The U.S. Centers for Disease Control and Prevention says a patient has been hospitalized with a severe case of H5N1 infection in Louisiana, making it the first instance of a severe illness linked to the virus in the United States.

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.

A Louisiana patient is critically ill with severe respiratory symptoms from H5N1 bird flu, marking the 61st U.S. human case this year. California has declared a state of emergency. CBS News medical contributor Dr.