Screwworm cases move closer
By Kelsey Bell
Shackelford County
Extension Agent
Those of us that work in agriculture and wildlife industries have been watching the Northern advancement of the New World Screwworm since 2023. Unfortunately, it’s now getting way too close for us to be comfortable. As of the writing of this article, 12 cases of NWS have been confirmed in six Texas counties, with the furthest northern case being in Tom Green County, roughly 100 miles from us.
The New World Screwworm is a parasitic fly that lays eggs in open wounds of warm-blooded animals. The larvae (maggots) feed on living tissue, causing severe damage and even death if left untreated. The pest was eradicated from the U.S. in the 1960s. It has occasionally re-emerged into Central America and Mexico since then and has been successfully controlled through the release of sterile males.
Animal owners should monitor their livestock regularly, and wildlife where possible. Signs associated with potential infestation include foul-smelling wounds with visible maggots, biting or licking at wounds, lesions in navels, ears or wound sites, and unusual restlessness or lethargy.
If you suspect a case, do not move the animal and report it immediately. You may contact your veterinarian or the Texas Animal Health Commission at 1-800-550-8242. Texas Parks and Wildlife is the leading agency regarding potential wildlife cases. I am here and ready to help you through the process as well.
The best preventative measures you can take are to treat wounds promptly and maintain sanitation until they are completely healed.
Look for information from sources you can trust. Texas A&M AgriLife Extension has a website for all things NWS at tx.ag/screwworm. You can also sign up for the Texas Agriculture Alert System at agalert.tamu.edu.
The Texas Animal Health Commission has an interactive map of Infestation Zones and Surveillance Zones at www.tahc.texas.gov/emergency/nws.html. USDA APHIS confirmed detections of NWS can be found at screwworm.gov.
Shackelford and Callahan County producers are invited to attend an informational meeting hosted by the two AgriLife Extension offices and the Callahan County Vet Clinic. The meeting will be held July 9 from 6 to 8:30 p.m. at the Baird High School Gymnasium. More details will be released soon.
Texas A&M AgriLife is also offering a New World Screwworm Preparedness and Response Education Course to help Texas producers, wildlife managers and animal owners understand inspection, reporting and treatment of the New World Screwworm. The course is available at tx.ag/nwstrainingcourse.
The New World Screwworm is a serious but well understood pest. We have eradicated it before, and I feel confident that we will again. If you have further questions, please reach out to me at Kelsey.Bell@ag.tamu.edu.
