The Trump administration is temporarily banning imports of cattle, horses, and bison through ports along the southern border due to rapid spread of the dangerous flesh-eating New World Screwworm in Mexico.
An outbreak of them has been discovered on farms 700 miles from the US border in Mexico, officials said. So, what is the Screwworm? They're fly larvae named for tiny mouth hooks (hence the 'screw' in their name) that burrow into animals and sometimes in rare cases humans. Per NPR, "The maggots feast on the flesh and blood of their host ... Left untreated, the parasitic infection can kill a full-grown cow within one to two weeks."
U.S. Department of Agriculture Secretary Brooke Rollins announced the suspension, stating, "Due to the threat of New World Screwworm, I am announcing the suspension of live cattle, horse, and bison imports through U.S. southern border ports of entry effective immediately."
The USDA reported the first case of NWS in Mexico in November 2024, and suspended imports when tests found them closer to the U.S. border. No being is spared by the fly maggots, which can cause serious and often deadly damage to animals, including pets, livestock, wildlife, birds, and in rare cases, humans.
The USDA said restrictions on live animal imports from Mexico will continue on a month-to-month basis until containment is achieved.
Secretary Rollins emphasized the importance of protecting the livestock industry and food supply, stating the action wasn't anything against Mexico, but "The protection of our animals and safety of our nation’s food supply is a national security issue of the utmost importance."
This isn't the first time Screwworms have popped up in the South. NPR reported that in 1976, an outbreak in Texas affected more than 1.4 million cattle and hundreds of thousands of sheep and goats. "If such an outbreak were to occur now, it's estimated that would cost the Texas economy $1.8 billion, according to a USDA analysis."
The way they were eradicated then was releasing sterile versions of the male Screwworm that mated with the female and caused a generation of the tiny beasts that couldn't lay eggs. There's no word yet on whether a similar attempt is going to be made to curtail this outbreak.