Chagas Disease

• Chagas disease is a parasitic infection that occurs in Central and South America.
• Chagas disease is usually spread by the feces of the reduviid bug, an insect that infests mud, adobe, or thatch houses. People get infected when they unknowingly rub bug feces into their eyes or mouth or into a bite wound. Infection can be also be transmitted by blood transfusions or organ transplants. An infected woman can pass the infection to her baby during pregnancy, at delivery, or while breastfeeding.
• Chagas disease can cause symptoms soon after infection, but many people do not become ill until many years later. Persons with weakened immune systems are at greatest risk of severe infections and complications.
• Most travelers to Central and South America are not at risk for Chagas disease. To prevent getting Chagas disease: 1) avoid sleeping in thatch, mud, or adobe houses, 2) use insecticides, and 3) be aware of the risk of blood transfusions.

What is Chagas disease?

Chagas disease is a parasitic disease that is an important health problem in Central and South America. Chagas disease is also called American trypanosomiasis [tri-PAN-o-so-MY-a-sis].

What is the infectious agent that causes Chagas disease?

Chagas disease is caused by the parasite Trypanosoma cruzi.

Where is Chagas disease found?

Chagas disease is confined to South and Central America.

How do people get Chagas disease?

• Chagas disease is usually spread by the feces of reduviid bugs, insects that live in cracks and holes of poorly constructed houses and outbuildings in South and Central America. The bugs become infected after biting an infected animal or person. Once infected, the bugs pass Trypanosoma parasites in their feces. People get infected when they unknowingly rub bug feces into their eyes or mouth or into a skin wound or bite. People can also become infected by eating uncooked food contaminated with infected bug feces.
• Chagas disease can be transmitted by contaminated blood transfusions or by organ transplants.
• Infected women can pass the infection to their babies during pregnancy, at delivery, or while breastfeeding.

What are the signs and symptoms of Chagas disease?

Some people can be infected and never develop symptoms. For those who do, Chagas disease has three stages, each with different symptoms.

• Acute infection -- A few people (about 1% of cases) have symptoms soon after infection. The most recognized acute symptom is swelling of the eye on one side of the face, usually at the bite wound or where feces were rubbed into the eye. Other symptoms are tiredness, fever, enlarged liver or spleen, swollen lymph glands, and sometimes a rash, loss of appetite, diarrhea, and vomiting. Infants and very young children can get an often-fatal swelling of the brain.
• Indeterminate stage: During the indeterminate stage, about 8 to 10 weeks after infection, infected persons have no symptoms.
• Chronic infection: Some people develop serious, irreversible damage to the heart or intestinal tract that appears 10 to 20 years after infection. Heart-related problems include an enlarged heart, altered heart rate or rhythm, heart failure, or cardiac arrest. Enlargement of parts of the digestive tract can result in severe constipation or problems with swallowing.

How soon after exposure do symptoms appear?

Acute symptoms can occur within a few days to weeks. Most people do not have symptoms until the chronic stage of infection, 10 to 20 years after first being infected.

How is Chagas disease diagnosed?

Chagas disease is diagnosed by a blood test.

Who is at risk for Chagas disease?

Chagas disease primarily affects low-income people living in poorly constructed homes in rural areas in South and Central America. People who sleep in houses made from mud, adobe, or thatch are at greatest risk. The acute disease generally occurs in children, whereas chronic symptoms usually appear later in life. Persons with weakened immune systems are at risk of severe infections and complications.

Travelers who stay in hotels, resorts, or other well-constructed housing facilities are not at risk for getting Chagas disease.

What is the treatment for Chagas disease?

Medicine given during the acute stage of infection is usually effective. Once the disease has progressed to the later stages, there is no effective cure.

How common is Chagas disease?

Worldwide, an estimated 16 million to 18 million people are infected with Chagas disease. Of those infected, an estimated 50,000 die each year.

How can Chagas disease be prevented?

• There is no vaccine or drug to prevent Chagas disease. When traveling to areas where Chagas disease occurs, follow these precautions:
• Avoid sleeping in poorly constructed thatch, mud, or adobe houses. If that is not possible, use a bednet.
• Use insecticides to kill insects and reduce the risk of transmission.
• Be aware of the risk of contracting Chagas disease through blood transfusions. In many countries, the blood supply is not well screened.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.

Return to Infectious Facts Index

Return to DHPE Main Page