California officials have declared a state of emergency over the spread of bird flu, which is tearing through dairy cows in that state and causing sporadic illnesses in people in the U.S.

Public concern over bird flu ratcheted up this week as the H5N1 virus continued its sweep through the nation's dairy and poultry farms and the first American was hospitalized with a severe infection.

A patient in Louisiana has been hospitalized with a severe case of H5N1 bird flu, the US Centers for Disease Control and Prevention said, the first such case in the United States.

A person in Louisiana has been hospitalized with a severe case of the bird flu. It is the first known human H5N1 infection in the United States, according

The H5N1 strains are becoming more concerning as the first severe U.S. case has been detected and California declared a state of emergency.

While the risk to the public remains low, we will continue to take all necessary steps to prevent the spread of this virus.” The move comes on the heels of a Louisiana resident being hospitalized with bird flu (H5N1),

Bird flu virus has swept through farms across the nation’s largest dairy producing state. All human cases had been mild - until now.