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,

With reports of the first human death from bird flu in the US, some Americans are feeling an uncomfortable flashback to the early days of Covid-19, when infectious disease experts were talking about a new virus that was sending people to the hospital with respiratory infections.

CDC officials say they extended the guidance now because they are seeing more H5N1 patients whose illness they cannot track back to an infected bird or cow.

The U.S. Centers for Disease Control and Prevention is asking that people with flu severe enough to require hospitalization be tested for bird flu.

Officials from the Centers for Disease Control and Prevention recommend that hospitals speed up testing people who are hospitalized with the flu for H5N1 bird flu. Healthcare workers in hospitals