The H5N1 virus is not new to science and was responsible for an outbreak of avian influenza in Scotland in 1959. H5N1 is not the only bird flu virus. There are numerous strains. For example, an outbreak in 2003 of the H7N7 bird flu virus in the Netherlands led to the destruction of more than 30 million birds, about a third of the country's poultry stock. __
