The effect of trypanomicidal treatment upon established
histopathological Trypanosoma cruzi
induced lesions was
studied in Swiss mice. The animals were inoculated with 50
trypomastigotes and infection was allowed to progress without
treatment for 99 days. After this period, the animals were divided
in three groups, treated for 30 days with either placebo,
benznidazole (200 mg/kg/day) or nifurtimox (100 mg/kg/day). These
treatments induced 94 and 100% cure rates respectively as detected
by xenodiagnosis and reduction of antibody levels. Autopsies and
histopathological studies of heart, urinary bladder and skeletal
muscle performed on day 312 after infection showed almost complete
healing without residual lesions. As long periods were allowed
between infection, treatment and autopsy, the results indicate that
tissue lesions depend, up to advances stages, on the continuous
presence of the parasite.
