Typically through feces of the triatomine insect (reduviid bug), may occur when a bug bite is scratched; may also be transmitted through blood transfusion or organ transplantation, from mother to infant, and by consuming contaminated food or beverages.
Endemic in Mexico and Central and South America. The risk to travelers is extremely low, but they could be at risk if staying in poor-quality housing in endemic areas.
Acute illness typically develops ≥1 week after exposure and lasts up to 90 days. A chagoma may develop at the site of infection; for example, the Romaña sign (edema of the eyelid and ocular tissues). Most infected people never develop symptoms but remain infected throughout their lives. Approximately 20%–30% of patients will develop chronic manifestations of Chagas disease after a prolonged period without any clinical disease. Chronic Chagas disease usually affects the heart; clinical signs include conduction system abnormalities, ventricular arrhythmias, and in late-stage disease, congestive cardiomyopathy. Less common chronic gastrointestinal problems may ensue (such as megaesophagus or megacolon). Reactivation disease can occur in immunocompromised patients.
During the acute phase, parasites may be detectable in fresh preparations of buffy coat or stained peripheral blood specimens. After the acute phase, diagnosis requires 2 or more serologic tests (most commonly, ELISA and the immunofluorescent antibody test).
Antitrypanosomal drug treatment is always recommended for acute, early congenital, and reactivated T. cruzi infection and for chronic T. cruzi infection in children aged <18 years old. In adults, treatment is usually recommended. In the United States, treatment drugs (benznidazole and nifurtimox) are provided by CDC under investigational protocols. Contact CDC (email@example.com; 404-718-4745) for assistance with clinical management.
Bern C. Antitrypanosomal therapy for chronic Chagas’ disease. N Engl J Med. 2011 Jun 30;364(26):2527–34.
Bern C, Montgomery SP, Herwaldt BL, Rassi A Jr, Marin-Neto JA, Dantas RO, et al. Evaluation and treatment of Chagas disease in the United States: a systematic review. JAMA. 2007 Nov 14;298(18):2171–81.
Rassi A Jr, Rassi A, Marin-Neto JA. Chagas disease. Lancet. 2010 Apr 17;375(9723):1388–402.