What is Chagas disease and How Chagas Disease Spread?  

The Chagas disease almost affects 7 million people in Latin America, is a severe and life-threatening disease. Still, it is curable if it is treated with the appropriate antiparasitics. Find out how to avoid it.

Chagas disease is the common name for the parasitic disease caused by Trypanosoma cruzi. It is, therefore, trypanosomiasis, which, since it occurs mainly in the Latin American area, receives the surname of ‘American.’ Thus, American trypanosomiasis and Chagas disease refer to the same infection.

According to WHO data, it is estimated that around seven million people are infected with T. Cruz worldwide, the majority in Latin America, since only in this region are there 100 million people at risk of infection, and the disease causes 12,000 deaths each year. However, the pathology has already spread to other areas of the planet. According to the WHO, in recent decades, it is being diagnosed more and more in the United States of America and Canada, in many European countries, and some countries of the Western Pacific.

Trypanosoma cruzi is a protozoan parasite transmitted by the bite of a bed bug of the genus Triatoma. These bed bugs hide during the day, generally in cracks in old or poor-quality houses (generally rural areas), and at night they feed on human blood through a bite. They are known as kissing bugs because one of the most common places to find the bite is in the area around the mouth, although they can bite in any area of ​​exposed skin. The person instinctively scratches, leading the stool to the wound, and this is how the trypanosome enters the body.

Chagas disease can be severe and even fatal, as up to 30% of patients suffer from heart problems, and over time, it can cause sudden death from arrhythmias or heart failure. Without treatment, it also causes digestive disturbances, among other problems, but if the person is treated with the appropriate antiparasitics, they can fully recover.

How Chagas Disease Is Spread

Not all bed bugs in the triatoma genus are infested with trypanosome. But if an infested bed bug bites the person, they will surely contract Chagas disease.

Trypanosome is a parasite that reaches the healthy bed bug after it bites animals (wild or domestic) or humans infected with trypanosome. When this happens, the parasite multiplies in the gut of the bed bug. For this reason, when an infested bed bug bites a healthy person, it will not carry the parasite in the blood. But when defecating near the wound, it will leave trypanosomes with the stool, which will contact the damage by involuntary scratching, penetrating the person’s blood.

When the parasite reaches human blood, the first thing it does is infect striated muscle fibers in different locations or phagocytes (immune cells whose main function is to eliminate remains of bacteria, antigen-antibody complements, and other waste substances). They begin to multiply within muscle cells or the phagocyte, going through different evolution stages until said cell can no longer harbor parasites and break down.

The parasites spread through the blood, although they can infect other cells, since only within them can they multiply.

When a bed bug bites the infected person, it carries away blood with free parasites, and the cycle begins again by biting a different person.

Other ways of transmitting the disease

Other forms of transmission can also occur, although, in humans, the most frequent form is through the bite of the bed bug ( vector transmission; the bed bug is the vector that carries the parasite).

These alternative routes are:

  • Blood transfusion and organ transplantation: rare, given the controls that are carried out.
  • Contagion through the placenta to the fetus or from the infected mother to her newborn baby.
  • Accidental contagion: in the laboratory.
  • Through breast milk: rare, but documented.