Pathogenesis and infection dynamics of high pathogenicity avian influenza virus (HPAIV) H5N6 (clade 2.3.4.4b) in pheasants and onward transmission to chickens

• Published in: Virology (New York, N.Y.) Vol. 577; pp. 138 - 148
• Main Authors: Liang, Yuan, Hjulsager, Charlotte K., Seekings, Amanda H., Warren, Caroline J., Lean, Fabian Z.X., Núñez, Alejandro, James, Joe, Thomas, Saumya S., Banyard, Ashley C., Slomka, Marek J., Brown, Ian H., Larsen, Lars E.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-12-2022
• Subjects: Avian; Chicken; Epidemic; Game bird; HPAIV; Influenza; Pathogenesis; Pheasant; Transmission; Epidemic; Pheasant; Pathogenesis; Influenza; Transmission; Game bird; Avian; Chicken; HPAIV
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2022.10.009

High pathogenicity avian influenza viruses clade 2.3.4.4 H5 have spread among wild birds worldwide during recent years causing annual die-offs among wild birds and outbreaks in poultry in multiple European countries. The outbreaks significantly impact the poultry and game bird sectors. Infected game birds may act as a bridging species potentially enabling spread of virus into commercial and backyard premises. In this study, the pathogenesis and transmission of a HPAIV clade 2.3.4.4b H5N6 virus was investigated in pheasants and chickens. Efficient virus transmission was detected between pheasants over multiple rounds of naïve pheasant introductions and onwards to chickens. Mortality of up to 100% was observed for both infected pheasants and chickens. Intra-species transmission from chicken to chicken was less efficient. The study confirmed that clade 2.3.4.4b H5N6 HPAIV is highly virulent in pheasants and emphasises the role of pheasants as a bridging host for the infection of commercial poultry.
•Pheasants inoculated with clade 2.3.4.4b H5N6 HPAIV were susceptible to infection.•Transmission of the HPAIV was successful among pheasants and onwards to chickens.•Intra-species transmission from chicken to chicken was less efficient.•Differences in pathogenesis were observed among infected pheasants and chickens.•Pheasants infected with HPAIV could potentially play a role in the spread of the virus to poultry.