USDA Detects New World Screwworm in Texas Elk, Expands Surveillance Zone

The US Department of Agriculture announced Wednesday that a flesh-eating parasite, the New World screwworm, was identified in an elk harvested on a game ranch in Pecos County, Texas. This is the first confirmed wildlife case in the United States, leading the Texas animal health commission to modify a previously defined infested zone. Additional surveillance efforts are being coordinated by the USDA and the Texas parks and wildlife department across the region.

Texas wildlife division director Alan Cain called on hunters and landowners to remain alert for screwworm symptoms throughout the hunting season. The parasite, eliminated from the US many years ago, has been advancing northward from Central America via Mexico, prompting a year-long ban on Mexican cattle imports and a temporary halt to livestock imports last year. Trade resumed in August through an Arizona port, but the outbreak has strained cattle supplies and driven beef prices to record highs. Earlier this year, a calf in Zavala County near the border tested positive, and dozens of other cases—including a horse and a dog—have been reported nationwide.