Department of Defense taps Texas State to study Chagas disease threat to military bases

Paula Stigler Granados, assistant professor in the School of Health Administration.

Paula Stigler Granados, assistant professor in the School of Health Administration, has been awarded a two-year, $700,000 grant to study Chagas disease in the southwestern United States.

Granados’ project, “Chagas Disease Surveillance and Readiness Along U.S. Mexico Border and Ports of Entry,” was funded by the Department of Defense through the Global Health Engagement Research Initiative.

Chagas disease is spread by triatomine insects commonly known as kissing bugs. When they bite humans, they can pass on parasites that can infect their hosts and go undetected for years or even decades. In some people who are infected, when symptoms—including heart and sometimes intestinal problems—may finally appear, the damage may be untreatable, irreversible and fatal.

“We have these bugs that are infected with the parasites across the southern half of the United States,” Granados explained. “They have always been here. The closer we look, the more we realize we’re all potentially at higher risk than we previously thought we were quite simply because we weren’t looking for it.”

The Department of Defense became concerned about the issue after several cases of Chagas disease in military working dogs at Lackland Air Force Base in San Antonio. They subsequently discovered a large number of kissing bugs around the base, potentially threatening the health of base personnel. Remediation efforts were put in place, but the potential vulnerability of bases throughout the southern half of the U.S. was concerning. 

"What we’re trying to do is see what the kissing bug population looks like in or near some of these military installations along our southern border to try and determine the risk to our military population and population at large," Granados said. "We already know that 60-70% of our kissing bugs in Texas are infected with the parasite, because there has been some great research done here on the subject. We’re expanding some of that testing across additional U.S.-Mexico border states and focusing on the areas where we have military installations."

Granados introduced members of the U.S. Army Public Health Command-Central from San Antonio to colleagues she knew at the Navy Preventive Medicine Unit Five in San Diego, the San Diego State University School of Public Health and University of Texas at El Paso. The two services and university partners are combining resources to deal with the problem. They will be providing trainings for the other teams in their specialties to more effectively trap, collect and test kissing bugs for the parasite that causes Chagas disease as well as analyze the data collected. 

“It’s a great collaboration that brings public health partners across the southern U.S. together that may not have otherwise been working together,” said Granados. 

Another component of Granados' work is an ambitious plan to look for asymptomatic or chronic carriers of Chagas disease within the military population. All new recruits are tested for HIV when they enter U.S. military service. Those blood samples are then stored in a biorepository, which Granados hopes to access for testing for Chagas. 

"We hope to get samples from the biorepository to test for antibodies to Chagas disease," she said. "These de-identified samples will come from service members who have served in specific areas of the U.S. where kissing bugs are known to be prevalent. 

"There are a lot of species of kissing bugs in the U.S., and some transmit the parasite easier than others. We have about 10 different species in Texas alone, but we haven’t really studied them very well," she said. "It’s a three-pronged approach: looking at bugs, looking at blood to see if there are cases out there we haven’t recognized and then analyzing that data to see how we can inform policies that would prevent the spread of this disease."