Clinical Presentation of Influenza in Unselected Children Treated as Outpatients

BACKGROUND:Influenza causes a great disease burden on children especially in the outpatient setting. The signs and symptoms of influenza in unselected children treated as outpatients have not been previously published. METHODS:We assessed the clinical presentation of influenza in a prospective study of respiratory infections in preenrolled cohorts of children ≤13 years of age during 2 consecutive respiratory seasons (2231 child-seasons of follow-up). We examined the children and obtained a nasal swab for the detection of influenza during every episode of illness, regardless of the presence or absence of fever or the severity of the symptoms. RESULTS:Influenza was virologically confirmed in 372 children, of whom 353 (95%) providing complete data on the signs and symptoms were included in the analyses. A total of 95% of these children were febrile, and 50% had fever ≥39.0°C. Among children