Abstract

Despite expansive studies over the past century, the epidemiology of invasive meningococcal disease (IMD) has remained elusive in some of its aspects. The following review attempts to summarize the past and current trends in the etiology of IMD. Data was collected through the analysis of peer-reviewed studies and surveillance data on national, sub-national and regional levels performed using various search engines such as pubmed (www.ncbi.nlm.nih.gov/pubmed/), regional WHO homepages (www.who.int) and department of health websites. Despite the establishment of improved surveillance, the reasons for the differences in IMD epidemiology between endemic and epidemic settings are not fully understood. Factors influence the timing and distribution of epidemics including climatic, socio-economic and cultural factors involving changes in human lifestyle, natural growth of the human population, crowding and increased mobility. These have also strongly affected the global population structure of Neisseria meningitides and are still currently responsible for changing patterns in IMD epidemiology. In recent years, much interest has arisen on the subject due to both the development of conjugate vaccines and to the continuing occurrence of outbreaks, many of them in industrialized countries. With antimicrobial resistance on the rise, effective and affordable vaccines along with continued surveillance are needed to help combat this complex disease.

Key words: Meningococcal meningitis, epidemiology, vaccines, antimicrobial resistance, surveillance.