the aim of the present study was to investigate the presence of trypanosoma cruzi in the heart, liver, lung, and kidneys, using hemoculture and pcr analysis, of mice infected with different parasite strains during the acute and chronic phases of infection. parasitemia curves revealed strain-specific biological behaviors. for the y and jlp strains, the acute phase of infection started at days six and ten post-infection, parasitemia peaked at days seven and 15 post-infection, the chronic phase started at days nine and 28 post-infection, and animals started dying at days 19 and 120 post-infection, respectively. when the two strains were compared, the jlp strain exhibited reduced and slower replication rates associated with a delayed peak of parasitism and reduced parasite burdens. however, parasites were detected in all studied organs using pcr analysis. the capacity of both strains to infect different organs likely influences disease pathogenesis.