U.S. Combats New World Screwworm
September 2, 2026
As U.S. New World screwworm cases rise, NMPF is working closely with USDA on New World screwworm monitoring and prevention efforts, including a discussion on cleaning, disinfection, and dairy animal movements.
NMPF is updating its New World screwworm fact sheets to reflect new information from USDA as it becomes available.
Three new domestic cases of New World screwworm in August brought the total confirmed U.S. infestations to 47. No cases have been reported in wildlife, and no New World screwworm flies have been detected in U.S. fly traps.
With no additional New World screwworm cases detected since the initial June 7 detection, USDA APHIS has approved the release of New Mexico’s only NWS infested zone, lifting movement restrictions and allowing normal intrastate and interstate movement of livestock and pets to resume.
In Texas, state animal health officials are also beginning to scale back restrictions in designated areas, including portions of Gillespie, Kerr, Kimble, La Salle, and Webb counties, removing NWS inspection and movement certificate requirements as surveillance data support a reduced risk of infestation. While these actions reflect progress in containment and eradication efforts, movement restrictions remain in other designated NWS infested zones in Texas.
Mexican officials confirmed a new case of New World screwworm along the border in Juarez, just days before the port in Douglas, AZ, begin a phased reopening to Mexican livestock on Aug. 24. USDA announced on Aug. 10 that the new domestic sterile fly production facility under construction in Edinberg, TX is now set to open in spring of 2027, seven months ahead of schedule.
FDA issued an Emergency Use Authorization (EUA) on Aug. 7 for an additional product to prevent New World screwworm. CLiK Extra (dicyclanil topical suspension) wound spray is not authorized as a treatment option for an active infestation. The drug is not authorized for use in female dairy cattle producing milk for human consumption. Treated calves and calves born to treated cows must not be processed for veal.
