Research explores approved medicine to protect livestock from pests
The New World screwworm has re-emerged as a serious threat to livestock, wildlife, and agricultural trade in the United States. As cases continue to raise concern, researchers are exploring new ways to protect animals and reduce the impact of this damaging pest.
A research project supported through a special agricultural grant is investigating whether an existing FDA-approved medicine called nitisinone can be used to kill screwworm larvae. The study aims to provide livestock producers and veterinarians with an additional tool to help manage infestations and improve animal health.
"New World screwworm is a significant and urgent threat to animal health, U.S. producers’ profitability, competitiveness and the food supply chain," said Dr. Jasmine Bruno, FFAR scientific program director. "This research could expand the limited options available for controlling New World screwworm. By evaluating a drug already approved for human use, the project could accelerate the path toward veterinary applications by building on existing safety data."
Scientists have become interested in nitisinone because previous research showed the drug can kill several blood-feeding insects and pests. These include mosquitoes, ticks, bed bugs, stable flies, and other arthropods. Researchers discovered that the medicine blocks a key enzyme needed by these pests, making it a promising option for screwworm control.
The project is being led by researchers from the University of Notre Dame, including Dr. Lee Haines and Dr. Álvaro Acosta-Serrano. Their team is using a closely related species, known as the secondary screwworm, to study how the drug affects larvae and adult flies.
"We've already demonstrated nitisinone’s transformative ability to kill other blood-feeding insects, and applying this knowledge to screwworms opens up a timely new frontier in livestock protection," Dr. Haines said.
He added, "Growing up on a farm, I watched our animals suffer from other blood-sucking insect pests every summer, and that experience taught me early on just how much these tiny predators can wear an animal (and the farmer) down. We are eager to build on our recent breakthroughs in vector-borne diseases to develop a much-needed and complementary tool for protecting U.S. livestock and producers from the screwworm populations expanding across the country."
A major focus of the research is determining whether nitisinone can safely and effectively kill screwworm larvae in wound environments where infestations commonly develop. Scientists are also examining how the drug influences insect growth, reproduction, and survival.
The findings will help researchers determine proper dosage levels and evaluate whether the treatment could be used in larger studies involving primary screwworm populations. If successful, the approach could accelerate the development of new veterinary tools because the medicine already has an established safety record in humans.
Experts believe new solutions are urgently needed because some existing treatments have shown reduced effectiveness, while available control options remain limited. Developing additional methods of protection could strengthen preparedness against future outbreaks and help safeguard livestock production.
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