In this section
Meningitis and encephalitis Meningococcal disease Lumbar puncture Antimicrobial guidelines
White cell count
Age
Neutrophils (x 106/L)
Lymphocytes (x 106/L)
Protein (g/L)
Glucose CSF:blood ratio (total)
Lactate (mmol/L)
<1 month
0#
<22
<1.0
≥0.6 (or ≥2.0 mmol/L)
0.9-2.5
>1 month
0
≤5
<0.4
≥0.6 (or ≥2.5 mmol/L)
1.0-2.0
Note: # Some studies have found that up to 5% of white blood cells in the CSF of neonates without meningitis, comprise neutrophils
Glucose (CSF:blood ratio)
Bacterial meningitis
100-10,000*
<100
>1.0*
<0.4*
>2.0* (>4.0 is strongly predictive of bacterial meningitis)
Viral meningitis
10-1000*
0.4-1.0*
Usually normal
<2.0
TB meningitis
50-1000*
1.0-5.0*
<0.3*
>2.0
Note: *may be normal
Delays in laboratory analysis of CSF can alter cell counts as a result of lysis in the CSF. There is progressive reduction in both neutrophils and lymphocytes after 4 hours
For emergency advice and paediatric or neonatal ICU transfers, see Retrieval services
Lumbar puncture Meningitis Meningococcal infection
Last updated October 2024