H5N1 is a type of avian influenza virus (bird flu virus) that has mutated[1] through antigenic drift into dozens of highly pathogenic varieties, but all currently belonging to genotype Z of avian influenza virus H5N1. Genotype Z emerged through reassortme...

What is avian flu? Avian or bird flu is an infection caused by an influenza virus that occurs naturally in wild birds. Often referred to as the H5N1 virus, bird flu is spread easily among birds and can sicken and kill domesticated birds such as chicke...