Annual report of the Australian Meningococcal Surveillance Programme, 1998. The Australian Meningococcal Surveillance Programme.

The National Neisseria Network has undertaken meningococcal isolate surveillance by means of a collaborative laboratory-based initiative since 1994. The phenotype (serogroup, serotype and serosubtype) and antibiotic susceptibility of 323 isolates of Neisseria meningitidis from invasive cases of meningococcal disease were determined in 1998. Ninety per cent of the invasive isolates were either serogroup B or C. Serogroup B strains predominated in all States and Territories and were isolated from sporadic cases of invasive disease. Serogroup B phenotypes were diverse. Serogroup C isolates were most prominent in New South Wales, especially in adolescents and young adults. C:2a:P1.5 was the most frequently encountered phenotype and C:2b:P1.5,2 strains were also distributed widely. About three-quarters of all isolates showed decreased susceptibility to the penicillin group of antibiotics (MIC 0.06 to 0.5 mg/L). Four isolates showed reduced susceptibility to rifampicin, one to ciprofloxacin and one to chloramphenicol.