Purulent Bacterial Meningitis in the Russian Federation: Epidemiology and Immunization

Relevance: Purulent bacterial meningitis and invasive meningococcal disease remain relevant throughout the world and are of particular concern due to high mortality and disability rates, as well as regular outbreaks of meningococcal infections. 
Objective: To establish epidemiological features of purulent bacterial meningitis and meningococcal disease in the Russian Federation and to highlight the problem of immunization. 
Materials and methods: Data were collected at the Russian Reference Center for Bacterial Meningitis Monitoring of the Central Research Institute of Epidemiology in the personified system for registering cases of purulent bacterial meningitis, including meningococcal disease, meningitis of non-meningococcal and unknown etiology. We examined 28,440 registered cases.
Results: We established that three pathogens, that is, meningococcus, pneumococcus and Haemophilus influenzae, accounted for 84 % of all cases of bacterial meningitis, the most vulnerable age group being children under 5 years of age. Despite a general decrease in the incidence of purulent bacterial meningitis in the Russian Federation in 2010–2019, we noted an increasing incidence of pneumococcal meningitis and invasive meningococcal disease by the end of the study period. In terms of age, the 10-year observation period demonstrated a decrease in the incidence of invasive meningococcal disease in children and its rise among adolescents and young adults; an increase in the incidence of pneumococcal meningitis in adults and a null decrease in children; and the absence of a downward trend in the incidence of Haemophilus meningitis in children. 
Discussion: Organization of epidemiological monitoring of bacterial meningitis within the system of epidemiological surveillance in the Russian Federation in 2010, its testing and 12-year implementation has enabled us to trace changes in the incidence, mortality, and fatality of the disease and to establish age groups at risk. To reduce the burden of the disease, it is expedient to further improve the existing immunization programs in the Russian Federation.