Recurring incursions and dissemination of novel Eurasian-origin H5Nx avian influenza viruses in Atlantic Canada

Ishraq Rahman; Cassidy N G Erdelyan; Anthony V Signore; Ifeoluwa Ayilara; Jordan Wight; Megan E B Jones; Daniel S Sullivan; Oliver Lung; Tamiko Hisanaga; Sabina I Wilhelm; Joshua T Cunningham; Christopher R E Ward; Johanna Bosch; Gregory J Robertson; Karen Gosse; Meghan Baker; Beverly Dawe; Stéphane Lair; Jennifer F Provencher; Kathryn E Hargan; Yohannes Berhane; Andrew S Lang

doi:10.1093/ve/veae111

Recurring incursions and dissemination of novel Eurasian-origin H5Nx avian influenza viruses in Atlantic Canada

Virus Evol. 2024 Dec 17;10(1):veae111. doi: 10.1093/ve/veae111. eCollection 2024.

Authors

Ishraq Rahman¹, Cassidy N G Erdelyan², Anthony V Signore², Ifeoluwa Ayilara², Jordan Wight¹, Megan E B Jones^{3

4}, Daniel S Sullivan^{2

5}, Oliver Lung^{2

5}, Tamiko Hisanaga², Sabina I Wilhelm⁶, Joshua T Cunningham⁷, Christopher R E Ward⁶, Johanna Bosch⁷, Gregory J Robertson⁷, Karen Gosse⁸, Meghan Baker⁹, Beverly Dawe⁹, Stéphane Lair¹⁰, Jennifer F Provencher¹¹, Kathryn E Hargan¹, Yohannes Berhane^{2

12

13

14}, Andrew S Lang¹

Affiliations

¹ Department of Biology, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada.
² National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB R3E 3M4, Canada.
³ Canadian Wildlife Health Cooperative, Atlantic Region, Charlottetown, PEI C1A 4P3, Canada.
⁴ Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI C1A 4P3, Canada.
⁵ Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2M5, Canada.
⁶ Canadian Wildlife Service, Environment and Climate Change Canada, Mount Pearl, NL A1N 4T3, Canada.
⁷ Wildlife Research Division, Environment and Climate Change Canada, Mount Pearl, NL A1N 4T3, Canada.
⁸ The Rock Wildlife Rehabilitation Centre, Torbay, NL A1K 1A5, Canada.
⁹ Animal Health Division, Department of Fisheries, Forestry and Agriculture, Government of Newfoundland and Labrador, St. John's, NL A1E 3Y5, Canada.
¹⁰ Centre Québécois sur la Santé des Animaux Sauvages/Canadian Wildlife Health Cooperative, Faculté de Médecine Vétérinaire, Université de Montréal, St. Hyacinthe, QC J2S 2M2, Canada.
¹¹ Environment and Climate Change Canada, Science and Technology Branch, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
¹² Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada.
¹³ Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
¹⁴ Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON NIG 2W1, Canada.

Abstract

Wild birds are important hosts of influenza A viruses (IAVs) and play an important role in their ecology. The emergence of the A/goose/Guangdong/1/1996 H5N1 (Gs/GD) lineage marked a shift in IAV ecology, leading to recurrent outbreaks and mortality in wild birds from 2002 onwards. This lineage has evolved and diversified over time, with a recent important derivative being the 2.3.4.4b sub-lineage, which has caused significant mortality events in wild bird populations. An H5N1 clade 2.3.4.4b virus was transmitted into North America from Eurasia in 2021, with the first detection being in Newfoundland and Labrador in Atlantic Canada, and this virus and its reassortants then spread broadly throughout North America and beyond. Following the first 2021 detection, there have been three additional known incursions of Eurasian-origin strains into Atlantic Canada, a second H5N1 strain in 2022 and two H5N5 strains in 2023. In this study, we document a fifth incursion in Atlantic Canada that occurred in 2023 by another H5N5 strain. This strain spread throughout Atlantic Canada and into Quebec, infecting numerous species of wild birds and mammals. Genomic analysis revealed mammalian-adaptive mutations in some of the detected viruses (PB2-E627K and PB2-D701N) and mutations in the hemagglutinin (HA) and neuraminidase (NA) genes that are associated with enhanced viral fitness and avian transmission capabilities. Our findings indicate that this virus is continuing to circulate in wildlife, and confirms Atlantic Canada is an important North American entry point for Eurasian IAVs. Continued surveillance and genomic analysis of IAVs detected in the region is crucial to monitor the evolution of these viruses and assess potential risks to wildlife and public health.

Keywords: H5N5; clade 2.3.4.4b; gulls; highly pathogenic avian influenza; viral dissemination.