title: Epizootic emergence of Usutu virus in wild and captive birds in Germany.
abstract: This study aimed to identify the causative agent of mass mortality in wild and captive birds in southwest Germany and to gather insights into the phylogenetic relationship and spatial distribution of the pathogen. Since June 2011, 223 dead birds were collected and tested for the presence of viral pathogens. Usutu virus (USUV) RNA was detected by real-time RT-PCR in 86 birds representing 6 species. The virus was isolated in cell culture from the heart of 18 Blackbirds (Turdus merula). USUV-specific antigen was demonstrated by immunohistochemistry in brain, heart, liver, and lung of infected Blackbirds. The complete polyprotein coding sequence was obtained by deep sequencing of liver and spleen samples of a dead Blackbird from Mannheim (BH65/11-02-03). Phylogenetic analysis of the German USUV strain BH65/11-02-03 revealed a close relationship with strain Vienna that caused mass mortality among birds in Austria in 2001. Wild birds from lowland river valleys in southwest Germany were mainly affected by USUV, but also birds kept in aviaries. Our data suggest that after the initial detection of USUV in German mosquitoes in 2010, the virus spread in 2011 and caused epizootics among wild and captive birds in southwest Germany. The data also indicate an increased risk of USUV infections in humans in Germany.
authors.affiliation: German Mosquito Control Association, KABS, Waldsee, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Becker
authors.forename: Hanna
authors.initials: H
authors.lastname: Jöst
authors.forename: Ute
authors.initials: U
authors.lastname: Ziegler
authors.forename: Martin
authors.initials: M
authors.lastname: Eiden
authors.forename: Dirk
authors.initials: D
authors.lastname: Höper
authors.forename: Petra
authors.initials: P
authors.lastname: Emmerich
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Fichet-Calvet
authors.forename: Deborah U
authors.initials: DU
authors.lastname: Ehichioya
authors.forename: Christina
authors.initials: C
authors.lastname: Czajka
authors.forename: Martin
authors.initials: M
authors.lastname: Gabriel
authors.forename: Bernd
authors.initials: B
authors.lastname: Hoffmann
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
authors.forename: Klara
authors.initials: K
authors.lastname: Tenner-Racz
authors.forename: Paul
authors.initials: P
authors.lastname: Racz
authors.forename: Stephan
authors.initials: S
authors.lastname: Günther
authors.forename: Michael
authors.initials: M
authors.lastname: Wink
authors.forename: Stefan
authors.initials: S
authors.lastname: Bosch
authors.forename: Armin
authors.initials: A
authors.lastname: Konrad
authors.forename: Martin
authors.initials: M
authors.lastname: Pfeffer
authors.forename: Martin H
authors.initials: MH
authors.lastname: Groschup
authors.forename: Jonas
authors.initials: J
authors.lastname: Schmidt-Chanasit
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000821:virology*; D001717:Birds; D018349:Encephalitis Viruses, Japanese / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D005858:Germany; D007150:Immunohistochemistry; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction