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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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Failoc-Rojas VE, Silva-Díaz H, Maguiña JL, Rodriguez-Morales AJ, Díaz-Velez C, Apolaya-Segura M, Valladares-Garrido MJ. Evidence-based indications for ivermectin in parasitic diseases: An integrated approach to context and challenges in Peru. Parasite Epidemiol Control 2023; 23:e00320. [PMID: 37731824 PMCID: PMC10507222 DOI: 10.1016/j.parepi.2023.e00320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/07/2023] [Accepted: 07/29/2023] [Indexed: 09/22/2023] Open
Abstract
Ivermectin has emerged as a therapeutic option for various parasitic diseases, including strongyloidiasis, scabies, lice infestations, gnathostomiasis, and myiasis. This study comprehensively reviews the evidence-based indications for ivermectin in treating parasitic diseases, considering the unique context and challenges in Peru. Fourteen studies were selected from a systematic search of scientific evidence on ivermectin in PubMed, from 2010 to July 2022. The optimal dosage of ivermectin for treating onchocerciasis, strongyloidiasis, and enterobiasis ranges from 150 to 200 μg/kg, while lymphatic filariasis requires a higher dose of 400 μg/kg (Brown et al., 2000). However, increased dosages have been associated with a higher incidence of ocular adverse events. Scientific evidence shows that ivermectin can be safely and effectively administered to children weighing less than 15 kg. Systematic reviews and meta-analyses provide strong support for the efficacy and safety of ivermectin in combating parasitic infections. Ivermectin has proven to be an effective treatment for various parasitic diseases, including intestinal parasites, ectoparasites, filariasis, and onchocerciasis. Dosages ranging from 200 μg/kg to 400 μg/kg are generally safe, with adjustments made according to the specific pathology, patient age, and weight/height. Given Peru's prevailing social and environmental conditions, the high burden of intestinal parasites and ectoparasites in the country underscores the importance of ivermectin in addressing these health challenges.
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Affiliation(s)
- Virgilio E. Failoc-Rojas
- Instituto de Evaluación de Tecnologías en Salud e Investigación, EsSalud, Lima, Peru
- Universidad San Ignacio de Loyola, Lima, Peru
| | - Heber Silva-Díaz
- Facultad de Medicina Huamana, Universidad de San Martín de Porres, Chiclayo, Peru
| | - Jorge L. Maguiña
- Instituto de Evaluación de Tecnologías en Salud e Investigación, EsSalud, Lima, Peru
- School of Medicine, Universidad Científica del Sur, Lima, Peru
| | - Alfonso J. Rodriguez-Morales
- Grupo de Investigación Biomedicina, Faculty of Medicine, Fundacion Universitaria Autónoma de las Américas, Pereira, Colombia
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut 1102, Lebanon
| | - Cristian Díaz-Velez
- Facultad de Medicina, Universidad Privada Antenor Orrego, Trujillo, Peru
- Instituto Nacional Cardiovascular, INCOR, EsSalud, Lima, Peru
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Bhwana D, Siewe Fodjo JN, Amaral LJ, Vandevenne L, Francis F, Challe DP, Mmbando BP, Colebunders R. Disability assessment among persons with epilepsy in Mahenge, an onchocerciasis-endemic area in Tanzania: A cross-sectional study. Epilepsy Behav 2023; 146:109367. [PMID: 37523798 DOI: 10.1016/j.yebeh.2023.109367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/17/2023] [Accepted: 07/20/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND A high prevalence of epilepsy has been observed in the onchocerciasis-endemic focus of Mahenge, Tanzania. This study sought to assess the degree of disability experienced by persons with epilepsy (PWE) in Mahenge and identify associations with sociodemographic and clinical features. METHOD This cross-sectional study was conducted in Mahenge, Tanzania, between February and July 2020. PWE were recruited from the Mahenge epilepsy clinic and four neighbouring rural villages (Mdindo, Mzogezi, Mzelezi and Sali). Data were collected using the 36-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) questionnaire for adults. For children aged 5-17 years, we used the Module on Child Functioning developed by UNICEF and the Washington Group. Questionnaires were administered by trained research assistants. Descriptive statistics were performed, and multivariable analyses (gamma and logistic regressions) were conducted. RESULTS A total of 321 adults (45.5% males) and 48 children (55.3% males) with epilepsy participated. The overall median WHODAS 2.0 score was 4.8% (IQR: 0.9-18.9). The most affected disability domain was 'participating in the society' (median score: 12.5%, IQR: 0-29.2). Fifteen (31.3%) of the children with epilepsy had a disability in at least one domain of the child functioning module, with the 'accepting change' domain harbouring the highest proportion of disabled children (12.5%). Higher seizure frequency and longer epilepsy duration were associated with more disability. CONCLUSION PWE in Mahenge experience variable degrees of disability. The affected domains indicate the need for societal rehabilitation of PWE in various community and/or social activities. Peer-support groups were instituted at the study sites to address these needs.
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Affiliation(s)
- Dan Bhwana
- National Institute of Medical Research, Tanga, P.O Box 5004, Tanzania.
| | | | - Luís-Jorge Amaral
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium.
| | - Lauren Vandevenne
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium.
| | - Filbert Francis
- National Institute of Medical Research, Tanga, P.O Box 5004, Tanzania.
| | - Daniel P Challe
- National Institute of Medical Research, Tanga, P.O Box 5004, Tanzania.
| | - Bruno P Mmbando
- National Institute of Medical Research, Tanga, P.O Box 5004, Tanzania.
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Siewe Fodjo JN, Van Cutsem G, Amaral LJ, Colebunders R. Mortality among persons with epilepsy in onchocerciasis-endemic and non-endemic areas of sub-Saharan Africa: A systematic review and meta-analysis. Seizure 2023; 110:253-261. [PMID: 37451075 DOI: 10.1016/j.seizure.2023.07.006] [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: 04/08/2023] [Revised: 07/03/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023] Open
Abstract
PURPOSE To document epilepsy-related mortality in sub-Saharan Africa (SSA) and investigate possible associations with onchocerciasis endemicity. METHODS Systematic review with meta-analysis. Searches were performed in PubMed and Google Scholar (search terms: 'epilepsy'; 'mortality/death'; 'sub-Saharan Africa'). Included studies were classified as high-risk or low-risk for onchocerciasis based on documented endemicity data. Pooled mortality rates and annual case fatality rates (CFR) were calculated, and risk factors for mortality among persons with epilepsy (PWE) were investigated using meta-regression analysis. RESULTS The 28 eligible studies reported 30 epilepsy surveys, of which 9 (30.0%) were conducted in onchocerciasis high-risk sites. The pooled epilepsy mortality rate was 20.9 (95% CI: 5.9-74.4) per 100,000 person-years, and the pooled CFR was 36.2 (95% CI: 23.9-54.4) per 1,000 PWE per year, albeit with substantial between-study heterogeneity. Compared to onchocerciasis low-risk sites, high-risk sites had higher pooled mortality (342.9 versus 10.0 per 100,000 PY; p<0.001) and CFR (57.0 versus 26.6 per 1,000 PWE per year; p = 0.001). Mortality of PWE was almost five-fold that of people without epilepsy (mortality risk ratio: 4.9; 95% CI: 3.5-6.8). Studies in onchocerciasis high-risk sites and the study which recruited only PWE with nodding syndrome were associated with higher CFR (p = 0.044 and p = 0.002, respectively). The leading causes of epilepsy-related death were status epilepticus (58.5%), drowning (15.7%), and sudden unexpected death in epilepsy (10.1%). CONCLUSION Epilepsy mortality remains high in SSA. Most reported causes of death among PWE might be averted by improving seizure control. Better epilepsy prevention and care are urgently needed, particularly in onchocerciasis-endemic settings.
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Affiliation(s)
| | - Gilles Van Cutsem
- Global Health Institute, University of Antwerp, Belgium; Translational Neurosciences, University of Luxembourg, Luxembourg; Centre for Infectious Disease Epidemiology and Research, University of Cape Town, South Africa
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Ngarka L, Siewe Fodjo JN, Ambomatei C, Njamnshi WY, Taryunyu Njamnshi JN, Nfor LN, Mengnjo MK, Njamnshi AK. Epidemiology of epilepsy and relationship with onchocerciasis prevalence in villages of the Ntui Health District of Cameroon. Epilepsy Behav 2023; 142:109184. [PMID: 36972641 PMCID: PMC7614422 DOI: 10.1016/j.yebeh.2023.109184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
BACKGROUND A strong association between epilepsy and onchocerciasis endemicity has been reported. We sought to document the epidemiology of epilepsy in onchocerciasis-endemic villages of the Ntui Health District in Cameroon and investigate how this relates to the prevalence of onchocerciasis. METHODS In March 2022, door-to-door epilepsy surveys were conducted in four villages (Essougli, Nachtigal, Ndjame, and Ndowe). Ivermectin intake during the 2021 session of community-directed treatment with ivermectin (CDTI) was investigated in all participating village residents. Persons with epilepsy (PWE) were identified through a two-step approach: administration of a 5-item epilepsy screening questionnaire followed by clinical confirmation by a neurologist. Epilepsy findings were analyzed together with onchocerciasis epidemiological data previously obtained in the study villages. RESULTS We surveyed 1663 persons in the four study villages. The 2021 CDTI coverage for all study sites was 50.9%. Overall, 67 PWE were identified (prevalence of 4.0% (IQR: 3.2-5.1) with one new-onset case during the past 12 months (annual incidence of 60.1 per 100,000 persons). The median age of PWE was 32 years (IQR: 25-40), with 41 (61.2%) being females. The majority (78.3%) of PWE met the previously published criteria for onchocerciasis-associated epilepsy (OAE). Persons with a history of nodding seizures were found in all villages and represented 19.4% of the 67 PWE. Epilepsy prevalence was positively correlated with onchocerciasis prevalence (Spearman Rho = 0.949, p = 0.051). Meanwhile, an inverse relationship was observed between distance from the Sanaga river (blackfly breeding site) and the prevalence of both epilepsy and onchocerciasis. CONCLUSION The high epilepsy prevalence in Ntui appears to be driven by onchocerciasis. It is likely that decades of CDTI have likely contributed to a gradual decrease in epilepsy incidence, as only one new case occurred in the past year. Therefore, more effective elimination measures are urgently needed in such endemic areas to curb the OAE burden.
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Affiliation(s)
- Leonard Ngarka
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon; Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon.
| | - Joseph Nelson Siewe Fodjo
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Division of Operational Research in Health, Ministry of Public Health, Yaoundé, Cameroon.
| | | | - Wepnyu Yembe Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon; Division of Operational Research in Health, Ministry of Public Health, Yaoundé, Cameroon.
| | | | - Leonard N Nfor
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon.
| | - Michel K Mengnjo
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon.
| | - Alfred K Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon; Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon; Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon.
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Hadermann A, Amaral LJ, Van Cutsem G, Siewe Fodjo JN, Colebunders R. Onchocerciasis-associated epilepsy: an update and future perspectives. Trends Parasitol 2023; 39:126-138. [PMID: 36528471 DOI: 10.1016/j.pt.2022.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
Abstract
Onchocerciasis-associated epilepsy (OAE) is an important neglected public health problem in areas with high ongoing onchocerciasis transmission. The risk that children in such areas develop epilepsy is related to their Onchocerca volvulus microfilarial (mf) load. Before the implementation of mass treatment with ivermectin, microfilariae were detected in cerebrospinal fluid (CSF). More recently, neither O. volvulus microfilariae nor DNA were detected in CSF or brain tissue; however, these samples were obtained years after seizure onset. It is possible that during fever-induced increased blood-brain barrier permeability, microfilariae enter the brain and, upon dying, cause an inflammatory reaction inducing seizures. Including OAE in the onchocerciasis disease burden estimation may mobilise extra resources for onchocerciasis disease elimination and treatment/care of OAE-affected persons/families.
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Affiliation(s)
- Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Belgium
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Siewe Fodjo JN, Ngarka L, Njamnshi WY, Enyong PA, Zoung-Kanyi Bissek AC, Njamnshi AK. Onchocerciasis in the Ntui Health District of Cameroon: epidemiological, entomological and parasitological findings in relation to elimination prospects. Parasit Vectors 2022; 15:444. [PMID: 36443885 PMCID: PMC9702945 DOI: 10.1186/s13071-022-05585-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 09/20/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Despite decades of community-directed treatment with ivermectin (CDTI), onchocerciasis transmission persists in Cameroon and has been associated with increased risk for epilepsy in endemic communities. We investigated the onchocerciasis situation in the Ntui Health District (a known onchocerciasis focus in Cameroon where the Sanaga River constitutes the main source of black fly vectors) using parasitological, entomological and serological parameters. METHODS In July 2021, community-based surveys were conducted in four villages (Essougli, Nachtigal, Ndjame and Ndowe). Onchocerciasis was diagnosed via microscopic examination of skin snips. Using rapid diagnostic tests, we screened children aged 3-6 years for Ov16 antibodies as a proxy for recent onchocerciasis transmission. Monthly black fly biting rates were obtained from the two riverside villages (Nachtigal and Essougli) for 12 consecutive months (July 2021 to June 2022) using the human landing catch technique. Some black flies were dissected each month to check for infection. RESULTS Overall, 460 participants were recruited; mean age was 32.1 (range: 3-85) years with 248 (53.9%) being males. Among skin snipped participants (n = 425), onchocerciasis prevalence was 14.6%. Participants with epilepsy (n = 25) were more often skin snip positive (45.8% vs 12.7%; P < 0.001) and had higher microfilarial loads (9.2 ± 22.0 vs 0.7 ± 3.5 microfilariae/skin snip; P < 0.001) compared to their peers without epilepsy. Eight (6.5%) of the 123 tested children were Ov16 seropositive. The breeding sites we investigated along the Sanaga River during the current study harbored fewer vectors (annual biting rates reaching 530,322 vs 606,370 in the Mbam River) and exhibited lower black fly infection rates (annual transmission potentials reaching 1479 vs 4488 in the Mbam River) when compared to recent entomological reports in Cameroon. CONCLUSION Despite substantial biting rates, black fly infection rates (by microscopy) in the Ntui Health District were rather low resulting in overall low transmission potentials in study villages. Thanks to CDTI, O. volvulus infection in both humans and insects is on the decrease. However, there is evidence that O. volvulus is still endemic in these communities. Reducing the vector population will further accelerate onchocerciasis elimination prospects.
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Affiliation(s)
- Joseph Nelson Siewe Fodjo
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon ,grid.460723.40000 0004 0647 4688Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon
| | - Leonard Ngarka
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon ,grid.460723.40000 0004 0647 4688Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon ,grid.412661.60000 0001 2173 8504Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon
| | - Wepnyu Yembe Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon ,grid.412661.60000 0001 2173 8504Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon ,grid.415857.a0000 0001 0668 6654Ministry of Public Health, Division of Health Operations Research, Yaoundé, Cameroon
| | - Peter Ayuk Enyong
- grid.29273.3d0000 0001 2288 3199Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Anne-Cécile Zoung-Kanyi Bissek
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon ,grid.412661.60000 0001 2173 8504Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon ,grid.415857.a0000 0001 0668 6654Ministry of Public Health, Division of Health Operations Research, Yaoundé, Cameroon
| | - Alfred Kongnyu Njamnshi
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon ,grid.460723.40000 0004 0647 4688Neurology Department, Central Hospital Yaoundé, Yaoundé, Cameroon ,grid.412661.60000 0001 2173 8504Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé, Cameroon
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Dolo H, Konipo FDN, Sow F, Kane F, Sangare M, Daou M, Sangare M, Sangho O, Koné H, Coulibaly FD, Coulibaly SY, Doumbia SS, Koita A, Sangaré B, Djimdé S, Goita S, Bagayoko T, Dem AB, Fomba Z, Gari M, Kotchene CE, Orsot KE, Diarra D, Colebunders R, Coulibaly YI, Sangho H, Maiga YM, Doumbia S. Prevalence and risk factors associated with epilepsy in six health districts of Mali: a community-based cross-sectional and nested case-control study. Neuroepidemiology 2022; 56:127-137. [PMID: 35045422 DOI: 10.1159/000522021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 01/10/2022] [Indexed: 11/19/2022] Open
Abstract
In resource-limited countries, epilepsy prevalence is underestimated and little is known about its risk factors. Objectives: This study aimed to determine the prevalence and risk factors for epilepsy in six health districts (HD) in Mali. Methods A community-based cross-sectional and nested-case-control study was conducted in 180 villages with the highest number of suspicious epilepsy cases (SEC) in the six study HD. The SEC were observed as part of a Phase 1 screening conducted by community health workers (CHWs). For the nested case-control study, one case was matched with at least one control based on residence and age. A case of epilepsy was any person diagnosed with convulsive epilepsy after clinical assessment by a neurologist. A control was a person diagnosed as normal after neurological assessment by a neurologist. Data were collected on sociodemographic characteristics, familial and medical history of epilepsy, consanguinity, place of delivery, pre-term birth, length/type of delivery, and history of meningitis and cerebral malaria. A univariate and multivariate binomial logistic regression model was used to analyse factors associated with epilepsy. Results A total of 1,506 cases of epilepsy and 2,199 controls were enrolled in six HDs. The mean prevalence of epilepsy was 2‰, with the highest in Kenieba (3‰), a previously meso-endemic-onchocerciasis HD, and the lowest in Kadiolo (1.5‰), an hypo-endemic-onchocerciasis HD. Age [aOR=1.02 (95% CI 1.02-1.03)], history of cerebral malaria [aOR=11.41 (95% CI 8.86-14.85)], history of meningitis [aOR=1.95 (95% CI 1.16-3.29)], living in the HD of Tominian [aOR= 1.69 (95% CI 1.29-2.22)], delayed delivery [aOR= 3.21 (95% CI 2.07-5.07)] and dystocia [aOR= 3.37 (95% CI 2.03-5.73)] were all significantly associated with epilepsy. Discussion/Conclusion The prevalence of epilepsy (3‰) in a previously meso-endemic-onchocerciasis HD was much lower than the prevalence (13.35‰) documented in onchocerciasis endemic areas in 2000. This decrease epilepsy prevalence in the previously meso-endemic-region was induced by onchocerciasis and the reduction was due to an effective community direct treatment with ivermectin programme. Cerebral malaria and obstetrical complications were the main risk factors for epilepsy and interventions improving malaria prevention/treatment and optimising prenatal and obstetrical care need to be implemented to reduce incidence.
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Affiliation(s)
- Housseini Dolo
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
- Département d'Enseignement et de Recherche en Santé Publique et Spécialités, FMOS, USTTB, Bamako, Mali
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | | | - Fanta Sow
- Département d'Enseignement et de Recherche en Santé Publique et Spécialités, FMOS, USTTB, Bamako, Mali
| | - Fousseyni Kane
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
| | - Modibo Sangare
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
| | - Mariam Daou
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Moussa Sangare
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
- Département d'Enseignement et de Recherche en Santé Publique et Spécialités, FMOS, USTTB, Bamako, Mali
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | - Oumar Sangho
- Département d'Enseignement et de Recherche des Sciences Biologiques et Médicales (DERSBM), Faculté de Pharmacie (FAPH), USTTB, Bamako, Mali
| | - Harouna Koné
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | - Fousseyni D Coulibaly
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | | | - Salif Seriba Doumbia
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | - Abdou Koita
- Département de Neurologie, Centre Hospitalo Universitaire, Gabriel Toure, Bamako, Mali
| | - Birama Sangaré
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Samba Djimdé
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Sekouba Goita
- Département de Neurologie, Centre Hospitalo Universitaire, Gabriel Toure, Bamako, Mali
| | - Tenimba Bagayoko
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Aly Badhara Dem
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Zoumana Fomba
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Mamadou Gari
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | | | - Kissy Elvira Orsot
- Unité Filariose, International Center of Excellence in Research, USTTB, Bamako, Mali
| | - Dansine Diarra
- Faculté d'Histoire et de Geography, Université des Sciences Sociales et de Gestion de Bamako (USSGB) Bamako, Bamako, Mali
| | | | | | - Hamadoun Sangho
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
- Département d'Enseignement et de Recherche en Santé Publique et Spécialités, FMOS, USTTB, Bamako, Mali
| | - Youssoufa M Maiga
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
- Département de Neurologie, Centre Hospitalo Universitaire, Point G, Bamako, Mali
| | - Seydou Doumbia
- Faculté de Medecine et d'Odonto Stomatologie (FMOS), Université Des Sciences, Des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
- Département d'Enseignement et de Recherche en Santé Publique et Spécialités, FMOS, USTTB, Bamako, Mali
- University Clinical Research Center (UCRC), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
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Siewe Fodjo JN, Vieri MK, Ngarka L, Njamnshi WY, Nfor LN, Mengnjo MK, Hendy A, Enyong PA, Palmer D, Basanez MG, Colebunders R, Njamnshi AK. 'Slash and clear' vector control for onchocerciasis elimination and epilepsy prevention: a protocol of a cluster randomised trial in Cameroonian villages. BMJ Open 2021; 11:e050341. [PMID: 34475178 PMCID: PMC8413955 DOI: 10.1136/bmjopen-2021-050341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION Onchocerciasis, caused by the filarial nematode Onchocerca volvulus, remains endemic in Cameroon despite decades of community-directed treatment with ivermectin (CDTI). CDTI is often hampered by coendemicity with loiasis (another filariasis caused by Loa loa) in some areas. Strong epidemiological evidence suggests that O. volvulus infection increases the risk for onchocerciasis-associated epilepsy (OAE) among Cameroonian children. This highlights the urgent need to strengthen onchocerciasis elimination programmes in mesoendemic/hyperendemic areas. Novel alternative strategies, such as the 'slash and clear' (S&C) vector control method, may be required to complement ongoing CDTI to accelerate elimination of transmission. The short-term impact of S&C on the biting rates of the blackfly vectors has been demonstrated in other settings. However, its long-term effectiveness and impact on parasitological and serological markers of onchocerciasis transmission as well as on OAE are still unknown. METHODS AND ANALYSIS We aim to assess the effectiveness of annual S&C interventions combined with CDTI in reducing onchocerciasis transmission and epilepsy incidence. Eight onchocerciasis-endemic villages located <5 km from the Mbam or Sanaga rivers will be randomised to two arms: four villages will receive yearly CDTI only for two consecutive years (Arm 1), while the other four villages will receive CDTI plus annual S&C for 2 years (Arm 2). Study outcomes (blackfly biting rates, infectivity rates and seroprevalence of onchocerciasis antibodies (Ov16 antibodies) in children, prevalence of microfilaridermia and epilepsy incidence) will be monitored prospectively and compared across study arms. We expect that S&C will have an added benefit over CDTI alone. ETHICS AND DISSEMINATION The protocol has received ethical approval from the institutional review board of the Cameroon Baptist Convention Health Board (reference number: IRB2021-03) and has been registered with the Pan African Clinical Trials Registry. Findings will be disseminated at national and international levels via meetings and peer-reviewed publications. TRIAL REGISTRATION NUMBER PACTR202101751275357.
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Affiliation(s)
- Joseph Nelson Siewe Fodjo
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
- Faculty of Medicine and Health Sciences, Global Health Institute, University of Antwerp, Wilrijk, Belgium
| | - Melissa Krizia Vieri
- Faculty of Medicine and Health Sciences, Global Health Institute, University of Antwerp, Wilrijk, Belgium
| | - Leonard Ngarka
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
| | - Wepnyu Y Njamnshi
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
| | - Leonard N Nfor
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
| | - Michel Karngong Mengnjo
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
| | - Adam Hendy
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Peter A Enyong
- Research Foundation in Tropical Diseases and Environment, Buea, Cameroon
| | - Dennis Palmer
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
| | | | - Robert Colebunders
- Faculty of Medicine and Health Sciences, Global Health Institute, University of Antwerp, Wilrijk, Belgium
| | - Alfred K Njamnshi
- Brain Research Africa Initiative (BRAIN) & Neuroscience Lab, Faculty of Medicine and Biomedical Sciences, The University of Yaounde I, Yaounde, Cameroon
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Ademuwagun IA, Rotimi SO, Syrbe S, Ajamma YU, Adebiyi E. Voltage Gated Sodium Channel Genes in Epilepsy: Mutations, Functional Studies, and Treatment Dimensions. Front Neurol 2021; 12:600050. [PMID: 33841294 PMCID: PMC8024648 DOI: 10.3389/fneur.2021.600050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/01/2021] [Indexed: 12/19/2022] Open
Abstract
Genetic epilepsy occurs as a result of mutations in either a single gene or an interplay of different genes. These mutations have been detected in ion channel and non-ion channel genes. A noteworthy class of ion channel genes are the voltage gated sodium channels (VGSCs) that play key roles in the depolarization phase of action potentials in neurons. Of huge significance are SCN1A, SCN1B, SCN2A, SCN3A, and SCN8A genes that are highly expressed in the brain. Genomic studies have revealed inherited and de novo mutations in sodium channels that are linked to different forms of epilepsies. Due to the high frequency of sodium channel mutations in epilepsy, this review discusses the pathogenic mutations in the sodium channel genes that lead to epilepsy. In addition, it explores the functional studies on some known mutations and the clinical significance of VGSC mutations in the medical management of epilepsy. The understanding of these channel mutations may serve as a strong guide in making effective treatment decisions in patient management.
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Affiliation(s)
- Ibitayo Abigail Ademuwagun
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Solomon Oladapo Rotimi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Steffen Syrbe
- Clinic for Pediatric and Adolescent Medicine, Heidelberg University, Heidelberg, Germany
| | | | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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In pursuit of a cure: The plural therapeutic landscape of onchocerciasis-associated epilepsy in Cameroon - A mixed methods study. PLoS Negl Trop Dis 2021; 15:e0009206. [PMID: 33621233 PMCID: PMC7946181 DOI: 10.1371/journal.pntd.0009206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/10/2021] [Accepted: 02/04/2021] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND A high prevalence of epilepsy has been observed in several onchocerciasis-endemic villages in the Sanaga River basin, Cameroon. Recent studies suggest that ivermectin, a drug that is distributed annually with the aim of eliminating onchocerciasis, may have a protective effect against acquiring onchocerciasis-associated epilepsy (OAE). This study, therefore, provides an in-depth understanding of both the complex therapeutic landscape for epilepsy as well as the experiences related to the 'community-directed treatment with ivermectin' (CDTI) campaign in order to identify a more trenchant path forward in the fight against epilepsy. METHODOLOGY/PRINCIPAL FINDINGS Based on a mixed methods study combining a qualitative strand with a quantitative survey, we found that epilepsy was perceived to have had an epidemic emergence in the past and was still considered an important health issue in the study area. Socio-economic status, availability and accessibility of drugs and practitioners, as well as perceived aetiology shaped therapeutic itineraries for epilepsy, which included frequenting (in)formal biomedical health care providers, indigenous and/or faith healing practitioners. Ivermectin uptake for onchocerciasis was generally well known and well regarded. The CDTI faced structural and logistical bottlenecks undermining equal access and optimal adherence to the drug. CONCLUSIONS/SIGNIFICANCE Locally accessible, uninterrupted, sustainable and comprehensive health-service delivery is essential to help alleviate the epilepsy burden on afflicted households. Addressing structural challenges of CDTI and communicating the potential link with epilepsy to local populations at risk could optimize the uptake of this potentially significant tool in OAE prevention.
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Progress towards onchocerciasis elimination in Côte d'Ivoire: A geospatial modelling study. PLoS Negl Trop Dis 2021; 15:e0009091. [PMID: 33566805 PMCID: PMC7875389 DOI: 10.1371/journal.pntd.0009091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/01/2021] [Indexed: 11/19/2022] Open
Abstract
Background Côte d’Ivoire has had 45 years of intervention for onchocerciasis by vector control (from 1975 to 1991), ivermectin mass drug administration (MDA) (from 1992 to 1994) and community directed treatment with ivermectin (CDTi) from 1995 to the present. We modeled onchocerciasis endemicity during two time periods that correspond to the scale up of vector control and ivermectin distribution, respectively. This analysis illustrates progress towards elimination during these periods, and it has identified potential hotspots areas that are at risk for ongoing transmission. Methods and findings The analysis used Ministry of Health skin snip microfilaria (MF) prevalence and intensity data collected between 1975 and 2016. Socio-demographic and environmental factors were incorporated into a predictive, machine learning algorithm to create continuous maps of onchocerciasis endemicity. Overall predicted mean MF prevalence decreased from 51.8% circa 1991 to 3.9% circa 2016. The model predicted infection foci with higher prevalence in the southern region of the country. Predicted mean community MF load (CMFL) decreased from 10.1MF/snip circa 1991 to 0.1MF/snip circa 2016. Again, the model predicts foci with higher Mf densities in the southern region. For assessing model performance, the root mean squared error and R2 values were 1.14 and 0.62 respectively for a model trained with data collected prior to 1991, and 1.28 and 0.57 for the model trained with infection survey data collected later, after the introduction of ivermectin. Finally, our models show that proximity to permanent inland bodies of water and altitude were the most informative variables that correlated with onchocerciasis endemicity. Conclusion/Significance This study further documents the significant reduction of onchocerciasis infection following widespread use of ivermectin for onchocerciasis control in Côte d’Ivoire. Maps produced predict areas at risk for ongoing infection and transmission. Onchocerciasis might be eliminated in Côte d’Ivoire in the future with a combination of sustained CDTi with high coverage, active surveillance, and close monitoring for persistent infection in previously hyper-endemic areas. Côte d’Ivoire is endemic for onchocerciasis (also known as “river blindness”). This neglected tropical disease is transmitted by biting black flies that breed in fast flowing rivers. From 1975 to 1991, onchocerciasis control was based on weekly aerial spraying of the insecticide temephos, on black fly breeding sites. Vector control, however, was mostly focused on the northern and central parts of the country. From 1992 to present, mass treatment with ivermectin was implemented in all endemic areas, including forested regions in the south. Here we present the first geospatial estimates of onchocerciasis endemicity over time. Using the machine learning algorithm quantile regression forest, we implemented models to: identify important socio-demographic and environmental factors that correlate with onchocerciasis infection; predict the prevalence and density of infection in areas without ground-truth data; delineate remaining infection hotspots. Our results show that Côte d’Ivoire has made very significant progress in reducing infection parameters over time, and they may help to inform future interventions to achieve the goal of onchocerciasis elimination in Côte d’Ivoire.
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Gumisiriza N, Vieri MK, Colebunders R. Nodding syndrome, many questions remain but we can prevent it by eliminating onchocerciasis. Brain Commun 2021; 3:fcaa228. [PMID: 33502388 PMCID: PMC7811754 DOI: 10.1093/braincomms/fcaa228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nolbert Gumisiriza
- Department of Psychiatry, Kabale University School of Medicine, Kabale, Uganda
- Infectious Disease Institute, Makerere University, Kampala, Uganda
- Correspondence to: Nolbert Gumisiriza; Kabale University School of Medicine; Plot 364 Block 3 Kikungiri Hill, Kabale Municipality, Kabale, Uganda E-mail:
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Luna J, Metanmo S, Boumediene F, Mbelesso P, Auditeau E, Ajzenberg D, Preux PM. Onchocerciasis in tropical neurology: A scoping review. J Neurol Sci 2021; 421:117314. [PMID: 33493958 DOI: 10.1016/j.jns.2021.117314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence. METHODOLOGY A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings. RESULTS Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis. CONCLUSION The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.
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Affiliation(s)
- Jaime Luna
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Salvatore Metanmo
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Farid Boumediene
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Pascal Mbelesso
- Department of Neurology, Amitié Hospital, Bangui, Central African Republic
| | - Emilie Auditeau
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Daniel Ajzenberg
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Pierre-Marie Preux
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France.
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Colebunders R, Njamnshi AK, Menon S, Newton CR, Hotterbeekx A, Preux PM, Hopkins A, Vaillant M, Siewe Fodjo JN. Onchocerca volvulus and epilepsy: A comprehensive review using the Bradford Hill criteria for causation. PLoS Negl Trop Dis 2021; 15:e0008965. [PMID: 33411705 PMCID: PMC7790236 DOI: 10.1371/journal.pntd.0008965] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The possibility that onchocerciasis may cause epilepsy has been suggested for a long time, but thus far, an etiological link has not been universally accepted. The objective of this review is to critically appraise the relationship between Onchocerca volvulus and epilepsy and subsequently apply the Bradford Hill criteria to further evaluate the likelihood of a causal association. METHODS PubMed and gray literature published until September 15, 2020, were searched and findings from original research were synthesized. Adherence to the 9 Bradford Hill criteria in the context of onchocerciasis and epilepsy was determined to assess whether the criteria are met to strengthen the evidence base for a causal link between infection with O. volvulus and epilepsy, including the nodding syndrome. RESULTS Onchocerciasis as a risk factor for epilepsy meets the following Bradford Hill criteria for causality: strength of the association, consistency, temporality, and biological gradient. There is weaker evidence supporting causality based on the specificity, plausibility, coherence, and analogy criteria. There is little experimental evidence. Considering the Bradford Hill criteria, available data suggest that under certain conditions (high microfilarial load, timing of infection, and perhaps genetic predisposition), onchocerciasis is likely to cause epilepsy including nodding and Nakalanga syndromes. CONCLUSION Applying the Bradford Hill criteria suggests consistent epidemiological evidence that O. volvulus infection is a trigger of epilepsy. However, the pathophysiological mechanisms responsible for seizure induction still need to be elucidated.
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Affiliation(s)
- Robert Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- * E-mail:
| | - Alfred K. Njamnshi
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé Cameroon
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
| | - Sonia Menon
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Charles R. Newton
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - An Hotterbeekx
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Pierre-Marie Preux
- Institute of Epidemiology and Tropical Neurology, INSERM UMR1094, University of Limoges, Limoges, France
| | - Adrian Hopkins
- Neglected and Disabling Diseases of Poverty Consultant, Kent, United Kingdom
| | - Michel Vaillant
- Competence Center in Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
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The Role of the Maridi Dam in Causing an Onchocerciasis-Associated Epilepsy Epidemic in Maridi, South Sudan: An Epidemiological, Sociological, and Entomological Study. Pathogens 2020; 9:pathogens9040315. [PMID: 32344586 PMCID: PMC7238195 DOI: 10.3390/pathogens9040315] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 11/24/2022] Open
Abstract
Background: An epilepsy prevalence of 4.4% was documented in onchocerciasis-endemic villages close to the Maridi River in South Sudan. We investigated the role of the Maridi dam in causing an onchocerciasis-associated epilepsy epidemic in these villages. Methods: Affected communities were visited in November 2019 to conduct focus group discussions with village elders and assess the OV16 seroprevalence in 3- to 9-year-old children. Entomological assessments to map blackfly breeding sites and determine biting rates around the Maridi River were conducted. Historical data regarding various activities at the Maridi dam were obtained from the administrative authorities. Results: The Maridi dam was constructed in 1954–1955. Village elders reported an increasing number of children developing epilepsy, including nodding syndrome, from the early 1990s. Kazana 2 (the village closest to the dam; epilepsy prevalence 11.9%) had the highest OV16 seroprevalence: 40.0% among children 3–6 years old and 66.7% among children 7–9 years old. The Maridi dam spillway was found to be the only Simulium damnosum breeding site along the river, with biting rates reaching 202 flies/man/h. Conclusion: Onchocerciasis transmission rates are high in Maridi. Suitable breeding conditions at the Maridi dam, coupled with suboptimal onchocerciasis control measures, have probably played a major role in causing an epilepsy (including nodding syndrome) epidemic in the Maridi area.
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