Chagas << CHAH guhs >> disease is the most serious parasitic disease in Latin America. It is caused by a single-cell parasite called Trypanosoma cruzi. The parasite is transmitted to people through the feces (waste) of the blood-sucking kissing bug. Medical experts estimate that as many as 7 million people in Latin America are infected with the parasite. Chagas disease is the most economically harmful parasitic disease in Latin America because many affected adults become too sick to work.
Children are often infected with the Chagas parasite in areas where it is common. Infected individuals usually initially experience a mild illness or no symptoms at all. However, about 30 percent of individuals become seriously ill with chronic (ongoing) Chagas disease 10 to 30 years after the initial infection. The chronic illness often produces the same symptoms as heart disease and may cause death. Symptoms may include an enlarged heart, heart failure, abnormal heart rhythm, and cardiac arrest. Chronic Chagas disease may also produce digestive or neurologic symptoms.
The disease is named for the Brazilian scientist Carlos Chagas. He first isolated the parasite in 1909 while investigating what was believed to be an outbreak of malaria among railroad workers in Brazil. He published a detailed description of the disease and the parasite in 1911.
Transmission.
The Chagas parasite is present in many wild animals, including rodents, opossums, raccoons, and armadillos. Kissing bugs usually live in nests of animals and birds and acquire the parasite by feeding on infected animals. As people move into previously wild areas and destroy the natural habitat, kissing bugs have readily adapted to living in houses and feeding on people.
Kissing bugs hide in cracks and crevices in walls and roofs during the day. Homes constructed of adobe or other natural materials in Latin America provide habitat for the insects. At night, they crawl down to bite and feed on the blood of people as they sleep. The bugs can consume four to eight times their own body weight in blood. To do so, they must excrete liquid feces as they feed. People are infected when they unconsciously rub the feces into the bite wound or into their eyes, nose, or mouth as they sleep. The Chagas parasite can also be transmitted from infected mothers to their babies while they are still in the womb or during birth. In addition, the parasite can be transmitted by contaminated food, by blood transfusions, and by organ transplants.
Treatment.
Chagas disease can be cured if the patient takes antiparasitic medications soon after the initial infection. However, Chagas infection is rarely detected early. No vaccine to prevent it has been developed. There are few effective treatments for the disease in the later, chronic stages. Health care providers emphasize programs that teach people who are at risk about ways to avoid becoming infected. These programs focus on modifying houses to make them less suitable as kissing bug habitats. In addition, in most countries in the Americas, blood and organs for donation are now screened for Chagas disease before they are given to other people.
