U.S. livestock producers are being urged to remain alert as federal and state authorities respond to a new outbreak of New World Screwworm in Veracruz, Mexico just 370 miles from the Texas border. The discovery has prompted the U.S. Department of Agriculture (USDA) to suspend livestock imports from parts of Mexico and fast-track countermeasures to prevent the flesh-eating pest from entering the United States.

Livestock Import Ban Reinstated

The USDA announced this week that it is halting imports of cattle, bison, and horses through southern border ports. This move comes just weeks after officials began reopening trade routes that had been closed due to earlier screwworm detections. The new case in Veracruz marks the northernmost detection in recent years, signaling a troubling shift in the parasite’s range.

“Given the proximity to the U.S. border and the nature of screwworm infestations, we are taking swift action to protect American livestock,” said USDA Secretary Kate Rollins in a press statement.

USDA Launches Massive Sterile Fly Strategy

In response, the USDA is ramping up its Sterile Insect Technique (SIT) a biological control strategy that involves releasing sterile screwworm flies to reduce wild populations. Key initiatives include:

Construction of a new $8.5 million sterile fly dispersal facility at Moore Air Base in South Texas.

Expansion of fly production in Mexico and Panama, with a target of 400 million sterile flies per week.

Initial fly releases expected along the Texas Mexico border within 18 months.

“This is one of the most aggressive and forward-looking responses we’ve ever implemented for an invasive livestock pest,” said Dr. Alan Pierce, USDA’s lead entomologist on the project.

State Warnings Issued Across the U.S.

While the outbreak remains south of the border, agriculture departments in states like Minnesota, Nebraska, and Kansas have issued alerts to producers. Authorities emphasize that while the current risk is low in northern regions, summer conditions and animal movements can increase the chance of transmission.

What to Watch For

Livestock producers are advised to closely monitor their animals for signs of screwworm infestation, which include:

Open wounds with foul-smelling discharge

Visible maggots in cuts or abrasions

Signs of pain, agitation, or weight loss in affected animals

Immediate veterinary attention is critical, as untreated infestations can lead to severe tissue damage and death.

How to Respond

Inspect livestock daily, especially during transport or after medical procedures.

Report suspected cases to your state veterinarian or USDA Animal and Plant Health Inspection Service (APHIS).

Avoid transporting animals from or through affected regions without thorough health checks.

A National Effort

The USDA’s efforts are part of a multi-agency collaboration with Mexico, Panama, and regional governments to contain the pest before it crosses into the U.S. The last major screwworm outbreak in the U.S. was eliminated in 1982 after decades of coordinated control efforts.

Experts warn that a return of the parasite could cost the U.S. livestock industry billions of dollars in losses.