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

Although there have been reports of human-human transmission of H5N1 in the past, it’s extremely rare and has caused alarm ...

In what could be the first cases of bird flu spreading between humans in the United States, a group of potential H5N1 ...

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

A cluster of healthcare workers has been tested for H5N1 bird flu in what could be the first cases of human-to-human spread of the virus.

More than a month after a person in Missouri mysteriously fell ill with H5-type bird flu, investigators in the state are ...

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

A second health worker who cared for a person hospitalized in Missouri with H5N1 bird flu developed mild respiratory symptoms ...

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

Seven people in contact with a patient hospitalized with bird flu also developed symptoms, the C.D.C. reported. Some are ...

A third close contact of a patient in Missouri who was hospitalized with H5N1 bird flu has reported that they also ...

At least one household member and six healthcare workers who encountered the index case-patient are being investigated after ...