High Rates of Positive Hemocultures in Children and Teenagers Seropositive for Trypanosoma cruzi in the State of Rio Grande do Sul, Brazil

The infection by Trypanosoma cruzi, the aethiological agent of Chagas' disease, is a serious public health problem in most of the Latin American countries. In Brazil, it is estimated that around five million people are infected by T. cruzi and 25 million live in areas of risk. In the South region of Brazil, the State of Rio Grande do Sul is the most important endemic area of human Chagas' disease. The infection rate by T. cruzi in different municipalities in the southern region of the state varies from 17.6% to 19.6%. Characterization of several T. cruzi strains isolated from the wild and domestic transmission cycles in Rio Grande do Sul shows that these parasite populations are highly polymorphic, as demonstrated by isoenzyme and random amplified polymorphic DNA analysis