USDA Confirms 41 New World Screwworm Cases in U.S., Expands Eradication Program

The U.S. Department of Agriculture (USDA) has confirmed 41 cases of the New World screwworm parasite in the United States since June, chiefly in Texas and one in New Mexico. The first case since the 1960s was detected on June 3 in Zavala County, Texas, with additional confirmed infestations in Schleicher County – the first ever there – and other Texas counties.

USDA is intensifying its eradication effort using the sterile insect technique (SIT). A joint U.S.–Panama facility produces more than 100 million sterile pupae weekly, and a new $750 million plant in Edinburg, Texas, will eventually release up to 300 million sterile flies per week. Approximately 600 baited traps have been deployed along the U.S.–Mexico border and in northern Mexican states to capture wild flies.

State officials, including Texas Commissioner Sid Miller, say existing biosafety and animal‑movement protocols have helped limit spread, and no widespread infestation is evident. Veterinarians advise livestock owners to inspect animals for wounds and report any signs promptly. The USDA has no current plans to reopen the southern cattle border for trade.