Epidemiology & Risk Factors

Chagas disease, or American trypanosomiasis, is caused by the parasite Trypanosoma cruzi. Infection is most commonly acquired through contact with the feces of an infected triatomine bug (or "kissing bug"), a blood-sucking insect that feeds on humans and animals.

Infection can also occur from:

mother-to-baby (congenital),
contaminated blood products (transfusions),
an organ transplanted from an infected donor,
laboratory accident, or
contaminated food or drink (rare)

Chagas disease is endemic throughout much of Mexico, Central America, and South America where an estimated 8 million people are infected. The triatomine bug thrives under poor housing conditions (for example, mud walls, thatched roofs), so in endemic countries, people living in rural areas are at greatest risk for acquiring infection. Public health efforts aimed at preventing transmission have decreased the number of newly infected people and completely halted vectorborne transmission in some areas. Infection acquired from blood products, organ transplantation, or congenital transmission continues to pose a threat.

By applying published seroprevalence figures to immigrant populations, CDC estimates that more than 300,000 persons with Trypanosoma cruzi infection live in the United States. Most people with Chagas disease in the United States acquired their infections in endemic countries. Although there are triatomine bugs in the U.S. , only rare vectorborne cases of Chagas disease have been documented.