US confirms first flesh-eating screwworm detection in wildlife, in Texas elk

The US Department of Agriculture (USDA) said on Wednesday that it has confirmed the first case of the New World screwworm, a flesh-eating parasite, in US wildlife. The affected animal was an elk in Pecos County, Texas, found on a game ranch and reported after a hunter harvested it.

According to the USDA, the Texas Animal Health Commission will modify an infested zone that was set up earlier. The USDA and the Texas Parks and Wildlife Department are carrying out additional wildlife surveillance in the area.

Alan Cain, director of the Texas wildlife division, urged hunters and landowners to watch for signs of the screwworm while in the field this season.

Background and market impact

The pest was eradicated from the US decades ago but has surged north from Central America through Mexico. In response, Washington imposed a ban on Mexican cattle imports that has lasted more than a year. The US halted livestock imports from Mexico last year to keep the screwworm out, then resumed trade in August at one Arizona port under a phased reopening plan.

The halt has tightened US cattle supplies and pushed beef prices to record highs for American consumers.

Despite those measures, the screwworm was detected in June on a calf in Zavala County, Texas, near the US-Mexico border. Dozens of cases have been found in the US since then this year, including in a horse and a dog.