Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2016
Publication Date: N/A
Technical Abstract: Waterfowl are the natural hosts of avian influenza (AI) virus. The majority of AI viruses are classified as low pathogenicity (LP) based on their virulence in chickens, which are the reference species for pathotype testing and can be any of the 16 hemagglutinin subtypes (H1-16). Circulation of H5 or H7 subtype LPAI viruses in gallinaceous birds can select for mutations which result in the highly pathogenic (HP) phenotype. Infection of waterfowl with HPAI virus occurs as spill-over from gallinaceous poultry and one virus lineage has been repeatedly found in wild waterfowl since 2006 which has resulted in intercontinental spread of the virus. Since wild waterfowl typically do not carry HPAI viruses data on the susceptibility among species and virulence is lacking. An exception is the A/goose/Guangdong/1996 (Gs/GD/96) H5 HPAI virus lineage of viruses of which several variants have become endemic in domestic poultry and waterfowl in Asia. Most experimental studies have been conducted with viruses of the Gs/GD/1996 lineage and the majority have been with Mallard or Pekin ducks, but studies with Muscovy ducks, geese, and diving ducks have been conducted with a small subset of virus isolates. The clinical outcome of exposure varies among species and virus strain, which is suggested by field data. The most common presentation is sub-clinical infection or mild, self-resolving disease (i.e. fever and anorexia). However some isolates can cause more severe disease, often neurological signs, and mortality in some waterfowl species.