Diagnosis and Management of Bacterial Meningitis in the Paediatric Population: A Review

Table 3

Lumbar puncture findings¹ [3, 9].

CSF finding	Normal^2	Viral	Bacterial	Partially treated bacterial
White cell count (cells/mm^3)	<5	<1000	>1000	>1000
PMNs	0	20–40%	>85–90%	>80%
Protein (mg/dL)	<40	Normal or <100	>100–200	60–100+
Glucose (mmol/L)	≥2.5	Normal	Undetectable–<2.2	<2.2
Blood to glucose ratio	≥0.6	Normal	<0.4	<0.4
Positive gram stain	—	—	75–90% (depending on organism)	55–70%
Positive culture	—	—	>70–85%	<85%

¹Other investigations may also be performed on CSF to exclude nonbacterial causes of meningitis depending on the clinical scenario; including India Ink staining or antigen testing for Cryptococcus neoformans, Herpes simplex virus (HSV), cytomegalovirus (CMV) and enterovirus PCR.
² Values for paediatric patients >1 month of age; some values vary for neonates [16].
Neonates: white cell count may be higher (<20 in the form of lymphocytes); normally zero PMNs, however some studies have found up to 5% PMNs in neonates without meningitis.
Neonates: normal protein <100 mg/dL.