WHAT IS IT?
Avian influenza, commonly called bird flu, is an infectious viral disease of birds. Avian influenza viruses are caused by the influenza (flu) Type A. These viruses occur naturally among wild aquatic birds worldwide. Wild aquatic birds usually do not get sick. The birds that are host to the flu Type A are gulls, terns, wild ducks, geese and swans. Domestic poultry, other birds and other animal species can become infected. Human infections are possible but they are rare and the viruses do not spread easily to other people. Illnesses in humans range from mild to severe. Low pathogenic avian influenza (LPAI) H7N9 and high pathogenic avian flu (HPAI) Asian H5N1 have been responsible for most human illnesses to date.