Highly Pathogenic Avian Influenza H5N5 in a Polar Bear and Atlantic Walrus, Svalbard, 2026, with Widespread Seroconversion in Polar Bears
Knut Madslien, Johanna Hol Fosse, Jon Aars, Cathrine Arnason Bøe, M Oerbaek Andersen, Kayla J. Buhler, Ingvild Fjeldheim, Britt Gjerset, Torild Jørgensen, Ida Kristin Myhrvold, Andreas Rohringer, Kjersti Sturød, Morten Tryland, Bjørnar Ytrehus, Ragnhild Tønnessen, Ingebjørg Helena Nymo
The paper reports the first confirmed case of HPAIV H5N5 in a polar bear and Atlantic walrus in Svalbard, with widespread seroconversion in polar bears following initial bird detections.
bioRxiv · Jul 20, 2026 · PreprintMolecular Biology