Submitted to: Merck Veterinary Manual
Publication Type: Book / Chapter
Publication Acceptance Date: 6/1/2019
Publication Date: 7/1/2019
Citation: Swayne, D.E. 2019. Avian influenza. In: Allen, D.G., Carter, K.K., Constable, P.D., Dart, A., Davies, P.R., Davies, J.L., Quesenberry, K.E., Swayne D.E., editors. Merck Veterinary Manual. 12th edition. Kenilworth, NJ: Merck & Co, Inc. p. 1-8. Available: https://www.merckvetmanual.com/poultry/avian-influenza/avian-influenza.
Interpretive Summary: Avian influenza is a viral infection found in domestic poultry and a wide range of other birds. Wild waterfowl and shorebirds are often asymptomatic carriers. Low pathogenicity strains typically cause respiratory signs. High pathogenicity strains may cause widespread organ failure and sudden, high mortality. Diagnosis is by viral isolation or detection of the viral genome or specific antibodies. Antibiotics may help control secondary bacterial infection in flocks affected by low pathogenicity strains. Antiviral drugs are not approved or recommended. Prevention is accomplished by biosecurity. Vaccines matched for antigenic type can reduce clinical signs and reduce viral shedding in infected flocks, but use in the USA requires regulatory approval. Human infections have occurred, usually as isolated, individual cases of the H5 strain.
Technical Abstract: Avian influenza (AI) is a viral infection of domestic poultry, and pet, zoo, and wild birds. In domestic poultry, AI viruses are typically of low pathogenicity (LP), causing subclinical infections, respiratory disease, or drops in egg production, but a few AI viruses are highly pathogenic (HP), causing severe systemic disease with multiple organ failure and high mortality.