New World Screwworm Outbreak

The New World screwworm, a flesh-eating parasite, has spread into Mexico, alarming U.S. officials who have halted imports of live cattle, horses, and bison across the Southern border. Efforts to eradicate the pest go back decades, with a successful strategy in the 1960s and '70s. The U.S. and Mexico are working together to prevent the spread of this parasite.