*common pathogenic serogroup A, B, C, W, X, Y
*seasonal epidemics by group A, C
**meningitis belt
*sporadic cases by e.g. group B
**Latin America
**Norway
**New Zealand
*immunity generated by polysaccharide capsule except B
**may be the reason that herd immunity development relatively slow and sporadic outbreaks continue in above countries
==epidemiology==
*highest < 2 y/o and adolescent
*annual outbreak during dry season in meningitis belt
**dry winds make people's nose drier resulting in easy
why natural carriage differs between countries?why ANZAC are the highest in the world outside meningitis belt ==transmission==*aerosol*fomite*adolescent activity
==clinical picture==