An evaluation of two immunological methods in the diagnosis of bacterial meningitis: the effect of ultrasonic treatment of the cerebrospinal fluid.

Counterimmunoelectrophoresis (CIE) and fluorescent antibody (FA) technique were evaluated in the diagnosis of bacterial meningitis caused by Neisseria meningitidis (groups A, B, C), Streptococcus pneumoniae and Haemophilus influenzae type b. FA was positive in 80% and CIE in 70% of the 59 cases of bacterial meningitis investigated. Ultrasonic treatment of the cerebrospinal fluid (CSF) increased the efficacy of CIE from 50% to 70%. By FA it was possible to demonstrate bacterial antigen in CSF up to 3 days after the beginning of antibacterial therapy. Bacterial antigens could be demonstrated by the two immunological methods from 2 to 24 days when stored at 20 degrees C. At storage at 4 degrees C the antigens were demonstrable for 2 to 13 weeks by FA and for 2 to 10 weeks by CIE.