The use of counter-immuno-electrophoresis to identify causative organisms in bacterial meningitis: experience in Cape Town.

Crebrospinal fluid (CSF) from 142 patients was tested for the presence of Haemophilus influenzae, pneumococcal and meningococcal antigens by counter-immuno-electrophoresis with commercial antisera. Group- or type-specific antigen was detected in the CSF of 67% of 64 patients with meningitis proved by culture to be due to these organisms, and in 10 of 25 patients with purulent meningitis but negative cultures. No false positive results were obtained in 24 normal CSF specimens, or in the CSF of 29 patients with meningitis caused by other organisms. The diagnostic usefulness of this specific, relatively simple and rapid procedure is confirmed.