Among cases with confirmed bacterial pneumonia, 77% had CRP ≥40 mg/l compared with 17% of 556 RSV pneumonia cases. The Receiver Operating Curve (ROC) analysis produced an AUC of 0.87, indicating very good discrimination; a cut-point of 37.1 mg/l best discriminated bacterial pneumonia (sensitivity 77%) from RSV (specificity 82%). This evidence concerns the gene CRP and bacterial pneumonia.