California officials have declared a state of emergency over the spread of bird flu. It is affecting milk cows in that state and causing illnesses in some people in other U.S. states.
The avian influenza virus, or bird flu, has spread among wild birds, farm birds and many mammal species.
The virus is known as Type A H5N1. It was identified for the first time in U.S. milk cows in March. Since then, bird flu has been found in about one third of U.S. states.
The U.S. Centers for Disease Control and Prevention (CDC) is following the number of cases and is reporting the latest details on its website. Most of the illnesses have been mild. Health officials said that one person in Louisiana was hospitalized with the nation’s first known severe illness caused by the virus.
