Outbreak dynamics of highly pathogenic avian influenza virus H5N1, clade 2.3.4.4b BB, in Black-headed gulls in Germany, 2023: data set on phylogeographic analysis

In summer 2022, a novel reassortant between circulating gs/GD clade 2.3.4.4b Influenza A highly pathogenic Influenza H5 viruses and H13 strains emerged  on the west coast of France and is now designated as European genotype BB. The spread of this genotype was massive across Europe, affecting poultry and a wide range of wild bird species. Among these, both black-headed gulls (Chroicocephalus ridibundus) and common terns (Sterna hirundo) were the main hosts of genotype BB and dominated its epidemiology in Europe as a whole and in Germany in particular. Here, we focus on these two species and investigate the spread and impact of HPAIV H5N1 genotype euBB during winter 2022/2023 and summer 2023 in Germany.