Chagas Disease (American Trypanosomiasis)

What is Chagas disease?

Chagas disease (also called American trypanosomiasis) is an illness you get from infection with a parasite. The parasite is spread by triatomine bugs (“kissing bugs”), mostly in Mexico and Central and South America.

The thing about Chagas is that most people don’t know they’re infected. Many people don’t have any symptoms in the initial (acute) phase. But without treatment, most people enter a long-term (chronic) infection phase. Years or even decades later, you can develop severe complications that affect your heart and digestive system.

How common is Chagas disease?

Experts estimate that about 6 to 7 million people worldwide have Chagas disease — and many don’t know they have it. About 280,000 people in the U.S. are infected.

What are the symptoms of Chagas disease?

Symptoms of acute Chagas disease include:

• Fever.
• Body aches.
• Fatigue.
• Headache.
• Diarrhea.
• Vomiting.
• Redness or rash in the bite area, sometimes turning into an ulcer (chagoma).
• Severely swollen eyelid (Romañas sign).

Most people don’t have symptoms of the initial infection, and when they do, the symptoms are often mild.

Chronic Chagas infection

Without treatment, most people go on to have a chronic infection. About 30% to 40% of people with Chagas develop serious complications. Symptoms of complications include:

• Chest pain.
• Heart palpitations.
• Shortness of breath.
• Dizziness.
• Fainting.
• Fatigue.
• Difficulty swallowing (dysphagia).
• Constipation.
• Heartburn.
• Bloating.

What causes Chagas disease?

The parasite Trypanosoma cruzi (T. cruzi) causes Chagas. It’s carried by triatomine bugs — commonly called “kissing bugs,” “chinche besuconas” or “vinchucas” — and spreads through their poop.

How do you get Chagas disease?

Triatomines feed off the blood of mammals, including humans. The bugs tend to live in straw and mud. They often feed at night, when you’re sleeping.

When the bugs feed, they poop. If the poop carrying the parasite gets into the bite or your eyes, nose or mouth, it can get into your bloodstream. Once you’re infected, the parasites can reproduce and move from your bloodstream to your tissues.

In addition to kissing bugs, Chagas can also spread through:

• Pregnancy and childbirth (from a pregnant person to the fetus).
• Contaminated food.
• Blood transfusion or organ transplant (though blood and organ donors are now screened for Chagas).

Is Chagas disease contagious?

No, Chagas isn’t contagious (spread directly from person to person). But if you have Chagas and you have cracks and bleeding around your nipples from breastfeeding (chestfeeding), your baby could get Chagas from milk contaminated with infected blood.

Where is Chagas disease found?

Chagas is found in rural areas in North, South and Central America. It’s most common in Argentina, Brazil and Mexico.

Is Chagas disease in the U.S.?

Yes. You can get Chagas in the U.S. It’s more common in southern states.

What are the risk factors for Chagas disease?

You might be at higher risk for Chagas disease if you:

• Live in or used to live in a home with mud walls, a thatched (straw) roof or limited window screening in rural South America, Central America or Mexico. Living in areas where you might be bitten a lot increases your risk.
• Received a blood transfusion before universal blood screening for American trypanosomiasis began (between 1990 and 2007 for most countries).
• Were born to someone who has or once had Chagas disease.

What are the complications of Chagas disease?

Acute Chagas disease can sometimes cause myocarditis (heart muscle inflammation) or meningoencephalitis (brain inflammation). These are more common in children or people with compromised immune systems.

Chronic Chagas disease may cause serious complications that affect your heart, brain and digestive tract. These can be life-threatening and may be something you may have to manage for the rest of your life. Chronic Chagas complications include:

• Arrhythmia (unusual heart rate or rhythm).
• Cardiac arrest (sudden death).
• Dilated cardiomyopathy (enlarged heart).
• Heart failure.
• Enlarged esophagus.
• Enlarged colon.

How is Chagas disease diagnosed?

Healthcare providers diagnose a Chagas infection with a blood test to look for antibodies to the parasite. If you have symptoms of heart or digestive issues, you may also need additional tests, including:

• Echocardiogram.
• Electrocardiogram (EKG/ECG).
• X-ray or CT scan.
• Cardiac biopsy.
• Upper endoscopy.
• Colonoscopy.

How is Chagas disease treated?

Providers use antiparasitic medications to treat Chagas, including benznidazole and nifurtimox. These are most effective when used in the acute phase or early in the chronic phase.

If you have complications of chronic Chagas, you might need additional treatments. These could include surgery, anticoagulants or antiarrhythmic medications.

Side effects of treatment

Benznidazole and nifurtimox can have unpleasant side effects that can keep people from taking them as long as they need to. These include:

• Loss of appetite.
• Nausea and vomiting.
• Headaches.
• Dizziness.
• Anxiety and depression.
• Insomnia.
• Muscle pain.

Can Chagas disease be prevented?

If you live in or travel to areas where Chagas disease is common, you can reduce your risk by:

• Using insecticide spray around houses and other structures.
• Making sure buildings and sleeping areas are well-sealed.
• Using netting to protect yourself from triatomine bugs.
• Not drinking unpasteurized juices or eating food that could be contaminated with T. cruzi or triatomine poop.

Consider being screened for Chagas if you’re pregnant or plan to become pregnant and you’ve been in an area where Chagas spreads.

What can I expect if I have Chagas disease?

If you treat Chagas early, you have a better chance of getting rid of the parasites before they can cause serious complications. You’ll need to take medications for a month or more.

Antiparasitics may be less effective at curing chronic infections, but they might reduce your risk of severe complications. If you have a chronic infection, you and your provider will need to monitor your health closely to treat any complications as soon as possible. You may need to manage certain health issues for the rest of your life.

What’s the outlook for Chagas disease?

Chagas disease can lead to many different outcomes. A small number of people die from acute Chagas disease and a small number of people clear the infection without symptoms or treatment.

But most people who aren’t treated develop a chronic infection. Many people can live for decades with a chronic infection without developing complications. Some people develop life-threatening or long-lasting complications.

Experts estimate about 12,000 people die of Chagas disease every year.

When should I see my healthcare provider?

Talk to your provider if you’ve lived in or visited an area where Chagas is common and:

• You have heart or digestive conditions.
• You want to be screened (including before or during pregnancy).

When should I go to the ER?

Go to the emergency room if you have symptoms of severe illness, including:

• Severe headache.
• Stiff neck.
• Chest pain.
• Severe diarrhea or vomiting.
• Confusion or altered mental state.

What questions should I ask my doctor?

It might be helpful to ask your provider:

• What are my treatment options?
• How do I take this medication?
• How long will I need to take this medication?
• What symptoms should I look out for?
• When should I follow up with you?