Chagas’ disease (American; trypanosomiasis, trypanosomiasis cruzi) is an illness of the Americas which can take the form of either an acute, febrile, generalized infection or a chronic process. The cause is a protozoan, Trypanosoma cruzi, which is harbored by both domesticated and wild animals. When it is transmitted to humans by insects, this essentially untreatable disease is associated with fever, edemas, and enlargement of the lymph nodes and can cause dilation of parts of the digestive tract leading to megacolon and megaesophagus as well as cardiac enlargement and failure. In fact, Chagas’ disease is the leading cause of cardiac death of young adults in parts of South America.

Distribution and Incidence

The disease, which probably had its origins in Brazil, is limited to the Western Hemisphere, with heavy concentrations in Brazil, Argentina, Chile, and Venezuela. Cases are also reported in Peru, Mexico, and most other Central and South American countries along with the Caribbean islands and the United States.

Epidemiology and Etiology

T. cruzi, a member of the class Mastigophora, family Trypanisomidae, has over 100 vertebrate hosts including dogs, cats, armadillos, opossums, monkeys, and humans. Unlike other trypanosomes it does not multiply in the bloodstream, but rather lives within various tissues of the host and multiplies by binary fission. It is transmitted by reduvid bugs that ingest the trypanosome during a blood meal from a vertebrate host. The trypanosomes in turn develop in the intestines of the bug, and, while they neither enter its saliva nor are injected when the bug bites, they do pass out in its feces.