Abstract:
The life cycle of Trypanosoma cruzi is digenetic, comprising developmental stages in an invertebrate host (vector) as well as a mammalian host. Well over a 100 species of blood feeding triatomines may harbor T. cruzi, while a variety of wild and domestic mammals, in addition to humans, can serve as the mammalian hosts. In the triatomine vector, only extracellular developmental forms of the parasite occur. Epimastigotes, which are slender flagellated replicative forms, attach to the lumen of the vector digestive tract, multiply in the anterior midgut, and differentiate into metacyclic trypomastigotes in the hindgut. Metacyclic trypomastigotes, which are capable of infecting the mammalian host, are released along with the triatomine feces, from where they are involuntarily placed in the bite wound or the mucous membranes of the eyes by the bitten individual.
