Quarantine in Texas: US races to contain deadly flesh-eating parasite

Screwworm detected on farm decades after livestock threat was first eradicated in the United States

Following the ⁠first confirmation of screwworm, a flesh-eating parasite, on a US farm in decades, federal and state officials have fanned out in South Texas, where a calf was found infested this week.

US Agriculture Secretary Brooke Rollins said on Thursday no other infestations of cattle or other animals have been detected around the confirmed case.

The case in La Pryor, Texas, was a blow to US cattle ranchers who have been bracing for a domestic outbreak of New World screwworm as the fly advanced north through ‌Mexico over the past year.

The US Department of Agriculture broke ground in April on a facility to produce sterile flies, which experts describe as the best tool for combating the pest, but it will not come online until late 2027.

The federal agency and Texas officials quickly halted the movement of animals in a 20-km (12.4-mile) area around the case and took other steps to prevent the parasite from spreading.

Now, every major road out of La Pryor, Texas, is marked with a blinking orange road sign urging all vehicles carrying livestock to pull over to a checkpoint staffed with sheriffs and state personnel who inspect the animals for signs of screwworm.