Chagas Disease: Symptoms, Causes, Treatment & Complete Guide
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What Is Chagas Disease?
Chagas disease is an illness caused by the parasite Trypanosoma cruzi, carried in the feces of the triatomine or kissing bug. It is common in South and Central America and Mexico. An often mild acute phase can be followed 10 to 20 years later by serious heart and digestive complications. Medicines can kill the parasite in the acute phase.
What the research says
Benznidazole cleared parasites from the blood but did not stop heart disease from progressing once cardiomyopathy was established. In 2,854 patients with Chagas cardiomyopathy followed for a mean of 5.4 years, the main clinical outcome (death, cardiac arrest, ventricular tachycardia, pacemaker or defibrillator insertion, transplant, new heart failure, stroke or thromboembolism) occurred in 27.5% on benznidazole versus 29.1% on placebo (hazard ratio 0.93, 95% CI 0.81–1.07), even though blood PCR turned negative in 66.2% versus 33.5% at the end of treatment. (Morillo et al., N Engl J Med, 2015) [3]
Chagas disease is linked to a higher risk of stroke. In a systematic review of 7 studies (6 in the meta-analysis), the pooled risk of stroke was higher in people with Chagas disease in the 2 cohort studies (RR 1.92, 95% CI 1.20–3.06) and prevalence was higher in the 4 cross-sectional studies (PR 1.63, 95% CI 1.22–2.18), although the certainty of the evidence was rated very low. (Santos et al., Cad Saude Publica, 2026) [4]
Food-borne outbreaks are an important and sometimes deadly route of infection. A systematic review of 111 studies describing 114 oral-transmission outbreaks in six Latin American countries counted 1,293 cases and 77 deaths (case fatality 5.95%); among 941 patients with clinical data, 83.6% had an acute febrile illness and 25.4% had facial swelling. (Useche et al., Front Public Health, 2026) [5]
Chagas Disease at a Glance
Aspect | Summary |
What it is | Parasitic infection by Trypanosoma cruzi (American trypanosomiasis) |
Vector | Triatomine bug ("kissing bug"), also called reduviid |
Where | South America, Central America, Mexico; rarely southern U.S. |
Acute phase | Weeks to months; often no or mild symptoms |
Chronic phase | May appear 10–20 years later — or never |
Key complications | Heart failure, cardiac arrest, megaesophagus, megacolon |
Diagnosis | Physical exam + two or more blood tests |
Prevention | Bed nets, insecticide, repellent, housing awareness |
How the Chagas parasite reaches you — the kissing bug bite, contaminated feces, and the four-step transmission chain. Image by rinnit.com.
What Is Chagas Disease?
Chagas disease, also called American trypanosomiasis, is an illness caused by infection with the parasite Trypanosoma cruzi. The parasite is found in the feces of the triatomine bug. These bugs are also called reduviid bugs, and they may also be known as "kissing bugs" because they tend to bite people's faces.
The disease is common in South America, Central America, and Mexico. Rarely, Chagas disease has been found in the southern United States.
Chagas disease can infect anyone. Untreated, it can cause serious heart and digestive problems.
A critical point about timing: during the first (acute) phase of infection, treatment aims to kill the parasite. Later, it's no longer possible to kill the parasite — treatment then focuses on managing symptoms. There are also effective ways to prevent infection altogether.
What are the symptoms of Chagas disease?
Chagas disease can cause a sudden, brief illness — known as the acute phase — or become a long-lasting, chronic condition. Importantly, both stages can be free of symptoms, or there can be life-threatening symptoms in either phase.
Acute Phase
The acute phase lasts for weeks or months and often has no symptoms at all. If symptoms do appear, they're mostly mild:
Symptom | Notes |
Swelling at the infection site | Often at or near the bite |
Fever | General sign of infection |
Tiredness | Common during acute infection |
Rash | Skin reaction |
Body aches | Generalized discomfort |
Eyelid swelling | A distinctive early sign |
Headache | Generalized |
Loss of appetite | Digestive |
Nausea, diarrhea, or vomiting | Digestive |
Swollen glands | Lymph node response |
A larger liver or spleen | Enlarged organs |
Symptoms that come on during the acute phase most often go away on their own. But if the infection isn't treated, Chagas disease stays in the body — and sometimes moves to the chronic phase.
Chronic Phase
Symptoms of the chronic phase may appear 10 to 20 years after the infection starts — or there might be no symptoms at all. In severe cases, chronic Chagas disease symptoms may include:
Irregular heartbeat
Heart failure
Sudden cardiac arrest
Trouble swallowing
Stomach pain or constipation (trouble passing stool)
When should you see a doctor about Chagas disease?
See your healthcare professional if you have been in an area where Chagas disease is widespread and you have symptoms of the condition.
How does Chagas disease spread?
The cause of Chagas disease is the parasite Trypanosoma cruzi. The parasite spreads from an insect known as the triatomine bug, also called the kissing bug. The parasite can infect these insects when they swallow blood from an animal that is infected with the parasite.
The Bug's Nightly Routine
Triatomine bugs live mainly 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. The bugs often feed on people while they sleep.
The Transmission Chain
Infected bugs defecate (poop) after feeding. The stool leaves parasites on the skin. The parasites can then enter the body through:
The eyes
The mouth
A cut or scratch
The wound from the bug's bite
Scratching or rubbing the bite site — which often happens during sleep — helps the parasites enter the body. Once inside, the parasites multiply and spread.
Other Ways the Parasite Spreads
Chagas disease doesn't spread from being near an infected person. But the infection can also come from:
Transmission route | How it happens |
Contaminated food | Eating uncooked food that has feces from infected bugs |
Mother to child | Being born to a person infected with the parasite |
Blood or organ donation | Receiving donor blood or an organ from an infected person |
Laboratory exposure | Being exposed to the parasite while working in a lab |
Wild animals | Spending time in areas with infected wild animals, such as raccoons and opossums |
Chagas disease at a glance — definition, both phases, risk factors, and treatment & prevention. Image by rinnit.com.
What are the risk factors for Chagas disease?
Chagas disease risk is higher for people living in rural areas of Central America, South America and Mexico, in buildings with triatomine bugs, or receiving infected blood or organs.
Living in rural areas of Central America, South America, and Mexico
Living in a building that has triatomine bugs (mud, thatch, or adobe construction)
Getting blood or an organ from a donor who has the infection
A reassuring note for travelers: It's rare for travelers to the at-risk areas in South America, Central America, and Mexico to catch Chagas disease. Travelers tend to stay in buildings, such as hotels, that are less likely to have triatomine bugs — which are most often found in places made from mud, adobe, or thatch. However, travelers should not eat salads, uncooked vegetables, and unpeeled fruits in these areas.
What complications can Chagas disease cause?
If Chagas disease moves to the long-lasting chronic phase, serious heart or digestive complications can develop:
Heart failure. Heart failure happens when the heart becomes so weak or stiff that it can't pump enough blood to meet the body's needs.
Megaesophagus. This rare condition is caused by dilation (widening) of the esophagus — the tube through which food travels from the mouth to the stomach. It can cause trouble with swallowing and digestion.
Megacolon. This condition is caused by widening of the colon and produces stomach pain, swelling, and trouble passing stool (constipation).
Complication | Organ affected | What goes wrong |
Heart failure | Heart | Too weak or stiff to pump enough blood |
Irregular heartbeat / sudden cardiac arrest | Heart | Electrical system damage from the parasite |
Megaesophagus | Esophagus | Abnormal widening; trouble swallowing and digesting |
Megacolon | Colon | Abnormal widening; pain, swelling, constipation |
How is Chagas disease diagnosed?
Your healthcare professional starts with a physical exam, asking about your symptoms and anything that put you at risk of Chagas disease.
If you have symptoms of Chagas disease, two or more blood tests can confirm the diagnosis.
If you're diagnosed with Chagas disease, you're likely to have more tests. These can show whether the disease has become chronic and caused heart or digestive complications:
Test | What it shows |
Electrocardiogram | Records the heart's electrical activity |
Chest X-ray | Can show an enlarged heart |
Echocardiogram | Uses sound waves to capture moving images of the heart — changes in structure or function |
Abdominal X-ray | Shows the stomach, intestines, and colon |
Upper endoscopy | A thin, lighted endoscope goes into the throat to show images of the esophagus |
How is Chagas disease treated?
Treatment for Chagas disease aims to kill the parasite and ease symptoms.
Phase | What treatment can do |
Acute phase | Medicines can kill the parasite |
Chronic phase | Medicines won't cure the disease, but may slow it and its most serious complications |
Antiparasitic Medicines
During the acute phase, the medicines benznidazole and nifurtimox (Lampit) may help. Both medicines are offered in the regions most affected by Chagas disease. In the United States, the medicines are approved for treatment of children younger than 18 with chronic infection.
Managing Complications
Other treatment depends on the symptoms:
Heart-related complications. Treatment may include medicines, a pacemaker or other devices to control heart rhythm. Surgery, or even a heart transplant, might be needed.
Digestive complications. Treatment may include diet changes, medicines, and corticosteroids. In severe cases, surgery might be needed.
How can Chagas disease be prevented?
Chagas disease prevention in high-risk areas includes avoiding mud, thatch or adobe houses, using insecticide-treated bed netting, using bug killers and applying insect repellent.
Don't sleep in a mud, thatch, or adobe house. These types of homes are more likely to harbor triatomine bugs than other types of buildings.
Use netting soaked with bug killer (insecticide) over the bed, with the sides tucked in.
Use bug killers to remove insects from a home.
Use insect repellent on exposed skin.
How should you prepare for a Chagas disease appointment?
You are likely to start by seeing your main healthcare provider, and you may then be referred to an infectious disease specialist.
Make a list of:
Your symptoms and when they began
Key personal information, including travel to other countries, major stresses, or recent life changes
All medicines, vitamins, and supplements you take, including doses
Questions to ask your healthcare professional
Questions to ask may include:
What's the most likely cause of my symptoms?
What tests do I need?
Is my condition likely to go away or to last?
What treatments are there?
I have these other health conditions. How can I best manage these conditions together?
Can I pass this condition to others? Are those who traveled with me likely infected?
Are there brochures or other printed material I can have? What websites do you suggest?
What to expect from your doctor — questions such as: Do your symptoms come and go or are they always with you? How severe are your symptoms? Does anything make your symptoms better? What makes them worse? Have you lived or traveled anywhere, such as Mexico, where the triatomine bug or Chagas disease is common?
Frequently Asked Questions
Is Chagas disease contagious between people?
No. Chagas disease doesn't spread from being near an infected person. It spreads through triatomine bug feces, contaminated food, mother-to-child transmission, infected blood or organs, or laboratory exposure.
What is the "kissing bug" and why does it bite my face?
The triatomine bug, nicknamed the kissing bug, tends to bite people's faces. It lives in mud, thatch, or adobe huts, hides in wall and roof crevices during the day, and comes out at night to feed on people while they sleep.
Can Chagas disease have no symptoms at all?
Yes — both the acute and chronic stages can be completely free of symptoms. That's one reason the disease can go unnoticed for 10 to 20 years before serious heart or digestive problems appear.
How is Chagas disease confirmed?
A physical exam plus two or more blood tests can confirm the diagnosis. Further tests such as electrocardiogram, echocardiogram, X-rays, and upper endoscopy check whether the disease has reached the chronic phase and damaged the heart or digestive tract.
Can the parasite still be killed in the chronic phase?
No. Once Chagas disease becomes chronic, medicines won't cure it. Antiparasitic drugs like benznidazole and nifurtimox work in the acute phase; chronic-phase care focuses on managing heart and digestive complications.
Is Chagas disease a danger to tourists in Latin America?
It's rare. Travelers usually stay in hotels and buildings less likely to harbor triatomine bugs, which favor mud, adobe, and thatch homes. Travelers should still avoid salads, uncooked vegetables, and unpeeled fruits in at-risk areas.
Can Chagas disease be prevented?
Yes. Key steps include avoiding sleeping in mud, thatch, or adobe houses; using insecticide-soaked bed nets with the sides tucked in; applying insecticide to remove bugs from homes; and using insect repellent on exposed skin.
Conclusion
The main lessons of this guide:
Chagas disease is a parasite story with two acts. The kissing bug bite starts a usually mild acute illness — but if untreated, the parasite stays in the body for decades and can silently damage the heart and digestive system.
Timing is everything. Antiparasitic medicines work only in the acute phase; once the disease becomes chronic, treatment shifts to managing complications — pacemakers, surgery, even heart transplant.
The disease is preventable. Simple measures — insecticide-treated bed nets, repellent, and housing awareness — break the transmission chain in high-risk regions.
This guide has walked you through the parasite, the kissing bug's nightly routine, both disease phases, the full complication list, the diagnostic pathway, and treatment options by phase. If you've lived or traveled in Latin America and have unexplained heart rhythm problems or digestive issues, that's your cue to ask your doctor about Chagas disease.
Disclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions about a medical condition.
References
Mayo Clinic Staff. Chagas disease — Symptoms and causes. Mayo Clinic. March 6, 2025. https://www.mayoclinic.org/diseases-conditions/chagas-disease/symptoms-causes/syc-20356212
Mayo Clinic Staff. Chagas disease — Diagnosis and treatment. Mayo Clinic. March 6, 2025. https://www.mayoclinic.org/diseases-conditions/chagas-disease/diagnosis-treatment/drc-20356218
Morillo CA, Marin-Neto JA, Avezum A, et al. Randomized trial of benznidazole for chronic Chagas' cardiomyopathy. N Engl J Med. 2015;373(14):1295-1306. PMID 26323937. https://doi.org/10.1056/NEJMoa1507574
Santos ACJ, Benitez JFD, Baldoni NR, et al. Association between Chagas disease and the occurrence of stroke: systematic review with meta-analysis. Cad Saude Publica. 2026;42:e00246125. PMID 42690336. https://doi.org/10.1590/0102-311XEN246125
Useche YM, Dinatale B, Bottasso OA, et al. Orally transmitted Chagas disease outbreaks in Latin America: a comprehensive systematic review and public health implications. Front Public Health. 2026;14:1911186. PMID 42774413. https://doi.org/10.3389/fpubh.2026.1911186
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