Meningococcal meningitis: global situation and control measures.

Both epidemics and sporadic cases of cerebrospinal meningitis (CSM) are known to occur. Among the different bacteria causing the disease, the most frequent etiological agents are Neisseria meningitis, Streptococcus pneumoniae and Haemophilus influenzae. The bacterial forms of meningitis constitute a serious public health problem in that they cause high mortality, particularly in children and in the elderly. Bacterial forms of meningitis, moreover, give rise to sequelae which have a significant, although poorly documented, socioeconomic impact. The epidemiological significance of the bacterial forms of meningitis varies in accordance with the country, the age of the individual affected, and the causative agent concerned. Of all causes of CSM, meningococcal infection is the most worrisome for the international community in that this infection is characterized by epidemics which create emergency situations not only in the country where the epidemic occurs, but also in neighbouring countries and beyond. Meningococcal infections are common in temperate and tropical climates. Sporadic cases appear throughout the year in both rural and urban areas with the greatest incidence in winter and spring. Like many other infections, CSM epidemics occur when the parasite/host (man)/environment relationship is such that it creates favourable conditions for the spread of infection (1).