1998 - Meningitis in Chad
22 April 1998
Disease Outbreak Reported
During 1996 and 1997 many countries in the African meningitis belt experienced severe epidemics of meningococcal meningitis with 188,341 cases reported from Africa in 1996 and 69,518 case in 1997. So far 7,595 cases have been reported from the WHO African Region in 1998. However not all countries are experiencing this generally reduced level of activity and recent weeks have witnessed a large outbreak in Chad. In the period 29th December 1997 to 22nd of March 1998 there have been 2835 cases and 239 deaths reported from Chad which is more than twice the annual total number of cases reported in Chad in 1996 (1,079 cases) and 1997 (1,123 cases).
The district of Bokoro reached the epidemic attack rate of 15 cases/100,000 per week in week 3 (12-18 January) with the capital N'Djamena crossing that threshold in week 8 (16-22 February). Vaccination campaigns have been carried out in districts where the weekly attack rate has exceeded 5 cases/100,000 population. This has resulted in 1,650,000 vaccinations carried out in 13 of 15 Prefectures. The security stock of meningococcal vaccine in place in order to respond to epidemic meningitis has been exhausted and additional vaccine has been supplied through MSF-Belgium and WHO.
The very real threat of epidemics of cerebrospinal meningitis during the hot dry season from late December to early May means that the countries of the "African meningitis belt" must continue to strengthen surveillance, reporting systems and rapid laboratory confirmation of the etiology. Having a security stock of vaccine is useful but early detection is crucial to mounting a response that can cut short these devastating epidemics.