Influenza: the disease and its complications.

Among the complications (fortunately relatively few), pneumonias are by far the most common, with about one half resulting from pneumococcal invasion. In the acutely ill, multiple antibiotic therapy may have to be initiated pending definitive etiologic diagnosis. Also, in epidemic or pre-epidemic situations, special measures are advocated for hospitals, since influenza so rapidly becomes the dominant nosocominal infection.