Chagas Disease Ignored in North America's Poorest Communities

Chagas disease is a parasitic infection most commonly transmitted through blood-feeding triatomine bugs, but it can also be spread through pregnancy, blood transfusion, and contaminated food or drink.

Scientists at National School of Tropical Medicine at Baylor College of Medicine (Houston TX, USA) and their colleagues have established a link between poverty and Chagas disease transmission that derives largely from poor-quality housing that facilitates triatomine bug invasion, together with lack of access to adequate health care and antenatal care.

When untreated in the acute stage, the disease becomes chronic and up to 30% or more of infected individuals will progress to Chagasic cardiomyopathy or megavisceral disease associated with debilitating morbidity or death. Today, Chagas disease is a leading cause of heart disease among people living in extreme poverty in the Western Hemisphere, especially in Latin America, where it is a major parasitic killer. The diagnosis of Chagas disease can be made by observation of the parasite in a blood smear by microscopic examination. A thick and thin blood smear are made and stained for visualization of parasites. However, a blood smear works well only in the acute phase of infection when parasites are seen circulating in blood.

Chagas disease infects an estimated 10 million people worldwide; however, much less is known about the true disease burden in North America. According to some preliminary estimates, Mexico ranks third and the United States of America seventh, in terms of the number of infected individuals with Chagas disease in the Western Hemisphere, where 99% of the cases occur. It is also estimated that 40,000 pregnant North American women may be infected with T. cruzi at any given time, resulting in 2,000 congenital cases through mother-to-child transmission.

A lack of facilities offering diagnosis and treatment of Chagas disease has prevented at-risk and infected people from receiving the critical and often life-saving attention they need. While two drug treatments currently exist, they cause undesirable adverse effects, are unsafe for pregnant women, and are not approved for use in the USA. Bernard Pecoul, MD, MPH, the executive director the Drugs for Neglected Diseases initiative (DNDi; Geneva, Switzerland) and coauthor of the study said, “It is urgent to diagnose and treat patients with what we have available today, until research and development efforts deliver true breakthroughs for the millions in need.” The study was published on October 31, 2013, in the journal Public Library of Science Neglected Tropical Diseases.

Related Links:
Baylor College of Medicine 
Drugs for Neglected Diseases initiative