Officials confirm 6 cases of New World screwworm in Texas

Federal officials have confirmed a total of six cases of New World screwworm in Texas as of June 11, 2026.

New World Screwworm in Texas

The latest:

Since June 3, six cases of New World screwworm have been reported to the USDA. The cases have been found in Zavala, La Salle, Gillespie and Edwards counties. The pest has been found in cattle and goats.

Officials initially reported an additional case involving a dog in Andrews County on June 8. However, after further epidemiological investigation, authorities determined the animal lives in Lea County, New Mexico, and the case was reclassified as New Mexico's first confirmed New World screwworm infection.

The veterinarian who submitted samples from the dog is based in Texas, officials said. Early reports indicated the dog had recently traveled to Mexico.

The Texas Parks and Wildlife Department said updates will be provided as additional cases are confirmed. The agency has established a public information page and said situation reports will be updated daily when new detections occur.

Quarantine in place

There is currently a quarantine in place due to an established New World Screwworm Infested Zone in parts of the following Texas counties: Edwards, Gillespie, Kerr, Kimble, La Salle, Sutton, Uvalde, Val Verde, Webb, Zavala.

According to the Executive Director Orders issued, all warm-blooded animals in a zone may not move out of the zone without prior authorization from the Texas Animal Health Commission (TAHC).

View the zone map.

Warm-blooded animals moving outside an infested zone must contact the TAHC to set up an inspection. During this inspection, an animal health official will fill out an animal movement certificate listing the product used for prevention or treatment and the animals' official ID. This certificate will need to accompany the animal movement. Additional guidance can be provided during an initial inspection request call to TAHC.

What is New World Screwworm?

The New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals, posing a significant threat to livestock, wildlife and, in rare cases, humans.

Officials advised livestock owners and veterinarians to remain vigilant and report suspected infestations to the appropriate authorities. The Texas Animal Health Commission is handling livestock-related cases, while the Texas Department of State Health Services oversees human infestation reports.

Identifying the New World screwworm

The New World screwworm fly looks similar to other flies. It can be identified through its large orange eyes, yellow face, metallic blue body, and three stripes along its back.

Are humans at risk?

Though the risk to the public remains low, people can sometimes get an NWS infestation if they visit areas where the fly is present, such as Mexico, Central America or parts of South America and the Caribbean.  People who do the following in areas with NWS might be at greater risk of infestation:

• People who sleep outdoors during the day (unhoused, campers)
• People who primarily work outdoors
• Ranchers and those who work with animals
• People with an open wound
• Those with diabetes or other skin conditions

DSHS urges people to take precautions by following these steps to prevent NWS infestation:

• Keep open wounds clean and covered
• Sleep indoors or in screened shelters, and keep window screens in good repair
• Wear loose-fitting, long-sleeved shirts and pants to prevent scrapes and insect bites
• Use an EPA-registered insect repellent to prevent insect bites
• Treat clothing and gear with products containing 0.5% permethrin, which is an insecticide and repellent.

People who see or feel larvae in or on their wounds should immediately contact their healthcare provider. If you think you might have been exposed to C. hominivorax or think you might have an NWS infestation, contact your healthcare provider.

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