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 Louisiana patient was hospitalized with a severe case of bird flu in the first death in the U.S. caused by the H5N1 virus.

The first person has died of bird flu in the United States, the Louisiana Department of Health confirmed on Monday. The patient, who was exposed to non-commercial backyard flock and wild birds, was over age 65 and had underlying medical conditions,