The FDA issued an Emergency Use Authorization on Aug. 7 for a drug to protect sheep, cattle, goats, and swine from New World Screwworm infestation, as the flesh-eating parasitic fly threatens to re-enter the United States from Mexico after a six-decade absence.
The authorization expands on an earlier emergency authorization covering horses, reflecting the growing urgency of the threat at the U.S.-Mexico border, according to USDA’s Animal and Plant Health Inspection Service.
New World Screwworm was eradicated from the United States in the 1960s through a massive federal program that used sterile insect technology to wipe out the pest. The parasite has re-emerged in Mexico and is threatening northward spread into U.S. livestock populations.
The screwworm larvae feed on the living tissue of warm-blooded animals, creating potentially fatal wounds. An infestation of U.S. cattle herds could devastate the beef industry, which generates more than $100 billion in annual economic activity.
APHIS has been coordinating surveillance and response at southern border livestock entry points. The agency is working with Mexican counterparts to contain the outbreak south of the border while preparing defensive measures domestically.
A confirmed U.S. outbreak would trigger immediate trade restrictions on American beef exports under international animal health protocols, potentially costing the livestock industry billions in lost market access.
The EUA allows veterinarians and livestock producers to access the protective drug before it completes the standard FDA approval process, enabling a faster response to the emerging threat.