Trypanosmoa rangeli is a species of trypanosoma, and is considered to be non-pathogenic in humans and other mammals. Its geographical range overlaps that of Trypanosoma cruzi, as does its vector and host species. However, this parasite is found in the salivary glands of the triatomine bug vector, suggesting a different kind of transmision. Furthermore, the blood stage typomastigotes of the two parasites are morphoogically distinct.
Host infection occurs when the infected triatomine bug vector consumes blood from the host, and simultaneously releases fecal matter containing trypomastigote parasites, which then enter the bite wound. Once the trypomastigotes have penetrated surrounding cells, they transform into amastigotes and multiply by binary fission. Intracellular amastigotes transform into typomastigotes and bust out of the cell, entering the bloodstream. An uninfected vector becomes infected by consuming the blood of an infected host. The ingested trypomastigote transforms into an epimastiote once it has reached the vector midgut. The parasite multiplies and then transforms into a trypomastigote after reaching the hindgut.