The changing epidemiology of meningococcal meningitis after introduction of bivalent A/C polysaccharide vaccine into school-based vaccination programs in Egypt.

BACKGROUND: The strategy recommended by the World Health Organization (WHO) to curtail outbreaks of meningococcus in Africa is enhanced surveillance with administration of oily chloramphenicol as well as vaccination when incidence thresholds are exceeded. The role of capsular polysaccharide meningococcal vaccine in outbreak prevention has been the subject of considerable debate. The Egyptian Ministry of Health and Population initiated a school-based vaccination program with bivalent A/C capsular polysaccharide vaccine in 1992. This investigation reviews data on meningococcal meningitis in Egypt comparing years before and after introduction of the vaccine.
METHODS: This is a retrospective review of several sources to examine the rates and serogroups of meningococcal meningitis before and after the introduction of the meningococcal A/C vaccine in Egypt.
FINDINGS: Between 1967 and 1991, outbreaks of meningococcal disease were documented with a periodicity of 8 years in Egypt. However, there has not been an outbreak since 1991 and over the same period, there has also been a progressive decline in the baseline incidence of meningococcus. Also, a shift from a serogroup A to serogroup B predominance in meningococcal disease was noted during the study period. These data suggest that there has been an alteration in the epidemiology of meningococcal disease in Egypt that coincided with the implementation of the school-based vaccination program.
INTERPRETATION: Routine use of the bivalent A/C meningococcal vaccine may be an alternative for the control and prevention of meningococcal disease in high-risk areas including the "meningitis belt".