[Changing epidemiology of meningococcal disease]

Area of Science:

• Epidemiology
• Microbiology
• Public Health

Background:

• Invasive meningococcal disease (IMD) epidemiology shows significant geographical and temporal variations in incidence and serogroup distribution.
• Global immunization efforts, including adolescent vaccination in North America and mass campaigns in Sub-Saharan Africa, have reduced disease burden.
• In France, IMD surveillance relies on mandatory reporting and genetic characterization, with the disease remaining a concern due to its impact on young children and a 10% case fatality rate.

Purpose of the Study:

• To analyze the current epidemiology of invasive meningococcal disease in France.
• To assess the impact of vaccination programs on IMD incidence and serogroup distribution.
• To evaluate vaccination coverage rates and their effectiveness in achieving herd immunity.

Main Methods:

• Mandatory notification system for IMD cases in France.
• Genetic characterization of meningococcal strains at the National reference Center for meningococci.
• Analysis of incidence rates, serogroup distribution, and vaccination coverage data.

Main Results:

• IMD incidence in France is low (0.7–1.6 cases per 100,000), but it disproportionately affects young children.
• Vaccination against serogroup C has shown success in reducing incidence in Europe.
• Vaccination coverage rates for serogroup C vaccines, especially among adolescents, are insufficient to establish herd immunity in France.

Conclusions:

• Despite overall low incidence, IMD remains a significant public health issue in France, particularly for vulnerable populations.
• Achieving adequate vaccination coverage, especially in adolescents, is crucial for preventing outbreaks and controlling the disease.
• Continued surveillance and genetic characterization are essential for monitoring and responding to evolving meningococcal epidemiology.