The virus in the first severe human bird flu case in the U.S. was found to have mutated. Newsweek's live blog is closed.

Will Clement, a USDA senior adviser for communications, said in an email: “Since first learning of H5N1 in dairy cattle in ...

Here's what you need to know about California officials declaring a state of emergency over the spread of bird flu in dairy ...

There have been almost 60 human cases of the H5N1 bird flu virus ... to step up surveillance for bird flu after the first case was detected in a child in the US. The US Department of Agriculture ...

A small but growing number of H5N1 avian influenza ... to step up surveillance for bird flu after the first case was detected in a child in the United States. A small but growing number of H5N1 ...

The World Health Organization on Thursday urged countries to step up surveillance for bird ... flu after the first case was detected in a child in the United States. A small but growing number of ...

A small but growing number of H5N1 avian influenza infections have been detected in humans around ... “What we really need globally, in the US and abroad, is much stronger surveillance in animals: in ...

For influenza viruses, imperfection is a strength. They constantly mutate, producing new strains that challenge immune ...