USDA confirms first New World screwworm detection in US wildlife

The USDA Animal and Plant Health Inspection Service (APHIS) has confirmed the first detection of New World screwworm (NWS) in wildlife in the United States. The parasite was found in an elk located on a game ranch in Pecos County, Texas. The case was reported after the animal was harvested by a hunter.¹

In response, the Texas Animal Health Commission will modify a previously established infested zone, while USDA and the Texas Parks and Wildlife Department (TPWD) conduct additional wildlife surveillance in the area.¹

“Early reporting is one of the most important tools we have to protect wildlife, livestock, and pets in the United States,” APHIS stated in its announcement.¹

Why wildlife detection matters

According to APHIS, all warm-blooded wildlife species are susceptible to NWS, and infested animals that go untreated die quickly, a dynamic that can reduce wildlife populations.² The agency describes wildlife surveillance as crucial to controlling NWS outbreaks because wild animals can carry the pest over wide areas and across state lines.

That mobility makes wildlife a concern not only for wild species but also for the livestock and companion animals that share the same landscape. Monitoring screwworm in wild populations is an important part of protecting other animals, the agency noted.²

Hunters as front-line observers

The detection highlights the role hunters, landowners, outdoor enthusiasts, and wildlife professionals play in identifying and stopping the spread of NWS, according to APHIS.¹ People who spend time outdoors near infested areas are often among the first to encounter affected animals, which makes their observations especially valuable to surveillance and response efforts.¹

With hunting seasons continuing in Texas and other states, APHIS is urging hunters to stay alert for signs of NWS when observing, harvesting, or processing wildlife. Signs include:¹

• Larvae in wounds or body openings
• Open, draining, or enlarging wounds
• Foul-smelling injuries
• Animals that appear weak, lethargic, isolated, or in distress
• Signs of infestation around the nose, mouth, ears, eyes, or genital areas

How to report suspected cases

APHIS advises that maggot infestations in live or very recently dead wild animals be reported right away.² In Texas, suspected wildlife cases should be reported to TPWD. Outside Texas, especially in areas near the US-Mexico border, suspected cases can be reported by calling 866-4USDA-WS (866-487-3297) or by contacting a local USDA Wildlife Services office.² Fast reporting helps animal health officials respond quickly and limit the pest’s spread, according to the agency.¹

Resources for veterinary teams and partners

The APHIS Screwworm.gov wildlife page offers materials veterinary teams can use or share with clients who hunt, manage land, or work with wildlife.² Resources include a quick guide for hunters on spotting and reporting NWS, as well as a chart outlining approved NWS treatments for different wildlife species, with available products, use guidance, and safety notes.²

The agency also provides a Wildlife Partner Toolkit that includes printable fact sheets and pocket cards, ready-to-publish articles, a social media kit, key messages, and suggested text for hunting regulation booklets, guides, and licensing websites. Links to US Department of the Interior wildlife health preparedness tools are also available.²

References

1. USDA confirms first detection of New World screwworm in U.S. wildlife. News release. USDA Animal and Plant Health Inspection Service. October 21, 2026. Accessed October 23, 2026. https://www.aphis.usda.gov/news/agency-announcements/usda-confirms-first-detection-new-world-screwworm-us-wildlife
2. New World screwworm: a threat to wildlife. USDA Animal and Plant Health Inspection Service. Updated September 1, 2026. Accessed October 23, 2026. https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/stop-screwworm/wildlife