title: Isolation of influenza A(H3N2)v virus from pigs and characterization of its biological properties in pigs and mice.
abstract: Recently, a novel reassortant virus, influenza A(H3N2)v [A(H3N2)v], was identified as the causative pathogen in 307 human cases of influenza in the United States. A(H3N2)v contains the matrix gene from the 2009 pandemic H1N1 (pH1N1) virus, while its other genes originate from H3N2 viruses with triple-reassorted internal genes. In this study, we isolated three A(H3N2)v viruses from commercial pigs in Korea that showed similarities with published human A(H3N2)v viruses in eight segment sequence alignments. After genetic characterization, the pathogenicity of one of these viruses was assessed in pigs and mice. Infection of pigs with this novel virus resulted in mild interstitial pneumonia with marked oronasal shedding of viral RNA for about 14 days. In mice, the virus replicated efficiently in the lungs; viral RNA was detected up to 9 days post-inoculation. However, the virus did not cause severe disease or death in mice, despite the administration of a high infectious dose (10(5.2) TCID50). This study demonstrates that A(H3N2)v causes a high morbidity rate with low virulence; however, global monitoring of A(H3N2)v outbreaks in mammals will be needed to determine whether this novel subtype will shift to a highly pathogenic virus.
authors.affiliation: Animal Disease Diagnostic Division, Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, 430-757, Republic of Korea.
authors.forename: Seong-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Hee-Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Young-Hwa
authors.initials: YH
authors.lastname: Jin
authors.forename: Jeong-Ji
authors.initials: JJ
authors.lastname: Yeoul
authors.forename: Kyoung-Ki
authors.initials: KK
authors.lastname: Lee
authors.forename: Jae-Ku
authors.initials: JK
authors.lastname: Oem
authors.forename: Myoung-Heon
authors.initials: MH
authors.lastname: Lee
authors.forename: Choi-Kyu
authors.initials: CK
authors.lastname: Park
mesh_terms: D000818:Animals; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D007251:Influenza, Human / Q000821:virology; D008168:Lung / Q000473:pathology / Q000821:virology; D051379:Mice; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000503:physiopathology / Q000662:veterinary* / Q000821:virology; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D016865:Reassortant Viruses / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D056910:Republic of Korea; D013552:Swine / Q000821:virology; D013553:Swine Diseases / Q000503:physiopathology* / Q000821:virology*; D014774:Virulence
chemical_list: D012367:RNA, Viral