Diva Strategies for Avian Influenza

Avian influenza viruses (AIVs) are single-stranded RNA viruses belonging to the Influenza virus A genus of the Orthomyxoviridae family. The segmented genome encodes ten or 11 proteins, depending on the strain. These proteins are the prominent outer surface glycoproteins HA and neuraminidase (NA), the matrix (M2) ion channels, the matrix (M1) protein, which is found lining the inner side of the lipid envelope of the virus, three polymerases (PA,PB1 and PB2), one NSP (NS1), a nuclear export protein (NEP) and a recently described accessory protein (PB1-F2) with pro-apoptotic activity [3]. AIVs can be classified into different subtypes based on the possession of one of the 16 antigenically distinct HA antigens, typed from H1 to H16, and one of nine NA antigens, typed from N1 to N9. Clinically, AIVs can be classified as low-pathogenic AI (LPAI), and highly pathogenic AI (HPAI) on the basis of the severity of the disease they cause in susceptible birds.