Bacterial meningitis is a potentially life-threatening disease that is associated with substantial neurological morbidity and mortality. Accurate diagnosis is essential to improve outcome and prevent antibiotic overuse. Here we try to explore new biological markers for the diagnosis of the central nervous system infection disease.

To investigate the diagnosis value of procalcitonin,interleukin-6, agiotensininⅡin the cerebrospinal fluid in the central nervous system infection disease.

Inclusion Criteria:

1. Aged 13 years or older;
2. At least two of the following clinical characteristics:headache, fever, neck stiffness, mental symptoms or consciousness impairment or seizures
3. Patients' family signed informed consent.

Exclusion Criteria:

1. Contraindications to lumbar puncture
2. Patients with active malignancy

More than 12 years old; meet the clinical diagnostic criteria for the central nervous system infection disease