Chagas Disease Unfamiliar to Many U.S. Physicians

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. For screening blood donated for transfusion, antibody detection tests are available.

The disease is spread by infected insects called triatomine bugs and is only transmitted on the American continents. Infection can also occur through blood transfusions, ingestion of contaminated food or drink, organ transplants, and from an infected mother to her unborn child. For obstetricians and gynecologists in the U.S., increased awareness around Chagas disease is important because many newly diagnosed patients are identified among blood donors who are women of childbearing age and at risk of transmitting the infection to their newborns. Although congenital Chagas disease is relatively rare in the US, the estimated 300 annual cases are similar to other rare diseases for which all newborns in the U.S. are routinely screened at birth.

A survey published in the October 2010 issue of the American Journal of Tropical Medicine and Hygiene, revealed that knowledge and understanding of this condition is low among obstetrician-gynecologists. The survey results found that only 3% of the physicians surveyed considered their knowledge about Chagas disease excellent or good compared to a large majority (88%) who described their knowledge as limited or very limited; almost 10% of those surveyed reported never having heard of the disease at all. One-third of survey respondents did not know what causes the disease, and only 58% were able to identify it correctly as a parasitic infection.

Jennifer R. Verani, M.D., from the Center for Disease Control and Prevention (CDC; Atlanta, GA; USA), said, "The good news about the survey results is that the majority of physicians respondents were not misinformed, they just did not have information about Chagas disease.” Edward T. Ryan, M.D., President of American Society of Tropical Medicine and Hygiene, added, "There are potentially 100,000 women living in the U.S. who are at risk of infecting their unborn babies. We need to educate obstetricians, family practitioners, nurse midwives, and pediatricians about Chagas, especially those who care for families from Latin America."

If left untreated, Chagas disease can cause complications such as cardiomyopathy, heart disease, heart failure, enlargement of the colon, enlargement of the esophagus and malnutrition. An estimated 20% to 30% of patients will develop the cardiovascular/digestive complications, decades after the initial infection.

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