Trypanosoma cruzi in a caviomorph rodent: parasitological and pathological features of the experimental infection of Trichomys apereoides (Rodentia, Echimyidae).

To understand the interaction of Trypanosoma cruzi with caviomorph rodents, which supposedly have an ancient co-evolutionary history with this parasite, experimental infection of laboratory reared Trichomys apereoides with several isolates of both genotypes of the parasite was studied. Parasitemia, pattern of hematic cells, specific humoral immune response, histopathological features and parasite clearance were appraised. T. apereoides maintained stable infections independent of the T. cruzi genotype as demonstrated by positive PCR results in analyses of several tissues after a 5 months follow-up. The acute phase was characterized by abundant and disseminated presence of amastigotes, vacuolization and/or myocytolysis. Lymphocytosis was a common feature. The chronic phase was characterized mainly by lymphomacroeosinophilic infiltrates independent of the inoculated T. cruzi isolate. T. cruzi of different genotypes did not show any tissular preference in T. apereoides.