Screwworm Surge in Texas: What Ranchers and Pet Owners Must Know

Screwworm Threat Across Texas: Facts and Response

The U.S. Department of Agriculture confirmed the first U.S. case of the New World screwworm in a newborn calf in Texas this June, and the tally has risen to ↑ 24 confirmed animal infections, all in Texas, spanning cattle, a goat and a dog that roamed from New Mexico. What is a screwworm? It is a parasitic fly whose larvae feed on living tissue, unlike ordinary maggots that consume only dead matter. Female flies deposit eggs in open wounds, eyes, nostrils or anal regions of mammals, and the hatching larvae can trigger sepsis and death within weeks if untreated.

Human health risk and food safety

USDA officials stress that screwworm does not transmit to people and poses no food‑safety hazard; meat from affected livestock can be consumed after proper processing. The agency has also linked the outbreak’s timing to climate‑driven northward migration of the fly, a pattern reminiscent of post‑pandemic shifts in vector‑borne diseases.

“We need every farmer, veterinarian and pet owner to report a suspect wound immediately,” says Anne Kimmerlein, veterinary epidemiologist at Mars Veterinary Health.

Pet owners should inspect wounds daily; signs such as rapid swelling, discharge or tiny white eggs warrant veterinary care. Treatment options include FDA‑authorized anti‑parasitic tablets that kill larvae within hours.

Control strategy: sterile‑male releases versus bait traps

The USDA has deployed millions of sterile male flies, a technique that succeeded in the 1960s but now faces criticism from Texas Agriculture Commissioner Sid Miller, who argues that the current output—↓ 100 million per week from existing facilities—is insufficient. Miller advocates a hybrid approach that adds insecticide‑laced bait stations, a method that reportedly eliminated 95 % of flies during the 1970s outbreak, though experts caution that data are mixed and that the pesticide once used is now banned as a carcinogen.

Scientists at GeneConvene are testing a gene‑editing process that would produce exclusively male flies, potentially doubling output and reducing costs, a development the EPA is reviewing under emergency use authority.

For now, federal and state agencies urge immediate reporting of any suspected case, rapid treatment of affected animals, and continued monitoring of fly movement via cross‑border surveillance. As Reuters notes, coordinated action remains the best chance to prevent a wider spread.

Reported by: Elena Rostova

Socio-Economic Trends Analyst