Louisiana tightens livestock restrictions as New World screwworm cases spread in Texa

"Just a little more than two weeks ago, the screwworm was 20 to 30 miles south of the Texas border," Strain said. "Now we've seen cases more than 30 miles north of the border."

The New World screwworm is a flesh-eating fly whose larvae infest open wounds in livestock, wildlife, pets, and, in rare cases, humans. The pest was eradicated from the United States in the 1960s through a large-scale sterile fly program, but has steadily moved north through Central America and Mexico in recent years.

Federal and state officials are now relying on that same strategy to prevent further spread. More than 400 million sterile flies are being released near confirmed Texas cases to disrupt reproduction. Strain said the federal government aims to increase that number to more than 500 million sterile flies per week.

"The goal is to stop it where it is in Texas," Strain said. "We eradicated it once before, and we will eradicate it again."

The U.S. Department of Agriculture has assigned at least 70 federal personnel to the affected area, where surveillance and quarantine zones have been established around confirmed cases.

Louisiana's emergency order, issued by state veterinarian Dr. Daniel Myrick, requires all livestock entering the state from Texas to be accompanied by health certificates certifying the animals did not originate from or pass through areas where screwworm has been detected.

Animals coming from designated surveillance zones face additional requirements, including permits from the Louisiana Department of Agriculture and Forestry, individual identification, and veterinary inspections. Health certificates and permits are valid for only seven days.

Strain emphasized that no cases have been detected in Louisiana and that the nearest confirmed infection remains more than 450 miles from the state's border.

Still, officials are preparing livestock producers and veterinarians for the possibility of an outbreak.

"We're educating producers on what to look for, how to treat cases and who to call if they suspect an infestation," Strain said.

If a suspected case is found, veterinarians would collect samples for testing at the National Veterinary Services Laboratories. A confirmed case would trigger an emergency response, including the release of sterile flies and expanded monitoring of livestock and wildlife within a roughly 12-mile radius.

While the parasite is not transmitted directly from animal to animal, officials worry about its potential impact on agriculture and wildlife populations if it becomes established.

Strain estimated that a widespread outbreak in Texas could cause between $1.5 billion and $2 billion in economic losses. Louisiana could face damages exceeding $1 billion if the pest spreads into the state.

"The biggest concern is the economic impact on producers," Strain said. "There would be increased monitoring, increased labor costs, and increased treatment costs. It could also have a devastating effect on wildlife populations."

Officials say infected animals can often be treated quickly with existing medications, but eradication efforts can take weeks or months because sterile flies must continuously outnumber fertile flies to break the reproductive cycle.

The federal government is expected to spend more than $1 billion on eradication and containment efforts, with sterile flies being produced at facilities in Panama, Mexico, and the United States.

For now, Louisiana officials are urging livestock owners and veterinarians to remain vigilant.

"If you have a wound and think you might have New World screwworm, contact your local veterinarian immediately," Strain said.