The usefulness of hematological parameters and cerebrospinal fluid indexes in the differential diagnosis of acute bacterial from viral meningitis

Central nervous system (CNS) infection is a medical emergency with an important cause of mortality worldwide. The 79 patients with confirmed acute CNS infection (48 bacterial and 31 viral meningitis) were evaluated. Bacterial meningitis score, cerebrospinal fluid (CSF)/serum glucose ratio, and CSF/serum albumin ratio had the highest AUCs (Area under the Curves) (0.873, 0.843, 0.810, respectively) for discriminating bacterial meningitis. Neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte ratio (PLR) and CSF lactate dehydrogenase (LDH) have a good ability for the differential diagnosis of bacterial meningitis. CSF/serum glucose ratio, NLR (with a cut-off value> 8.87), large unstained cell (LUC), total protein, albumin, and procalcitonin levels were found to be predictors for mortality. NLR can be used as a biomarker to differentiate bacterial meningitis from viral meningitis and to predict the prognosis of CNS infection. CSF/serum albumin ratio and CSF LDH can be used to predict bacterial meningitis as well as CSF/serum glucose ratio.