The Prevalence of Onchocerciasis-Associated Epilepsy in Mundri West and East Counties, South Sudan: A Door-to-Door Survey

Abstract

A two-phase survey of epilepsy was conducted in selected villages in Mundri West and East Counties (26 June–8 July, 2021), an onchocerciasis-endemic area in Western Equatoria State in South Sudan. In the first phase, households were visited by a trained research team to identify persons suspected to have epilepsy. In the second phase, persons suspected to have epilepsy were interviewed and examined by a clinician to confirm the diagnosis. A total of 364 households agreed to participate in the survey, amounting to 2588 individuals. The epilepsy screening questionnaire identified 91 (3.5%) persons with suspected epilepsy, of whom the diagnosis of epilepsy was confirmed by a clinician in 86 (94.5%). The overall prevalence of confirmed epilepsy was 3.3% (95% CI: 2.7–4.1%), and of nodding syndrome was 0.9% (95% CI: 0.6–1.4%). In 61 (16.8%) households there was at least one person with epilepsy. Only 1212 (46.9%) of 2583 people took ivermectin during the last distribution round in 2021. The annual epilepsy incidence was 77.3/100,000 (95% CI: 9.4–278.9/100,000) and the annual epilepsy mortality was 251.2/100,000 (95% CI: 133.8–428.7/100,000). In conclusion, a high prevalence and incidence of epilepsy was observed in villages in Mundri. Urgent action is needed to prevent children from developing onchocerciasis-associated epilepsy by strengthening the local onchocerciasis-elimination programme.

Effect of Onchocerciasis Elimination Measures on the Incidence of Epilepsy in Maridi, South Sudan: A Three-Year Prospective Study

“…Living close to rivers was observed as a risk factor for epilepsy in all onchocerciasis meso-and hyper-endemic areas where this was investigated, e.g. in Mundri [7,37] and Mvolo [8] in South Sudan, and in the Mbam and Sanaga river valleys in Cameroon [38,39].…”

Impact of annual community-directed treatment with ivermectin on the incidence of epilepsy in Mvolo, a two-year prospective study

“…Additionally, the coverage was also calculated per age group. This methodology, relying on individual self-reports of ivermectin intake, is consistent with established methodologies employed in similar settings [ 14 , 47 , 48 ] and has demonstrated reliability as an indicator of treatment adherence in impact studies [ 49 ].…”

Effect of onchocerciasis elimination measures on the incidence of epilepsy in Maridi, South Sudan: a three-year prospective study

“…Not taking ivermectin was found to be a risk factor for epilepsy in Maridi but not in other onchocerciasis endemic areas. [7,8,37] Even a higher proportion of ivermectin intake has been reported among persons with epilepsy in Mundri in South Sudan [37,40]. The latter may be because persons with epilepsy may be more likely not to be away from home for farming during ivermectin distribution.…”

“…Living close to rivers was observed as a risk factor for epilepsy in all onchocerciasis meso-and hyper-endemic areas where this was investigated, e.g. in Mundri [7,37] and Mvolo [8] in South Sudan, and in the Mbam and Sanaga river valleys in Cameroon [38,39].…”

“…Annual or biannual community-directed treatment with ivermectin (CDTi) is the cornerstone intervention for the elimination of onchocerciasis [2]. Epidemiological studies have documented high prevalence and incidence of epilepsy in onchocerciasis-endemic areas with sub-optimal onchocerciasis elimination programmes and high ongoing O. volvulus transmission [3][4][5][6][7][8]. Most persons with epilepsy (PWE) in these areas meet the criteria of onchocerciasis-associated epilepsy (OAE) [5,9,10].…”