CRP and influenza: PCT, but not CRP, was different between influenza-positive and influenza-negative individuals (P = 0.03), but median values were the same for both groups, with overlapping confidence intervals (CI) (influenza-negative, 0.1 [95% CI 0.1 to 0.1]; influenza-positive, 0.1 [0.1 to 0.18]).