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.

Animal health worker Eduardo Lugo treats the wounds of a cow as Chihuahua ranchers intensify surveillance for the screwworm after the U.S. suspended cattle imports following the detection of the parasite in southern Mexico,

The US Secretary of Agriculture has announced ports will be closed to the livestock trade at the southern border after Mexican cattle tested positive for the flesh-eating New World screwworm (NWS)."We must see additional progress combatting NWS in Veracruz and other nearby Mexican states in order to reopen livestock ports along the Southern border,