The U.S. Centers for Disease Control said on Thursday its analysis of samples from the first severe case of bird flu in the country last week showed mutations not seen in samples from an infected backyard flock on the patient's property.

Here’s what to know about the United States’ first confirmed severe case of H5N1 avian influenza—and how to protect yourself.

Last week, the case was confirmed in a Louisiana resident over the age of 65, who was experiencing serious respiratory issues.