Onchocerciasis-associated epilepsy: an explorative case-control study with viral metagenomic analyses on Onchocerca volvulus [version 2; peer review: 2 approved]

Background A high prevalence of onchocerciasis-associated epilepsy (OAE) has been observed in onchocerciasis-endemic areas with high ongoing Onchocerca volvulus transmission. However, the pathogenesis of OAE remains to be elucidated. We hypothesise that the O. volvulus virome could be involved in inducing epilepsy. With this study, we aim to describe the O. volvulus virome and identify potential neurotropic viruses linked to OAE. Methods In Maridi County, an onchocerciasis endemic area in South Sudan with a high prevalence of OAE, we will conduct an exploratory case-control study enrolling 40 persons aged 12 years and above with palpable onchocerciasis nodules. Cases will be participants with OAE (n=20), who will be age- and village-matched with controls without epilepsy (n=20). For each study participant, two skin snips at the iliac crest will be obtained to collect O. volvulus microfilariae, and one nodulectomy will be performed to obtain adult worms. A viral metagenomic study will be conducted on microfilariae and adult worms, and the O. volvulus virome of persons with and without OAE will be compared. The number, size, and localisation of onchocerciasis nodules in persons with and without OAE will be described. Moreover, the pre- and post-nodulectomy frequency of seizures in persons with OAE will be compared. Ethics and dissemination The protocol has been approved by the Ethics Committee of the University of Antwerp and the Ministry of Health of South Sudan. Findings will be disseminated nationally and internationally via meetings and peer-reviewed publications. Registration ClinicalTrials.gov registration NCT05868551 (https://clinicaltrials.gov/study/NCT05868551). Protocol version 1.1, dated 09/05/2023

Epilepsy-related stigma and cost in two onchocerciasis-endemic areas in South Sudan : a pilot descriptive study

Introduction: Epilepsy is a major public health concern in sub-Saharan Africa, particularly in resource-limited rural villages where persons with epilepsy (PWE) are often confronted with a wide treatment gap, frequent stigma and high cost of epilepsy care. We investigated stigma and economic cost related to epilepsy in the states of Maridi and Amadi in South Sudan, two onchocerciasis endemic areas with high epilepsy prevalence. Methods: Between November 2019 and February 2020, community-based surveys were conducted in eight villages of Maridi and Amadi States. Consenting PWE were identified via a door-to-door approach, and perceived stigma was assessed using the validated Kilifi stigma scale. Additional data about household income, as well as epilepsy-related direct and indirect costs were collected. Results: 239 PWE were recruited (95 from Maridi, 144 from Amadi). Stigma scores were higher in Maridi compared to Amadi (mean scores: 13.9 vs 6.5, p < 0.001). Mean weighted epilepsy costs per month in Maridi (38.4 USD) were double those observed in Amadi (17.6 USD). The main epilepsy-related expenditure was the purchase of anti-epileptic drugs (AED). Stigma scores correlated with epilepsy cost (Spearman-rho = 0.24, p < 0.001) and were positively associated with traditional medicine use (regression estimate = 1.9; p = 0.027). Conclusion: In rural South Sudan, PWE and their families often experienced stigma from the community. Higher perceived stigma was associated with traditional medicine use, which increased the overall cost of epilepsy management. Demystifying epilepsy and making AED more accessible would improve the quality of life of PWE and their families, and reduce the economic burden of epilepsy

Epilepsy-related stigma and cost in two onchocerciasis-endemic areas in South Sudan: A pilot descriptive study

Introduction: Epilepsy is a major public health concern in sub-Saharan Africa, particularly in resource-limited rural villages where persons with epilepsy (PWE) are often confronted with a wide treatment gap, frequent stigma and high cost of epilepsy care. We investigated stigma and economic cost related to epilepsy in the states of Maridi and Amadi in South Sudan, two onchocerciasis endemic areas with high epilepsy prevalence. Methods: Between November 2019 and February 2020, community-based surveys were conducted in eight villages of Maridi and Amadi States. Consenting PWE were identified via a door-to-door approach, and perceived stigma was assessed using the validated Kilifi stigma scale. Additional data about household income, as well as epilepsy-related direct and indirect costs were collected. Results: 239 PWE were recruited (95 from Maridi, 144 from Amadi). Stigma scores were higher in Maridi compared to Amadi (mean scores: 13.9 vs 6.5, p < 0.001). Mean weighted epilepsy costs per month in Maridi (38.4 USD) were double those observed in Amadi (17.6 USD). The main epilepsy-related expenditure was the purchase of anti-epileptic drugs (AED). Stigma scores correlated with epilepsy cost (Spearman-rho = 0.24, p < 0.001) and were positively associated with traditional medicine use (regression estimate = 1.9; p = 0.027). Conclusion: In rural South Sudan, PWE and their families often experienced stigma from the community. Higher perceived stigma was associated with traditional medicine use, which increased the overall cost of epilepsy management. Demystifying epilepsy and making AED more accessible would improve the quality of life of PWE and their families, and reduce the economic burden of epilepsy

Effect of Ivermectin Treatment on the Frequency of Seizures in Persons with Epilepsy Infected with Onchocerca volvulus

A clinical trial performed in the Democratic Republic of Congo (DRC), among persons with epilepsy (PWE) infected with Onchocerca volvulus treated with anti-seizure medication suggested that ivermectin reduces the seizure frequency. We assessed the effect of ivermectin treatment on seizure frequency in PWE with and without anti-seizure medication in three onchocerciasis endemic areas (Maridi, South Sudan; Aketi, DRC; and Mahenge, Tanzania). Pre- and 3&ndash;5 months post-ivermectin microfilariae densities in skin snips and seizure frequency were assessed. After ivermectin, the median (IQR) percentage reduction in seizure frequency in the study sites ranged from 73.4% (26.0&ndash;90.0) to 100% (50.0&ndash;100.0). A negative binomial mixed model showed that ivermectin significantly reduced the seizure frequency, with a larger decrease in PWE with a high baseline seizure frequency. Mediation analysis showed that ivermectin reduced the seizure frequencies indirectly through reduction in microfilariae densities but also that ivermectin may have a direct anti-seizure effect. However, given the short half-life of ivermectin and the fact that ivermectin does not penetrate the healthy brain, such a direct anti-seizure effect is unlikely. A randomized controlled trial assessing the ivermectin effect in people infected with O. volvulus who are also PWE on a stable anti-seizure regimen may be needed to clarify the causal relationship between ivermectin and seizure frequency

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

A two-phase survey of epilepsy was conducted in selected villages in Mundri West and East Counties (26 June&ndash;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&ndash;4.1%), and of nodding syndrome was 0.9% (95% CI: 0.6&ndash;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&ndash;278.9/100,000) and the annual epilepsy mortality was 251.2/100,000 (95% CI: 133.8&ndash;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

Surveillance for onchocerciasis-associated epilepsy and OV16 IgG4 testing of children 6-10 years old should be used to identify areas where onchocerciasis elimination programs need strengthening

To eliminate onchocerciasis-associated morbidity, it is important to identify areas where there is still high ongoing Onchocerca volvulus transmission. Between 2015 and 2021, door-to-door surveys were conducted in onchocerciasis-endemic villages in Cameroon, the Democratic Republic of Congo (DRC), Nigeria, South Sudan, and Tanzania to determine epilepsy prevalence and incidence, type of epilepsy and ivermectin therapeutic coverage. Moreover, children aged between six and 10 years were tested for anti-Onchocerca antibodies using the Ov16 IgG4 rapid diagnostic test (RDT). A mixed-effect binary logistic regression analysis was used to assess significantly associated variables of Ov16 antibody seroprevalence. A high prevalence and incidence of epilepsy was found to be associated with a high Ov16 antibody seroprevalence among 6–10-year-old children, except in the Logo health zone, DRC. The low Ov16 antibody seroprevalence among young children in the Logo health zone, despite a high prevalence of epilepsy, may be explained by a recent decrease in O. volvulus transmission because of a decline in the Simulium vector population as a result of deforestation. In the Central African Republic, a new focus of O. volvulus transmission was detected based on the high Ov16 IgG4 seropositivity among children and the detecting of nodding syndrome cases, a phenotypic form of onchocerciasis-associated epilepsy (OAE). In conclusion, Ov16 IgG4 RDT testing of 6–10-year-old children is a cheap and rapid method to determine the level of ongoing O. volvulus transmission and to assess, together with surveillance for OAE, the performance of onchocerciasis elimination programs

Correction: Dusabimana et al. Surveillance for Onchocerciasis-Associated Epilepsy and Ov16 IgG4 Testing of Children 6&ndash;10 Years Old Should Be Used to Identify Areas Where Onchocerciasis Elimination Programs Need Strengthening. Pathogens 2022, 11, 281

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