ATLANTA — The Centers for Disease Control and Prevention (CDC) confirmed that a new human case of the H5N1 strain of avian influenza has been reported in Louisiana — the first in the state and, notably, the first severe case in the country, requiring hospitalization to treat the infected person.

The United States has confirmed its first known severe human infection of H5N1 bird flu, in a person in Louisiana believed to have contracted the virus through contact with sick or dead birds in a backyard flock.