|KWON, JUNG-HOON - Kyungpook National University|
|BERTRAN, KATERI - Institute De Recerca I Tecnologia Agroalimentaries (IRTA)|
|LEE, DONG-HUN - Konkuk University|
|CRIADO, MIRIA - Auburn University|
Submitted to: Emerging Microbes & Infections
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2023
Publication Date: 6/12/2023
Citation: Kwon, J., Bertran, K., Lee, D., Criado, M.F., Killmaster, L.F., Pantin Jackwood, M.J., Swayne, D.E. 2023. Diverse infectivity, transmissibility and pathobiology of clade 188.8.131.52 H5Nx highly pathogenic avian influenza viruses in chickens. Emerging Microbes & Infections. 12:2218945. https://doi.org/10.1080/22221751.2023.2218945.
Interpretive Summary: Highly pathogenic avian influenza viruses (HPAIVs) of the Eurasian subtype H5Nx clade 184.108.40.206 are a major threat to poultry and are disseminated by wild birds. These viruses have spread globally since 2014 and have evolved into different H5 genetic subgroups. In this study, chickens were inoculated with one of seven different H5Nx viruses from subgroups 220.127.116.11a, b, c, and e to determine the infectivity, transmissibility, and pathobiology of these HPAIVs. All the viruses caused high mortality in infected chickens, but the levels of infectivity and transmissibility of the viruses varied. Viruses from subgroup 18.104.22.168e had 100% transmissibility in chickens. However, viruses from subgroups 22.214.171.124a and c showed 67% transmissibility, and 126.96.36.199b viruses showed no transmission. Understanding the pathogenicity of novel HPAIVs in poultry is important to predicting disease outbreak patterns and establishing effective control strategies.
Technical Abstract: Clade 188.8.131.52 Eurasian lineage H5Nx highly pathogenic avian influenza virus (HPAIV) has become the globally dominant clade and caused global outbreaks since 2014. The clade 184.108.40.206 viruses have evolved into eight hemagglutinin subgroups (220.127.116.11a-h). In this study, we evaluated the infectivity, pathobiology and transmissibility of seven clade 18.104.22.168 viruses (two 22.214.171.124a, two 126.96.36.199b, one 188.8.131.52c and two 184.108.40.206e) in chickens. The two clade 220.127.116.11e viruses caused 100% mortality and transmissibility in chickens. However, clade 18.104.22.168a and c viruses showed 80–90% mortality and 67% transmissibility. Clade 22.214.171.124b viruses showed 100% mortality, but no transmission to co-housed chickens was observed based on lack of seroconversion. All the infected chickens died showing systemic infection, irrespective of subgroup. The results highlight that all the clade 126.96.36.199 HPAIVs used in this study caused high mortality in infected chickens, but the transmissibility of the viruses in chickens was variable in contrast to that of previous Eurasian-lineage H5N1 HPAIVs. Changes in the pathogenicity and transmissibility of clade 188.8.131.52 HPAIVs warrant careful monitoring of the viruses to establish effective control strategies.