Cerebro spinal fluid analysis in childhood bacterial meningitis

The aim of this study was to analyze the lumbar puncture of all suspected cerebrospinal fluid (CSF) for suspected meningitis.

This study was undertaken in the department of Child Health, the Royal Hospital. The details of CSF of all files of the children who had undergone lumbar puncture for suspected meningitis from January 1, 2004 to December 31, 2004; were enrolled for the study.

A total of 395 lumbar punctures were done to exclude bacterial meningitis. Out of the 142 CSF studies in neonates, 17 (12%) had the cytology suggestive of bacterial meningitis and 15 (88%) of them being culture positive. The commonest pathogen was Group B Streptococcus (70%).The bacterial antigens were positive only in 41% of the confirmed cases of bacterial meningitis, all being that of Group B Streptococcus and gram stain positivity in 45 percent of cases. In the 1- 3 months group all the 17 lumbar punctures were normal. Of the 179 lumbar punctures done in 3-18 months group, only 11(6%) were abnormal, 72% being culture positive. Streptococcus pneumonia was the commonest organism (88%). Bacterial antigens were positive only in 2 of the 8 culture positive cases where gram stain was positive in 4 out of 8 cases. Irritability, lethargy and sick looking appearance were present in all the positive cases. None of the 28 children from 18 months to 5 years had abnormal CSF or positive CSF culture.

Based on the fact that only 7% of the 395 CSF studies were abnormal, we conclude that better clinical judgment and diagnostic criteria are warranted, before laying out guidelines for lumbar puncture to confirm or exclude the diagnosis of bacterial meningitis. Besides fever and convulsions as indicators for CSF studies clinical parameters such as irritability, lethargy and sick looking appearance are better indicators.