Influenza, also known as "flu," is a common
respiratory infection that can be severe and even life-threatening. Each year
more than 36,000 persons, especially older individuals and those with chronic
medical conditions, die from influenza in the United States. The February
23, 2005, issue of JAMA includes an article that
evaluates the accuracy of diagnosing influenza. This Patient Page is adapted
from one previously published in the November 3, 2004, issue of JAMA.