title: Possible sources and spreading routes of highly pathogenic avian influenza virus subtype H5N1 infections in poultry and wild birds in Central Europe in 2007 inferred through likelihood analyses.
abstract: Recurrent outbreaks of H5N1 HPAIV occurred in several Central European countries in 2007. In-depth phylogenetic analyses which included full-length genomic sequences of the viruses involved were performed to elucidate possible origins of incursions and transmission pathways. Tree reconstructions as well as host-shift and ancestral area inferences were conducted in a maximum likelihood framework. All viruses belonged to a separate subgroup (termed "EMA-3") within clade 2.2, and, thus, were distinct from two lineages of HPAIV H5N1 viruses (termed "EMA-1" and "EMA-2") present in the same geographic area in 2006. Analysis of concatenated coding regions of all eight genome segments significantly improved resolution and robustness of the reconstructed phylogenies as compared to single gene analyses. At the same time, the methodological limits to establish retrospectively transmission networks in a comparatively small geographic region and spanning a short period of time became evident when only few corroborating field-epidemiological data are available. Ambiguities remained concerning the origin of the EMA-3 viruses from a region covering Southeast Germany and the Czech Republic as well as routes of spread to other European countries. AIV monitoring programmes in place for wild birds and poultry in these countries did not reveal presence of these viruses in either population. Host switches between domestic poultry and wild bird populations occurred several times. Analysis of outbreaks in Northeast Germany and nearby Northern Poland in December 2007 demonstrated that geographic and even temporal vicinity of outbreaks does not necessarily indicate a common source of incursion.
authors.affiliation: Ernst-Moritz-Arndt-Universität, Institute of Zoology, Soldtmannstr. 23, 17487 Greifswald, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Haase
authors.forename: Elke
authors.initials: E
authors.lastname: Starick
authors.forename: Sasan
authors.initials: S
authors.lastname: Fereidouni
authors.forename: Günter
authors.initials: G
authors.lastname: Strebelow
authors.forename: Christian
authors.initials: C
authors.lastname: Grund
authors.forename: Anett
authors.initials: A
authors.lastname: Seeland
authors.forename: Carmen
authors.initials: C
authors.lastname: Scheuner
authors.forename: Dietmar
authors.initials: D
authors.lastname: Cieslik
authors.forename: Krzystof
authors.initials: K
authors.lastname: Smietanka
authors.forename: Zenon
authors.initials: Z
authors.lastname: Minta
authors.forename: Olga
authors.initials: O
authors.lastname: Zorman-Rojs
authors.forename: Miroslav
authors.initials: M
authors.lastname: Mojzis
authors.forename: Teufik
authors.initials: T
authors.lastname: Goletic
authors.forename: Veronique
authors.initials: V
authors.lastname: Jestin
authors.forename: Bodo
authors.initials: B
authors.lastname: Schulenburg
authors.forename: Oliver
authors.initials: O
authors.lastname: Pybus
authors.forename: Thomas
authors.initials: T
authors.lastname: Mettenleiter
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
authors.forename: Timm
authors.initials: T
authors.lastname: Harder
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001717:Birds; D004196:Disease Outbreaks; D005060:Europe / Q000453:epidemiology; D006388:Hemagglutinins / Q000235:genetics; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D016013:Likelihood Functions; D009439:Neuraminidase / Q000235:genetics; D010802:Phylogeny; D058974:Phylogeography; D013997:Time Factors
chemical_list: D006388:Hemagglutinins; D009439:Neuraminidase