Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: July 5, 2007
Publication Date: April 1, 2008
Citation: Suarez, D.L. 2008. Influenza A virus. In: D.E. Swayne, editor. Avian Influenza. Amea, IA: Wylie-Blackwell. p. 3-22.
Influenza A viruses are important veterinary and human health pathogens around the world. Avian influenza (AI) virus in poultry is unusual in that it can cause a range of disease symptoms from a subclinical infection to being highly virulent with 100% mortality. The difference between low pathogenicity (LP) viruses and high pathogenicity (HP) viruses can be as small as a single amino acid change in the hemagglutinin fusion cleavage site. Therefore it is important not only to assess an AI virus’s ability to cause disease in poultry, but also to assess the potential for AI viruses to cause disease in poultry. AI viruses also have a wide host range, including mammals, and can represent a zoonotic risk. Additionally, the main reservoir for the AI viruses are in wild birds, therefore complete eradication is not possible. All these factors make AI viruses an important but difficult pathogen to control in poultry.