Mass mortality among colony-breeding seabirds in the German Wadden Sea in 2022 due to distinct genotypes of HPAIV H5N1 clade 2.3.4.4b

In 2022, the German Wadden Sea experienced severe mass mortality among colony-breeding seabirds, primarily sandwich terns, common terns, and a northern gannet colony, due to distinct genotypes of high-pathogenicity avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b. Phylogenetic analysis identified two dominant genotypes, Ger-10–21 N1.2 and Ger-10–21 N1.5, suggesting viral transmission from the British Isles into the North Sea coastal region. The outbreaks exhibited significant spatiotemporal connectivity, linking colonies in Germany to those in Belgium, the Netherlands, Denmark, and Poland. With several affected species being endangered, the study highlights the potential long-term population impacts of HPAIV epizootics.

Pohlmann, A., Stejskal, O., King, J., Bouwhuis, S., Packmor, F., Ballstaedt, E., Hälterlein, B., Hennig, V., Stacker, L., Graaf, A., Hennig, C., Günther, A., Liang, Y., Hjulsager, C., Beer, M., & Harder, T. (2023). Mass mortality among colony-breeding seabirds in the German Wadden Sea in 2022 due to distinct genotypes of HPAIV H5N1 clade 2.3.4.4b. Journal of General Virology, 104(4). https://doi.org/10.1099/jgv.0.001834