The number of confirmed New World screwworm cases in the United States has risen to 20 — 19 in Texas and one in New Mexico — after the flesh-eating parasite turned up in a bovine in Medina County, according to FOX 7 Austin’s Amber Kite, whose June 25 reporting cited federal and state animal-health agencies.
The Medina detection, confirmed June 23, pushed the outbreak south and east of the Big Bend cluster that has driven most recent activity and prompted what the same reporting describes as immediate state action.
In response, Texas Animal Health Commission Executive Director Dr. Lewis R. Dinges signed a new executive order on June 24 declaring “Infested Zone 09,” the latest in a widening lattice of quarantine boundaries the agency has stood up since the outbreak began. The order, as FOX 7 reports, imposes strict movement restrictions across designated parts of Bandera, Medina and Uvalde counties.
Under the terms Dr. Dinges signed, the Commission says, no warm-blooded animal may leave a designated infested zone without prior authorization, and hides, carcasses and animal parts capable of hosting the pest are barred from leaving until a Commission representative inspects, treats and clears them — with unauthorized movement subject to administrative penalties and criminal prosecution.
The Medina case did not arrive in isolation. FOX 7 reports that three domestic cattle cases were confirmed June 23 in Terrell County, one day after a case was confirmed in a Terrell County goat on June 22, and that state agricultural officials regard those concentrated detections as significant focal points for containment.
Every confirmed U.S. case to date has involved domestic animals rather than wildlife, FOX 7 reports, and there have been no reports of locally acquired human infestations, with the Texas Department of State Health Services maintaining monitoring and the Texas Animal Health Commission noting that any infection would be caught in federal meat inspection and kept out of the food supply. The Commission reiterates that the parasite lays eggs in open wounds — branding sites, castration cuts, tick bites — and that untreated animals can die within a week.
The USDA has launched sterile-fly dispersal flights over affected regions, including Crockett and Terrell counties, and rapid-response teams caution that additional cases are likely in the coming days because the sterile insect technique prevents future generations from reproducing but does not kill larvae already incubating in animals.
With a roughly 21-day life cycle, officials project several reproductive cycles before local populations collapse. Agriculture Secretary Brooke Rollins, quoted by FOX 7, framed the spread as serious but anticipated: “These developments obviously represent a serious threat to our livestock and wildlife, but they haven’t caught us off guard.”
Across the border, Mexico has reported more than 29,000 cases since November 2024, with roughly 1,800 currently active, underscoring why Texas regulators keep drawing new zones rather than relaxing the ones already in place. Livestock owners are urged to inspect animals daily for non-healing or foul-smelling wounds and to report suspected cases immediately to the Texas Animal Health Commission at 512-719-0700, with wildlife concerns directed to Texas Parks and Wildlife.