Meningococcal disease in Catalonia 1 year after mass vaccination campaign with meningococcal group C polysaccharide vaccine

Background: The aim of this study was to investigate the clinical and epidemiological characteristics of meningococcal disease in Catalonia (Spain) after vaccination with the polysaccharide vaccine. Patients and Methods: Cases were collected by the Statutory Diseases Reporting System. Results: 176 cases were reported, an overall incidence of 2.9/100,000 persons/year. 60% of cases occurred during winter and spring. The case fatality rate was 6.3%. The highest age incidence was in children under 2 years of age (48/100,000 persons/year). Comparison of the cases detected by the Statutory Diseases Reporting System with those obtained by the Microbiological Reporting System shows that meningococcal disease surveillance in Catalonia was relatively complete (95.7%), with a positive predictive value of 66.3%. 115 cases (65%) were culture-confirmed with a rate of 1.9/100,000 persons/year. 86 (75%) cases were due to Neisseria meningitidis serogroup B and 21 to serogroup C (18%). Conclusion: Although infections due to serogroup C have decreased after mass vaccination with the polysaccharide vaccine, it is likely that the number of infections will decrease further with the conjugate meningococcal group C vaccine.