Understanding American Trypanosomiasis (Chagas Disease)

Receiving a diagnosis of American trypanosomiasis, more commonly known as Chagas disease, can feel overwhelming, especially if you have never heard of it before. It is often called a “silent” or “neglected” disease because many people do not have symptoms for years, and many healthcare providers in the United States may not be familiar with it ^[1][2]. However, being diagnosed is a critical first step toward taking control of your health. With proper monitoring and care, many people live long, full lives.

What is Chagas Disease?

Chagas disease is caused by a parasite (a microscopic organism that lives off another living thing) called Trypanosoma cruzi (T. cruzi) ^[3]. While it is most common in rural parts of Mexico, Central America, and South America, it is also found in the United States ^[4][5].

In the U.S., it is estimated that between 290,000 and 347,000 people are living with the infection, yet fewer than 1% of these cases have been identified ^[3][6]. This underdiagnosis is largely due to a lack of awareness among doctors in non-endemic areas (places where the disease is not typically found) ^[1].

How the Parasite Enters the Body

The most common way people get Chagas is through vector-borne transmission involving an insect called a triatomine bug, also known as a “kissing bug” ^[4].

• The Bite: The bug usually bites people on the face while they sleep ^[7].
• The Infection: The bug does not pass the parasite through its bite. Instead, it defecates (poops) near the bite wound. When a person accidentally rubs the bug’s waste into the bite, their eyes, or their mouth, the parasite enters the bloodstream ^[7].

Other Ways Chagas Spreads

While “kissing bugs” are the primary source, the parasite can also be transmitted in other ways:

• Congenital (Mother-to-Child): An infected mother can pass the parasite to her baby during pregnancy or childbirth ^[8]. This occurs in about 5% to 10% of births from infected mothers ^[9].
• Oral: Eating food or drinking unpasteurized juice (like acai or sugar cane) contaminated with the waste of infected bugs. This is primarily a risk in endemic regions of Latin America and is exceptionally rare in the United States ^[7].
• Medical Procedures: Though rare today due to strict screening, the parasite can be spread through blood transfusions or organ transplants from an infected donor ^[10][11].

The Two Phases of Infection

Chagas disease typically moves through two distinct stages:

1. The Acute Phase: This lasts for a few weeks or months immediately after infection. Most people have no symptoms, or very mild ones like fever, fatigue, or swelling at the site of the bite [CDC].
2. The Chronic Phase: If the infection is not treated, the parasite remains in the body for life.
   • Indeterminate Phase: About 70% of people with the chronic infection stay in this “hidden” phase. They have no symptoms and may never feel sick ^[12].
   • Symptomatic Phase: Approximately 20% to 30% of people may eventually develop heart or digestive problems, often decades after the initial infection ^[12][13].

Three Stabilizing Facts for You

• Most people stay healthy: Roughly 70% of people with the chronic infection never develop the severe symptoms associated with the disease ^[12].
• Knowledge is power: Finding out you have the infection allows you to start regular monitoring (like an ECG or heart tracing) so that if any changes occur, they can be managed early ^[14].
• Treatment is available: Medications like benznidazole and nifurtimox can kill the parasite, especially when the infection is caught early [CDC]. Even for adults in the chronic phase, doctors can evaluate if treatment is right for you to help prevent future complications [CDC].

Monitoring is the most important part of your care. By working with your doctor to keep an eye on your heart and digestive health, you can manage this condition effectively.