A multidisciplinary team of researchers is working to develop fast-acting wound treatments that could give livestock producers and veterinarians a new tool to combat New World screwworm infestations.

The $1.86 million project is led by the Texas A&M Engineering Experiment Station and brings together researchers from Texas A&M University, Virginia Tech and Texas Tech University. The goal is to create treatments that can be applied directly to an infested animal as soon as screwworm larvae are discovered.

Filling a Critical Gap in Screwworm Response

New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals. Infestations can cause severe wounds and can be fatal to livestock, wildlife and companion animals if they are not quickly treated.

The parasite has been spreading through Central America and Mexico, raising concerns about its potential impact on the U.S. livestock industry.

The Sterile Insect Technique remains the primary method used to suppress screwworm populations across large areas. The technique involves releasing large numbers of sterile male flies, which mate with wild females without producing viable offspring. Over time, this reduces the overall fly population.

However, sterile fly releases do not provide immediate treatment for an animal that is already infested. The new research is intended to address that gap by creating products that ranchers and veterinarians could apply directly to affected wounds.

Researchers Testing Three Treatment Options

The research team is developing three field-ready formulations designed to kill screwworm larvae while reducing the amount of medication required.

The proposed treatments include:

  • A wound-conforming foam designed to remain in place and provide extended coverage.
  • A bio-adhesive spray that could be quickly applied directly to an affected wound.
  • An immersion wash intended for situations where large numbers of animals may need treatment.

The formulations combine reduced doses of synthetic macrocyclic lactones — a class of antiparasitic drugs — with botanical compounds such as neem and eugenol.

Researchers hope the combination will rapidly kill screwworm larvae and interrupt their life cycle while minimizing chemical residues in treated animals.

Reducing Whole-Animal Drug Exposure

Existing emergency treatments can kill screwworm larvae, but some require medication that affects the entire animal even when the infestation is confined to a single wound.

The experimental foam and spray are being designed to concentrate treatment at the wound itself, potentially allowing a much smaller amount of medication to be used.

Researchers will evaluate how effectively the formulations kill young screwworm larvae and determine how long treatment residues may remain in cattle. That information could eventually help establish appropriate animal health and food-safety guidelines.

Preparing for a Possible Screwworm Emergency

The project goes beyond developing the treatments themselves. Researchers also plan to create operating procedures, quality-control specifications and a cost-benefit framework that could assist the U.S. Department of Agriculture with stockpiling and emergency response planning.

The ultimate goal is to develop treatments that could be produced, stored and rapidly deployed if New World screwworm becomes established in U.S. livestock.

For Texas producers, having an effective treatment that can be immediately applied to an infested animal could become an important second line of defense alongside regional efforts to control screwworm populations.