Meningococcal disease in Australia; looking at the past, thinking of the future.

In 1987 an unexpected change in the epidemiology of meningococcal disease began in Australia. The change was accompanied by an outbreak of serogroup A meningococcal disease among Aboriginal central Australians, and was followed by a progressive rise in notifications of disease caused by both serogroup B and C nationwide. Over the last 4 years, the notification rate has plateaued at 2.1-2.3 per 100,000 population. Virulent clonal groups of serogroup A and C meningococci that have caused outbreaks appear to be identical to strains that have caused large outbreaks in other countries. We cannot predict where and when the next outbreak will occur. However, we can plan to respond swiftly when it does. This report presents an overview of the observed trends, the association between the microbiology and epidemiology of meningococcal disease, and the relevance of this association to outbreaks, with recommendations for management.