Since November 2023, more than 12.1 million birds on commercial flocks have been affected in Sioux County, Iowa, alone. In flocks where bird flu is detected, all birds are destroyed to prevent the spread of the disease, according to reporting by Investigate Midwest.

A commercial flock of approximately 240,000 egg-laying hens in O'Brien County has been stricken with highly pathogenic avian influenza (HPAI, or bird flu), the Iowa Department of Agriculture and Land Stewardship said Sunday.