USDA reports three new cases of screwworm, bringing total to 15

Source: Reuters

June 21, 2026 8:02 PM EDT Updated 10 hours ago


June 21 (Reuters) - The number of U.S. cases of New World screwworm has risen ​to 15 after three more animals tested positive ‌in Texas, the Department of Agriculture said in a post on social media on Sunday.

The USDA announcement comes nearly three weeks after the first ​domestic screwworm infestation in six decades was found in ​a Texas calf.

New World screwworm is a parasitic fly ⁠that eats warm-blooded animals alive and can infect livestock, pets, ​wildlife and, in rare cases, people. The larvae burrow into ​the living tissue of animals and cause severe wounds that can eventually kill, leading to signficant economic losses for ranchers.

The USDA said it will ​continue aggressive eradication efforts in affected areas, including the dispersal ​of tens of millions of sterile flies that halt screwworm reproduction. One lamb ‌in ⁠Crockett County and two calves in Edwards County, Texas tested positive for screwworm in the past 24 hours, according to the USDA's Sunday evening post on X.

Read more: https://www.reuters.com/business/healthcare-pharmaceuticals/usda-reports-three-new-cases-screwworm-bringing-total-15-2026-06-22/