The reemergence of the New World screwworm, which poses significant health risks for livestock, has prompted the Department of Agriculture to halt cattle shipments from Mexico to the United States. The move marks at least the second time this year that cattle imports from Mexico have been suspended over the parasitic fly.

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,