The Chagas Disease Fact Sheet

The Chagas Disease Fact Sheet

Written by Andrea Bass-Werner

What is Chagas disease?

Also referred to as American Trypanosomiasis because it only exists in the Americas, Chagas disease is a sickness caused by the Trypanosoma Cruzi; an insect-born flagellate protozoan parasite. Chagas is the most lethal parasitic disease in Latin America because it causes more than 50,000 deaths per year. More than 18 million people are chronically infected carriers of the disease, and over 100 million more are at risk of being infected with the parasite, against which, there is still no effective treatment.

Where is Chagas disease found?

Chagas disease is endemic to all of Latin America and transmitted mainly in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. It is sometimes transmitted in the south of the United States.

How is Chagas disease spread?

The disease is spread through the byte of Triatoma bugs (or "kissing" bugs) that are infected with the parasite trypanosome cruzi. The cycle begins when the bugs become infected after biting an animal or person who is already infected with the parasite, and ends when the bugs bite a healthy person or animal, spreading the infection to them.

People can become infected with Chagas by unknowingly touching their eyes, mouth, or open cuts after having come into contact with infective triatome bug feces; and by bugs directly depositing infected feces in their eyes or by eating uncooked food contaminated with triatome bug feces. An emerging concern is the spread of the infection through donated blood and organs, and from the infected mother to her child during pregnancy.

Can Chagas disease cause serious illness?

Yes, Chagas can cause serious illness and is potentially fatal. Many people get the infection during childhood, ignore the early symptoms which are not considered severe, and the disease is allowed to progress unchecked until serious symptoms develop some 20 to 30 years later. By which time, it is usually too late to revert the damage caused by the parasite.

Who is most at risk for Chagas disease?

Poor people living in rural areas of Latin America are at most risk of being infected by the disease. Inexpensive housing constructed with adobe bricks, mud walls and thatched roofs are full of crevices and places that are ideal for the kissing bugs to rest and hide in very close proximity to their food supply (i.e. human blood).

Also at risk is any person visiting the endemic areas and sleeping in sub-standard accommodations. Volunteers going to the jungles, Engineers working in the oil fields, tourists seeking adventures in nature, etc. are all at risk. Travellers visiting those countries and planning to stay in hotels, resorts, or other well-constructed housing facilities are not at high risk of getting Chagas disease naturally. Those travellers who visit the urban areas of endemic countries are at very little risk of being infected.

Transfusion of blood and organ transplantation is also a risk to be considered since donated blood is not screened for Chagas in Canada.

What are the symptoms of Chagas disease?

Chagas disease has three stages: Acute, Indeterminate, and Chronic. Each stage has its own characteristic clinical presentation and only the indeterminate phase is asymptomatic. Not everyone infected with Chagas will develop symptoms or serious complications, and some of the patients will not survive the first stage, especially young children under two years of age.

1. Acute stage: Acute symptoms only occur in about one out of one hundred cases (1%). The most indicative symptom of acute Chagas infection is the Romaña's sign, in which a person's eye lids on one side of the face swell, usually at the bite wound or where the insect's feces came in contact with intact mucosa, or accidentally rubbed into the eye; and chagoma, (an inflammatory nodule composed of parasitized cells, histiocytes, and a periphery of neutrophilic granulocytes) is observed at the entry site. Other symptoms of the acute phase are non-specific to Chagas and may include:

* fatigue

* fever

* subcutaneous edema

* enlarged