Identification of bacterial aetiology in acute meningitis.

Background: The lack of rapid and sensitive test remains a key issue in diagnosing meningitis and affordability impedes using the molecular techniques. However, conventional PCR is currently becoming more affordable.

Objectives: Optimize and establish a multiplex PCR and to compare the above PCR to Cerebrospinal fluid (CSF) culture and antigen detection in sensitivity and specificity for the detection of bacterial meningitis.

Methods: CSF specimens were collected from patients with suspected acute meningitis admitted to Teaching Hospital, Peradeniya from December 2016 to March 2017. A multiplex PCR was used to detect Neisseria meningitides, Streptococcus pneumonia and Haemophilus influenzae.

Results: Eighty specimens of CSF were collected during the study period. The mean duration to sample collection was 4.78(SD 2.6) from the onset of symptoms. None of the samples given positive CSF culture. CSF antigen detection was performed on 50 specimens and all were negative. Of the total samples, eight yielded positive PCR results. In two of the positives, the full report was normal, one was suggestive of viral aetiology and five were suggestive of bacterial aetiology. Three were positive for S.pneumoniae and five for H.influenzae. positive PCR results were associated with a shorter time gap between hospitalization and sample collection and a larger CSF volume.

Conclusion: Findings of the study highlight the usefulness and recommendation of multiplex PCR in the diagnosis of pathogens causing acute bacterial meningitis. Collection of an adequate volume of CSF early in the illness, without delay may improve the diagnosis.