Table 1 The inclusion criteria for the paediatric meningitis cohort in this study

1. Bacterial meningitis group

 a) Bacterial meningitis: Samples with positive gram staining, culture or PCR

 b) Suspected bacterial meningitis: at least 4 of the following are present: fever, rash, neurologic impairment/seizures or altered mental status, CSF protein > 0.5 g/L, CSF glucose < 2.8 mmol/L, and CSF WBC > 20

2. Viral meningitis group

 a) Viral meningitis: Samples with positive PCR or anti-virus antibody test

 b) Suspected viral meningitis: Presence of clinical symptoms of meningitis without bacterial characteristics (as mentioned in 1b)

3. Noninfected control group

 Absence of CNS infection. Here, benign intracranial hypertension, febrile convulsion and acute cerebellar ataxia were mainly involved