Opossums (Didelphis marsupialis) captured in intensely
urbanized areas of the city of Caracas, Venezuela, were found
infected with Trypanosoma cruzi. The developmental cycle of
trypomastigote-epimastigote-metacyclic infective
trypomastigote, usually occurring in the intestine of the
triatomine vector, was taking place in the anal odoriferous
glands of the opossums. Material from the glands, inoculated
in young, healthy opossums and white mice by different routes,
subcutaneously, intraperitoneally, orally, and into the eye,
induced T. cruzi infections in all animals.
Parasitemia, invasion of cardiac and skeletal muscle, and
intracellular multiplication of amastigotes were observed.
Inoculation of metacyclics from anal glands, cultured in LIT
medium, gave equivalent results. All opossums survived; all
mice died. Excreta of opossums may thus transmit Chagas'
disease by contamination, even in urban areas where insect
vectors are not present.
