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Lakwo TL, Alinda P, Jada SR, Tionga M, Marcello CDR, War DGD, Colebunders R. 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. Res Rep Trop Med 2024; 15:59-71. [PMID: 38895129 PMCID: PMC11184223 DOI: 10.2147/rrtm.s464874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
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 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.
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Affiliation(s)
| | - Peter Alinda
- Ministry of Health, Vector Control Division, Kampala, Uganda
| | | | | | | | - Deng Gai Dual War
- Ministry of Health, National Malaria Control Program, Juba, South Sudan
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- Department of Tropical Disease Pathology, Liverpool School of Tropical Medicine, Liverpool, UK
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Siewe Fodjo JN, Ekome SRE, Njamnshi JNT, Njamnshi WY, Njamnshi KG, Ngarka L, Njamnshi AK. Community Perceptions of Blackfly Nuisance and Acceptability of the "Slash and Clear" Vector Control Approach in the Ntui Health District of Cameroon: A Qualitative Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2024; 21:658. [PMID: 38928904 PMCID: PMC11204025 DOI: 10.3390/ijerph21060658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/15/2024] [Accepted: 05/19/2024] [Indexed: 06/28/2024]
Abstract
Besides being vectors of the onchocerciasis parasite, blackflies are a source of nuisance in onchocerciasis-endemic communities. We investigated the experience of residents in the Ntui Health District (Cameroon) regarding blackfly nuisance and assessed their perceptions of a novel "Slash and Clear" (S&C) intervention for blackfly control. Focus group discussions were conducted before and after S&C implementation (respectively, in February 2022 and December 2023). Blackflies were known to emerge from the river areas and cause disease. To prevent blackfly bites, the population often covered their body with protective clothing and applied various substances (kerosene, oil, or lemon) to their skin. Post-intervention data showed reduced blackfly nuisance, and the willingness to sustain blackfly control in the long-term was unanimous among community leaders and members, including the village volunteers who implemented the S&C intervention. In conclusion, blackfly nuisance is evident in the Ntui onchocerciasis focus of Cameroon and led to a panoply of coping practices, some of which could be detrimental to their health. Implementing S&C for blackfly control is well accepted and could sustainably alleviate the nuisance caused by blackflies while simultaneously breaking the onchocerciasis transmission cycle.
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Affiliation(s)
- Joseph Nelson Siewe Fodjo
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
- Global Health Institute, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium
| | - Serge Raoul Ekukole Ekome
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
| | - Julius Ndi Taryunyu Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
| | - Wepnyu Yembe Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
- Division of Operational Research in Health, Ministry of Public Health, N°8 Rue 3038 quartier du Lac (Yaoundé III), Yaoundé P.O. Box 3595, Cameroon
| | - Kongnyu G. Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
| | - Leonard Ngarka
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
- Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé 1, Yaoundé P.O. Box 1364, Cameroon
- Neurology & Clinical Neuroscience Department, Yaoundé Central Hospital, Yaoundé P.O. Box 87, Cameroon
| | - Alfred K. Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon; (S.R.E.E.); (J.N.T.N.); (W.Y.N.); (K.G.N.); (L.N.)
- Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé 1, Yaoundé P.O. Box 1364, Cameroon
- Neurology & Clinical Neuroscience Department, Yaoundé Central Hospital, Yaoundé P.O. Box 87, Cameroon
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Kamoen O, Jada SR, Rovarini JM, Abd-Elfarag G, Amaral LJ, Bol Y, Siewe Fodjo JN, Colebunders R. Evaluating epilepsy management in an onchocerciasis-endemic area: Case of Maridi, South Sudan. Seizure 2024:S1059-1311(24)00133-X. [PMID: 38714396 DOI: 10.1016/j.seizure.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/30/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024] Open
Abstract
PURPOSE The epilepsy prevalence in Maridi County, South Sudan, in 2018 was 43.8 (95% CI: 40.9-47.0) per 1000 persons; 85.2% of the identified persons with epilepsy (PWE) met the criteria of onchocerciasis-associated epilepsy. To address this health problem, an epilepsy clinic was established at Maridi County Hospital in 2020. In August 2023, the impact of the clinic on the lives of PWE and their families was evaluated. METHODS At the Maridi epilepsy clinic, data routinely collected by primary healthcare workers as part of patient care was reviewed. We also analyzed findings from two household surveys conducted in 2018 and 2022, which assessed the impact of the clinic on epilepsy care. Moreover, four households, each with four PWE, were visited in a high epilepsy prevalence area. PWE were examined by a neurologist, and in-depth interviews were conducted with family members. RESULTS The proportion of PWE on anti-seizure medication increased by 39.7% (95%CI: 35.3-44.2) between 2018 and 2022. The proportion of PWE reporting daily seizures decreased from 27.3% in 2018 to 5.3% in 2022. Of the 754 PWE seen in the clinic in July 2023, only 17 (2.3%) reported side effects. During household visits in July 2023, 13/173 (7.5%) of the visited PWE were found without remaining anti-seizure medication. A high level of epilepsy-related stigma was observed in all visited households. CONCLUSION The Maridi epilepsy clinic positively impacted the lives of PWE in Maridi. Similar initiatives should be accessible for all PWE living in onchocerciasis-endemic areas. Evidence-based information about OAE is needed to decrease misconceptions and epilepsy-related stigma.
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Affiliation(s)
- Olivia Kamoen
- Department of Neurology, Heilig Hart Ziekenhuis, Lier, Belgium
| | | | | | - Gasim Abd-Elfarag
- Access for Humanity, Juba, South Sudan; School of Public Health, University of Juba, Juba, South Sudan; Health and Social Sciences Research Institute-South Sudan, Juba, South Sudan
| | | | - Yak Bol
- Neglected Tropical Disease Programme, Ministry of Health, Juba, South Sudan
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Colebunders R, Hadermann A, Njamnshi AK, Mmbando BP, Kamoen O, Siewe Fodjo JN. Onchocerciasis-associated epilepsy and biomarkers. PLoS Negl Trop Dis 2024; 18:e0011808. [PMID: 38722830 PMCID: PMC11081238 DOI: 10.1371/journal.pntd.0011808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 11/20/2023] [Indexed: 05/13/2024] Open
Affiliation(s)
| | - Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Alfred K. Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
- Neuroscience Lab, Faculty of Medicine & Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon
| | - Bruno P. Mmbando
- National Institute for medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Olivia Kamoen
- Department of Neurology, Heilig Hart Ziekenhuis, Lier, Belgium
| | - Joseph Nelson Siewe Fodjo
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
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Widdess-Walsh P. River Epilepsy-A Preventable Form of Epilepsy. Epilepsy Curr 2024; 24:174-176. [PMID: 38898913 PMCID: PMC11185214 DOI: 10.1177/15357597241235785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
Effect of Onchocerciasis Elimination Measures on the Incidence of Epilepsy in Maridi, South Sudan: A 3-Year Longitudinal, Prospective, Population-Based Study. Jada SR, Amaral LJ, Lakwo T, Carter JY, Rovarini J, Bol YY, Logora MY, Hadermann A, Hopkins A, Fodjo JNS, Colebunders R. Lancet Glob Health . 2023;11(8):e1260-e1268. doi:10.1016/S2214-109X(23)00248-6 . PMID: 37474232 . Background: High onchocerciasis transmission predisposes endemic communities to a high epilepsy burden. The 4.4% epilepsy prevalence documented in 2018 in Maridi, South Sudan, prompted the strengthening of onchocerciasis elimination measures. Community-directed treatment with ivermectin was implemented annually in 2017, 2018, and 2019, interrupted in 2020, and re-implemented biannually in 2021. We aimed to assess the effect of these interventions, along with slash and clear vector control on the incidence of epilepsy, including nodding syndrome. Methods: In this longitudinal, prospective, population-based study, we did a two-stage house-to-house epilepsy survey before (May 10-30, 2018) and after (March 9-19, 2022) the strengthening of onchocerciasis elimination interventions in South Sudan. Strengthening also included the implementation of a community-based slash and clear vector control method that we initiated in 2019 at the Maridi dam (the main blackfly breeding site). Eight sites were surveyed near the Maridi dam and inclusion required residence in one of these sites. All household residents were first screened by community workers, followed by confirmation of the epilepsy diagnosis by trained clinicians. The primary outcome was epilepsy incidence, including nodding syndrome, which was assessed via self-reported new-onset epilepsy in the previous 4 years of each survey, confirmed by clinician assessment. Findings: The preintervention survey included 17 652 people of whom 736 had epilepsy (315 female and 421 male), and the post-intervention survey included 14 402 people of whom 586 had epilepsy (275 female and 311 male). When biannual community-directed treatment with ivermectin was initiated in 2021, the intervention’s coverage rose by 15.7% (95% CI 14.6-16.8); although only 56.6% of the population took ivermectin in 2021. Between 2018 and 2022, epilepsy incidence decreased from 348.8 (307.2-395.8) to 41.7 (22.6-75.0) per 100 000 person-years. Similarly, the incidence of nodding syndrome decreased from 154.7 (127.6-187.3) to 10.4 (2.7-33.2) per 100 000 person-years. The identified risk factors for epilepsy were: living closer to the Maridi dam, being aged between 6 and 40 years, not taking ivermectin, and being male. Interpretation: In onchocerciasis-endemic areas with high epilepsy prevalence, strengthening onchocerciasis elimination interventions can decrease the incidence of epilepsy, including nodding syndrome. Additional efforts are needed to increase community-directed treatment with ivermectin coverage and sustain blackfly control in Maridi.
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Van Cutsem G, Siewe Fodjo JN, Hadermann A, Amaral LJ, Trevisan C, Pion S, Colebunders R. Onchocerciasis-associated epilepsy: Charting a path forward. Seizure 2024:S1059-1311(24)00123-7. [PMID: 38677953 DOI: 10.1016/j.seizure.2024.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024] Open
Abstract
This narrative review intends to inform neurologists and public health professionals about Onchocerciasis-Associated Epilepsy (OAE), a neglected public health problem in many remote onchocerciasis-endemic areas. For epidemiological purposes, we define OAE as sudden-onset of convulsive and non-convulsive seizure types, including head nodding seizures (nodding syndrome) in a previously healthy child aged 3 to 18 years in the absence of any other obvious cause for epilepsy, all happening within an area with high ongoing Onchocerca volvulus transmission. Several OAE pathophysiological mechanisms have been proposed, but none has been proven yet. Recent population-based studies showed that strengthening onchocerciasis elimination programs was followed by a significant reduction in the incidence of OAE and nodding syndrome. Treating epilepsy in onchocerciasis-endemic regions is challenging. More advocacy is needed to provide uninterrupted, free access to anti-seizure medication to persons with epilepsy in these remote, impoverished areas. It is crucial todevelop policies and increase funding for the prevention and treatment of OAE to reduce the associated burden of disease, notably via the establishment of morbidity management and disability prevention programs (MMDP). Moreover, effective collaboration between onchocerciasis elimination and mental health programs is imperative to alleviate the burden of OAE. This synergy promises reciprocal advantages and underscores the need for a comprehensive approach to address this multifaceted challenge.
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Affiliation(s)
- G Van Cutsem
- Department of Neurology, Centre Hospitalier de Luxembourg, Luxembourg; Faculty of Science, Technology and Medicine, University of Luxembourg, Luxembourg; Centre for Infectious Disease Epidemiology and Research, University of Cape Town, South Africa
| | - J N Siewe Fodjo
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - A Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - L-J Amaral
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - C Trevisan
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - S Pion
- Institute of Research for Sustainable Development, Montpelier, France
| | - R Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Belgium.
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Metanmo S, Winkler AS. Response to "Nodding Syndrome Associated with Onchocerciasis". Neuroepidemiology 2024:1-4. [PMID: 38631300 DOI: 10.1159/000538697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024] Open
Affiliation(s)
- Salvatore Metanmo
- Inserm U1094, IRD U270, University of Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, Omega Health, Limoges, France
| | - Andrea Sylvia Winkler
- Department of Neurology, Center for Global Health, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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Hadermann A, Jada SR, Amaral LJ, Colebunders R, Bol YY, Siewe Fodjo JN. Rapid diagnostic testing for onchocerciasis in Maridi (South Sudan) before and after improving elimination strategies: a repeated cross-sectional survey. OPEN RESEARCH EUROPE 2024; 3:206. [PMID: 38617116 PMCID: PMC11016167 DOI: 10.12688/openreseurope.16093.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/29/2024] [Indexed: 04/16/2024]
Abstract
Background 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.
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Affiliation(s)
- Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Flanders, 2610, Belgium
| | | | - Luís-Jorge Amaral
- Global Health Institute, University of Antwerp, Antwerp, Flanders, 2610, Belgium
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Flanders, 2610, Belgium
| | - Yak Yak Bol
- Neglected Tropical Diseases Programme, Ministry of Health, Juba, South Sudan
| | - Joseph N Siewe Fodjo
- Global Health Institute, University of Antwerp, Antwerp, Flanders, 2610, Belgium
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Amaral LJ, Jada SR, Ndjanfa AK, Carter JY, Abd-Elfarag G, Okaro S, Logora MY, Bol YY, Lakwo T, Fodjo JNS, Colebunders R. Impact of annual community-directed treatment with ivermectin on the incidence of epilepsy in Mvolo, a two-year prospective study. PLoS Negl Trop Dis 2024; 18:e0012059. [PMID: 38512994 PMCID: PMC10986994 DOI: 10.1371/journal.pntd.0012059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/02/2024] [Accepted: 03/08/2024] [Indexed: 03/23/2024] Open
Abstract
OBJECTIVES The potential impact of cumulative community-directed treatment with ivermectin (CDTI) on epilepsy epidemiology in Mvolo County, South Sudan, an onchocerciasis-endemic area with high epilepsy prevalence, was investigated. Annual CDTI was introduced in 2002 in Mvolo, with interruptions in 2016 and 2020. METHODS Comprehensive house-to-house surveys in Mvolo (June 2020 and 2022) identified cases of epilepsy, including probable nodding syndrome (pNS). Community workers screened households in selected sites for suspected epilepsy, and medical doctors confirmed the diagnosis and determined the year of seizure onset. The incidence of epilepsy, including pNS, was analysed using 95% confidence intervals (CIs). Data on ivermectin intake and onchocerciasis-associated manifestations (itching and blindness) were collected. RESULTS The surveys covered 15,755 (2020) and 15,092 (2022) individuals, identifying 809 (5.2%, 95% CI: 4.8-5.5%) and 672 (4.5%, 95% CI: 4.1-4.8%) epilepsy cases, respectively. Each survey reported that a third of the surveyed population experienced skin itching, and 3% were blind. Epilepsy incidence per 100,000 person-years gradually declined, from 326.5 (95% CI: 266.8-399.1) in 2013-2015 to 96.6 (95% CI: 65.5-141.7) in 2019-2021. Similarly, pNS incidence per 100,000 person-years decreased from 151.7 (95% CI: 112.7-203.4) to 27.0 (95% CI: 12.5-55.5). Coverage of CDTI was suboptimal, reaching only 64.0% of participants in 2019 and falling to 24.1% in 2021 following an interruption in 2020 due to COVID-19 restrictions. Additionally, while 99.4% of cases had active epilepsy in 2022, less than a quarter of these had access to antiseizure medication. CONCLUSIONS The observed decrease in epilepsy incidence despite suboptimal CDTI coverage highlights the potential impact of onchocerciasis control efforts and underscores the need to strengthen these efforts in Mvolo County and across South Sudan. As a proactive measure, Mvolo and neighbouring counties are transitioning to biannual CDTI. Furthermore, the substantial epilepsy treatment gap in Mvolo should be addressed.
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Affiliation(s)
| | | | | | | | - Gasim Abd-Elfarag
- Amref Health Africa, South Sudan
- Access for Humanity, Juba, South Sudan
- School of Public Health, University of Juba, Juba, South Sudan
| | | | - Makoy Yibi Logora
- Neglected Tropical Diseases Unit, Ministry of Health, Juba, South Sudan
| | - Yak Yak Bol
- Neglected Tropical Diseases Unit, Ministry of Health, Juba, South Sudan
| | - Thomson Lakwo
- Vector Control Division, Ministry of Health, Kampala, Uganda
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Hadermann A, Jada SR, Sebit WJ, Deng T, Bol YY, Siewe Fodjo JN, De Coninck L, Matthijnssens J, Mertens I, Polman K, Colebunders R. Onchocerciasis-associated epilepsy: an explorative case-control study with viral metagenomic analyses on Onchocerca volvulus. F1000Res 2023; 12:1262. [PMID: 38439783 PMCID: PMC10911407 DOI: 10.12688/f1000research.138774.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/06/2023] [Indexed: 03/06/2024] Open
Abstract
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.
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Affiliation(s)
- Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, 2610, Belgium
| | | | - Wilson J. Sebit
- Public Health Laboratory, Ministry of Health South Sudan, Juba, South Sudan
| | | | - Yak Y. Bol
- Neglected Tropical Diseases Unit, Ministry of Health South Sudan, Juba, South Sudan
| | | | - Lander De Coninck
- Laboratory of Viral Metagenomics, KU Leuven, Leuven, Flanders, 3000, Belgium
| | - Jelle Matthijnssens
- Laboratory of Viral Metagenomics, KU Leuven, Leuven, Flanders, 3000, Belgium
| | - Inge Mertens
- Health Unit, VITO (Vlaamse Instelling voor Technologisch Onderzoek), Mol, 2400, Belgium
- Centre for Proteomics, University of Atwerp, Antwerp, Belgium
| | - Katja Polman
- Department of Health Sciences, VU Amsterdam, Amsterdam, 1081, The Netherlands
- Department Public Health, Institute of Tropical Medicine, Antwerp, 2600, Belgium
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Colebunders R, Hadermann A, Siewe Fodjo JN. The onchocerciasis hypothesis of nodding syndrome. PLoS Negl Trop Dis 2023; 17:e0011523. [PMID: 37590176 PMCID: PMC10434893 DOI: 10.1371/journal.pntd.0011523] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023] Open
Abstract
Nodding syndrome (NS) is a phenotypic presentation of onchocerciasis-associated epilepsy (OAE). OAE is an important public health problem in areas with high ongoing Onchocerca volvulus transmission. OAE, including NS, is preventable by strengthening onchocerciasis elimination programs. The presence of tau in OAE postmortem brains could be the consequence of neuroinflammation directly or indirectly induced by O. volvulus. Omics research is needed to investigate whether O. volvulus worms contain a neurotropic virus.
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Affiliation(s)
| | - Amber Hadermann
- Global Health Institute University of Antwerp, Antwerp, Belgium
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Kamgno J, Djeunga HN. Further evidence of the potential causative relationship between onchocerciasis and epilepsy. Lancet Glob Health 2023; 11:e1152-e1153. [PMID: 37474214 DOI: 10.1016/s2214-109x(23)00310-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 06/23/2023] [Indexed: 07/22/2023]
Affiliation(s)
- Joseph Kamgno
- Higher Institute for Scientific and Medical Research, Yaoundé, Cameroon); Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon.
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