By Emmy Powell
Communications Specialist

Cases of New World screwworm in Mexico continue to increase.

Mexico has recorded 5,920 cases of New World screwworm in animals as of Aug. 30, a significant increase from the 3,853 cases reported in July, according to Mexican government data. Currently, 743 cases remain active.

The sharp increase has raised alarms for U.S. livestock and wildlife.

“Every new screwworm case in Mexico is a reminder of what’s at stake for Texas ranchers,” Tracy Tomascik, Texas Farm Bureau associate director of Commodity and Regulatory Activities, said. “This pest threatens the health of our herds and the economic stability of rural communities that rely on livestock.”

Although most of the cases were found in cattle, the Mexican government also reported infestations in dogs, horses, pigs and sheep.

Ranchers in Texas and the U.S. are encouraged to stay vigilant and report any suspicious wounds to the Texas Animal Health Commission.

“The increase in screwworm cases in Mexico is a warning sign. Texas can’t afford to let our guard down,” Tomascik said. “Ranchers need strong prevention measures in place to keep this destructive pest from crossing the border.”

Those prevention efforts include the U.S. Department of Agriculture’s recent announcement of constructing a domestic sterile insect production facility at Moore Air Base in Edinburg. Once complete, it is expected to produce up to 300 million sterile flies per week.

The sterile insect technique is the only proven method for eradicating the New World screwworm.

About New World screwworm
New World screwworm, Cochliomyia hominivorax, is a flesh-eating parasite that targets warm-blooded animals, including cattle, horses, sheep, goats, birds, wildlife and even pets. Its larvae feed on living tissue, often causing severe injury or death if untreated.

The screwworm was eradicated from the U.S. in the 1960s. But recent cases in Mexico have raised concern about the pest re-entering the U.S.

In July, Texas Farm Bureau launched screwwormtx.org, a resource website alongside The Screwworm Coalition of Texas.

The site features a detailed list of educational events related, with additional guidance on practical steps to minimize risk coming soon.

Visit screwwormtx.org for the latest updates, resources and educational materials on the New World screwworm.