A week ago today, on 22 November, the Chief Veterinary Officer of Mexico notified the USDA’s Animal and Plant Health Inspection Service (APHIS) of a positive detection of New World screwworm (NWS) in Mexico. The NWS was found in a cow in the southern Mexico state of Chiapas, at an inspection checkpoint close to the border with Guatemala. NWS are fly larvae that infest living tissue of warm-blooded animals, causing infection.Effective 22 November, and until further notice, APHIS is temporarily suspending the importation of live animals originating from, or transiting across, Mexico based on the confirmation of New World Screwworm in cattle.Screwworm (Cochliomyia hominivorax) is a potentially devastating pest. When NWS fly larvae burrow – or...