Submitted to: Waterbird Society
Publication Type: Abstract Only
Publication Acceptance Date: 10/3/2005
Publication Date: 10/27/2005
Citation: Swayne, D.E., Stallknecht, D. 2005. The changing role of waterbirds in avian influenza virus ecology [abstract]. In: Proceedings of Waterbirds 2005, November 25-27, 2005, Tainen, Taiwan. p.64.
Technical Abstract: Various wild waterbirds, especially of the order Anseriformes and Charadriiformes, are natural hosts of low pathogenicity avian influenza (LPAI) viruses. Such viruses are classified into 16 hemagglutinin (H1-16) and nine neuraminidase (N1-9) subtypes thus producing 144 potential combinations. These LPAI viruses are adapted to various wild birds and have no apparent deleterious effect on their populations. On several occasions, these LPAI viruses have been transferred from wild birds to domestic poultry where they have adapted to the new host and produced mild disease. For some strains of H5 and H7 LPAI viruses, mutational changes in the hemagglutinin have produced high pathogenicity avian influenza viruses (HPAI). These viruses cause high death losses in chickens (Gallus domesticus) and other gallinaceous birds, but rarely have they infected or caused disease in wild birds. The Asian H5N1 HPAI virus was first detected in domestic geese (Anser anser) in China during 1996. The viruses circulating in Hong Kong during 1997 had limited ability to infect and cause disease in various wild birds under experimental conditions. However, since 2000, the Asian H5N1 viruses have had increased ability to replicate in ducks (Anas platyrhynchos) and some lineages of H5N1 cause disease and death. The Asian H5N1 viruses have been recovered from several species of wild birds found dead. Recently, mortality in wild birds has been reported in China and Mongolia among wild birds.