Meta-analysis of epilepsy prevalence in West Africa and its relationship with onchocerciasis endemicity and control
Résumé
Background: A high prevalence and incidence of epilepsy has been reported in onchocerciasis-endemic regions
in Central and East Africa. There is compelling epidemiological evidence suggesting that this high burden is
caused by onchocerciasis-associated epilepsy (OAE).We hypothesized that OAE had also occured inWest African
onchocerciasis foci.
Methods: We searched PubMed, the African Journals Online platform and grey literature for population-based
epilepsy studies inWest African countries. Epilepsy and onchocerciasis prevalence data were extracted. The precontrol
onchocerciasis endemicity in the study siteswas estimated from historical data of onchocerciasis control
programmes. The prevalence of epilepsy in different sites was analysed, taking into account onchocerciasis
endemicity and the duration of control.
Results: The pooled prevalence of epilepsy in theWest African study sites was 13.14 per 1000 (95% confidence
interval 11.28–15.00). Higher pre-control endemicity and a shorter duration of onchocerciasis control were both
associated with increased epilepsy prevalence (p<0.001). Two studies in Ivory Coast that provided detailed
descriptions of persons with epilepsy in onchocerciasis-endemic settings revealed that most of them had
features of OAE (73.7% and 83.3%, respectively).
Conclusions: Our findings suggest that before and during the early years of implementing onchocerciasis control
inWest Africa, high onchocerciasis endemicity resulted in a high prevalence of OAE and that subsequent control
efforts significantly reduced the prevalence of OAE.