Experimental benznidazole treatment of Trypanosoma cruzi II strains isolated from children of the Jequitinhonha Valley, Minas Gerais, Brazil, with Chagas disease

摘要

Trypanosoma cruzi strains from distinct geographic areas show differences in drug resistance and associationbetween parasites genetic and treatment response has been observed. Considering that benznidazole (BZ) can reducethe parasite burden and tissues damage, even in not cured animals and individuals, the goal is to assess thedrug response to BZ of T. cruzi II strains isolated from children of the Jequitinhonha Valley, state of Minas Gerais,Brazil, before treatment. Mice infected and treated with BZ in both phases of infection were compared with the untreatedand evaluated by fresh blood examination, haemoculture, polymerase chain reaction, conventional (ELISA)and non-conventional (FC-ALTA) serologies. In mice treated in the acute phase, a significant decrease in parasitaemiawas observed for all strains. Positive parasitological and/or serological tests in animals treated during the acuteand chronic (95.1-100%) phases showed that most of the strains were BZ resistant. However, beneficial effect wasdemonstrated because significant reduction (p < 0.05%) and/or suppression of parasitaemia was observed in miceinfected with all strains (acute phase), associated to reduction/elimination of inflammation and fibrosis for two/eightstrains. BZ offered some benefit, even in not cured animals, what suggest that BZ use may be recommended at leastfor recent chronic infection of the studied region.