An epidemiological study of the area around the Americana reservoir (S. Paulo, Brazil), following suspicion of several autochthonous human cases of schistosomiasis mansoni, was made. Six active foci were disclosed, the following species of mollusks having been found in the general area: Biomphalaria tenagophila; B. straminea; B. peregrina; Drepanotrema cimex; D. lucidum; Lymnaeidae; Ancylidae and Physidae. Specimens of Biomphalaria tenagophila from the foci revealed indices of infection ranging from 0,9 to 45.0 percent for Schistosoma mansoni cercariae. Laboratory mice infected […]