Utah agriculture agency warns screwworm could spread north; readies sampling kits and movement controls

A Utah Department of Agriculture and Food (UDAF) staff member warned that Cochliomyia hominivorax, commonly called the screwworm, is moving north through Central America and Mexico and could reestablish in the United States, with potentially heavy economic and animal-health costs.

The presenter described the fly’s life cycle and clinical signs in animals, outlined containment tools used by federal and state authorities—including quarantine, movement controls, larval sampling and the sterile‑insect technique—and said UDAF is assembling sampling kits and working with partners to update response plans.

The warning follows increased detections in Panama beginning in 2023 and the November finding of a local case in Mexico; the presenter said authorities recently confirmed a case roughly 370 miles from the U.S. border in a calf with no travel history, indicating local transmission in that part of Mexico. "If this is not treated, it is fatal to the animals," the UDAF staff member said, noting that the pest affects all warm‑blooded animals, including people.

Why it matters: Screwworm infestations destroy tissue, reduce production and can cause animal death; historical eradication of the pest from the U.S. in 1968 required a nationwide campaign. The presenter cited an estimate that a…