Influenza. More than mom and chicken soup.

Influenza is an epidemic respiratory illness caused by one of three viral subtypes: A, B, or C. Influenza A causes higher mortality than influenza B and C and is often responsible for pandemics and yearly epidemics of this common, infectious disease. Clinically, patients with influenza present with an abrupt onset of fever, malaise, headache, and a dry, hoarse cough. These symptoms usually last three to five days. Amantadine and rimantadine may be used to prevent and to treat influenza A infection, but not B or C. Ribavirin, however, may be effective treatment for severe influenza pneumonia caused by either A or B subtype, although it is not FDA approved for this application. Annual influenza vaccination should be administered between mid-October and mid-November to any person at increased risk for complications. Health-care workers, those in close contact with high-risk individuals, and personnel vital to community function should also be immunized.