Life Cycle of Trypanosoma cruzi

Life Cycle of Trypanosoma cruzi

• An infected triatomine insect vector ("kissing bug") takes a blood meal and releases trypomastigotes in its feces near the site of the bite.
• Trypomastigotes enter the host through the bite wound or intact mucosal membranes, such as the conjunctiva.
• Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes(1).
• The amastigotes multiply by binary fission(3) and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes(4).
• Trypomastigotes infect cells from a variety of tissues and transform into intracellular amastigotes in new infection sites.
• The bloodstream trypomastigotes do not replicate, different from the African trypanosoma.
• When the parasites enter another host or are ingested by another vector.
• The kissing bug becomes infected by feeding on a human or animal.
• The ingested trypomastigotes transform into epimastigotes(5)
• epimastigotes multiply and differentiate in the midgut(7)
• trypomastigotes differentiate into the infective metacyclic trypomastigotes(8).

Chagas Disease

• Chagas disease has an asymptomatic phase and can present with an acute phase and a chronic phase.
• The acute phase is usually asymptomatic but can present with nonspecific somatic symptoms.
• Rarely, the acute phase may be more severe with potential cardiac or neurologic symptoms.
• Nodular lesions around the vector's feeding site.
• Chagas as palpable and peri ocular firm swelling, commonly referred to as occurring on the eyelids are common.
• Most acute cases resolve over a period of a few weeks or months.
• A subclinical chronic form of the disease.