A group of scholars at the University of Georgia and Texas A&M University has been awarded over $4 million from governmental and private entities to aid in research on Chagas disease.

The investigation will encompass several initiatives concentrated on the disease’s frequency, diagnostic methods for identifying the parasite responsible, and treatment strategies to avert infection and illness in dogs. The primary objective is to leverage the outcomes to assist humans as well.

Supported by a $3 million grant from the National Institutes of Health, UGA’s Rick Tarleton will co-direct a project aimed at developing strategies to identify, treat, and assess treatment results in dogs in Texas. The aim is to propose optimal practices that prevent the onset of cardiac issues, a severe potential consequence of Chagas disease, and to build resistance to potential future infections.

The researchers will collaborate with dogs that have been naturally infected with Chagas disease. As the disease manifests similarly in dogs and humans, dogs serve as an effective model for investigating the treatment’s efficacy.

“There are numerous vital questions regarding treatment effectiveness and the immunity that recovered individuals possess against future infections that are not easily examined in humans but can be investigated within these dog populations experiencing high transmission rates in Texas,” stated Tarleton, Regents Professor in UGA’s Franklin College of Arts and Sciences.

A rising risk to canine and human well-being

Tens of millions across the Americas are affected by Chagas disease.

Chagas disease is predominantly overlooked. The parasite that triggers it, Trypanosoma cruzi, is transmitted by blood-sucking insects referred to as kissing bugs, which inhabit North, Central, and South America.

The condition, which frequently arises in both humans and dogs, as well as various other mammals, often goes undetected in its early stages. However, a chronic infection can lead to severe heart and digestive issues, highlighting the importance of early diagnosis and immediate treatment.

Though the majority of human cases of Chagas disease are reported from South and Central America and Mexico, the parasite and its insect vector are present in abundance across the southern United States. Outdoor animals — especially working dogs — are particularly susceptible to infection.

“The regions we are researching display annual new infection rates of 20% to 30%,” remarked Tarleton. “These typically are severe infections, leading to dogs either dying or developing conditions that impede their ability to work.”

Texas has become a central point for kissing bugs.

“Regrettably, Texas has emerged as a focal area for infected kissing bugs, wildlife, and dogs throughout the region,” stated Dr. Sarah Hamer, a professor in the Texas A&M College of Veterinary Medicine and a lead investigator on the projects.

“These initiatives will propel Chagas disease research forward to comprehend the mechanisms behind natural infections, disease, and treatment effects,” Hamer remarked. “These projects integrate numerous facets of biomedical research. We’re executing field and laboratory investigations, treating dogs, assessing clinical results, and examining ecological factors. It truly embodies a ‘One Health’ perspective.”

A One Health strategy for Chagas disease research

Identifying Chagas is complex — for both humans and canines. False negatives occur, preventing individuals from realizing they or their pets are infected, thus delaying treatment.

Even when the disease is diagnosed swiftly, managing the condition can be difficult.

The primary medications currently utilized to treat Chagas, as administered, are not consistently effective. However, they are the only available treatment option. Tarleton’s prior research in mice and other species indicates that their efficacy can be enhanced by adjusting the dosing schedule.

To tackle these challenges, the researchers will monitor infected dogs using a combined methodology involving sensitive tests to detect both the parasite DNA and the body’s immune response to infection. The team will concurrently evaluate a revised dosing approach for the existing antiparasitic medication, administering fewer but stronger doses over an extended period to enhance effectiveness.

“Recording health data from such a vast population of dogs will likely aid in understanding why the disease manifests differently.” —Dr. Sarah Hamer, Texas A&M

“The medication we are using is an established treatment for Chagas disease in humans,” noted Dr. Ashley Saunders, a professor in the Texas A&M College of Veterinary Medicine and a primary investigator on the projects. “However, Dr. Tarleton has demonstrated that the parasites do not respond to this medication while in a dormant state. By altering the drug administration protocol to extend dosing over a longer duration, the dormant parasites can be eradicated when they become active again.”

In a related study funded by the United States Department of Homeland Security, the researchers will also observe DHS-owned working dogs trained in regions where Chagas disease is prevalent. The aim is to understand the exposure pathways for the dogs and the implications it may have on their heart health, as well as to devise monitoring and treatment strategies tailored for these working canines.

“One of the advantages of monitoring dogs is that Chagas can lead to various health problems,” Saunders explained. “Some dogs develop heart abnormalities, while many continue to live and perform well for years. Others may succumb suddenly, often without prior knowledge of the disease.”

“Documenting health information from a large cohort of dogs should help us understand why the disease presents itself differently,” Hamer expressed.

Enhancing management of canine Chagas disease

With ongoing support from the American Kennel Club Canine Health Foundation, the team will treat and monitor individual pet dogs brought to Texas A&M’s Small Animal Teaching Hospital while establishing a staging system for Chagas disease in dogs.

“The staging system we create will assist in categorizing the disease’s severity, making it simpler to identify which dogs will gain the most from drug therapy,” Saunders mentioned. “This scoring system will align closely with our enhanced diagnostic and treatment strategies.”

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