Symptoms and Signs of Chagas Disease (American Trypanosomiasis)

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Medically Reviewed on 3/11/2019

Doctor's Notes on Chagas Disease (American Trypanosomiasis)

Chagas Disease (American Trypanosomiasis) is a disease caused by protozoan trypanosomes transmitted by bloodsucking triatomine bugs to humans, endemic in South America but occasionally found in the U.S., and capable of causing damage to the heart and central nervous system. The disease has an acute phase and, in some people, a chronic phase. Signs and symptoms of the acute phase include fever, swelling at the bite site, rash, eyelid swelling (usually only one eye involved and termed Romana’s sign) and enlargement of spleen and liver; these usually resolve without treatment. However, untreated disease may return in about 10-20 years in some infected people and cause symptoms of irregular heartbeats, difficulty in swallowing, abdominal pain, severe constipation, enlarged colon, congestive heat failure and sudden cardiac arrest.

The cause of Chagas disease is the parasite Trypanosoma cruzi, which is transmitted during a bite or blood meal or in its feces by an insect known as the triatomine bug or “kissing bug”. The parasites can enter the body through the eyes, mouth, bite site or scratches in the skin. Over years, they may survive and slowly cause life-threatening symptoms described above by damaging organs like the heart and GI tract.

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.