title: Studies of H5N1 influenza virus infection of pigs by using viruses isolated in Vietnam and Thailand in 2004.
abstract: To determine whether avian H5N1 influenza viruses associated with human infections in Vietnam had transmitted to pigs, we investigated serologic evidence of exposure to H5N1 influenza virus in Vietnamese pigs in 2004. Of the 3,175 pig sera tested, 8 (0.25%) were positive for avian H5N1 influenza viruses isolated in 2004 by virus neutralization assay and Western blot analysis. Experimental studies of replication and transmissibility of the 2004 Asian H5N1 viruses in pigs revealed that all viruses tested replicated in the swine respiratory tract but none were transmitted to contact pigs. Virus titers from nasal swabs peaked on day 2, and low titers were detected in the liver of two of the four pigs tested. Our findings indicate that pigs can be infected with highly lethal Asian H5N1 viruses but that these viruses are not readily transmitted between pigs under experimental conditions.
authors.affiliation: Division of Virology, Department of Infectious Diseases, Mail Stop 330, St. Jude Children's Research Hospital, 332 N. Lauderdale St., Memphis, TN 38105-2794, USA.
authors.forename: Young Ki
authors.initials: YK
authors.lastname: Choi
authors.forename: Tien Dzung
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Hiroichi
authors.initials: H
authors.lastname: Ozaki
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Webby
authors.forename: Pilaipan
authors.initials: P
authors.lastname: Puthavathana
authors.forename: Chantanee
authors.initials: C
authors.lastname: Buranathal
authors.forename: Arunee
authors.initials: A
authors.lastname: Chaisingh
authors.forename: Prasert
authors.initials: P
authors.lastname: Auewarakul
authors.forename: N T H
authors.initials: NT
authors.lastname: Hanh
authors.forename: Sia Kit
authors.initials: SK
authors.lastname: Ma
authors.forename: Pui Yan
authors.initials: PY
authors.lastname: Hui
authors.forename: Yi
authors.initials: Y
authors.lastname: Guan
authors.forename: Joseph Sriyal Malik
authors.initials: JS
authors.lastname: Peiris
authors.forename: Robert G
authors.initials: RG
authors.lastname: Webster
mesh_terms: D000818:Animals; D053124:Influenza A Virus, H5N1 Subtype; D009980:Influenza A virus / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000635:transmission / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000473:pathology / Q000821:virology*