Epidemiology of epilepsy in Wulu County, an onchocerciasis-endemic area in South Sudan.

BACKGROUND

We sought to investigate the epidemiology of epilepsy in Wulu County (Lakes State, South Sudan), and document the onchocerciasis transmission status in the study villages.

METHODS

In February 2024, a community-based epilepsy study was conducted Wulu County and participants were surveyed via a door-to-door approach in five villages, namely: Kombi, Makundi Center, Tonjo, War-Pac, and Woko. All village residents were asked about ivermectin intake during the 2023 round of community-directed treatment with ivermectin (CDTI). In addition, children aged 3-9 years were tested for Ov16 antibodies using a rapid diagnostic test. Epilepsy diagnosis in screened individuals was confirmed by a physician.

RESULTS

We surveyed 1355 persons in the five study sites. The overall CDTI coverage in 2023 was 67.4 %. Fifty-five persons with epilepsy (PWE) were identified (prevalence 4.1 %) and a history of nodding seizures was noted in 11/55 (20 %) PWE. The mean age of PWE was 21.5 ± 9.6 years, with 32 (58.2 %) being males. Epilepsy onset frequently occurred under 5 years of age (38.6 % of cases). In two PWE, seizure onset occurred during the past 12 months (annual incidence: 147.6 per 100,000 persons). Twenty-nine PWE (52.7 %) were taking anti-seizure medicines, but only five were taking them daily. Overall, Ov16 seroprevalence in children aged 3-9 years (n = 119) was 15.1 % and differed across villages, peaking at 30.9 % in Woko village where epilepsy prevalence was also highest (7.1 %). Of the 35 recorded deaths during the past two years, 9 (25.7 %) occurred in PWE. Annual estimates for epilepsy mortality and fatality rates were 323.7 per 100,000 persons and 7031.3 per 100,000 PWE, respectively.

CONCLUSION

High epilepsy prevalence was found in Wulu, particularly in villages with persistent onchocerciasis transmission. Frequent epilepsy onset among under-fives suggests that perinatal/early childhood etiologies are common. Appropriate measures should be instituted to prevent and treat epilepsy in Wulu villages.