Surveillance of live birds for active and past infections reveals the impact of highly pathogenic H5N1 on seabird populations in Atlantic Canada

2026/01/01 by Ishraq Rahman, Jordan Wight, Joshua T. Cunningham +32 · 1 voice · 2 citations
Medicine · #Influenza Virus Research Studies #Respiratory viral infections research #Virology and Viral Diseases

paper · doi:10.1139/cjm-2025-0195

openalex publication_date 2026/01/01 · openalex created_date 2026/01/20 · openalex updated_date 2026/07/23

Abstract

Highly pathogenic avian influenza clade 2.3.4.4b H5Nx viruses (HPAIVs) have caused significant mortality in wild birds. We investigated active avian influenza virus (AIV) infections and assessed seroprevalence based on general nucleoprotein-specific and H5-specific antibodies in seabirds in Atlantic Canada during 2022-2023. Results were compared to seroprevalence data from 2011 to 2016 to evaluate changes in infection rates following the incursion of HPAIV. We sampled 1073 wild live birds belonging to 14 species. Active H5Nx infections were detected only in 2022, with the highest prevalence in Common Murres (64%), followed by Black-legged Kittiwakes (13%). Differences in seroprevalence were observed between years and species, with both Common Murres and Atlantic Puffins exhibiting higher rates after HPAIV incursion, particularly for anti-H5-specific antibodies. Seroprevalence also differed between locations, and age-related differences in exposure were observed with juvenile birds having much lower seroprevalence than adult birds, particularly among gulls. Despite no active infections being detected in 2023, high seroprevalence across species suggests persisting immunity and/or recent virus circulation. These findings underscore the importance of serological monitoring in tracking AIV dynamics, as antibody detection provides critical insights into past HPAIV exposure even when active infection rates are low.

Citations

• Origin and evolution of highly pathogenic H5N1 avian influenza in Asia
• Highly pathogenic avian influenza is an emerging disease threat to wild birds in North America
• High pathogenicity avian influenza (H5N1) in Northern Gannets ( <i>Morus bassanus</i> ): Global spread, clinical signs and demographic consequences
• Geographic, ecological, and temporal patterns of seabird mortality during the 2022 HPAI H5N1 outbreak on the island of Newfoundland

Cited by

• Spatiotemporal dynamics and ecological risk factors of highly pathogenic avian influenza A(H5N1) in Canadian wildlife: A One Health surveillance analysis
• Effects of highly pathogenic avian influenza on the behaviour and survival of a colonial breeding seabird

Discussions

• Congrats to CABE’s Sydney Collins, Dr. Montevecchi & Dr. Bitton on their recent paper! 🐦🧫 Led by Ishraq Rahman, the study found avian flu active in NL seabirds in 2022 (but not 2023), with antibodie [bsky, 2 points, 1 comments]

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