The CDC says the risk of bird flu to the general public is low, but public health experts say they are worried the virus could mutate and become more transmissible.

On Monday, Louisiana health officials announced that a person hospitalized last month with a severe case of avian influenza — also known as H5N1 bird flu — died. This is the first human death from bird flu in the U.S.

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