Federal officials have confirmed six cases of New World screwworm in livestock across four Texas counties, with a seventh case originally attributed to Texas, which has been reclassified as the first detection in New Mexico.
The cases have been reported to the U.S. Department of Agriculture since June 3 and involve cattle and goats in Zavala, La Salle, Gillespie, and Edwards counties, according to the agency’sonline tracker.
An additional case involving a dog in Andrews County was initially reported on June 8. After an epidemiological investigation, officials determined the animal lives in Lea County, New Mexico, and reclassified the case as that state’s first confirmed New World screwworm infection. Officials said the veterinarian who submitted the samples is based in Texas, and early reports indicated the dog had recently traveled to Mexico.
Quarantine and movement restrictions
A quarantine is in effect across portions of 10 Texas counties designated as part of an established New World Screwworm Infested Zone: Edwards, Gillespie, Kerr, Kimble, La Salle, Sutton, Uvalde, Val Verde, Webb, and Zavala.
Under Executive Director Orders, warm-blooded animals inside the zone may not be moved out without prior authorization from the Texas Animal Health Commission. Owners moving animals outside the zone must contact the commission to arrange an inspection, during which an animal health official completes a movement certificate listing the prevention or treatment product used and the animal’s official identification. The certificate must accompany the animal during transport.
Gov. Greg Abbott activated the Texas State Emergency Operations Center to support the state’s response to the reemergence of the pest, which Texas previously eradicated decades ago.
The Texas Parks and Wildlife Department said situation reports will be updated daily as new detections occur.
About the pest
The New World screwworm is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals, posing a threat to livestock, wildlife, and, in rare cases, humans. The adult fly can be identified by its large orange eyes, yellow face, metallic blue body, and three stripes along its back.
The Texas Animal Health Commission is handling livestock-related cases, while the Texas Department of State Health Services oversees human infestation reports.
Risk to humans
Officials said the risk to the public remains low, but people can contract an infestation in areas where the fly is present, including Mexico, Central America, and parts of South America and the Caribbean. Those at greater risk include people who sleep outdoors, outdoor workers, ranchers and others who work with animals, individuals with open wounds, and people with diabetes or other skin conditions.
The Department of State Health Services recommends keeping wounds clean and covered, sleeping indoors or in screened shelters, wearing loose-fitting long sleeves and pants, using an EPA-registered insect repellent, and treating clothing and gear with products containing 0.5% permethrin.
People who see or feel larvae in or on a wound should contact a healthcare provider immediately.
