Comparison of Phadebact coagglutination tests with counterimmunoelectrophoresis for the detection of bacterial antigens in cerebrospinal fluid.

One hundred and seventeen specimens of cerebrospinal fluid from 94 patients were examined for the presence of pneumococcal and Haemophilus influenzae type b antigens using counterimmunoelectrophoresis and coagglutination tests. The coagglutination method using Phadebact reagents was as sensitive as counterimmunoelectrophoresis, but culture was a more sensitive diagnostic procedure than either test. A meningococcus coagglutination reagent, included in a prototype meningitis diagnostic kit, was also found to be as sensitive as counterimmunoelectrophoresis when tested on culture-positive cerebrospinal fluid specimens. Coagglutination tests for the detection of bacterial antigen are useful supportive tests when used in conjunction with direct microscopy and culture for bacterial pathogens.