What is avian influenza (avian flu/bird flu)?
Avian influenza, or avian flu, is a common, naturally occurring virus in birds that has many forms or subtypes. Scientists believe all birds are susceptible to infection by some form of avian flu, but some birds, like waterfowl, can be infected with the virus but develop no signs of illness. In addition, the potency (virulence) varies greatly among the various subtypes of the avian flu virus. Virulence is classified as either low pathogenic avian influenza (LPAI) or high pathogenic avian influenza (HPAI). Most avian flu subtypes are LPAI and cause little or no signs of illness in domestic or wild birds and pose no threat to human health. These subtypes are found every year in waterfowl. HPAI viruses are associated with the H5 and H7 subtypes. Some strains of the H5 and H7 subtypes are extremely infectious and fatal to domestic poultry, sometimes posing a threat to human health.
Avian influenza, or avian flu, is a common, naturally occurring virus in birds that has many forms or subtypes. Scientists believe all birds are susceptible to infection by some form of avian flu. Some birds, like waterfowl, can be infected with the virus but develop no signs of illness. In addition, the potency (virulence) varies greatly among the various subtypes of the avian flu virus. Virulence is classified as either low pathogenic avian influenza (LPAI) or high pathogenic avian influenza (HPAI). Most avian flu subtypes are LPAI and cause little or no signs of illness in domestic or wild birds and pose no threat to human health. These subtypes are found every year in waterfowl. HPAI viruses are associated with the H5 and H7 subtypes. Some strains of the H5 and H7 subtypes may be extremely infectious and fatal to domestic poultry, sometimes posing a threat to human health, too.
