RESEARCH NOTE - Identification of a Transmission Focus of Schistosoma mansoni in the Southernmost Brazilian State, Rio Grande do Sul

摘要

The southern known limit of occurrence of Schistosoma mansoni Sambon 1907 in Brazil was the northeast of the State of Santa Catarina. In Rio Grande do Sul (RS) , Brazil's southernmost state, Biomphalaria tenagophila, B. straminea and B. peregrina were known to occur, but both mollusc and human infection was never documented as autochthonous. The infected child found in São Valentim, RS, came with his family from the endemic area in Minas Gerais and was not considered as an autochthonous infection by the Sucam. B. glabrata was reported for the first time in RS after the finding of S. mansoni eggs in a patient (OJSP) living in Esteio (20 km from Porto Alegre), that was initially considered as an imported infection. An extended epidemiological investigation gave support to the idea of an autochthonous infection, even though the source of infection could not be identified.