Epidemiology of bacterial meningitis in Niamey, Niger, 1981-96.

ABSTRACT

PIP: The study presented information on the epidemiology of bacterial meningitis in Niamey, Niger from 1981 to 1996 using retrospective surveillance. During the 15-year period, 7078 cases of laboratory-diagnosed bacterial meningitis were identified. 3 years (1984-85, 1985-86, and 1994-95) were considered to be epidemic years, and in these years incidence of bacterial meningitis exceeded 140 cases/100,000 population. The major pathogens were Neisseria meningitidis (57.7%), Streptococcus pneumoniae (13.2%), and Haemophilus influenzae (Hib) (9.5%). Mean annual incidence of bacterial meningitis was 101/100,000 population with an average annual mortality rate of 17 deaths/100,000. Both S. pneumoniae and Hib had caused more meningitis deaths than N. meningitidis, as observed over the 7-year period for which data were available. Meanwhile, N. meningitidis was the major cause of meningitis in persons aged 1-40 years. Meningitis was more common among males than females and was more prevalent during dry seasons. Incidence of meningococcal meningitis was higher (74.3%) in children under 15 years of age, and over 40% of these cases occurred in children below 5 years old. Infants aged less than 1 year had the highest incidence and mortality rates; neonatal (1 month of age) meningitis was identified in 101 cases. The high rate of endemic illness and deaths due to meningitis in sub-Saharan Africa could be prevented through the use of available vaccines such as meningococcal polysaccharide vaccines and Hib conjugate vaccines.