Screwworm Reaches Texas Wildlife as Officials Race to Contain a Resurgent Threat

Screwworm Reaches Texas Wildlife as Officials Race to Contain a Resurgent Threat
The discovery of New World screwworm larvae in a Texas elk has turned a livestock problem into a broader wildlife alarm, testing whether officials can contain a parasite that has been moving north through Mexico.

The elk, found on a game ranch in Pecos County after being harvested by a hunter, is the first confirmed case in U.S. wildlife. The USDA and Texas Parks and Wildlife Department have begun additional surveillance, while the Texas Animal Health Commission plans to modify an existing infested zone. Hunters have been urged to report open or enlarging wounds, foul odors, visible maggots or signs of weakness in animals.

Officials frame the detection primarily as a surveillance and containment challenge. Alan Cain, director of Texas’ wildlife division, said: “We encourage all hunters and landowners to be vigilant for signs of New World screwworm while they are out in the field this season.” That message reflects the immediate distinction between the wildlife case and a confirmed food-safety crisis: the USDA says the parasite does not affect food safety, although it can damage meat production.

The wider economic picture is more troubling. The flesh-eating fly lays eggs in wounds or body openings, and its larvae feed on living tissue; the parasite can infect livestock and, rarely, humans. After decades of eradication in the United States, it has advanced from Central America through Mexico. Washington’s restrictions on Mexican cattle imports helped limit the threat but tightened U.S. supplies and pushed beef prices to record highs. The parasite was already detected in a Texas calf in June, with additional cases reported in a horse and a dog.

The elk finding therefore broadens the risk, rather than fundamentally changing the official response: surveillance is expanding, but the economic and ecological consequences remain difficult to contain.