A new report suggests that more Americans may be walking around with bird flu − and not even know it. Researchers from the Centers for Disease Control and Prevention randomly tested 150 veterinarians for H5N1, or bird flu, antibodies, which would indicate if they had a recent infection.

A new study shows the bird flu has silently spread from animals to some veterinarians. It echoes two smaller studies that detected evidence of infection in previously undiagnosed farmworkers.

An older woman in southeast Wyoming is hospitalized with bird flu, state health department officials said Friday. It's the state's first human case of Type A H5N1 influenza, which is spreading through animals and some people.