title: Evidence for an independent third Usutu virus introduction into Germany.
abstract: Usutu virus (USUV) is an arbovirus within the genus flavivirus, which was first introduced to Southern Europe approximately twenty years ago causing epizootics among wild and captive birds. In Germany USUV was initially discovered in wild birds, mainly Common blackbirds (Turdus merula), in the Upper Rhine valley in southwest of the country in 2011 and has not spread much northwards since. Phylogenetic analyses revealed that the still ongoing USUV epidemic is caused by two different USUV strains, USUV-Germany belonging to the USUV Europe 3 lineage and USUV-Bonn belonging to the USUV Africa 3 lineage. The two strains were introduced independently. In August 2015 a new USUV strain, named USUV-Berlin, was isolated in Vero cells from two carcasses of juvenile Great grey owls (Strix nebulosa) kept in the Zoological Garden Berlin, which had suffered from a hyperacute fatal systemic infection. Both owls carried high USUV genome loads. Full-length USUV genomes sequences were determined and phylogenetic analysis demonstrated a close relationship with a Spanish mosquito-derived sequence from 2006. Immunohistochemical antigen detection in organ samples of the owls showed the typical USUV infection patterns. According to the phylogenetic analysis, USUV-Berlin belongs to the Africa 2 lineage, and can thus be distinguished from the other strains circulating in Germany. Repeated findings of different USUV strains suggest more frequent introductions into Central Europe and a higher mobility of this virus than assumed to date.
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Ziegler
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Fast
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Eiden
authors.affiliation: Berlin-Brandenburg, State Laboratory, Gerhard-Neumann-Str. 2, 15236 Frankfurt (Oder), Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Bock
authors.affiliation: Berlin-Brandenburg, State Laboratory, Gerhard-Neumann-Str. 2, 15236 Frankfurt (Oder), Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schulze
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hoeper
authors.affiliation: Zoological Garden Berlin AG, Hardenbergplatz 8, 10787 Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ochs
authors.affiliation: Berlin-Brandenburg, State Laboratory, Gerhard-Neumann-Str. 2, 15236 Frankfurt (Oder), Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Schlieben
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Keller
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
authors.forename: Dorothee E
authors.initials: DE
authors.lastname: Zielke
authors.affiliation: Bernhard-Nocht-Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany.
authors.forename: Renke
authors.initials: R
authors.lastname: Luehken
authors.affiliation: Bernhard-Nocht-Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cadar
authors.affiliation: Leibniz-Centre for Agricultural Landscape Research (ZALF), Institute of Land Use Systems, Eberswalder Straße 84, 15374 Müncheberg, Germany.
authors.forename: Doreen
authors.initials: D
authors.lastname: Walther
authors.affiliation: Bernhard-Nocht-Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel, Hamburg, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Schmidt-Chanasit
authors.affiliation: Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany. Electronic address: martin.groschup@fli.bund.de.
authors.forename: Martin H
authors.initials: MH
authors.lastname: Groschup
mesh_terms: D000818:Animals; D000836:Animals, Zoo; D001715:Bird Diseases / Q000453:epidemiology / Q000821:virology*; D004196:Disease Outbreaks / Q000662:veterinary; D005416:Flavivirus / Q000145:classification* / Q000235:genetics; D018177:Flavivirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D005858:Germany / Q000453:epidemiology; D010802:Phylogeny; D020305:Strigiformes
keywords: Arbovirus; Emerging virus; Germany; Immunohistochemistry; Usutu virus; Virus phylogeny