First-Ever Test of Cure for Chagas Disease Determines Treatment Effectiveness

An estimated 6 to 8 million individuals across the globe are infected with Trypanosoma cruzi, the parasite responsible for Chagas disease, which claims over 10,000 lives annually. This disease doesn’t just affect humans; numerous mammals, including wildlife and domestic dogs, are also susceptible to infection. In current drug trials, clinicians can only determine when a treatment has failed. There remains a pressing need for a reliable test of cure—one that can confirm whether a drug has successfully eliminated the infection. A major challenge in confirming the effectiveness of treatment is that the immune system often keeps the infection under control, making parasite levels undetectable by existing tests due to their limited sensitivity. A new test protocol now offers the ability to detect low levels of T. cruzi, enabling accurate diagnosis in monkeys, dogs, and humans.

Researchers at the University of Georgia’s Center for Tropical and Emerging Global Diseases (Athens, GA, USA) performed extensive PCR testing on samples from naturally infected macaque monkeys, dogs, and humans. To improve detection, the team fragmented the DNA, helping it distribute more evenly within the sample—a step not included in standard PCR testing. The macaques, infected in a manner consistent with human and canine transmission, were monitored monthly over a year. A subset also underwent additional testing, with samples collected seven times in four weeks. Alongside PCR, researchers cultivated T. cruzi from blood samples, validating that the new protocol can detect infections even when parasite levels are extremely low. Given the similar disease progression in macaques, humans, and dogs, the researchers are confident that this method is broadly applicable across species.

Comparable results were observed when the protocol was applied to samples from naturally infected dogs and humans. The development of new drug treatments for Chagas disease is urgently needed, yet without an effective test of cure, researchers can only identify treatments that fail. Although the new protocol proves effective, it is also resource-intensive and time-consuming, making it expensive. To address this, the researchers explored technologies aimed at speeding up the process and reducing costs. They are currently developing a method that allows for the analysis of larger samples more quickly. Enhancing speed and cost-efficiency significantly increases the likelihood that the test can be adopted in clinical environments.

“This test of cure is a real game changer for drug treatment studies,” said Brooke White, lead researcher of the study. “We are already working with other research groups in hopes of creating a quicker and cheaper method of testing parasite load in their drug treatment studies in macaques, dogs and humans.”

Related Links:
Center for Tropical and Emerging Global Diseases