5, 3 år), som havde feber (≥ 37. 8° C) plus enten hoste eller forkølelse var 67% af de influenzapositive patienter smittet med influenza A og 33% med influenza B.
In a study of otherwise healthy children (65% influenza-positive) aged 1 to 12 years (mean age 5.3 years) who had fever (≥ 37.8 °C) plus either cough or coryza, 67% of influenza-positive patients were infected with influenza A and 33% with influenza B.