New World Screwworm
Animal Health
USDA has confirmed that New World Screwworm has been detected in the United States. Currently there are no movement restrictions or further instruction for Utah Producers. This page will be continually updated as new information is released.
New World Screwworm (NWS) is a fly, and the larvae of this fly burrow into living tissue of warm-blooded animals, causing large wounds and death in untreated animals. The fly was eradicated from the United States in 1968, but an increase in cases in Central America in 2023 and 2024 has led to the discovery of the fly in Mexico. USDA is working closely with Mexico to try to stop the spread of NWS before it can reach our southern border. If NWS is reintroduced to the United States, it could cost billions in treatment costs, production and death losses, and control measures. It is critical for animal owners and veterinarians to be aware of the signs of NWS and to report any suspicious cases immediately to the State Veterinarian’s office.