The latest developments are highly concerning, as they raise the possibility that the H5N1 virus has evolved the ability to ...

None of the health care workers or other contact have tested positive for avian flu antibodies so far — but could their ...

Another health care worker who was exposed to a Missouri patient who tested positive for bird flu developed respiratory symptoms but wasn't tested for the flu.

Four additional healthcare workers in Missouri who came in contact with a hospitalized bird flu patient developed mild ...

Testing is ongoing among five health care workers and a household member exposed to the infected person who all came down ...

In what could be the first cases of bird flu between humans in the US, a group of potential H5N1 infections in Missouri has now grown to 8.

The CDC said an investigation into a human H5N1 bird flu infection in Missouri has found four additional health care workers ...

A total of 94 healthcare workers were possibly exposed to the state's first human bird flu case, and the nation's first ...

Four additional healthcare workers in Missouri who had contact with a hospitalized patient infected with bird flu developed ...

Four more health-care workers who tended to a person hospitalized with H5N1 bird flu have revealed that they had respiratory ...

Four healthcare workers in Missouri who came into contact with a bird flu patient developed mild respiratory symptoms, but ...

"Even sporadic cases of human-to-human transmission indicate a big change in the virus and suggest it is exploring new ...