The U.S. Department of Agriculture has again halted imports of Mexican cattle into the United States due to the spread of the damaging livestock pest New World Screwworm in Mexico. Screwworms are parasitic flies whose females lay eggs in wounds on warm-blooded animals,

Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality (SENASICA) reported a new case of New World Screwworm (NWS) in Ixhuatlan de Madero, Veracruz in Mexico, which is approximately 160 miles northward of the current sterile fly dispersal grid,

The U.S. has shut its southern border to livestock imports again after a flesh-eating parasite was found further north in Mexico than previously reported, raising alarm among American agriculture officials.