with confirmed influenza A(H1N1,H3N2) or influenza B virus infection by real time RT-PCR (rRT-PCR), age between 18-65 years old, axillary temperature ≥38ºC and with at least two constitutional symptoms (headache, chill, myalgia ，or fatigue) and one respiratory symptom (cough ，sore throat,or coryza) . Illness onset had to be within 36 hours, and informed consent was obtained.