45 research outputs found
Effect of Ivermectin Treatment on the Frequency of Seizures in Persons with Epilepsy Infected with Onchocerca volvulus
No full textA 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 3–5 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% (26.0–90.0) to 100% (50.0–100.0). 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
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
No full textAbstract: 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 (OAF). 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
Community perception of epilepsy and its treatment in onchocerciasis-endemic villages of Maridi county, western equatoria state, South Sudan
No full textAbstract: Objective: To assess the community's perception of epilepsy and its treatment in onchocerciasis-endemic villages of Maridi County, Western Equatoria State, South Sudan. The study was conducted prior to the setting up of a community-based intervention to manage the important disease burden caused by onchocerciasis-associated epilepsy in these villages. Method: Five focus group discussions (FGD) were conducted with community leaders and with persons with epilepsy (PWE) and their families between November and December 2019. Results: Villages close to the Maridi dam were considered to be most affected by epilepsy. Misconceptions about the cause and treatment of epilepsy were identified. Most people believed that epilepsy is caused by bad spirits and is contagious, transmitted through saliva, air, and contact with PWE. Very few participants were aware of the link between onchocerciasis and epilepsy. Persons with epilepsy are restricted in their day-to-day activities and children with epilepsy are often denied going to school. Persons with epilepsy are stigmatized and seen as unfit for marriage. Most participants considered both traditional and medical treatment as ineffective. Uninterrupted anti-seizure treatment continuously was unaffordable for most families with one or more PWE. Conclusion: There is a need to establish a comprehensive epilepsy treatment program which addresses misconceptions about epilepsy and reduces epilepsy-related stigma. Explaining the link between onchocerciasis and epilepsy could lead to a reduction in epilepsy-related stigma. (C) 2021 The Author(s). Published by Elsevier Inc
Epidemiology of epilepsy in Wulu County, an onchocerciasis-endemic area in South Sudan
No full textAbstract: 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
Mvolo County, an Onchocerciasis Endemic Area in Western Equatoria State, South Sudan: An Entomological Study to Prepare for a "Slash and Clear" Community-Based Vector Control Intervention.
No full textBackground: Mvolo in Western Equatoria of South Sudan has been a hotspot for Onchocerca volvulus transmission since the 1940s. In Mvolo onchocerciasis is a disease of public health importance, associated with onchocerciasis-associated epilepsy including nodding syndrome.Methods: We conducted an entomological study to map the breeding sites of blackflies (Simulium damnosum, sensu lato) on the river Naam, to allow the removal of vegetation from vector breeding sites, the “slash and clear”. Three blackfly catching sites were established along the river. Focus group discussions were also conducted to assess the willingness of the communities to support the “slash and clear” intervention and the semi-annual distribution of ivermectin.Results: A total of 2466 female S. damnosum s.l. were caught in 14× 11h (06.00– 15.00) catches. The highest biting density of 4210.25 flies/month/h and monthly biting rate (MBR) of 11,482.25 bites/man/month were observed in November 2023. Biting density and MBR reduced to zero in the intervention site by April 2024. While the mean parity rate was 31% (CI: 0.2976± 0.9176). Two diurnal biting peaks were observed, one from 9:00– 10:00 (at the bridge site) and a prominent one from 14:00– 15:00 in the two catching sites in Mvolo. Along the river Naam, only one site was found productive for S. damnosum s.l.; and the larvae and adults were morphologically associated with the anthropophilic S. damnosum. The “slash and clear” intervention was implemented at Dogoyabolu along the river Naam. Communities expressed willingness to support a “slash and clear” intervention and the semi-annual distribution of ivermectin.Conclusion: S. damnosum active breeding was identified along the river Naam in a stretch of 3– 5 km close to human settlements. Highest blackfly biting density was 4210.25 flies/month/h, and two fly biting peaks were observed. A community “slash and clear” vector control was implemented, and will be prospectively monitored.</p
Mvolo County, an onchocerciasis endemic area in Western Equatoria State, South Sudan : an entomological study to prepare for a "slash and clear" community-based vector control intervention
No full textAbstract: Background: Mvolo in Western Equatoria of South Sudan has been a hotspot for Onchocerca volvulus transmission since the 1940s. In Mvolo onchocerciasis is a disease of public health importance, associated with onchocerciasis-associated epilepsy including nodding syndrome. Methods: We conducted an entomological study to map the breeding sites of blackflies (Simulium damnosum, sensu lato) on the river Naam, to allow the removal of vegetation from vector breeding sites, the "slash and clear". Three blackfly catching sites were established along the river. Focus group discussions were also conducted to assess the willingness of the communities to support the "slash and clear" intervention and the semi-annual distribution of ivermectin. Results: A total of 2466 female S. damnosum s.l. were caught in 14x11h (06.00-15.00) catches. The highest biting density of 4210.25 flies/month/h and monthly biting rate (MBR) of 11,482.25 bites/man/month were observed in November 2023. Biting density and MBR reduced to zero in the intervention site by April 2024. While the mean parity rate was 31% (CI: 0.2976 +/- 0.9176). Two diurnal biting peaks were observed, one from 9:00-10:00 (at the bridge site) and a prominent one from 14:00-15:00 in the two catching sites in Mvolo. Along the river Naam, only one site was found productive for S. damnosum s.l.; and the larvae and adults were morphologically associated with the anthropophilic S. damnosum. The "slash and clear" intervention was implemented at Dogoyabolu along the river Naam. Communities expressed willingness to support a "slash and clear" intervention and the semiannual distribution of ivermectin. Conclusion: S. damnosum active breeding was identified along the river Naam in a stretch of 3-5 km close to human settlements. Highest blackfly biting density was 4210.25 flies/month/h, and two fly biting peaks were observed. A community "slash and clear" vector control was implemented, and will be prospectively monitored
Onchocerciasis-associated epilepsy in Western Equatoria State, South Sudan
No full textAbstract: Onchocerciasis-associated epilepsy (OAE) is a neglected public health problem in remote African regions endemic to onchocerciasis with\ua0 suboptimal elimination programmes. OAE manifests in previously healthy children aged 3-18 years in the absence of any obvious cause\ua0 for epilepsy and is marked by a diverse range of seizure types, including head nodding seizures (nodding syndrome). This paper reviews\ua0 recent studies investigating the association between onchocerciasis and epilepsy in South Sudan. Surveys in Maridi, Mundri West, and\ua0 Mvolo Counties demonstrated a very high prevalence (3-6%) and incidence of epilepsy, as well as substantial onchocerciasis serological\ua0 prevalence (12-34%) in young children. However, a longitudinal population-based study conducted in Maridi and Mvolo showed that\ua0 strengthening onchocerciasis elimination programmes was followed by a significant and consistent reduction in the incidence of\ua0 epilepsy. Despite this progress, a large epilepsy treatment gap and a high level of misconceptions about epilepsy and epilepsy-related\ua0 stigma were observed. Treating epilepsy in onchocerciasis-endemic regions is challenging. More advocacy is needed to provide\ua0 uninterrupted access to free anti-seizure medication and promote community awareness programmes for improving the lives of persons\ua0 with epilepsy and their families in these impoverished areas
Rapid diagnostic testing for onchocerciasis in Maridi (South Sudan) before and after improving elimination strategies: a repeated cross-sectional survey [version 2; peer review: 2 approved, 1 approved with reservations]
No full textBackground
Maridi County is an onchocerciasis-endemic area in South Sudan. Annual community-directed treatment with ivermectin (CDTi) was instituted in Maridi since the early 2000s, but with low coverage. In 2021, the CDTi programme was strengthened to a six-monthly programme. Additionally, the community-based vector control strategy “Slash and Clear” has been implemented since 2019 at the Maridi Dam, the only blackfly breeding site in the area. This study assessed the effect of these reinforced onchocerciasis elimination interventions on the Onchocerca volvulus seroprevalence among young children, an indicator of ongoing transmission.
Methods
Baseline and follow-up serosurveys were conducted in Maridi in 2019 (prior to strengthening onchocerciasis elimination efforts) and 2023, respectively. During both surveys, children aged three to nine years were recruited from five study sites situated at different distances from the Maridi Dam. Ov16 antibodies were detected via rapid diagnostic tests (RDTs) using whole blood obtained by finger-pricking the participants. Baseline and follow-up Ov16 prevalence rates were calculated and compared.
Results
In 2019, the Ov16 seroprevalence among children aged three to nine years was 24.5% compared to 30.6% in 2023 (p=0.22). Both surveys found a particularly high Ov16 seroprevalence in the study site closest to the Maridi Dam (35.0% in 2019 and 44.0% in 2023, p=0.52). The Ov16 seroprevalence had a non-significant decreasing trend in the three-year-old children, from 12.5% (3/24) in 2019 to 8.8% (3/34) in 2023 (p=0.65).
Conclusion
The persistent Ov16 RDT seropositivity among three-year-old children in 2023 indicates ongoing O. volvulus transmission. Therefore, further strengthening of the onchocerciasis elimination programme is required. The study highlights the utility of RDTs in monitoring onchocerciasis transmission in highly endemic settings
Epilepsy in the onchocerciasis endemic area of Deim Zubeir, South Sudan: a household survey
No full textBackgroundHigh epilepsy prevalence and mortality has been reported in onchocerciasis-endemic areas with suboptimal elimination programs in South Sudan. In Deim Zubeir, an onchocerciasis-endemic area in Western Bahr El Ghazal state, demand for antiseizure medication is high, but epilepsy prevalence has never been investigated.MethodsA two-step household survey was conducted in four locations in Deim Zubeir over two weeks in July 2023. Trained local community volunteers screened household members for epilepsy using four screening questions, assessed blindness, and inquired about family members’ deaths in the past three years. Participants with suspected epilepsy were referred to a medical doctor for confirmation of the diagnosis.ResultsA total of 7,807 individuals in 1,803 households participated in the survey; 180 (2.3%) had epilepsy and 146 (1.9%) were blind in at least one eye. The point prevalence of active epilepsy was 23.1 (95% confidence interval [CI] 20.0-26.6) per 1,000 persons. The median age of persons with epilepsy (PWE) was 25 (interquartile range [IQR] 20-31.5) years; median age at onset of seizures was 14 (IQR 9-19) years; 36.4% of PWE had siblings with a history of seizures; 5.3% were blind in at least one eye; 40.7% had burn lesions and 24.7% had skin lesions compatible with onchocerciasis; 55% met the criteria for onchocerciasis-associated epilepsy (OAE). The mortality rate of PWE was 182.4 per 100,000 person-years (95%CI 132.8-232.0) and the epilepsy case fatality rate was 64.1 (95% CI 47.2-80.9) per 1,000 PWE per year. PWE were six times more likely to die within one year than people without epilepsy. Their median age of death was 21.5 (IQR 16-34) years compared to 41 (IQR 7-60) years for people without epilepsy.ConclusionThe prevalence of epilepsy and epilepsy-related mortality in Deim Zubeir is high, likely because of ongoing Onchocerca volvulus transmission. Strengthening the local onchocerciasis elimination program and ensuring consistent access to epilepsy care is urgently needed to prevent OAE and epilepsy-related mortality and morbidity. It is necessary to increase advocacy and funding to ensure early identification of epilepsy and uninterrupted, free access to antiseizure medication for PWE in this remote, impoverished area
Onchocerciasis-associated epilepsy : an explorative case-control study with viral metagenomic analyses on\ua0Onchocerca volvulus
No full textAbstract: 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
