Chagas Disease

Chagas disease, also known as American trypanosomiasis, is caused by the parasite Trypanosoma cruzi, which is transmitted by bugs called triatomines. The disease is common in Central America, Mexico, and South America, where nearly 11 million people are infected. The insect that causes the disease thrives in poor living conditions, such as houses with thatched roofs and mud walls, so people who live in rural areas are at highest risk. Many people in the United States who have Chagas disease were infected in endemic countries. If left untreated, infection is lifelong and can be life-threatening.

Causes

Chagas disease is transmitted to humans through contact with the feces of an infected triatomine or “kissing” bug, which survives by sucking the blood of humans and animals. Triatomines are found in houses made from mud, adobe, straw, and palm thatch. During the day, the bugs hide in the walls and roofs. During the night, they emerge from hiding to eat, defecate, and inoculate individuals as they sleep. Chagas disease can also be transmitted through blood transfusion, organ transplantation, laboratory exposure, maternal-fetal transmission, and contaminated food and drink. Chagas disease is not transmitted from person to person.

Complications

Complications associated with Chagas disease include cardiac conduction defects, apical aneurysm, thrombus formation, stroke, and death.

Assessment Findings

During the acute phase, which lasts 4 to 8 weeks, patients commonly have mild symptoms of febrile illness, such as fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. A small skin lesion, known as a chagoma, may develop at the site where the parasite enters the body. If swelling occurs around the eye, the eyelid may swell as well; this is known as Romaña’s sign. (See Romaña’s sign.)

Romaña’s Sign

Unilateral palpebral edema, also known as schizotrypanosomic conjunctivitis or Romaña’s sign (after the Argentinian researcher who first reported it in 1935), is a characteristic manifestation of Chagas disease.

Only gold members can continue reading. Log In or Register to continue