Stopping the burden of disease caused by onchocerciasis-associated epilepsy

There is growing epidemiological evidence that onchocerciasis (river blindness) can cause epilepsy (onchocerciasis-associated epilepsy, OAE), a major unrecognized public health problem in sub-Saharan Africa. However, the pathophysiological mechanism remains unknown. Neither the Onchocerca volvulus, nor its endosymbiont Wolbachia, appear to be able to pass the blood brain barrier (BBB). Annual community-directed treatment with ivermectin (CDTI), has limited efficacy in reducing OAE incidence. Therefore, we will 1] Investigate in onchocerciasis-endemic areas, in Cameroon, whether a community based vector control method “slash & clear” combined with CDTI is superior to CDTI alone to decrease the incidence of OAE; 2] Explore whether O. volvulus excretory/secretory products can cross the BBB and possibly trigger OAE, by comparing proteomic profiles of cerebro-spinal fluid of children with OAE with those of different stages of the parasite; 3] Explore whether O. volvulus infected blackflies may transmit a neutrotropic virus causing OAE, by testing blackflies and sera from OAE cases with Q-PCR targeting potential OAE specific viral sequences identified during a metagenomic case-control study in South Sudan. Our findings will provide context-specific evidence about a complementary strategy to accelerate onchocerciasis elimination and new insights into the underlying mechanisms of OAE, and as such contribute to reducing the burden and stigma of ‘river epilepsy’.