The CDC is now calling for subtyping of influenza A viruses in all hospitalized patients -- and on an accelerated timeline, ideally within 24 hours. Nirav Shah, MD, JD, principal deputy director of the CDC,

The Centers for Disease Control and Prevention today released an advisory recommending clinicians expedite subtyping of type A influenza samples from hospitalized patients, particularly individuals in an intensive care unit.

CDC officials say they extended the guidance now because they are seeing more H5N1 patients whose illness they cannot track back to an infected bird or cow.