Meningitis is an infection of the meninges, the thin lining that surrounds the brain and the spinal cord. Several different bacteria can cause meningitis and
Neisseria meningitidis
is one of the most important because of its potential to cause epidemics. Meningococcal disease was first described in 1805 when an outbreak swept through Geneva, Switzerland. The causative agent,
Neisseria meningitidis (the men-ingococcus), was identified in 1887.
Twelve subtypes or serogroups of
N. meningitidis have been identified and four (
N. meningitidis. A, B, C and W135) are recognized to cause epidemics. The pathogenicity, immunogenicity, and epidemic capabilities differ according to the serogroup. Thus the identification of the serogroup responsible of a sporadic case is crucial for epidemic containment.
