Utility of real time pcr in culture negative acute bacterial meningitis in pediatric age group

Introduction & objective: Acute Bacterial Meningitis (ABM) is a medical emergency which warrants early diagnosis. Pretreatment with antibiotic before lumbar puncture make interpretation of CSF culture difficult. Clinicians must rely on the other tests to determine the etiology of meningitis. Thus it is very important to ascertain the diagnostic efficacy of different tests employed. This study was aimed to evaluate Real Time PCR with other diagnostic methods in culture negative ABM in pediatric age group. Material & Method: 60 CSF samples from suspected cases of ABM were subjected to cytology, gram staining, biochemical analysis, culture as well as antigen detection by latex agglutination test (LAT) for S.pneumoniae, H.influenzae, N.meningitidis, E.coli, Gr.B Streptococcus and probe based Real Time PCR for S.pneumoniae, H.influenzae, N.meningitidis. Result: Among the five PCR positive samples for S. pneumoniae four were positive by LAT, of which only one was isolated by culture. Of the three PCR positive H.influenzae samples, two were positive by LAT but none yielded growth. All CSF samples demonstrating microorganism by any means (culture, LAT, RTPCR) had shown Polymorphonuclear leucocytosis & pus cells. Conclusion: This study emphasizes the need to subject pediatric CSF samples to Real Time PCR for identifying microorganism, showing polymorphonuclear leucocytosis & pus cells which may be missed on culture.