from the Paraiba do Sul River valley and similar parasitological behavior was found.
Biomphalaria tenagophila; Schistosoma mansoni