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

The bird flu virus found in a severely ill patient hospitalized in the United States has mutated to become better adapted to human airways, though there is no evidence it has spread beyond the individual,

After someone in southwest Louisiana was hospitalized with a severe case of bird flu, the first such illness reported in the United States, health workers swabbed the person’s nose and throat, looking for genetic clues about the virus.