Meningococcal serotypes and serogroup B disease in north-west Europe.

Examination of the trends of meningococcal infection in Norway, Iceland, Faroe Islands, Denmark, England and Wales, and the Netherlands, has shown that Neisseria meningitidis B:2b:P1.2 and/or B:2a:P1.2 phenotypes were associated with peaks of infection in the Netherlands in 1966, in Iceland 1976-77, and in England and Wales in 1973-75. These strains were present in all six countries in the decade 1970-80 but their prevalence is now practically negligible. In contrast the prevalence of the B:15:P1.16 phenotype has risen. In the Faroe Islands and northern Norway this change in serotype prevalence has been followed by rises in incidence of meningococcal disease; the same is happening in England and Wales but not yet in the other countries.