Chagas Disease Testing Practices Across Joint Base San Antonio

Area of Science:

• Infectious Diseases
• Tropical Medicine
• Military Health

Background:

• The prevalence and impact of Chagas disease within the United States military remain largely uncharacterized.
• Existing studies suggest a low incidence, but current diagnostic testing strategies are not well-defined.
• This research assesses current Chagas disease (American trypanosomiasis) diagnostic practices at a major military installation in South Texas.

Purpose of the Study:

• To evaluate the current diagnostic testing protocols for Chagas disease in a United States military population.
• To identify patient and clinical factors associated with Chagas disease testing.
• To assess the yield and appropriateness of current testing strategies.

Main Methods:

• A retrospective review of electronic health records was conducted for tests performed at Joint Base San Antonio from January 2022 to August 2024.
• Patient charts were analyzed to document demographic, clinical, and testing-related factors.
• Data on ordering specialties and documented risk factors were collected.

Main Results:

• A total of 75 Chagas disease tests were performed, with 9 (12%) on active-duty personnel.
• Most tested individuals were male (75%) and received outpatient care (72%).
• Testing was primarily driven by concerns for Chagas cardiomyopathy (45%) or pre-bone marrow transplant screening (38%). Only 36% of tested patients had documented risk factors. Of the four initial positive tests, only one was confirmed, occurring in a pre-transplant patient.

Conclusions:

• Current Chagas disease testing practices at Joint Base San Antonio do not effectively identify individuals with a high pretest probability of infection.
• There is a need to refine testing strategies within the Military Health System to focus on populations at increased risk.
• Improved targeting of testing is crucial for accurately determining the burden of Chagas disease in the military population.