Detection of bacterial antigens in cerebrospinal fluid by a latex agglutination test in 'septic unknown' meningitis and serogroup B meningococcal meningitis.

The latex agglutination test (Wellcogen) was evaluated specifically in cases of 'septic unknown' meningitis, with CSF findings characteristic of bacterial meningitis but with no bacterial organisms grown on CSF culture or seen on microscopy after Gram staining. In only 4 (12%) of 33 cases of 'septic unknown' meningitis were antigens identified in the CSF. This kit contains for the first time reagents for the detection of serogroup B Neisseria meningitidis antigens and was also evaluated for this bacteria. Only 6 (27%) of 22 serogroup B N. meningitidis cases were identified.