The lesions and prevalence of Trypanosoma cruzi in opossums and armadillos from southern Louisiana.

The prevalence of Trypanosoma cruzi in 48 opossums and 98 armadillos from southern Louisiana was studied. Sixteen opossums (33.3%) and 1 armadillo (1.1%) were positive for T. cruzi by blood culture. Hearts from 45 opossums and the tissues from the 1 blood culture-positive armadillo were available for histopathological examination. Although histopathology revealed T. cruzi pseudocysts in 6 opossums, 2 were not positive on blood culture. Therefore, 18 opossums (37.5%) were positive for T. cruzi. Twenty-two of 45 opossums had histological evidence of myocarditis. No lesion typical of infection with T. cruzi was observed in the armadillo tissues. These results substantiate that the opossum is a current reservoir host of T. cruzi infection in southern Louisiana and that armadillos may be of relatively minor importance.