Schistosomiasis has expanded to southern parts of Brazil. Between 2005-2007 the dispersion and the proliferation
of
Biomphalaria tenagophila
z was verified in the province of Corrientes near the Brazilian border. In order to
study the possibility that schistosomiasis might spread into the basins of the Paraná and Uruguay Rivers, 440 B.
tenagophila collected from 10 populations groups were experimentally exposed to infection with
Schistosoma mansoni
of the SJ
2
strain. Snails from five localities were susceptible. Frandsen’s index (TCP/100) shows that those snails
from Mirungá (11%), Aguacerito (2%) and Curupicay (2%) were Class I and not very compatible. Meanwhile, snails
from Copra (6%) and Pay-Ubre (22%), in the Paraná River basin, were Class II and poorly compatible.
