Chagas (CHAH-gus) disease is an inflammatory, infectious disease caused by the parasite Trypanosoma cruzi. This parasite is found in the feces of the triatomine (reduviid) bug. This bug is also known as the "kissing bug." Chagas disease is common in South America, Central America and Mexico, the primary home of the triatomine bug. Rare cases of Chagas disease have also been found in the southern United States.
Also called American trypanosomiasis, Chagas disease can infect anyone. Left untreated, Chagas disease later can cause serious heart and digestive problems.
During the acute phase of infection, treatment of Chagas disease focuses on killing the parasite. In people who have chronic Chagas disease, it's no longer possible to kill the parasite. Treatment in this later phase is about managing signs and symptoms. You can also take steps to prevent infection.
Chagas disease can cause a sudden, brief illness (acute), or it may be a long-lasting (chronic) condition. Symptoms range from mild to severe, although many people don't experience symptoms until the chronic stage.
The acute phase of Chagas disease, which lasts for weeks or months, is often symptom-free. When signs and symptoms do occur, they are usually mild and may include:
- Swelling at the infection site
- Body aches
- Eyelid swelling
- Loss of appetite
- Nausea, diarrhea or vomiting
- Swollen glands
- Enlargement of your liver or spleen
Signs and symptoms that develop during the acute phase usually go away on their own. In some cases, if the infection isn't treated, Chagas disease will advance to the chronic phase.
Signs and symptoms of the chronic phase of Chagas disease may occur 10 to 20 years after initial infection, or they may never occur. In severe cases, Chagas disease signs and symptoms may include:
- Irregular heartbeat
- Heart failure
- Sudden cardiac arrest
- Difficulty swallowing due to enlarged esophagus
- Stomach pain or constipation due to enlarged colon
When to see a doctor
See your doctor if you live in or have traveled to an area where Chagas disease is widespread and you have signs and symptoms of the condition. Symptoms may include swelling at the infection site, fever, fatigue, body aches, rash and nausea.
The cause of Chagas disease is the parasite Trypanosoma cruzi, which is spread from an insect known as the triatomine bug, or "kissing bug." These insects can become infected by this parasite when they swallow blood from an animal that is infected with the parasite.
Triatomine bugs live primarily in mud, thatch or adobe huts in Mexico, South America and Central America. They hide in crevices in the walls or roof during the day and come out at night — often feeding on sleeping humans.
Infected bugs defecate after feeding, leaving behind parasites on the skin. The parasites can then enter your body through your eyes, mouth, a cut or scratch, or the wound from the bug's bite.
Scratching or rubbing the bite site helps the parasites enter your body. Once in your body, the parasites multiply and spread.
You may also become infected by:
- Eating uncooked food contaminated with feces from bugs infected with the parasite
- Being born to a person who is infected with the parasite
- Getting a blood transfusion or an organ transplant from someone who was infected with the parasite
- Being accidentally exposed to the parasite while working in a lab
- Spending time in a forest that contains infected wild animals, such as raccoons and opossums
The following factors may increase your risk of getting Chagas disease:
- Living in poor rural areas of Central America, South America and Mexico
- Living in a residence that contains triatomine bugs
- Receiving a blood transfusion or organ transplant from a person who carries the infection
It's rare for travelers to the at-risk areas in South America, Central America and Mexico to catch Chagas disease because travelers tend to stay in well-constructed buildings, such as hotels. Triatomine bugs are usually found in structures built with mud or adobe or thatch.
If Chagas disease progresses to the long-lasting (chronic) phase, serious heart or digestive complications may occur. These may include:
- Heart failure. Heart failure occurs when your heart becomes so weak or stiff that it can't pump enough blood to meet your body's needs.
- Enlargement of the esophagus (megaesophagus). This rare condition is caused by the abnormal widening (dilation) of your esophagus. This can result in difficulty with swallowing and digestion.
- Enlargement of the colon (megacolon). Megacolon occurs when your colon becomes abnormally dilated, causing stomach pain, swelling and severe constipation.
If you live in a high-risk area for Chagas disease, these steps can help you prevent infection:
- Avoid sleeping in a mud, thatch or adobe house. These types of residences are more likely to harbor triatomine bugs.
- Use insecticide-soaked netting over your bed when sleeping in thatch, mud or adobe houses.
- Use insecticides to remove insects from your residence.
- Use insect repellent on exposed skin.
Nov 12, 2020
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- Papadakis MA, et al., eds. American trypanosomiasis (Chagas disease). In: Current Medical Diagnosis & Treatment 2021. 60th ed. McGraw Hill; 2021. https://accessmedicine.mhmedical.com. Accessed Oct. 19, 2020.
- Chagas disease: Detailed FAQs. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/chagas/gen_info/detailed.html. Accessed Oct. 19, 2020.
- Beryn C, et al. Chagas disease: Chronic Trypanosoma cruzi infection. https://www.uptodate.com/contents/search. Accessed Oct. 19, 2020.