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.

The rising incidence of bird flu in the Central Valley is raising serious concerns for public health and food safety. The detection of the virus in dairy cattle has sparked alarm, as it increases the risk of transmission to other animals and potentially to humans.

The bird flu outbreak has spread to all 50 states, these maps show. Here are the symptoms and what to do if you think you might be infected.

Los Angeles County health officials have identified three more cats with presumptive H5N1; the source of the virus has not yet determined, but experts suspect raw meat.

On the same day that the first severe case of the avian virus in the U.S. was disclosed in Louisiana, halfway across the country, California Gov. Gavin Newsom declared a state of emergency designed to expedite the state’s response to further outbreaks of H5N1, commonly known as bird flu.

California’s battle with bird flu has been intensified as two new confirmed cases have been found in Stanislaus and Los Angeles counties. The rate at which the flu lathers has led California Governor Gavin Newsom to declare a state of emergency on December 18.