South American Trypanosomiasis – Chagas Disease

This is a parasitic disease infecting humans and is usually found in South and Central America.

The Life Cycle

The infection in humans is transferred by the Reduviid bug, this night biting bug is about 3 cm long and defecates while it feeds. The feces of the bug left on the skin contain the Trypanosome parasites and humans are infected when the feces of the bug is rubbed into the area of the bug bite or when contaminated fingers with the bugs feces are rubbed in the eye.

The parasites may start up an inflammatory reaction at their site of entry, there may be swelling of the skin (Chagoma) or upper eye lid swelling of the eye (Romana’s sign)

The parasite wanders in the blood stream, divide and develop further until they are sucked out with blood by the Reduviid bug again. Trypanosomes then enter the bugs gut where they develop further and are released into the feces of the bug and the cycle starts again.

Signs and Symptoms

  • Fever
  • Generalized body swelling
  • Brain infection
  • Heart involvement
  • Damage to the nervous system


The parasite is found in blood under a microscope.


Most humans are infected because of ill housing as the bugs sometimes hide in the cracks of walls, so good housing and getting rid of the bugs are key. However no specific effective treatment is available.


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