A hunter who harvested a female elk at a game ranch in Pecos County, Texas, has handed federal officials an unwelcome first: the earliest confirmed case of New World screwworm in American wildlife. The U.S. Department of Agriculture announced Wednesday that the parasite, which has already sickened dozens of livestock and pets across Texas and New Mexico this year, has now crossed into a wild game species for the first time since the current outbreak began.
The elk was reported to officials after being harvested by the hunter, according to a statement from the USDA cited by Yahoo News, which first reported the finding. New World screwworm is a flesh-eating parasite whose maggots burrow into the open wounds of warm-blooded animals, and its detection in a game ranch animal rather than livestock raises new questions about how far the pest has spread beyond the fences meant to contain it. KSL News, which also covered the detection via Reuters reporting from Washington, noted the same Pecos County location and circumstances.
The elk case arrived alongside a second new detection reported the same day: a case in cattle in Otero County, New Mexico. As KVIA reported, the Texas Animal Health Commission plans to modify an infested zone it had already established in response to the outbreak, and the agency described seven active cases of the parasite in New Mexico and Texas combined as of that report.
A Count That Doesn't Quite Add Up
That seven-case figure sits awkwardly next to another number making the rounds this month. As of October 15, screwworm cases in the United States had reached 56 since June, according to a report from Texas Public Radio. Texas accounted for 52 of those confirmed animal cases, while New Mexico had reported four. The discrepancy between the seven active cases cited in one report and the 56 total cases cited in another isn't explained in available reporting — the two figures may reflect different reporting windows or definitions of an active case versus a cumulative total.
What is clear is that, as of October 15, all 56 confirmed cases involved domestic animals, with none confirmed in wildlife or feral animals, per the Texas Public Radio report. Wednesday's elk detection marks the first time that status has changed. The same report notes that screwworm is not considered a food-safety threat, since the parasite feeds on living tissue in open wounds rather than contaminating meat broadly.
Sterile Flies and Shifting Boundaries
Federal and state officials have leaned on a decades-old containment tool to fight the outbreak: releasing sterile flies to disrupt the parasite's reproduction, the same Texas Public Radio report states. The approach echoes the strategy that eradicated New World screwworm from the United States back in 1966 through the targeted release of sterilized male flies, according to background from the U.S. Geological Survey, after the parasite was once native to the southern U.S. and Central America.
Surveillance has also picked up the pest in its flying adult form. Officials recorded one wild screwworm fly detection during the current outbreak, found in a surveillance trap in Brewster County on September 25, Texas Public Radio reported. In New Mexico, officials have expanded their own surveillance and fly-trapping efforts to catch any additional spread, according to a report from Source NM.
New Mexico's Growing Tally
New Mexico's own case count has been climbing steadily. The state reported two additional cases earlier this month — a horse and a calf, both in Grant County — bringing its total to three and four cases, per the Source NM report. New Mexico's first case of the outbreak turned up back in June, in a dog in Lea County, the outlet noted.
Cross-border livestock movement has been a central piece of the response. The Santa Teresa Livestock Crossing reopened in September after being closed for more than a year over screwworm concerns, according to the KVIA report. Movement restrictions remain in place in parts of 12 Texas counties under an established New World Screwworm Infested Zone, per the Texas Animal Health Commission, and animals cannot leave those designated zones without the commission's prior authorization.
For now, officials have not detailed the elk's symptoms, how it was tested, or what happens next for the game ranch where it was found. The USDA's confirmation stands as the clearest sign yet that an outbreak once confined largely to livestock pens has found a foothold in the wild.
