The United States has reported its first outbreak of H5N9 bird flu in poultry on a duck farm in California, the World Organisation for Animal Health (WOAH) said on Monday. U.S. authorities also detected the more common H5N1 strain on the same farm in Merced County,

Bird flu has sickened several dozen people around the U.S. and left one person dead while egg price hikes and shortages have also affected consumers.

H5N9 is a rare subtype of the influenza A virus that can cause highly pathogenic avian influenza (HPAI), also known as bird flu. It's a reassortment strain that originated from the H5N1, H7N9, and H9N2 subtypes.