Comparative evaluation of three commercial products and counterimmunoelectrophoresis for the detection of antigens in cerebrospinal fluid.

Three commercial products and counterimmunoelectrophoresis were evaluated for their ability to detect microbial antigens of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in cerebrospinal fluid from 157 patients suspected of having meningitis. Thirty-four patients were diagnosed as having bacterial meningitis by culture, microscopy, or antigen detection. The overall results showed the following detection percentages; counterimmunoelectrophoresis, 76%; Phadebact CSF, 76%; Directigen, 82%, and Bactigen, 93%. The results with purified antigen revealed that latex agglutination was more sensitive than coagglutination, which in turn was more sensitive than counterimmunoelectrophoresis.