Team clarifies mystery of Chagas disease progression

In the Americas, Chagas disease affects 6 million people in 21 countries. It is caused by Trypanosoma cruzi parasites, which are transmitted by kissing bugs. (Credit: Heigen Villacarlos/Wikimedia Commons)

New research may shed light on how parasite strain diversity can affect Chagas disease progression and severity.

Chagas, a lesser-known and studied tropical disease, is caused by Trypanosoma cruzi parasites, which are transmitted by kissing bugs. In the Americas, the disease affects 6 million people in 21 countries, with approximately 30,000 new cases each year.

While most infected patients remain asymptomatic, about 20-40% will develop chronic heart disease years or decades after infection, and about 5% will develop digestive disease.

Treating people with Chagas is challenging because the disease progression is unpredictable, resulting in 14,000 deaths annually.

As reported in the journal Microbiology Spectrum, researchers have established a link between disease progression and parasite strain diversity.

They studied Rhesus macaques naturally infected with T. cruzi for two to three years, and found that those infected with mixtures of multiple strains were able to better control the parasite and stop the progression of the disease, while those with a progressive form of the disease had fewer strains.

“Since the 1980s, researchers have proposed that different strains could be associated with different disease outcomes due to the parasite’s genetic diversity, but decades of research failed to uncover clear associations,” says lead author Eric Dumonteil, associate professor of tropical medicine at Tulane University School of Public Health and Tropical Medicine.

“In finding a clear association, these results provide a new framework for the development of more effective treatments and vaccines.”

Studies are ongoing to further understand the interactions of various parasite strains during infection, Dumonteil says.

The research was conducted at the Tulane National Primate Research Center. Additional researchers from the Autonomous University of Yucatan in Mexico and Tulane collaborated on the study.

Source: Tulane University