CALCA and viral meningitis: Mean difference of PCT‐CSF between patients with community‐acquired bacterial meningitis and with viral meningitis was 0.71 ng mL−1 (95% CI: 0.17–1.25) and 0.73 ng mL−1 (95% CI: 0.19–1.27) for community‐acquired bacterial meningitis versus the noninfectious group.