Global trends in meningococcal disease.

The unambiguous identification of epidemic Neisseria meningitidis strains and their clear distinction from other less pathogenic meningococci is required for the global epidemiology of meningococcal disease. Until the recent development of multi-locus sequence typing (1), multi-locus enzyme electrophoresis (abbreviated MEE or MLEE) was the only method to permit large-scale analysis of N. meningitidis strains causing disease in various parts of the world and to document the intercontinental spread of particularly pathogenic organisms (2-8).