And it does matter. Even though the symptoms are similar, treatments for cold, flu, and bacterial infections such as pneumonia are very different. Antibiotics are ineffective against viral illnesses such as colds and influenza, but they are often prescribed, either because physicians suspect bacterial infections or because patients demand them. If the doctor knew specifically that the patient had influenza, they would not prescribe antibiotics, but in the absence of a specific diagnosis they often do because patients expect to be given something. Oxman is a staff physician in infectious diseases at the VA Medical Center in San Diego and is a professor at the University of California in San Diego.
Influenza is an acute respiratory infection caused by a variety of viruses.
It generally sweeps through communities during the winter months and can affect a large percentage of the population. The best way to prevent the flu is through vaccination, but production problems this year may mean the vaccine won't be available to some low-risk Americans until December or later. Some 74 million doses of flu vaccine were used last year, and health officials say that about the same amount of vaccine will be needed this season. The newly approved diagnostic test, manufactured by Quidel Corp., allows physicians to determine whether a patient has the flu with a simple nasal swab. If influenza is diagnosed early in the infection process, it can be treated with several antiviral drugs.