Low Yield of Positive Cerebrospinal Fluid (CSF) Culture and Bacterial PCR Tests In Paediatric Patients With A Normal CSF White Cell Count.

The aim was to review paediatric patients who had a positive cerebrospinal fluid culture or bacterial PCR test, yet had a normal CSF white cell count for age. Patients were included if they had a CSF sample sent for culture (between 2005 and 2015) or bacterial PCR (2010-2015), however neurosurgical and neurology patients were excluded. Of the 2,482 patients reviewed, there were 101 patients with laboratory-confirmed bacterial meningitis included, of which 27 were positive by culture and PCR, 26 by culture alone and 48 were positive by PCR only. Eighteen (18%) of these patients had CSF white cell counts within normal range. Only one case with a normal CSF white cell count, where the lumbar puncture was done after six days of antibiotics, was deemed to be clinically significant. Bacterial PCR should not be routinely requested in patients with a normal CSF white cell count, unless their blood culture is positive or unless clinically indicated based on the assessment of a senior paediatrician.