Changes in the evolution of meningococcal disease, 2001-2008, Catalonia (Spain).

Reported cases of meningococcal disease between 1997 and 2008 were analyzed to determine the evolution after the introduction of a conjugated vaccine. In <6 years, the incidence rate of serogroup C fell from 7.6 to 0.6 per 100,000 persons/year in the periods before (1997-2000) and after (2001-2007) the introduction of the conjugate vaccine. In serogroup B, the reduction was from 15.4 to 11.1. In <20 years case-fatality-rate increased only in serogroup B (3% and 7.4%, p=0.026). Serosubtype P1.15 was the most frequent in serogroup B (31%), mainly associated with serotype 4 (80%), and in serogroup C subtype P1.5 (36%), with serosubtype 2a (86%). Exhaustive surveillance of circulating meningococcal strains is essential.