New research aims to track outbreaks and detect drug resistance
According to Texas A&M University College of Veterinary Medicine & Biomedical Sciences, researchers are using advanced genomic tools to better understand New World screwworm populations and improve outbreak preparedness.
The research team received nearly $4 million in funding from the U.S. Department of Agriculture through its New World Screwworm Grand Challenge. The two-year project will study screwworm samples collected during the ongoing outbreak in Honduras.
New World screwworm is a parasitic fly whose larvae infest wounds and feed on living tissue. The parasite can cause severe injuries and may be fatal if animals are not treated quickly. Cattle are among the most affected species, but horses, sheep, goats, pigs, pets, wildlife and even humans can also be infected.
Although the pest was eliminated from the United States decades ago through a large-scale eradication effort, new outbreaks in Central America and Mexico have raised concerns. By 2026, screwworm cases had once again reached the United States, increasing the need for better monitoring and control tools.
"It doesn't discriminate," said Dr. Guilherme Verocai, an associate professor in the VMBS Department of Veterinary Pathobiology (VTPB) and director of the Parasitology Diagnostic Laboratory. "It will infest pretty much any living, warm-blooded animal."
The Texas A&M team is working with animal health specialists and government partners in Honduras to gain access to thousands of screwworm samples collected throughout the outbreak. Researchers will examine the samples to learn how screwworm populations change over time and across different locations.
Using advanced genomic technology, scientists plan to analyze nearly the entire genetic makeup of thousands of screwworms. This approach will provide a much more complete understanding of the parasite than previous studies, which focused on only a few genes.
Researchers believe the project will become the largest genetic study of New World screwworms ever conducted. High-performance computing systems will help process and compare the large amount of genetic data collected during the project.
One of the main goals is to determine whether screwworm populations are showing signs of resistance to drugs used to prevent and treat infestations. Drug-resistant screwworm populations have been reported in some parts of South America, making this a major concern for livestock health officials.
By comparing genetic information with field records and treatment histories, researchers hope to identify markers linked to reduced drug effectiveness. These discoveries could lead to the development of a molecular test capable of detecting resistant screwworm populations.
Scientists also expect the project to improve outbreak tracking. Genetic information can help identify relationships between screwworm populations from different regions and may reveal where future outbreaks originate.
Such information could help animal health officials respond more quickly if new cases appear in the United States. It may also help researchers understand how the parasite spreads across borders and changes over time.
The project could provide additional benefits by identifying parts of the screwworm genome that remain stable across populations. Those areas may become targets for future treatment methods or genetic control technologies.
Once completed, the genomic database will be shared with researchers in the United States, Central America and other regions. Access to this information may support further scientific discoveries and strengthen efforts to manage screwworm outbreaks.
Researchers say the goal is to provide practical tools that help veterinarians; livestock producers and animal health agencies respond effectively to one of the most damaging parasites affecting animals. By combining genetics, computing power and international collaboration, the project aims to strengthen preparedness and improve protection for livestock in the years ahead.
Photo Credit: Dr. Verocai-Texas A&M University