A strain of bird flu never seen before in the United States has been detected among poultry at a California farm.
The virus, called highly pathogenic H5N9, is a type of avian influenza, otherwise known as "bird flu." This is not the same type of bird flu that's already been spreading on dairy cow and poultry farms in the U.S., causing at least several dozen infections in humans. That virus is called H5N1.
