Multiple introductions and spread of novel reassortant highly pathogenic avian influenza A (H5N1) clade 2.3.4.4b viruses via wild birds, South Korea, 2024–2025
Between 14 October 2024 and 24 March 2025, 43 cases of clade 2.3.4.4b highly pathogenic avian influenza (HPAI) type A (H5N1) infections in wild birds and 1 case in a leopard cat were detected through the national HPAI surveillance program. We performed whole-genome sequencing of 51 isolates and investigated their phylo...