Avian Influenza Outbreak 2024. Dairy cattle in multiple states. H5n1 viruses were first identified in 1959 due to an outbreak in domesticated chickens in scotland.

The type of h5n1 that has been decimating bird populations for the last few years was first discovered in. Since the resurgence of highly pathogenic avian influenza (hpai) a (h5n1) virus, clade 2.3.4.4b, during 2021, these viruses have spread widely among birds worldwide,.