title: Characterization of virulent West Nile virus Kunjin strain, Australia, 2011.
abstract: To determine the cause of an unprecedented outbreak of encephalitis among horses in New South Wales, Australia, in 2011, we performed genomic sequencing of viruses isolated from affected horses and mosquitoes. Results showed that most of the cases were caused by a variant West Nile virus (WNV) strain, WNV(NSW2011), that is most closely related to WNV Kunjin (WNV(KUN)), the indigenous WNV strain in Australia. Studies in mouse models for WNV pathogenesis showed that WNV(NSW2011) is substantially more neuroinvasive than the prototype WNV(KUN) strain. In WNV(NSW2011), this apparent increase in virulence over that of the prototype strain correlated with at least 2 known markers of WNV virulence that are not found in WNV(KUN). Additional studies are needed to determine the relationship of the WNV(NSW2011) strain to currently and previously circulating WNV(KUN) strains and to confirm the cause of the increased virulence of this emerging WNV strain.
authors.affiliation: Elizabeth Macarthur Agriculture Institute, Menangle, New South Wales, Australia.
authors.forename: Melinda J
authors.initials: MJ
authors.lastname: Frost
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Judith H
authors.initials: JH
authors.lastname: Edmonds
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Prow
authors.forename: Xingnian
authors.initials: X
authors.lastname: Gu
authors.forename: Rodney
authors.initials: R
authors.lastname: Davis
authors.forename: Christine
authors.initials: C
authors.lastname: Hornitzky
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Arzey
authors.forename: Deborah
authors.initials: D
authors.lastname: Finlaison
authors.forename: Paul
authors.initials: P
authors.lastname: Hick
authors.forename: Andrew
authors.initials: A
authors.lastname: Read
authors.forename: Jody
authors.initials: J
authors.lastname: Hobson-Peters
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: May
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Doggett
authors.forename: John
authors.initials: J
authors.lastname: Haniotis
authors.forename: Richard C
authors.initials: RC
authors.lastname: Russell
authors.forename: Roy A
authors.initials: RA
authors.lastname: Hall
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Khromykh
authors.forename: Peter D
authors.initials: PD
authors.lastname: Kirkland
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004196:Disease Outbreaks; D005814:Genes, Viral; D006734:Horse Diseases / Q000453:epidemiology* / Q000821:virology*; D006736:Horses; D051379:Mice; D009517:New South Wales / Q000453:epidemiology; D016366:Open Reading Frames; D010802:Phylogeny; D014774:Virulence; D014901:West Nile Fever / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity*