IMD Exploration of serogroup and clonal complex

The sugar-based meningococcal capsule is very important because it protects the bacterium against the human immune response and is a component of effective vaccines.  The different capsules are called serogroups and of the twelve known (A, B, C, E, H, I, K, L, W, X, Y, and Z) almost all IMD is caused by only six (A, B, C, W, X, and Y).  Some meningococci have no capsule and very rarely cause disease.

Similarly, although there are very many clonal complexes (ccs), only a few of them cause most cases of IMD and these are called the ‘hyperinvasive meningococci’.  Combinations of clonal complex and serogroup change over time, with epidemics caused by hyperinvasive meningococci with a particular serogroup e.g. serogroup C clonal complex 11 (C:cc11).  Here we display the year, serogroup, clonal complex, region of England, and age group, enabling patterns of disease to be discerned.