Clinical characteristics of onchocerciasis-associated epilepsy in villages in Maridi County, Republic of South Sudan

Abstract

To describe the clinical manifestations of persons with epilepsy (PWE) in onchocerciasis endemic villages in South Sudan. Methods: During a survey in Maridi County in May 2018, PWE were interviewed and examined in their households by a clinical officer or medical doctor. Onchocerciasis-associated epilepsy (OAE) was defined as ≥2 seizures without any obvious cause, starting between the ages of 3-18 years in previously healthy persons who had resided for at least 3 years in the onchocerciasis endemic area. Results: Seven hundred and thirty-six PWE were included in the study; 315 (42.8%) were females; median age was 18 years. A variety of seizure types were reported: generalized tonic-clonic seizures in 511 PWE (69.4%), absences in 15 (2.0%), focal motor seizures with full awareness in 7 (1.0%), focal motor seizures with impaired awareness in 25 (3.4%), brief episodes of hallucinations in 316 (43.9%) and nodding seizures in 335 (45.5%). The median age of onset of all seizures was 10 years, and 8 years for nodding seizures. PWE with nodding seizures presented with more cognitive disabilities. The diagnostic criteria for OAE were met by 414 (85.2%) of the 486 PWE with complete information. Eighty (11.0%) PWE presented with Nakalanga features. Only 378 (51.4%) PWE were taking anti-epileptic treatment. Conclusion: PWE presented with a wide spectrum of seizures. The high percentage of PWE who met the diagnostic criteria for OAE suggests that better onchocerciasis control could prevent new cases. Urgent action is needed to close the anti-epileptic treatment gap. different seizure presentations including nodding syndrome (NS) [2,3]. NS was first investigated in 2001-2 in Lui and Amadi in Western Equatoria region, South Sudan, by a team led by the World Health Organization (WHO) [4]. Three small case control studies (82 pairs in total) performed during these investigations showed that infections with Onchocerca volvulus diagnosed by skin snips were more often

Ivermectin as an adjuvant to anti-epileptic treatment in persons with onchocerciasis-associated epilepsy: A randomized proof-of-concept clinical trial

“…In spite of this, we recently observed in South Sudan that certain PWE were not given ivermectin because the community considered that PWE should not take ivermectin. In villages in Maridi County in 2017, only 25.6% of PWE were treated with ivermectin [24] while the overall ivermectin coverage in persons above the age of 11 years was 50-60% [25]. Lower coverage among PWE compared to the general population has also been reported in Cameroon [26].…”

Nodding syndrome research, lessons learned from the NSETHIO project

“…In all onchocerciasis-endemic areas with high ongoing or recent O. volvulus transmission visited by NSETHIO team members, persons with OAE, including nodding seizures and Nakalanga features were identified (Colebunders et al 2018a;Siewe Fodjo et al 2019b, c). It was observed that persons with nodding seizures often have siblings with other forms of epilepsy suggesting that NS and other forms of epilepsy share a common etiological trigger (Colebunders et al 2018d).…”

“…It was observed that persons with nodding seizures often have siblings with other forms of epilepsy suggesting that NS and other forms of epilepsy share a common etiological trigger (Colebunders et al 2018d). However, a study performed in Maridi in South Sudan showed that persons who develop nodding seizures have more disabilities than persons with other forms of OAE (Colebunders et al 2018a). Recently, a correlation between skin mf density and seizure frequency was documented in the DRC (Siewe Fodjo et al 2019b).…”

“…However today there is growing support for using this definition as a tool to identify hotspots of high-ongoing onchocerciasis transmission (Mmbando et al 2018;Colebunders et al 2019). In onchocerciasis-endemic regions with high epilepsy prevalence such as in Cameroon and South Sudan, >70% of PWE satisfied the OAE criteria (Colebunders et al 2018a;Siewe Fodjo et al 2019c).…”

Ivermectin use in children below 15 kg: potential benefits for onchocerciasis and scabies elimination programmes

“…It is time that this recommendation is revisited. Indeed, we recently documented in onchocerciasis‐endemic areas that some children can already develop onchocerciasis‐associated epilepsy including nodding syndrome at the age of 3 years, when most of them still weigh < 15 kg . Moreover, a cohort study in an onchocerciasis‐endemic area in Cameroon showed that the risk to develop epilepsy later in life depends on the Onchocerca volvulus microfilarial density during childhood .…”