Trypanosoma cruzi

Abstract

Trypanosoma cruzi is the etiological agent of American trypanosomiasis, or Chagas disease, and is transmitted mainly by blood-sucking reduviid insects in endemic countries. Metacyclic trypomastigotes released in the feces during the insect blood meal enter a mammalian host through skin wounds or mucosal membranes and invade sur- rounding cells. After cell invasion, metacyclic trypomastigotes are restrained within a parasitophorous vacuole (PV), from where they escape, transform into amastigotes, and multiply in the cytosol. Later, following binary division, amastigotes differentiate back into highly motile trypomastigotes that are released upon cell lysis. They can infect neighboring cells, migrate to different tissues, or be ingested by an insect vector. The parasites in the tissues, as- sociated with an immune response, contribute to the chronic symptoms of the disease. Reactive oxygen species (ROS), among other factors, play an important role during parasite multiplication and interstage transformation.