PCR for the Detection of Influenza Viruses in Clinical Material

Influenza viruses are segmented, negative-stranded RNA viruses belonging to the family Orthomyxoviridae . They are classified into influenza A, B, and C on the basis of different epitopes on the nucleoprotein (NP) and matrix proteins (M). Influenza A viruses are further divided into subtypes H1N1, H2N2 and H3N2, based on differences in the hemagglutinin (HA) and neuraminidase (NA) genes. The ability of influenza viruses to undergo antigenic change in HA and NA enables the virus to evade the immune response of the host and to cause repeated infections and epidemic spread.