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Antiviral drugs can be effective in treating the flu, if they are started within the first 36 to 48 hours of infection. They have only modest benefit, if any, at treating other viruses which produce similar symptoms. Dr. Jonathan L. Temte and Dr. Jacob P. Prunuske of the University of Wisconsin School of Medicine and Public Health encouraged doctors to make a correct diagnosis before prescribing any of these drugs, because the side effects can be significant for some people.
Dr. Mark H. Ebell and Anna Afonso at The University of Georgia provided a review for physicians on how to diagnose influenza. These authors offered several motivations for accurate diagnosis, in addition to the decision about prescribing antiviral drugs. A correct diagnosis rules out other diagnoses, guides patient education, and lets the patient know what to expect.
It is not so easy, even for doctors, to diagnose influenza based solely on symptoms, Ebell and Afonso reported. The symptoms overlap those of other infections. Lab tests may be necessary. However, the most important symptoms are fever, cough, and acute onset (the illness develops quickly, over a period of a few days or less).
The Centers for Disease Control and Prevention lists possible influenza symptoms as follows:
3. Sore throat
4. Runny nose or stuffy nose
5. Muscle aches
8. Vomiting and diarrhea, more often in children than in adults.
Infected individuals often experience some or all of these. Complications of influenza include pneumonia, bronchitis, sinus infections, and ear infections, sometimes from secondary bacterial infections. Patients with complications experience more severe symptoms.
Dr. Barbara Michiels and colleagues at the University of Antwerp, Belgium, performed a study to see how many patients with flu symptoms actually have influenza. During five winter periods, 2002 to 2007, a group of general practitioners tested 4,597 patients with influenza-like illness. Overall, 52.6 percent actually had influenza.
So when you have flu symptoms, you may have influenza or you may have another infection. See your doctor for diagnosis.