Outbreaks of meningitis are a public health problem in sub-Saharan Africa where more than thousand cases are declared every year In Chad, the last outbreak happened between 1998 and 2001. The objective of this study is to describe epidemiologic profile of meningitis in the province of Logone Occidental from 1998 to 2001.
Methods: Study used epidemiologic data of surveillance's tools from years 1998 to 2001 in Chad.
Results: Data of the study indicated a two-yearly cycle with outbreaks in 1998 and 2000 occurring in endemic background during 1999 and 2001. The first cases began in January with an incidence rate close to 30 for 100.000/week. The epidemic peak occurred on the 11th week (1999-2001), on the 12th week (1998-2000) during dry season. Outbreak continued 9 weeks and stopped on the 16th week (April-May). The lethality average was 12% and reached 30% at the beginning of the outbreak.
Discussion: Despite vaccination campaigns during outbreaks, epidemiology did not change in Chad. Quality of epidemiological surveillance is not sufficient and political reaction is too slow. Moreover, human, material and financial deficiency add to these difficulties. Integrated vaccination against meningitis into the immunization preventive program was evocated but would not permit enough collective immunity. Biotope changes generated by human activity could contribute to perpetuating outbreaks. New outbreak of W135 meningitis in Burkina Faso (2002) may change the epidemiological profile of the meningitis in sub-Saharan Africa.
Conclusion: Meningitis outbreaks control using vaccination after the first cases appears to be limited, however this strategy must be evaluated in Chad to know vaccination covering, target population and protection after vaccination.