Molecular epidemiology of meningococci: application of DNA sequence typing.

Neisseria meningitidis is an invasive pathogen contributing significantly to childhood mortality worldwide. The organism is adapted to the human host and transmitted by close contact or droplet aerosols. In comparison to healthy carriage, invasive disease is a rare event. Nevertheless, due to a high case-fatality rate and the fact that meningococcal infection is a communicable disease, molecular typing of meningococci has been driven forward considerably in the past decades. Multilocus and antigen sequence typing data are assembled in large databases accessible via the internet. For epidemiological purposes, representative case ascertainment strategies are necessary if data are to be exploited for trend analysis, geographic visualization, detection of abnormalities such as outbreaks, and prediction of vaccine coverage. In Europe, a consensus for molecular typing has been achieved.