Chagas Disease (American Trypanosomiasis)

Chagas disease (also called American trypanosomiasis or “kissing bug disease”) is an illness you get from an infection with the Trypanosoma cruzi parasite. Triatomine bugs (“kissing bugs”) can carry this parasite and spread it through their poop. If a kissing bug bites you, it may poop near the break in your skin, letting the parasite enter your body.

Chagas disease affects people throughout North, Central and South America. It’s now endemic in the United States. This means you can expect to see new cases diagnosed in the U.S. on a regular basis.

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 can affect your heart and digestive system.

Experts estimate that about 8 million people worldwide have Chagas disease — and many don’t know they have it. About 280,000 people in the U.S. have the infection.

Symptoms of Chagas disease

Most people don’t have symptoms of the initial infection (acute phase). When they do, the symptoms are often mild. You may have:

• 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)

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
• Constipation
• Heartburn
• Bloating

Chagas disease causes

The parasite Trypanosoma cruzi (T. cruzi) causes Chagas. Kissing bugs carry this parasite in their poop. These bugs tend to live in straw and mud. They feed off the blood of mammals, including humans, often at night when you’re sleeping. Here’s how a kissing bug bite can lead to Chagas:

1. The bug bites you and starts feeding.
2. When it feeds, it poops.
3. The poop (carrying the parasite) can get into the bite wound or your eyes, nose or mouth.
4. From there, the parasite can get into your bloodstream.
5. Once you have the infection, the parasites can reproduce and move from your blood to your tissues.

In addition to kissing bug bites, Chagas can spread through:

• Vertical transmission (a fetus or baby may get the infection through the placenta, at birth or through breastfeeding)
• Contaminated food
• Blood transfusion or organ transplant (though blood and organ donors are now screened for Chagas)

What are the risk factors?

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
• Live in an area where kissing bug bites are more common
• 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

Complications of kissing bug disease

Acute Chagas disease can sometimes cause myocarditis (heart muscle inflammation) or meningoencephalitis (brain inflammation). These can be life-threatening and require immediate medical attention. These issues are more common in children or people with compromised immune systems.

Chronic Chagas disease may cause serious or life-threatening complications that affect your heart, brain and digestive tract. You may have to manage these issues for the rest of your life. Chronic Chagas complications include:

• Arrhythmia
• Cardiac arrest
• Dilated cardiomyopathy
• Heart failure
• Enlarged esophagus
• Enlarged colon

How doctors diagnose Chagas disease

Healthcare providers diagnose a Chagas infection with a blood test. This looks for antibodies (protective proteins from your immune system) 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
• Heart 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

If you have these side effects, tell your provider. It’s important to take your medicine exactly as prescribed to treat this condition.

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)

It might help 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?

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 can I expect if I have kissing bug 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 this condition?

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

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

Can Chagas disease be prevented?

If you live in or visit 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 against bugs
• Using netting to protect yourself from kissing 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.