title: Pathogenic influenza B virus in the ferret model establishes lower respiratory tract infection.
abstract: Influenza B viruses have become increasingly more prominent during influenza seasons. Influenza B infection is typically considered a mild disease and receives less attention than influenza A, but has been causing 20 to 50 % of the total influenza incidence in several regions around the world. Although there is increasing evidence of mid to lower respiratory tract diseases such as bronchitis and pneumonia in influenza B patients, little is known about the pathogenesis of recent influenza B viruses. Here we investigated the clinical and pathological profiles of infection with strains representing the two current co-circulating B lineages (B/Yamagata and B/Victoria) in the ferret model. Specifically, we studied two B/Victoria (B/Brisbane/60/2008 and B/Bolivia/1526/2010) and two B/Yamagata (B/Florida/04/2006 and B/Wisconsin/01/2010) strain infections in ferrets and observed strain-specific but not lineage-specific pathogenicity. We found B/Brisbane/60/2008 caused the most severe clinical illness and B/Brisbane/60/2008 and the B/Yamagata strains instigated pathology in the middle to lower respiratory tract. Importantly, B/Brisbane/60/2008 established efficient lower respiratory tract infection with high viral burden. Our phylogenetic analyses demonstrate profound reassortment among recent influenza B viruses, which indicates the genetic make-up of B/Brisbane/60/2008 differs from the other strains. This may explain the pathogenicity difference post-infection in ferrets.
authors.affiliation: Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.|Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
authors.forename: Stephen S H
authors.initials: SSH
authors.lastname: Huang
authors.affiliation: Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Banner
authors.affiliation: Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.|Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
authors.forename: Stephane G
authors.initials: SG
authors.lastname: Paquette
authors.affiliation: Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Leon
authors.affiliation: Immune Diagnostics & Research, Toronto, ON, Canada.
authors.forename: Alyson A
authors.initials: AA
authors.lastname: Kelvin
authors.affiliation: International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong, PR China.|Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.|Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.|Dipartimento di Scienze Biomediche, Universita' degli Studi di Sassari, Sassari, Sardinia, Italy.|Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kelvin
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005289:Ferrets; D006801:Humans; D009981:Influenza B virus / Q000302:isolation & purification / Q000502:physiology*; D007251:Influenza, Human / Q000821:virology*; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D012141:Respiratory Tract Infections / Q000473:pathology* / Q000821:virology*