In its announcement this week of the first human death from bird flu in the United States, health officials in Louisiana were quick to note that the patient was over age 65 and “reported to have underlying medical conditions.

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

Any time a person catches H5N1, or bird flu, their infection is a chance for the virus to mutate in the wrong direction. When someone dies from the bird flu—as an elderly Louisiana man did on Jan. 6,