Avian influenza H5N1 infection in humans has spread to seven U.S. states, growing from 46 cases last week to 52 cases this week.

NBC Universal, Inc. The bird flu virus hasn’t yet spread from person to person, the Centers for Disease Control and Prevention said Thursday, releasing findings from a monthslong probe into a patient ...

The case concerned health officials and experts because human-to-human transmission of the H5N1 strain of avian influenza could mark the start of a new pandemic.

Blood tests of several people who were in contact with a patient in Missouri who caught H5N1 bird flu without any known exposure to infected animals reveal that at least one of them — a person ...

Blood testing conducted by the Centers for Disease Control and Prevention has confirmed that one person in Missouri with no known exposure to cattle or poultry contracted H5N1 bird flu in August ...

As H5N1 bird flu spreads among California dairy herds and southward-migrating birds, health officials announced Friday six ...

H5N1, or bird flu, has been spreading among farm animals, wild birds and other animals and has infected 31 people, mostly farmworkers, in the U.S. After the Missouri patient fell ill, several ...

Opens in a new tab or window There's no evidence of human-to-human transmission of H5N1 bird flu among patients and healthcare workers in Missouri, the CDC said during a press briefing today.