title: Phylogenetic Analysis Supports Horizontal Transmission as a Driving Force of the Spread of Avian Bornaviruses.
abstract: BACKGROUND
  Avian bornaviruses are a genetically diverse group of viruses initially discovered in 2008. They are known to infect several avian orders. Bornaviruses of parrots and related species (Psittaciformes) are causative agents of proventricular dilatation disease, a chronic and often fatal neurologic disease widely distributed in captive psittacine populations. Although knowledge has considerably increased in the past years, many aspects of the biology of avian bornaviruses are still undiscovered. In particular, the precise way of transmission remains unknown.
  
  
  OBJECTIVE
  In order to collect further information on the epidemiology of bornavirus infections in birds we collected samples from captive and free-ranging aquatic birds (n = 738) and Passeriformes (n = 145) in Germany and tested them for the presence of bornaviruses by PCR assays covering a broad range of known bornaviruses. We detected aquatic bird bornavirus 1 (ABBV-1) in three out of 73 sampled free-ranging mute swans (Cygnus olor) and one out of 282 free-ranging Eurasian oystercatchers (Haematopus ostralegus). Canary bornavirus 1 (CnBV-1), CnBV-2 and CnBV-3 were detected in four, six and one out of 48 captive common canaries (Serinus canaria forma domestica), respectively. In addition, samples originating from 49 bornavirus-positive captive Psittaciformes were used for determination of parrot bornavirus 2 (PaBV-2) and PaBV-4 sequences. Bornavirus sequences compiled during this study were used for phylogenetic analysis together with all related sequences available in GenBank.
  
  
  RESULTS
  Within ABBV-1, PaBV-2 and PaBV-4, identical or genetically closely related bornavirus sequences were found in parallel in various different avian species, suggesting that inter-species transmission is frequent relative to the overall transmission of these viruses. Our results argue for an important role of horizontal transmission, but do not exclude the additional possibility of vertical transmission. Furthermore we defined clearly separated sequence clusters within several avian bornaviruses, providing a basis for an improved interpretation of transmission events within and between wild bird populations and captive bird collections.
authors.affiliation: Institute for Virology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Herrmann-Herder Str. 11, D-79104, Freiburg, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Rubbenstroth
authors.affiliation: Clinic for Birds and Reptiles, University of Leipzig, An den Tierkliniken 17, D-04103, Leipzig, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Schmidt
authors.affiliation: Clinic for Birds, Reptiles, Amphibians and Ornamental Fish, Centre for Clinical Veterinary Medicine, University Ludwig Maximilian Munich, Sonnenstr. 18, D-85764, Oberschleißheim, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Rinder
authors.affiliation: Clinic for Pets, Reptiles and pet and feral Birds, University of Veterinary Medicine Hannover, Bünteweg 9, D-30559, Hannover, Germany.
authors.forename: Marko
authors.initials: M
authors.lastname: Legler
authors.affiliation: Department of Research and Documentation, Eifel National Park, Urftseestraße 34, D-53937, Schleiden-Gemünd, Germany.
authors.forename: Sönke
authors.initials: S
authors.lastname: Twietmeyer
authors.affiliation: Research and Technology Centre Büsum, University of Kiel, Hafentörn 1, D-25761, Büsum, Germany.
authors.forename: Phillip
authors.initials: P
authors.lastname: Schwemmer
authors.affiliation: Institute for Virology, University of Bonn, Sigmund-Freud-Str. 25, D-53127, Bonn, Germany.|German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Corman
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D028981:Bornaviridae / Q000235:genetics* / Q000302:isolation & purification; D002171:Canaries / Q000821:virology; D005858:Germany / Q000453:epidemiology; D018701:Mononegavirales Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D046109:Passeriformes / Q000821:virology*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification
chemical_list: D012367:RNA, Viral