The Louisiana patient who contracted what officials said was the nation’s first “severe” case of avian influenza has died, the state health department said Monday. The person who contracted the H5N1 strain of highly pathogenic bird flu in southwest Louisiana had been hospitalized since mid-December.

The case in Louisiana is the first human death from bird flu in the U.S. during this current outbreak, but there was a death in Mexico back in May 2024 in a patient with no known exposure to farm animals. The case, much like the patient in Louisiana, was in a person with other underlying conditions, though it’s not clear what those may have been.

The patient, who was older than 65 and had underlying medical conditions, was hospitalized Dec. 18 in critical condition with severe respiratory illness.