Trypanosoma (Schizotrypanum) cruzi: histopathology in mice infected with strains isolated from Didelphis marsupialis from the Valley of Caracas (Venezuela)

ABSTRACT

The histopathological alterations produced in NMRI strain mice by isolates of Trypanosoma cruzi from Didelphis marsupialis captured near human dwellings in the valley of Caracas, Venezuela are described. The donor opossums showed pseudocysts and amastigotes and trypomastigotes only in the heart muscle, and few areas of discrete inflammations and lysis of some muscle cells. Mice were parasitized in the heart, skeletal muscle, jejunum, colon, liver, lung, urinary bladder, penis, seminal vesicle, prostate, pancreas, and brain. All the isolates produced histiolymphocyticinflammation, severe in cardiac and skeletal muscle, and light in the smooth muscle of the intestine and urinary bladder; certain of the isolates produced destruction of muscle fibers. These findings, together with the morphology and behavior reported in previous papers, suggest that the isolates from this mammal reservoir and from the local vector Panstrongylus geniculatus) belong to the same type. The possible venereal transmission through the parasitosis of the urogenital system is discussed. The necessity for characterization of strains of the parasite that have been isolated from areas of intense urbanization, where the ecological changes have reduced the number of host species, is emphasized; such studies may help to clarify the extreme heterogeneity of T. cruzi and the parasitoses it induces