title: Novel reassortment of Eurasian avian-like and pandemic/2009 influenza viruses in swine: infectious potential for humans.
abstract: Pigs are considered to be intermediate hosts and "mixing vessels," facilitating the genesis of pandemic influenza viruses, as demonstrated by the emergence of the 2009 H1N1 pandemic (pdm/09) virus. The prevalence and repeated introduction of the pdm/09 virus into pigs raises the possibility of generating novel swine influenza viruses with the potential to infect humans. To address this, an active influenza surveillance program was conducted with slaughtered pigs in abattoirs in southern China. Over 50% of the pigs tested were found to be seropositive for one or more H1 influenza viruses, most commonly pdm/09-like viruses. Out of 36 virus isolates detected, one group of novel reassortants had Eurasian avian-like swine H1N1 surface genes and pdm/09 internal genes. Animal experiments showed that this virus transmitted effectively from pig to pig and from pig to ferret, and it could also replicate in ex vivo human lung tissue. Immunization against the 2009 pandemic virus gave only partial protection to ferrets. The continuing prevalence of the pdm/09 virus in pigs could lead to the genesis of novel swine reassortant viruses with the potential to infect humans.
authors.affiliation: International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong, China.
authors.forename: Huachen
authors.initials: H
authors.lastname: Zhu
authors.forename: Boping
authors.initials: B
authors.lastname: Zhou
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Fan
authors.forename: Tommy T Y
authors.initials: TT
authors.lastname: Lam
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Antony
authors.initials: A
authors.lastname: Chen
authors.forename: Xinchun
authors.initials: X
authors.lastname: Chen
authors.forename: Honglin
authors.initials: H
authors.lastname: Chen
authors.forename: Robert G
authors.initials: RG
authors.lastname: Webster
authors.forename: Richard
authors.initials: R
authors.lastname: Webby
authors.forename: Joseph S M
authors.initials: JS
authors.lastname: Peiris
authors.forename: David K
authors.initials: DK
authors.lastname: Smith
authors.forename: Yi
authors.initials: Y
authors.lastname: Guan
mesh_terms: D000818:Animals; D002681:China; D005289:Ferrets; D006801:Humans; D066298:In Vitro Techniques; D009980:Influenza A virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D008168:Lung / Q000821:virology; D008297:Male; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000635:transmission / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D017422:Sequence Analysis, DNA; D013552:Swine / Q000821:virology*
chemical_list: D012367:RNA, Viral