Disease due to serogroup W135 Neisseria meningitidis.

Five cases of disseminated meningococcal disease due to serogroup W135 Neisseria meningitidis are presented. The cases ranged in age from 16 months to 23 years, and spanned a clinical spectrum from mild meningitis without rash or evidence of meningococcal septicemia to severe meningoencephalitis with fulminant meningococcemia, disseminated intravascular coagulation, and death. These cases demonstrate that serogroup W135 N meningitidis is fully pathogenic for man and capable of producing the full spectrum of disseminated meningococcal disease associated with other serogroups. Since this serogroup has recently emerged as a significant cause of disease in Europe, attention should be focused on the correct serogroup designation of strains of N meningitidis isolated from clinical material and reported as "nongroupable" by clinical laboratories, so that additional clinical and epidemiologic information may be obtained.