Asian avian flu
Asian highly pathogenic avian influenza (HPAI) A(H5N1) virus occurs mainly in birds and is highly contagious among them. HPAI Asian H5N1 is especially. Avian influenza refers to the disease caused by infection with avian (bird) influenza (flu) Type A viruses. These viruses occur naturally among wild aquatic birds. Avian influenza—known informally as avian flu or bird flu is a variety of influenza caused by Since , more than human cases of Asian HPAI H5N1 have been reported to the WHO, primarily from 15 countries in Asia, Africa, the Pacific, . (The H5N1 virus recently detected in U.S. wild birds is a new mixed virus (a reassortant) that is genetically different from the Asian avian H5N1 viruses). Flu viruses are constantly changing and animal flu viruses can change such that they may gain the ability to infect people easily and spread among people, causing a pandemic. Asian flu of , outbreak of influenza that was first identified in February in East Asia and that subsequently spread to countries worldwide. The Asian flu was the second major influenza pandemic to occur in the 20th century; it followed the influenza pandemic of –19 (also known as. Influenza A virus subtype H5N1, also known as A(H5N1) or simply H5N1, is a subtype of the influenza A virus which can cause illness in humans and many other animal species. A bird-adapted strain of H5N1, called HPAI A(H5N1) for highly pathogenic avian influenza virus of type A of subtype H5N1, is the highly pathogenic causative agent of H5N1 flu, commonly known as avian influenza ("bird flu").Class: Insthoviricetes.