American Trypanosomiasis (Chagas' Disease)

by CDC

Description

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi. Chagas' disease is usually transmitted by contact with the feces of an infected triatomine ("cone nose" or "kissing") bug. Transmission can also occur through blood transfusion and organ transplantation and congenitally through passage of parasites across the placenta.

Occurrence

Chagas' disease occurs in Mexico, Central America, and South America; acquisition of infection in the United States is rare. An estimated 11 million people are infected worldwide; of these, 15%-30% have clinical symptoms.

Risk for Travelers

Travelers rarely acquire Chagas' disease. Triatomine bugs typically infest poor-quality buildings constructed of mud, adobe brick, or palm thatch, particularly those with cracks or crevices in the walls and roof. Because the bugs primarily feed at night, travelers can greatly reduce their risk for acquiring infection by avoiding overnight stays in such dwellings and by not camping or sleeping outdoors in endemic areas. Travelers should be aware that blood products might not be routinely or adequately tested for T. cruzi prior to transfusion.

Clinical Presentation

Acute infection is usually asymptomatic but may be accompanied by local swelling at the site of inoculation, fever, and in 5%-10% of cases, meningoencephalitis, myocarditis or both. An asymptomatic phase follows the acute infection and lasts for life in 70%-80% of cases. Cardiomyopathy and/or intestinal "mega" syndromes (e.g., megaesophagus and megacolon) develop in the rest of infected persons 10-40 years after infection.

Prevention

No vaccine is available. Preventive measures include insecticide spraying of infested houses. Insecticide-impregnated bed nets may reduce the risk of infection for travelers who cannot avoid camping or sleeping outdoors or in poorly constructed houses in endemic areas.

Treatment

Treatment is recommended for all cases of acute infection, congenital infection, and reactivated infection in immunocompromised patients. Treatment of chronically infected persons (especially children) may eliminate parasites in up to 60% of cases. The drugs of choice are nifurtimox (under an investigational New Drug Protocol from the CDC Drug Service) or benznidazole (not available in the United States). Travelers should be advised to consult an infectious disease or tropical medicine specialist. Persons with chronic cardiac or gastrointestinal disease may benefit from symptomatic therapy.

About the Author

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The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.