Detecting polysaccharide antigen of Neisseria meningitidis group C in cerebrospinal fluid by dot-ELISA assay.

Cerebrospinal fluid (CSF) samples from 210 patients (200 with clinical evidence of bacterial meningitis, 10 with other clinical neurologic disease) were tested by a Dot-ELISA assay for detection of polysaccharide antigen of N. meningitidis group C. CSF samples were treated with EDTA 0.1 M, at pH 7.5 and heated to 90>C for 10 min. Polyclonal antiserum was purified by use of ethanol fractionation. The results were compared to those using bacterial culture (BC), latex agglutination (LA), counterimmunoelectrophoresis (CIE), and direct microscopy (DM) methods. Test results showed a correlation of 93.3%, 94.3%, 91.0% and 69.5% respectively, and sensitivity of 0.947 and specificity of 0.930. This study suggests that the dot-ELISA assay of CSF is a useful alternative technique for the diagnosis of group C meningitis.