ELISA--its evaluation in diagnosis of tuberculosis meningitis

Diagnostic utility of an enzyme linked immunosorbent assay (ELISA) in hospitalised patients with clinical symptoms suggestive of tuberculous meningitis (94 cases) was studied. CSF Anti-tubercular IgG antibody levels were estimated by ELISA in 44 cases of proven tuberculous meningitis, 24 proven pyogenic meningitis and in 48 non-tuberculous cases. The cut off dilution was established at a CSF dilution of 1 : 1 (undiluted) with positive and negative controls. The ELISA test had a sensitivity of 97.72% and a specificity of 95.35% using MSE antigen. When compared with conventional smear examination and culture isolation from specimens, the ELISA test proved statistically superior in the detection rate or diagnosis of clinically suspected tuberculous meningitis cases (P less than 0.05).