Tuberculous meningitis (TBM) is a medical emergency. Early diagnosis is of utmost importance to minimize morbidity and mortality. Polymerase chain reaction (PCR) seems to be a promising test for rapid and early diagnosis of TBM.
To investigate whether PCR detects tubercle bacilli in CSF specimens that are missed by direct microscopy and culture, and if so whether PCR has significant diagnostic value compared to conventional methods.
PCR, culture and acid- fast bacilli (AFB) were performed on CSF samples taken from 43 patients with TBM (based on clinical features and cytochemical parameters of the CSF) and 15 with non- TBM as control group.
Of the 43 CSF specimens from highly probable TBM patients, 33 were positive by PCR (76.7%), whereas only 5 was acid-fast microscopy (AFM) positive (11.6%) and 22 were culture positive (55.2%). No positive results were found by AFM, culture or PCR in the non-tuberculous control group.
The results of this study indicate that application of PCR is extremely useful for the diagnosis of TBM.The PCR is superior to the currently available techniques for the diagnosis of tuberculous meningitis in terms of sensitivity, specificity and rapidity and can play a critical role in the diagnosis of suspected cases.