title: Serological Evidence of Pandemic H1N1 Influenza Virus Infections in Greek Swine.
abstract: The introduction of the 2009 pandemic H1N1 (pH1N1) influenza virus in pigs changed the epidemiology of influenza A viruses (IAVs) in swine in Europe and the rest of the world. Previously, three IAV subtypes were found in the European pig population: an avian-like H1N1 and two reassortant H1N2 and H3N2 viruses with human-origin haemagglutinin (HA) and neuraminidase proteins and internal genes of avian decent. These viruses pose antigenically distinct HAs, which allow the retrospective diagnosis of infection in serological investigations. However, cross-reactions between the HA of pH1N1 and the HAs of the other circulating H1 IAVs complicate serological diagnosis. The prevalence of IAVs in Greek swine has been poorly investigated. In this study, we examined and compared haemagglutination inhibition (HI) antibody titres against previously established IAVs and pH1N1 in 908 swine sera from 88 herds, collected before and after the 2009 pandemic. While we confirmed the historic presence of the three IAVs established in European swine, we also found that 4% of the pig sera examined after 2009 had HI antibodies only against the pH1N1 virus. Our results indicate that pH1N1 is circulating in Greek pigs and stress out the importance of a vigorous virological surveillance programme.
authors.affiliation: Laboratory of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: C S
authors.initials: CS
authors.lastname: Kyriakis
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: V G
authors.initials: VG
authors.lastname: Papatsiros
authors.affiliation: Clinic of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: L V
authors.initials: LV
authors.lastname: Athanasiou
authors.affiliation: Laboratory of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Valiakos
authors.affiliation: Department of Virology, Animal and Plant Health Agency (APHA), Weybridge, UK.
authors.forename: I H
authors.initials: IH
authors.lastname: Brown
authors.affiliation: Anses, Ploufragan-Plouzané Laboratory, Swine Virology Immunology Unit, France.|European University of Brittany, France.
authors.forename: G
authors.initials: G
authors.lastname: Simon
authors.affiliation: Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Van Reeth
authors.affiliation: Fourth Department of Internal Medicine, University of Athens Medical School, Athens, Greece.|Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Tsiodras
authors.affiliation: Department of Animal Production, Technological Educational Institute of Thessaly, Larisa, Greece.
authors.forename: V
authors.initials: V
authors.lastname: Spyrou
authors.affiliation: Laboratory of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Billinis
mesh_terms: D000818:Animals; D006115:Greece / Q000453:epidemiology; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D058873:Pandemics; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology*; D015047:Zoonoses
keywords: Greece; H1N1 pandemic virus; Swine; influenza