Update Note: This article reports new information involving the first New World screwworm detection in U.S. wildlife following Nature World News' earlier coverage. Latest verified update: USDA announcement dated Oct. 21, 2026; case count of 59 as of Oct. 21, 2026, per USDA figures reported by DTN.

New World screwworm has been confirmed in a wild animal in the United States for the first time. The U.S. Department of Agriculture announced Oct. 21 that the parasite was found in an elk on a game ranch in Pecos County, Texas, reported after a hunter harvested the animal. The elk was already dead, so the case is listed as inactive.

The finding shifts the concern from cattle pens and horse barns to open country. Screwworm larvae feed on the living flesh of warm-blooded animals, and wild deer, elk and other game can carry an infestation across ranch fences where no one is checking them daily.

The timing matters for Texas hunters. Archery season is underway, the youth-only weekend runs Oct. 30 to Nov. 1 and the general deer season opens Nov. 7 across the state's North and South zones, putting large numbers of hunters in the field as the main early-warning network for a pest that is hard to spot in wildlife.

The Elk Case Changes the Picture

The United States had recorded 59 animal screwworm cases since the first detection on June 3, with seven active, as of Oct. 21, DTN reported, citing USDA. Pecos County had already logged five livestock cases, including an active cattle case reported Oct. 10. The same day as the elk announcement, New Mexico confirmed a case in a beef cow in Otero County.

Nature World News previously reported that a Grant County horse and calf pushed the U.S. count to 56 as New Mexico merged its infested zones. At that time, every confirmed case involved domestic animals. The elk is the first that does not.

USDA said the Texas Animal Health Commission will modify a previously established infested zone, and federal and state teams have increased wildlife surveillance in the area. Officials have not said whether more wild animals are infected, and no additional wildlife cases had been announced as of Oct. 28.

A Wildlife Foothold Worries Ranchers

The main tool against screwworm works best when the pest has few places to hide. The sterile insect technique releases huge numbers of sterile male flies, so wild females that mate with them lay eggs that never hatch. Agriculture Secretary Brooke Rollins said in a post cited by DTN that "More than 1.5 billion sterile flies have been released to stop the spread."

Wild animals complicate that strategy — infested livestock can be found, treated and quarantined, but deer and elk roam freely and an infested animal may hide in brush and die unseen, letting larvae drop to the soil and mature. South Texas veterinarian Gaylon Wilmeth-Burleson told Texas Public Radio earlier this year, "Unfortunately, with wildlife, there is no proven treatment."

Texas has an estimated 5.64 million white-tailed deer, according to TPWD figures reported by FOX 7. Historical accounts from earlier screwworm eras describe heavy losses of newborn fawns, which is why wildlife biologists and deer breeders have watched the current outbreak closely. USDA has not stated that a wildlife reservoir now exists. The Pecos County elk is a single confirmed case on a managed game ranch.

Inspection Tips for Hunters and Ranchers

Texas Parks and Wildlife Department officials are asking hunters to examine every animal before field dressing or moving it. Check the eyes, ears, nose, mouth, genitals and any wounds, and run your hands along the body, feet and between the toes for wounds with a foul smell or maggots, TPWD advised through FOX 7 Austin. TPWD Wildlife Division Director Alan Cain urged hunters and landowners to "be vigilant for signs of New World screwworm" this season.

Warning signs in any animal include open, draining or enlarging wounds, a strong rotten odor, visible maggots in a wound or body opening, and an animal that seems weak, isolated or in distress. A single maggot-infested carcass does not confirm screwworm, since ordinary blow flies also lay eggs in dead tissue, which is why officials want samples collected and tested.

Suspected cases in wildlife should be reported to TPWD at 512-389-4505 or to a local TPWD biologist. Livestock and pet cases go to the Texas Animal Health Commission's 24-hour line at 1-800-550-8242. USDA's guidance is direct: "If you see anything suspicious, report it immediately." Hunters should not try to treat or relocate an infested animal themselves.

Costs, Trade and What Comes Next

For ranchers, every new infested zone brings movement restrictions, inspections and treatment costs, and the outbreak has already disrupted cattle imports from Mexico. USDA reopened the Columbus, New Mexico, port to cattle on Oct. 26 and plans to reopen Nogales, Arizona, on Nov. 30, according to DTN. A spreading wildlife problem could slow those reopenings.

Capacity is the other constraint — USDA is building a sterile fly production plant at Moore Air Base in South Texas, projected at 300 million flies a week, but it is not yet finished. Until then, the program depends mostly on facilities in Panama and Mexico.

Public health officials consider the risk to people low, and no locally acquired human case has been reported in this outbreak. The next updates to watch are USDA's case dashboard, any revised Texas infested-zone map and results from expanded wildlife surveillance around Pecos County.

The bottom line: a single Texas elk is the first confirmed screwworm case in U.S. wildlife, and it is already inactive. The concern is what it signals about the pest reaching animals no one monitors daily, which makes hunters' inspections this season a frontline defense.

What Readers Want to Know

What was found in the Texas elk? New World screwworm, confirmed by USDA in a hunter-harvested elk on a Pecos County game ranch. It is the first U.S. wildlife case.

Is the elk case still active? No. The elk was already dead when reported, so USDA lists the case as inactive.

How many U.S. screwworm cases have there been? USDA counted 59 animal cases since June 3, with seven active, as of Oct. 21.

What should deer hunters check for? Wounds with maggots or a foul smell, especially around the eyes, ears, nose, mouth, genitals, feet and between the toes.

Who do I call about a suspected case? Wildlife cases go to TPWD at 512-389-4505. Livestock and pets go to the Texas Animal Health Commission at 1-800-550-8242.

Can people get screwworm from deer meat? Officials consider the risk to people low, and no locally acquired human case has been reported. Do not harvest or handle visibly infested animals without gloves.