tetano
Editor, Senior Moderator
Transbound Emerg Dis
. 2026 Feb 18:2026:2963364.
doi: 10.1155/tbed/2963364. eCollection 2026.
Highly Pathogenic Avian Influenza A (H5N1) Caused Mass Death Among Black-Legged Kittiwakes (Rissa tridactyla) in Norway, 2023
Grim Rømo[SUP] 1 [/SUP], Caroline Piercey Åkesson[SUP] 2 [/SUP], Tone Kristin Reiertsen[SUP] 3 [/SUP], Johanna Hol Fosse[SUP] 2 [/SUP], Cathrine Arnason Bøe[SUP] 2 [/SUP], Lars Austbø[SUP] 2 [/SUP], Johan Åkerstedt[SUP] 1 [/SUP], Maryam Saghafian[SUP] 2 [/SUP], Morten Helberg[SUP] 4 [/SUP], Olav Hungnes[SUP] 5 [/SUP], Britt Gjerset[SUP] 2 [/SUP], Silje Granstad[SUP] 1 [/SUP], Gørill Hogseth[SUP] 6 [/SUP], Siri Løtvedt[SUP] 7 [/SUP], Anne Døsen[SUP] 7 [/SUP], Ragnhild Tønnessen[SUP] 2 [/SUP]
Affiliations
In 2023, highly pathogenic avian influenza (HPAI) heavily affected gulls in Europe. In July, a mass mortality event was reported in the black-legged kittiwake (Rissa tridactyla) breeding colony at Ekkerøy in Northern Norway. The cause was confirmed to be infection with the HPAI H5N1 clade 2.3.4.4b virus, genotype EA-2022-BB. We describe the outbreak in kittiwakes, including pathological and virological investigations, and discuss the management and zoonotic potential. With more than 15,000 dead birds reported, we estimate that the outbreak caused a reduction in the kittiwake population at Ekkerøy of at least 50%. Diseased birds exhibited neurological signs. Necropsies of 10 birds revealed a peracute fatal systemic disease, with severe lesions in the brain and pancreas co-localizing with viral RNA and antigen. Vascular expression of α2,3-linked sialic acids (SAs) and viral RNA/antigen may reflect hematogenous viral spread. Further studies should investigate the long-term impact of HPAI on kittiwake populations.
Keywords: H5N1; HPAI; Norway; One Health; black-legged kittiwake; gulls; highly pathogenic avian influenza; pathology; receptors; virology.
. 2026 Feb 18:2026:2963364.
doi: 10.1155/tbed/2963364. eCollection 2026.
Highly Pathogenic Avian Influenza A (H5N1) Caused Mass Death Among Black-Legged Kittiwakes (Rissa tridactyla) in Norway, 2023
Grim Rømo[SUP] 1 [/SUP], Caroline Piercey Åkesson[SUP] 2 [/SUP], Tone Kristin Reiertsen[SUP] 3 [/SUP], Johanna Hol Fosse[SUP] 2 [/SUP], Cathrine Arnason Bøe[SUP] 2 [/SUP], Lars Austbø[SUP] 2 [/SUP], Johan Åkerstedt[SUP] 1 [/SUP], Maryam Saghafian[SUP] 2 [/SUP], Morten Helberg[SUP] 4 [/SUP], Olav Hungnes[SUP] 5 [/SUP], Britt Gjerset[SUP] 2 [/SUP], Silje Granstad[SUP] 1 [/SUP], Gørill Hogseth[SUP] 6 [/SUP], Siri Løtvedt[SUP] 7 [/SUP], Anne Døsen[SUP] 7 [/SUP], Ragnhild Tønnessen[SUP] 2 [/SUP]
Affiliations
- PMID: 41725838
- PMCID: PMC12917261
- DOI: 10.1155/tbed/2963364
In 2023, highly pathogenic avian influenza (HPAI) heavily affected gulls in Europe. In July, a mass mortality event was reported in the black-legged kittiwake (Rissa tridactyla) breeding colony at Ekkerøy in Northern Norway. The cause was confirmed to be infection with the HPAI H5N1 clade 2.3.4.4b virus, genotype EA-2022-BB. We describe the outbreak in kittiwakes, including pathological and virological investigations, and discuss the management and zoonotic potential. With more than 15,000 dead birds reported, we estimate that the outbreak caused a reduction in the kittiwake population at Ekkerøy of at least 50%. Diseased birds exhibited neurological signs. Necropsies of 10 birds revealed a peracute fatal systemic disease, with severe lesions in the brain and pancreas co-localizing with viral RNA and antigen. Vascular expression of α2,3-linked sialic acids (SAs) and viral RNA/antigen may reflect hematogenous viral spread. Further studies should investigate the long-term impact of HPAI on kittiwake populations.
Keywords: H5N1; HPAI; Norway; One Health; black-legged kittiwake; gulls; highly pathogenic avian influenza; pathology; receptors; virology.