What is a Highly Pathogenic Avian Influenza (HPAI) virus?
Highly pathogenic avian influenza viruses are influenza viruses that cause high mortality in domestic poultry. Highly pathogenic avian influenza viruses are associated with the H5 and H7 subtypes. Not all H5 and H7 subtypes are highly pathogenic. What is Bird Flu and what is HPAI H5N1? Bird Flu is a nonscientific term that was coined to describe the HPAI H5N1 viruses that have been present in Asia since 1997. This term has caused a great deal of confusion because it is often used as a synonym for avian influenza. HPAI H5N1 is a highly pathogenic H5N1 virus that has persisted in Asia at least since 1997. It is established in domestic poultry populations in Asia (primarily chickens and domestic ducks). In 1997, a human death resulting from HPAI H5N1 virus infection in Hong Kong was reported; there have been over 100 human cases with approximately 60 fatalities since that time. All human cases have occurred in Asia, and almost all of these cases have been linked to direct contact with inf
