Reports that cows have been infected despite farmers' preventive measures indicate there are multiple routes of transmission

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.

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.