More Americans may have had bird flu without suffering any symptoms, a new study finds. That could allow the virus to mutate ...

Avian influenza, or “bird flu,” is a disease caused by influenza A viruses that spread widely among wild birds, and can cause outbreaks in commercial and backyard poultry flocks. Though there ...

Veterinarians who worked with cattle had antibodies in their system that showed they had the H5N1 virus, though they exhibited no symptoms and none knew they were working with sick animals, according ...