Last updated: June 28, 2026. This is a developing situation. The case count and locations below reflect the latest information available and may change as USDA confirms new detections.

New World screwworm has been confirmed in the United States for the first time in decades, with cases in Texas and New Mexico drawing national headlines. The news is unsettling, and it has raised real questions for the people we hear from most: pet owners, livestock producers and anyone responsible for the health of an animal. There are no confirmed cases in North Carolina, and the current risk here is very low. The answers below cover what the parasite is, what to watch for and what to do.

We will update this page as the situation develops. For the latest information, visit screwworm.gov. We will update this page as the situation develops.

What is New World screwworm?

New World screwworm (NWS) is a parasitic fly. The adult is about the size of a common housefly or slightly larger. Females lay eggs in open wounds or body openings of warm-blooded animals, and when the eggs hatch, the larvae (maggots) burrow in and feed on living tissue. That feeding causes painful, foul-smelling wounds that can become serious if they are not treated early.

Where are the current cases?

As of June 28, USDA has confirmed 26 detections since the first case was found June 3. 25 are in Texas. A dog in Lea County, New Mexico, is both the first detection outside Texas and the first in a pet. USDA initially reported the dog as a Texas case, then reclassified it after determining the animal lives in New Mexico. Its travel history, including recent time in Mexico, is under investigation. Investigations into each case are ongoing, and the count may change.

What does this mean for North Carolina?

There are no confirmed New World screwworm detections in North Carolina, and the current risk here is very low. The North Carolina Department of Agriculture and Consumer Services Veterinary Division is monitoring the situation, and USDA maintains active surveillance to catch and contain the pest. Because screwworm spreads mainly when people move infested animals over long distances, the practical takeaway for North Carolina animal owners is the same as anywhere: Know the signs, check your animals regularly and call your veterinarian if you see a suspicious wound. We will update this page if the situation in our state changes.

Is my pet or my livestock at risk?

NWS can affect livestock, pets, wildlife and, less commonly, people. That said, USDA reports the overall risk to animals and people in the United States remains very low, supported by strong surveillance and a rapid response program. The confirmed cases so far are in Texas and New Mexico. The most important thing any owner can do is check animals regularly for wounds and keep an eye on newborns.

Can it spread to people or from person to person?

No. NWS is not contagious. It does not spread directly from animals to people or from one person to another. An infestation begins only when a female fly lays eggs on a wound or body opening. 

What should I look for?

Watch for these signs in animals:

• Maggots or white egg masses in wounds or body openings, including the nose, ears, genitalia or the navel of newborn animals.
• A foul odor or the smell of decay.
• Signs of pain, such as irritability, not eating, depression or pulling away from the rest of the herd.

Screwworm does not cause coughing or respiratory illness, so a cough alone is not a sign of NWS.

What do I do if I see a suspicious wound or maggots?

Contact your veterinarian right away. New World screwworm is a reportable disease in the United States, which means suspected cases must be reported to animal health officials. In North Carolina, you or your veterinarian can report a suspected case to the North Carolina Department of Agriculture and Consumer Services Veterinary Division at 919-707-3250, and veterinarians also report to the USDA Area Veterinarian in Charge. If a person has symptoms of myiasis (a maggot infestation), contact a health care provider, who should report suspected cases to the local or state health department.

Are all maggots screwworm?

No. A maggot infestation is called myiasis, and several flies including botflies and blowflies can cause it. An animal can even be infested by more than one species at once. Only an entomologist can confirm whether maggots are New World screwworm, which is why prompt veterinary involvement matters.

If one of my animals is infested, will my whole herd be culled?

No. Culling is not used to manage herds where individual animals are infested. Instead, a premises with a suspected case is placed under a hold order, which means animals cannot move until they are examined. Infested livestock are treated and quarantined until the wounds heal and there is no sign of reinfestation after 21 days. Euthanasia is reserved for rare cases, for humane reasons or when treatment is not possible.

Is the food supply safe?

Yes. NWS is not a food safety issue. It spreads only when a fly lays eggs in a wound, not through meat, poultry or dairy. Animals that recover from an infestation can enter the food supply if they meet all regulatory requirements and pass inspection by USDA’s Food Safety and Inspection Service (FSIS). Severely infested animals are not allowed into food production.

How is the USDA responding?

USDA and the state of Texas are leading the response. Eradication relies on the sterile insect technique, in which sterile flies are released so the population cannot reproduce. USDA has activated a sterile fly dispersal facility at Moore Air Base in Edinburg, Texas, and aerial dispersal is underway. Alongside that, USDA maintains intensive surveillance along the U.S.-Mexico border, including the use of thousands of insect traps across Texas, Arizona, New Mexico and California.

Will it spread rapidly across the country?

Screwworm thrives in tropical and subtropical climates and does not tolerate prolonged very dry, very hot or very cold weather. Because NWS is not contagious between animals and infestations are easy to recognize, its rapid spread has historically depended on people moving infested animals over long distances, which is exactly what movement controls and surveillance are designed to prevent.

How can I protect my animals?

• Check animals regularly for wounds, and check newborns and their navels.
• Keep wounds clean and covered when possible.
• Watch animals closely after procedures that create wounds, such as branding, dehorning, castration, or ear tagging.
• Call your veterinarian promptly if you see a worsening wound, unusual maggots or signs of pain.

Where can I learn more?

• USDA New World screwworm information: screwworm.gov
• View NWS Clinical Guidance [PDF]
• North Carolina Department of Agriculture and Consumer Services, Veterinary Division: ncagr.gov

This post reflects information available as of June 8, 2026, and will be updated as the situation develops.