The rapid and accurate diagnosis of influenza virus infection now is available to clinicians practicing in both outpatient and inpatient settings. Newly licensed reagents are reliable and "user friendly" and may impact care by providing an immediate diagnosis that allows appropriate antiviral therapy to be given and encourages judicious use of antibiotics. The diagnosis of influenza by viral culture also has become more mainstream, allowing health professionals to confirm diagnoses in individual patients, as well as to track the pattern of each "flu season" in the community.