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.

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

Ever since the virus known as H5N1 was identified in dairy cows in March, it’s continued to spread around the country — turning up in 200 herds over at least 14 states.

Earlier this month something concerning happened as avian flu continues to spread among dairy herds. A patient in Missouri tested positive for H5N1, the formal name for the virus. They ...