What is Chagas Disease?

NewsGuard 100/100 Score

Chagas disease or American trypanosomiasis is a disease that is caught from infected triatomine bugs or "kissing bugs". The disease can cause serious damage to the heart and stomach.

Chagas disease is more common in certain regions of the world including Mexico, Central America and South American countries such as Argentina, Bolivia, Brazil, Chile, Costa Rica, El Salvador, Ecuador, Colombia, and Venezuela.

Cause and transmission of Chagas disease

The infection is transmitted through the bite of a triatomine bug that has been infected with the protozoan parasite Trypanosoma cruzi.. The strains of T.cruzi are mostly divided into two categories, T. cruzi I and T. cruzi II. These are then further subdivided into T.cruzi Ia, Ib etc.

When the triatomine insect feeds on the blood of a mammal infected with T. cruzi, it ingests extracellular nondividing forms of the parasites called trypomastigotes. After several weeks, these develop into infective metacyclic trypomastigotes.

After the insect bites a human and feeds, it defecates on the skin and releases these trypomastigotes which can then enter the blood stream by passing through mucous membranes or cracks in the skin.

The bite may itch and scratching the site can lead to transmission of the parasite through tiny skin abrasions. The infection can also spread from a mother to her unborn baby, through blood transfusion when contaminated or infected blood is administered or through transplant of an infected organ.

Symptoms of Chagas disease

Chagas disease has an incubation period of around 5 to 14 days before symptoms start to manifest. In the initial few weeks or months after being bitten, a person may develop a mild fever with body ache and swelling at the site of the bite called a chagoma.

Other symptoms that may manifest include fatigue, rash, headache, nausea, diarrhea, vomiting, enlargement of the spleen and swollen glands.

However, this phase of the disease can be symptomless and it often passes without causing long-term complications and without requiring treatment. Some individuals, however, may develop long-term consequences of the infection and these can be severe and sometimes life threatening.

It may take 5 to 40 years for these symptoms to manifest. The symptoms of this later phase include:

  • Irregular heartbeat that may lead to sudden cardiac arrest or sudden death
  • Heart failure
  • Enlarged heart that is unable to pump blood efficiently
  • Stroke
  • Problems with the digestive system such as enlargement of the food pipe (esophagus) or colon.

Diagnosis and treatment

Chagas disease can be diagnosed through isolation of the parasite in blood and examination under a microscope. Tissues, blood or cerebrospinal fluid samples are stained with Giemsa or Wright stain and examined under the microscope. T. cruzi may be detected in the heart, skeletal and smooth muscle cells as well as in cells of the nervous system.

The parasite is also sometimes detected in the chagomas that develop. Thick or thin blood smears can be examined under the microscope but the parasite can be viewed more clearly in thin smears. The parasite may also be cultured and grown from blood or tissues, which may take 1 to 6 months.

In long term cases, serology is usually used to diagnose infection. The most commonly used tests include indirect immunofluorescence (IFA), enzyme-linked immunosorbent assays (ELISAs) and hemagglutination. Polymerase chain reaction (PCR) and Western blotting may also be used.

Patients with acute Chagas disease may be treated with antiparasitic agents. Patients with chronic disease may have cardiomyopathy, heart failure or an enlargement in the digestive system that may require surgical treatment.

There are no available vaccines against Chagas disease. Precautions may be taken to reduce the risk of infection by preventing bites. The kissing bugs usually feed at night and therefore adequate protection should be used at night. Wearing long-sleeved shirts and trousers and using bed nets and insect repellents, for example, is recommended. Any blood or organ donations need to be screened to prevent transmission.


  1. http://www.cdc.gov/parasites/chagas/resources/onepage.pdf
  2. http://www.cfsph.iastate.edu/Factsheets/pdfs/trypanosomiasis_american.pdf
  3. http://www.ucdenver.edu/academics/colleges/PublicHealth/research/centers/globalhealth/Documents/Trop%20Med%20Course%202011/2.5.%20ASTURIAS%20CHAGAS.pdf
  4. https://www.gov.uk/

Further Reading

Last Updated: Jul 7, 2023

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2023, July 07). What is Chagas Disease?. News-Medical. Retrieved on May 29, 2024 from https://www.news-medical.net/health/What-is-Chagas-Disease.aspx.

  • MLA

    Mandal, Ananya. "What is Chagas Disease?". News-Medical. 29 May 2024. <https://www.news-medical.net/health/What-is-Chagas-Disease.aspx>.

  • Chicago

    Mandal, Ananya. "What is Chagas Disease?". News-Medical. https://www.news-medical.net/health/What-is-Chagas-Disease.aspx. (accessed May 29, 2024).

  • Harvard

    Mandal, Ananya. 2023. What is Chagas Disease?. News-Medical, viewed 29 May 2024, https://www.news-medical.net/health/What-is-Chagas-Disease.aspx.


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
New study may shed light on how parasite strain diversity can impact Chagas disease progression