The specificity and sensitivity of CSF and blood glucose concentration in the diagnosis of neonatal meningitis.

In a prospective study of high-risk newborn infants, the specificity and sensitivity of CSF/blood glucose ratio were studied in 35 newborn infants with meningitis and 100 high-risk neonates without meningitis. High CSF/blood glucose ratios of 0.93 (0.17) (Mean (S.D.) ) for preterm infants and 0.96 (0.30) (Mean (S.D.) ) for term infants were observed. The CSF/blood glucose ratios of less than 0.6 for preterm meningitic and less than 0.5 for term meningitic infants had the highest specificity (100%). The corresponding sensitivity of these ratios in the diagnosis of meningitis was 74.3% and 71.4% respectively. Similarly, an absolute CSF glucose value of less than 1.3 mmol/l in infants with meningitis was highly specific. Nevertheless, complete clinical evaluation of the infant is important if bacterial meningitis is suspected and the decision to treat should not be based on CSF glucose findings alone.