Abstract

Objective: To compare the performance of traditional and newer diagnostic methods for diagnosis of tuberculous meningitis (TBM) along with detection of drug resistant TBM. Methods: Single cerebrospinal fluids sample from 281 suspected TBM patients was processed during August 2011 to July 2012 for acid fast bacilli (AFB) examination by Ziehl-Neelsen and auramine staining methods, AFB culture on Lowenstein-Jensen culture media, by microscope observation of drug susceptibility testing assay, and nucleic acid amplification tests by inhouse conventional PCR and in-house real time PCR targeting IS6110 insertion sequence. All the isolates were subjected to drug susceptibility testing for isoniazid, rifampicin, ethambutol and streptomycin by 1% proportion method. Results: The percentage positivity by AFB smear examination and culture on Lowenstein-Jensen media was 21% (59/281), 11.4% (32/281) respectively. The detection rate by conventional PCR was 33.1% (93/281). The real time PCR showed positivity rate of 44.8% (126/281). The extra detection by real time PCR was 11.7%. Only one isolate was multiple drug resistant and 22 (68.8%) were pan-susceptible. Remaining eight isolates showed either mono/poly drug resistant to first line antitubercular drugs. Conclusions: Real time PCR is a more sensitive and rapid method if it is appropriately adopted in clinical practice for diagnosis of TBM. Prevalence of multiple drug resistance Mycobacterium tuberculosis causing TBM is low.

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