title: Serum procalcitonin in viral and bacterial meningitis.
abstract: BACKGROUND
  In children with meningitis, there is a difficulty to verify the etiology as viral or bacterial. Therefore, intensive research has been carried out to find new and rapid diagnostic methods for differentiating bacterial from viral meningitis.
  
  
  OBJECTIVE
  The aim of this work was to study the behavior of procalcitonin (PCT) and whether it can be used to differentiate children with bacterial from those with viral meningitis. We also compared PCT to C-reactive protein (CRP) and white blood cell count.
  
  
  METHODS
  Forty children aged from 4 months to 12 years with clinically suspected meningitis were studied. Lumbar punctures were done for all cases before starting initial antibiotic treatment. According to the results of bacterial cultures and cerebrospinal fluid (CSF) cytochemical profile, our patients were classified into two groups: bacterial meningitis group and viral meningitis group. PCT, CRP, and leukocyte count were measured at the time of admission and after 3 days.
  
  
  METHODS
  Forty children aged from 4 months to 12 years with clinically suspected meningitis were studied. Lumbar punctures were done for all cases before starting initial antibiotic treatment. According to the results of bacterial cultures and cerebrospinal fluid (CSF) cytochemical profile, our patients were classified into two groups: bacterial meningitis group and viral meningitis group. PCT, CRP, and leukocyte count were measured at the time of admission and after 3 days.
  
  
  RESULTS
  PCT levels were significantly higher in patients with bacterial meningitis (mean, 24.8 ng/ml) compared to patients with viral meningitis (mean, 0.3 ng/ml) (P<0.001). PCT levels in bacterial meningitis group decreased after 3 days of starting treatment, but remained higher than viral meningitis group (mean, 10.5 ng/ml). All CSF parameters, blood leukocytes, and CRP showed overlapping values between the two groups. Serum PCT with cut off value >2 ng/ml showed sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 66%, 68%, and 100%, respectively, for the diagnosis of bacterial meningitis.
  
  
  CONCLUSIONS
  Serum procalcitonin level has a better diagnostic and prognostic value than CRP or leukocyte count to distinguish between bacterial and viral meningitis. It is also a good indicator of the efficacy of treatment of bacterial meningitis.
authors.affiliation: Department of Pediatrics, Zagazig University, Zagazig, Egypt.
authors.forename: Usama M
authors.initials: UM
authors.lastname: Alkholi
authors.forename: Nermin
authors.initials: N
authors.lastname: Abd Al-Monem
authors.forename: Ayman A
authors.initials: AA
authors.lastname: Abd El-Azim
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Sultan