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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #406244
Research Project: Intervention Strategies to Control Endemic and New and Emerging Influenza A Virus Infections in Swine

Location: Virus and Prion Research

Title: Divergent pathogenesis and transmission of highly pathogenic avian influenza A(H5N1) in swine

Author
item Arruda, Bailey
item Baker, Amy
item Buckley, Alexandra
item Anderson, Tavis
item TORCHETTI, MIA - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories
item HINES BERGESON, NICHOLE - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories
item KILLIAN, MARY - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories
item LANTZ, KRISTINA - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories

Submitted to: Emerging Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2024
Publication Date: 4/1/2024
Citation: Arruda, B.L., Baker, A.L., Buckley, A.C., Anderson, T.K., Torchetti, M., Hines Bergeson, N., Killian, M.L., Lantz, K. 2024. Divergent pathogenesis and transmission of highly pathogenic avian influenza A(H5N1) in swine. Emerging Infectious Diseases. https://doi.org/10.3201/eid3004.231141.
DOI: https://doi.org/10.3201/eid3004.231141

Interpretive Summary: Highly pathogenic avian influenza (HPAI) viruses have potential to cross species barriers and cause pandemics in humans. Since 2022, H5N1 HPAI has infected poultry, wild birds, and mammals across North America. Continued circulation in birds and infection of multiple mammalian species with strains possessing mammalian adaptation mutations increase the risk of infection and subsequent exchange of viral genes with influenza A viruses (IAV) endemic in swine. This exchange of genes increases the risk of transmission within and between swine holdings. We assessed the susceptibility of swine to avian and mammalian H5N1 HPAI strains using a pathogenesis and transmission model. All strains replicated in the lower respiratory tract of pigs and caused lesions in the respiratory tract consistent with IAV. Viral replication in the nasal cavity, transmission to contact pigs, lesions in the lung at the cellular level, and viral antigen distribution within the lung of mammalian isolates suggested potential mammalian binding adaptation. Mammalian adaptation and reassortment may increase the risk of incursion and transmission of HPAI in feral, backyard, or commercial swine.

Technical Abstract: Highly pathogenic avian influenza (HPAI) viruses have potential to cross species barriers and cause pandemics in humans. Since 2022, H5N1 HPAI belonging to the goose/Guangdong 2.3.4.4b hemagglutinin (HA) phylogenetic clade infected poultry, wild birds, and mammals across North America. Continued circulation in birds and infection of multiple mammalian species with strains possessing adaptation mutations increase the risk of infection and subsequent reassortment with influenza A viruses (IAV) endemic in swine. We assessed the susceptibility of swine to avian and mammalian 2.3.4.4b H5N1 HPAI strains using a pathogenesis and transmission model. All strains replicated in the lower respiratory tract of pigs and caused lesions consistent with IAV. Viral replication in the upper respiratory tract, transmission, histologic lesions, and antigen distribution of mammalian isolates suggested potential HA a2,6 binding adaptation. Mammalian adaptation and reassortment may increase the risk of incursion and transmission of HPAI in feral, backyard, or commercial swine.