Epidemiology of meningococcal meningitis in Sahel and Mongolia.

The epidemiological situation of meningococcal meningitis in the African meningitis belt and in Mongolia are presented. Studies on bacterial air pollution have been conducted in different types of dwellings in the two regions affected by meningococcal meningitis. Results have shown that during the dry (meningitis) season the air in dwellings is much more contaminated by bacteria, including those of oral origin, as a consequence of environmental conditions (crowding, activity, ventilation). A significant correlation between the bacterial counts and the incidence of meningococcal disease has been demonstrated. On the basis of the results obtained, measures can be recommended which could be used in the prevention of meningitis, especially in the case of a high prevalence of serogroups of meningococci other than those which can be efficiently controlled by immunization.