The bird flu has been infecting American flocks for years, leading to a series of infections and increased egg prices. But now, there's a new twist: A different strain has been detected in U.S. poultry.

The United States reported a first outbreak of H5N9 bird flu on a poultry farm, the World Organisation for Animal Health said on Monday. Highly pathogenic avian influenza, commonly called bird flu, has spread around the globe in the past years,