|Bertran, Kateri - Consultant|
|Lee, Dong-hun - Orise Fellow|
|Criado, Miria - Consultant|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/2/2018
Publication Date: 4/15/2018
Citation: Bertran, K., Lee, D., Criado, M., Pantin Jackwood, M.J., Spackman, E., Balzli, C.L., Suarez, D.L., Swayne, D.E. 2018. Pathobiology of clade 18.104.22.168 Intercontinental Group A H5Nx highly pathogenic avian influenza virus in minor gallinaceous poultry [abstract]. 10th International Symposium on Avian Influenza, April 15-18, Brighton, United Kingdom. Paper No. 177.
Technical Abstract: In 2014 and 2015, the United States experienced an unprecedented outbreak of Eurasian clade 22.214.171.124 H5 highly pathogenic avian influenza (HPAI) virus. Initial cases affected mainly wild birds and mixed backyard poultry species, while later outbreaks affected mostly commercial chickens and turkeys. The pathogenesis, transmission, and intra-host evolutionary dynamics of initial clade 126.96.36.199 HPAI viruses in the United States Eurasian H5N8 and reassortant H5N2 were investigated in minor gallinaceous poultry species including: Japanese quail, bobwhite quail, pearl guinea fowl, chukar partridges, and ring-necked pheasants. Low mean bird infectious doses (<2 to 3.7 log10) supported direct introduction and infection of these species as observed in mixed backyard poultry during the early outbreaks. Pathobiological features and systemic virus replication in all species were consistent with HPAI virus infection. Sustained virus shedding with transmission to contact-exposed birds, alongside long incubation periods, may enable unrecognized dissemination and adaptation to other gallinaceous species, such as chickens and turkeys. Next generation sequencing of excreted viruses revealed numerous low-frequency polymorphisms and 20 consensus-level substitutions, especially in Japanese quail and pearl guinea fowl and in internal proteins PB1 and PB2. This highlights virus genomic flexibility in gallinaceous, which increases chances to adapt to other species. Innate immune responses were characterized in lung, spleen, and brain of Japanese quail and chickens based on stage of infection. Our findings suggest that these gallinaceous poultry are permissive for infection and sustainable transmissibility with the 2014 initial wild bird-adapted clade 188.8.131.52 virus, with potential acquisition of mutations leading to host range adaptation.