Public health officials have warned that new mutations of bird flu with human flu could have dangerous consequences.

Doctors say the case of a teen left in critical condition shows H5N1 "can cause severe human illness." Mutations in the virus are deepening concerns about the spread of H5N1.

Teen's recovery from H5N1 bird flu raises concerns after genetic mutations suggest virus could become more dangerous to ...

In coming years, the bird flu may cost billions of dollars more in expenses and losses. Worse, the outbreak poses the threat ...

So far, the H5N1 virus isn't transmitted between people — but the CDC has found a mutation in a human case "concerning." ...

Each week some revelation about bird flu seems to flutter through the news cycle. Here's what the latest research is saying about how it is spreading and how to keep yourself and your pets safe.