Influenza is an acute, febrile illness caused by infection with influenza viruses (type A, B or C virus). Influenza viruses are transmitted by the respiratory route and cause large epidemics, which generally occur during the winter. The course of influenza disease ranges from self-limiting respiratory symptoms characterized by cough, headache, fever, and muscle aches in healthy individuals to complications such as bronchitis, acute otitis media, and pneumonia. Influenza is usually diagnosed clinically on the basis of characteristic symptoms of fever and cough. Rapid detection of virus in respiratory secretions also can be accomplished by antigen detection or molecular techniques. Four antiviral agents in two classes have been approved for prevention and treatment of influenza. Early antiviral treatment (oseltamivir or zanamivir) is recommended for patients at risk of complications. Vaccination reduces the risk ofpneumonia, hospitalization and death. Inactivated and live-attenuated vaccines are available.

Keywords: clinic, influenza, therapy, vaccine