|BROWN, JUSTIN - University Of Georgia|
|STALLKNECHT, DAVID - University Of Georgia|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/30/2009
Publication Date: 7/26/2009
Citation: Brown, J.D., Stallknecht, D.E., Swayne, D.E. 2009. Susceptibility of selected wild avian species to experimental infection with H5N1 high pathogenicity avian influenza virus [abstract]. Abstracts of the Immunobiology of Influenza Virus Infection Conference, July 26-28, 2009, Athens, Georgia. p. 20.
Technical Abstract: Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in wide diversity of wild avian species but, to date, the role that different species play in the transmission and maintenance of H5N1 HPAI viruses is poorly understood. To begin to address these uncertainties and provide data on relative susceptibility, viral shedding, and pathobiology of H5N1 HPAI virus in wild birds, we experimentally inoculated fifteen wild avian species with a subclade 2.2 H5N1 HPAI virus, A/Whooper Swan/Mongolia/244/05 (H5N1). In general, species susceptibility in these experimental trials paralleled existing field data: swans, geese, gulls, and sparrows were highly susceptible to the H5N1 HPAI virus, while dabbling ducks (Genus Anas) were infected but resistant to clinical disease. Although species-related variation regarding the onset and progression of disease was observed, the clinical syndrome was consistent between species, with neurologic deficits predominating. In species susceptible to clinical disease, the H5N1 HPAI virus replicated systemically with viral antigen expressed in multiple tissues of the body; however, the H5N1 HPAI virus consistently had the strongest predilection for the brain. In all species, oropharyngeal excretion of H5N1 HPAI virus was greater than cloacal shedding, both in titer and duration. This pattern of viral excretion is unique for avian influenza virus infection in waterfowl, which traditionally is characterized by predominantly gastrointestinal replication and fecal shedding. These data provide insight into the role that different wild avian species play in the epidemiology of H5N1 HPAI and are useful for interpreting field observations. However, the risk factors associated with transmission, geographic spread, and maintenance of H5N1 HPAI viruses in wild avian populations are not completely clear and gaps in our understanding still remain.