The death in Louisiana — involving a person with underlying health conditions — is the first human case in the United States linked to exposure to backyard birds, according to the federal Centers for Disease Control and Prevention.

The CDC has confirmed a total of 66 human cases of bird flu across the United States as of Friday, although the number is believed to be higher.

Health experts told Newsweek about the threats posed by the viruses and shared the best ways to protect oneself.

The U.S. has recorded its first human death from bird flu, in a patient hospitalized in Louisiana. The case was considered the country’s first severe human H5N1 infection.