None of the health care workers or other contact have tested positive for avian flu antibodies so far — but could their illness signal human-to-human transmission?

By Julie Steenhuysen (Reuters) -Four additional healthcare workers in Missouri who came in contact with a hospitalized bird flu patient developed mild respiratory symptoms but the virus was not confirmed in any of them,

In what could be the first cases of bird flu spreading between humans in the United States, a group of potential H5N1 infections in Missouri has now grown to eight. However, state health officials are still awaiting antibody tests to confirm whether the H5N1 infection is growing,

A total of 94 healthcare workers were possibly exposed to the state's first human bird flu case, and the nation's first without animal contact.

As of Monday evening, there is only one confirmed human case of bird flu in Missouri. The single case is one of 15 reported nationwide since 2022. However, the recent Missouri case is unusual... because there is no known animal link to that case.