H5N1, or bird flu, poses a limited risk to humans but remains a serious threat. Learn how it spreads, its symptoms, and key precautions to prevent infection.

Lithuania has reported an outbreak of highly pathogenic H5N1 avian influenza, commonly called bird flu, on a laying hen farm in the western part of the country, the World Organisation for Animal Health (WOAH) said on Wednesday.

What is H5N9 and how is it different from H5N1? Scientists classify bird flu viruses by which kind of two key proteins are inside of them: the hemagglutinin, like H5 or H3, and th