Estimates of the burden of meningococcal disease in Italy: implications for prevention and control

Meningococcal disease is an acute, severe bacterial infection caused by Neisseria meningitidis. The most common presentations of invasive meningococcal infection (IMD) are meningitis and sepsis, less common pathologic presentations include focal infections. IMD can develop from initial symptoms to death within 24 hours. As many as 20% of survivors have permanent sequelae. Infants < 1 year of age have the highest incidence and adolescents the highest carriage prevalence. In Italy, the incidence of IMD was 0.25 confirmed cases per 100,000 in 2011, but this may have been considerably underestimated due to under-detection and under-reporting. Recently, we estimated the impact of the MenC universal vaccination on the burden of meningococcal meningitis in Puglia by assessing the completeness of three registration sources (notifications, hospitalizations, and laboratory surveillance). The sensitivity of the three systems was 36.7% (95% CI: 17.5%-57.9%) and registrations lost nearly 28 cases/year in the period 2001- 2013. In the National Surveillance of Invasive Bacterial Diseases, serogroup B accounted for 64.9% of samples serotyped in 2011. Applying this percentage to the total number of hospitalizations for IMD registered in the same year (n = 256), we obtained an estimated 166 episodes attributable to serogroup B. Our work highlights the importance of enhancing surveillance for meningococcal disease and strengthening vaccinations against all preventable serogroups.