[Clinical symptoms of influenza infection in the 2002-2003 season].

The highest body temperature and clinical symptoms during the influenza infection were analyzed on 2,145 patients with influenza, (type A: 1,408cases, type B: 737cases: confirmed by a rapid diagnosis kit, Capilia FluA, B), and for 670 patients with a negative response to the rapid diagnosis kit (controls). The study was a multi-center study of the 2002-2003 influenza season. The percentages of patients with fever over 38 degrees C, 38.5 degrees C and 39 degrees C were significantly higher in influenza A than in influenza B or controls (16-64 yrs). Over 80% of the patients in all age groups of 0-6 yrs, 7-15 yrs, 16-64 yrs or over 64 yrs with influenza A or B had a cough. The percentage of patients with cough was significantly higher for patients with influenza A or B than for controls under 65 yrs. The percentages of influenza A or B patients with rhinorrhea or loss of appetite were significantly higher than in controls under 65 yrs. The percentage of patients reporting fatigue, headache or myalgia was significantly higher for influenza A than for controls of 16-64 yrs. Differences in symptoms, including fever, were minimal between influenza A and B patients under 16 yrs, and also among influenza A, B and controls in patients over 64 yrs. The percentage of patients with cough was not different among the three age groups by influenza A or B. However, the percentage of patients with rhinorrhea, loss of appetite, vomiting or diarrhea was higher in children under 16 yrs than in adults aged 16-64 yrs in influenza A or B. In conclusion, consideration must be given to the patient's age and the type of influenza when doing a symptomatic diagnosis of influenza. In addition, the use of a rapid diagnosis kit seems necessary for the diagnosis of influenza in elderly patients, who may have no specific symptoms of influenza.