Chagas disease, caused by a parasite, is spreading

DALLAS, Aug. 20, 2018 -- Chagas disease, caused by infection with a parasite called Trypanosoma cruzi (T cruzi), causes chronic heart disease in about one third of those infected. Over the past 40 years, Chagas disease has spread to areas where it had not traditionally been seen, including the United States, according to a new American Heart Association scientific statement published in the American Heart Association journal Circulation.

The statement. summarizes the most up-to-date information on diagnosis, screening and treatment of T cruzi infection. Infection occurs when feces from the infected blood sucking insect triatomine enters the skin through the bite site or in the eye. Triatomine insects are found in Central and South America, where they infest adobe houses and in the Southern United States. The disease can also be passed through contaminated food or drink, from pregnant mothers to their babies, and through blood transfusions and organ transplants.

The health risks of Chagas disease are well-known in Latin America where most cases are found in countries that include Brazil, Argentina, Bolivia, Paraguay, Mexico and El Salvador. However, doctors outside of Latin America are largely unaware of the infection and its connection to heart disease. Countries where infected individuals have been diagnosed include the United States with an estimated 300,000 cases, Spain with at least 42,000 cases, Italy, France, Switzerland, the United Kingdom, Australia and Japan.

"This statement aims to increase global awareness among physicians who manage patients with Chagas disease outside of traditionally endemic environments," said Maria Carmo Pereira Nunes, M.D., Ph.D, co-chair of the committee that produced the statement. "This document will help healthcare providers and health systems outside of Latin America recognize, diagnose and treat Chagas disease and prevent further disease transmission," said Pereira Nunes, who is a cardiologist at the Federal University of Minas Gerais in Belo Horizonte, Brazil.

Although 60-70 percent of people infected with T cruzi never develop any symptoms, those that do can develop heart disease, including heart failure, stroke, life threatening ventricular arrhythmias (heart rhythm abnormalities) and cardiac arrest. In the Americas, Chagas disease is responsible for more than seven times as many disability-adjusted life-years lost as malaria. However, if caught early, an infection can be cured with medications that have a 60 to 90 percent success rate, depending on when in the course of infection the patient is treated.

"Early detection of Chagas disease is critical, allowing prompt initiation of therapy when the evidence for cure is strong," said statement co-author Caryn Bern, M.D., M.P.H., professor of epidemiology and biostatistics at the University of California in San Francisco.

The risk of infection is extremely low for most travelers and residents of endemic countries. To minimize risk, people should avoid sleeping in houses with un-plastered adobe walls and/or thatch roofs, and avoid unpasteurized sugar cane juice, a├žai fruit juice and other juices when visiting affected countries.

Credit: 
American Heart Association