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Alternative Names Return to top
American trypanosomiasisDefinition Return to top
Chagas disease is an illness spread by insects. It is common in South and Central America.
Causes Return to top
Chagas disease is caused by Trypanosoma cruzi, a parasite related to the African trypanosome that causes sleeping sickness. It is spread by reduvid bugs and is one of the major health problems in South America, where 20 million people are infected. Due to immigration, about 500,000 people in the United States are believed to be infected.
Risk factors for Chagas disease include living in Central or South America, poverty, living in a hut where the reduvid bugs live in the walls, and receiving a blood transfusion from a person who carries the parasite but does not have active Chagas disease.
Chagas disease has two phases -- acute and chronic. The acute phase may have no symptoms or have very mild symptoms. Symptoms of the acute phase include swelling and reddening at the site of infection (where the blood-sucking insect caused the initial infection).
This may be followed by swelling of one eye. Lymph nodes that drain the area of the insect bite may become swollen. As the parasite spreads from the bite site, the patient develops fever, malaise, and generalized swelling of the lymph nodes. The liver and spleen may become enlarged.
The disease goes into remission after the acute phase and may become chronic with no further symptoms for many years. When symptoms finally develop, they appear as heart disease (cardiomyopathy) and digestive abnormalities.
Patients may develop heart failure. Swallowing difficulties may be the first symptom of digestive disturbances and may lead to malnutrition. Patients who have parasitic infection of the colon may experience abdominal pain and constipation. Death is usually caused by heart disease.
Symptoms Return to top
Exams and Tests Return to top
Treatment Return to top
The acute phase and reactivated Chagas disease should be treated. Infants born with the infection should also be treated.
Treating the chronic phase is recommended for both children and adults. Adult patients should talk to their doctor about whether to treat chronic Chagas disease.
Two drugs are used to treat this infection: benznidazole and nifurtimox.
Both drugs often have side effects. The side effects may worsen as the patient ages. Side effects may include:
Outlook (Prognosis) Return to top
About 30% of infected and untreated people will develop chronic or symptomatic Chagas disease. It may take more than 20 years from the time of the original infection to develop heart or digestive problems.
Abnormal heart rhythms (arrhythmias, ventricular tachycardia) may cause sudden death. Once heart failure develops, death usually occurs within several years.
Possible Complications Return to top
When to Contact a Medical Professional Return to top
Call for an appointment with your health care provider if you may be infected with Chagas disease.
Prevention Return to top
Insect control with insecticides and housing structures less conducive to high insect populations will help control spread of the disease.
Blood banks in Central and South America screen donors for previous exposure to the parasite, and the blood is discarded if the donor tests positive. Most blood banks in the US started screening for Chagas disease in 2007.
References Return to top
Neva FA. Treatment of Chagas' disease, African trypanosomiasis, and leishmaniasis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier, 2007;chap 365.
Update Date: 6/3/2008 Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Charlotte Grayson, MD, Private Practice specializing in Internal Medicine and Infectious Disease, Smyrna, GA. Review provided by VeriMed Healthcare Network (9/25/2006).
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