Chagas disease
DEFINITION
Chagas (CHAH-gus) disease is an inflammatory, infectious disease caused by a parasite found in the feces of the triatomine (reduviid) 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 been found in the southern United States, as well.
Also called American trypanosomiasis, Chagas disease can infect anyone, but is diagnosed most often in children. Left untreated, Chagas disease later can cause serious heart and digestive problems.
Treatment of Chagas disease focuses on killing the parasite in acute infection and managing signs and symptoms in later stages. You can take steps to prevent the infection, too.
CAUSES
The cause of Chagas disease is the parasite Trypanosoma cruzi, which is transmitted to humans from a bite from an insect known as the triatomine bug. These insects can become infected by T. cruzi when they ingest blood from an animal already 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, then come out at night — often feeding on sleeping humans.
Infected bugs defecate after feeding, leaving behind T. cruzi 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 T. cruzi-infected bugs
- Being born to a woman infected with T. cruzi
- Having a blood transfusion containing infected blood
- Getting an organ transplant containing viable T. cruzi
- Working in a laboratory where there’s an accidental exposure to the parasite
- Spending time in a forest that contains infected wild animals, such as raccoons and opossums
- Being around an infected pet
SYMPTOMS
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.
Acute phase
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
- Fever
- Fatigue
- Rash
- Body aches
- Eyelid swelling
- Headache
- 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. If left untreated, the infection persists and, in some cases, advances to the chronic phase.
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, however, Chagas disease signs and symptoms may include:
- Irregular heartbeat
- Congestive heart failure
- Sudden cardiac arrest
- Difficulty swallowing due to enlarged esophagus
- Abdominal 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 at risk of Chagas disease and you have signs and symptoms of the condition, such as swelling at the infection site, fever, fatigue, body aches, rash and nausea.
