http://www.cdc.gov/EID/content/13/12/1821.htm
The affected swans had nervous signs that included somnolence, incoordination, and ataxia (11) and gross pathology that included multifocal hemorrhagic necrosis in the pancreas, pulmonary congestion and edema, and subepicardial hemorrhages (13).
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Adult birds were generally more resistant to Vietnam/05 than juveniles


http://www.ncbi.nlm.nih.gov/pubmed/1...?dopt=Abstract
Teifke JP, Klopfleisch R, Globig A, Starick E, Hoffmann B, Wolf PU, Beer M, Mettenleiter TC, Harder TC.
Sterblichkeit in den wilden Wasservögeln wegen der Infektion mit in hohem Grade pathogenen Vogelgrippeviren (HPAIV) ist ein seltener Fall. Während des neuen Ausbruchs der in hohem Grade pathogenen Vogelgrippe in Deutschland, wurde die Sterblichkeit wegen H5N1 HPAIV unter Sing- und wie-heissen-doch-gleich-die-andern Schwänen als Teil einer schnellen Verbreitung dieses Virus beobachtet. Im Gegensatz zu früheren Reports schienen Schwäne, in hohem Grade empfindlilch zu sein und stellten die hauptsächlich betroffene Sorte dar..

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http://www.ncbi.nlm.nih.gov/pubmed/1...?dopt=Abstract
Vet Microbiol. 2007 Feb 25;120(1-2):9-16. Epub 2006 Oct 12.
Highly pathogenic avian influenza virus subtype H5N1 in Mute swans in the Czech Republic.
Nagy A, Machova J, Hornickova J, Tomci M, Nagl I, Horyna B, Holko I.
State Veterinary Institute Prague, National Reference Laboratory for Avian Influenza, Sidlistni 136/24, 165 03 Prague 6, Czech Republic. alexander.nagy@svupraha.cz
In order to determine the actual prevalence of avian influenza viruses (AIV) in wild birds in the Czech Republic extensive surveillance was carried out between January and April 2006. A total of 2101 samples representing 61 bird species were examined for the presence of influenza A by using PCR, sequencing and cultivation on chicken embryos. AIV subtype H5N1 was detected in 12 Mute swans (Cygnus olor). The viruses were determined as HPAI (highly pathogenic avian influenza) and the hemagglutinin sequence was closely similar to A/mallard/Italy/835/06 and A/turkey/Turkey/1194/05. Following the first H5N1 case, about 300 wild birds representing 33 species were collected from the outbreak region and tested for the presence of AIV without any positive result. This is the first report of highly pathogenic avian influenza subtype H5N1 in the Czech Republic. The potential role of swan as an effective vector of avian influenza virus is also discussed.

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