US halts Mexican cattle imports as flesh-eating nasty nears border

The move came just days after livestock trade resumed at the Douglas, Arizona port of entry.

PUBLISHED 1 DAY AGO

At its peak in late June, Mexico recorded 480 screwworm cases, now reduced to under 400.

WASHINGTON D.C.: The U.S. Department of Agriculture (USDA) has halted Mexican cattle imports after a new outbreak of the flesh-eating New World screwworm was reported roughly 370 miles from the U.S. border in Veracruz. The move came just days after livestock trade resumed at the Douglas, Arizona port of entry.

The New World screwworm (Cochliomyia hominivorax) is a species of fly whose larvae feed on the living tissue of warm-blooded animals. Females lay eggs in open wounds, and once hatched, the larvae burrow into flesh, causing severe pain, infection, and potentially death if untreated.

Though rare, humans can be infected by screwworm larvae, typically through open wounds. These cases require urgent medical attention, often involving surgical removal of larvae and antibiotic treatment.

At its peak in late June, Mexico recorded 480 screwworm cases, now reduced to under 400, according to the Agriculture Ministry. Mexican President Claudia Sheinbaum criticized the U.S. import ban as "exaggerated", asserting the outbreak is under control. "We hope that they will reopen very soon," she said Thursday.

U.S. officials, however, remain cautious. “Closing the border isn’t just justified, it’s essential,” said Bill Bullard of R-CALF USA. Secretary of Agriculture Brooke Rollins emphasized that further progress in affected Mexican states is necessary before reopening more ports.

The U.S. successfully eradicated screwworms through a sterile insect technique, where millions of sterilized male flies were released to mate with wild females, resulting in infertile eggs. To maintain that success, the USDA announced plans to build a sterile fly dispersal facility in Hidalgo County, Texas, and is considering a production facility as well.

Industry leaders are urging swift action. “We cannot wait any longer,” warned Colin Woodall of the National Cattlemen’s Beef Association. An infestation in the U.S. could severely disrupt cattle supplies, already at historic lows, and threaten broader agricultural and pet populations. Mexico’s beef industry expressed regret over the halt and noted its own efforts to deploy sterile flies in containment zones.