Normal
Bacterial Meningitis
Viral Meningitis
TB Meningitis
Fungal Meningitis
Opening Pressure (cm/H2O)
5-20
>30
Normal or slightly raised
Variable
Variable
Appearance
Clear, colourless
Turbid
'Gin' Clear
Fibrin web
Fibrin web
RBC
(per mm3)
(per mm3)
<3
Normal
Normal
Normal
Normal
WCC
(per mm3)
(per mm3)
<5
>500
(Up to 100,000)
(Up to 100,000)
<100
100-500
100-500
Cell Differential
Usually lymphocytes and monocytes
Neutrophilic (polymorphonuclear) pleocytosis
Lymphocytic (mononucleur) pleocytosis
Lymphocytic (mononucleur) pleocytosis
Lymphocytic (mononucleur) pleocytosis
Protein
(g/L)
(g/L)
0.2-0.4
>1
(High)
(High)
0.5-1
(Normal-high)
(Normal-high)
1.0-5.0
(High-very high)
(High-very high)
0.2-5.0
(Variable)
(Variable)
Glucose-Serum Ratio
0.5-0.66
(2.5-3.5 mmol/L)
(2.5-3.5 mmol/L)
<0.4
>0.6
<0.4
<0.4
Lactate
(mmol/L)
(mmol/L)
<2.8–3.5
Elevated
Normal
Elevated
Elevated
Microscopy and Gram Stain
-
60-80% positive Gram Stain
Negative
Negative
30% positive acid-fast stain
Culture
-
Up to 80% positive
Viral culture rarely positive (<5%)
30-50% positive
50-70% positive
PCR
-
-
HSV, VZV, enterovirus, CMV
-
-
Other
-
-
-
-
Cryptococcal Ag