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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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Arndts K, Kegele J, Ritter M, Prazeres da Costa C, Hoerauf A, Winkler AS. Active infection with Onchocerca volvulus and the linkage to epilepsy/nodding syndrome. PLoS Negl Trop Dis 2024; 18:e0012076. [PMID: 38722927 PMCID: PMC11081337 DOI: 10.1371/journal.pntd.0012076] [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: 12/22/2023] [Accepted: 03/16/2024] [Indexed: 05/13/2024] Open
Affiliation(s)
- Kathrin Arndts
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Josua Kegele
- Hertie Institute for Clinical Brain Research, Department of Neurology and Epileptology, University of Tübingen, Tübingen, Germany
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Clarissa Prazeres da Costa
- Center for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Andrea S. Winkler
- Center for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Department of Neurology, Technical University of Munich, Munich, Germany
- Department of Community Medicine and Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
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Tshimbombu TN, Shin M, Thesen T, Mesu’a Kabwa L, Blackmon K, Kashama JMKW, Jobst BC, Fontaine D, Olarinde I, Okitundu‐Luwa E‐Andjafono D. Review of epilepsy care in the Democratic Republic of the Congo. Epilepsia Open 2024; 9:467-474. [PMID: 38243880 PMCID: PMC10984300 DOI: 10.1002/epi4.12904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 01/22/2024] Open
Abstract
Epilepsy imposes a substantial burden on the Democratic Republic of Congo (DRC). These challenges encompass the lack of comprehensive disease surveillance, an unresolved understanding of its pathophysiology, economic barriers limiting access to essential care, the absence of epilepsy surgical capabilities, and deeply ingrained societal stigmas. Notably, the national prevalence of epilepsy remains undetermined, with research primarily concentrating on infectious factors like Onchocerca volvulus, leaving other potential causes underexplored. Most patients lack insurance, incurring out-of-pocket expenses that often lead them to opt for traditional medicine rather than clinical care. Social stigma, perpetuated by common misconceptions, intensifies the social isolation experienced by individuals living with epilepsy. Additionally, surgical interventions are unavailable, and the accessibility of anti-seizure medications and healthcare infrastructure remains inadequate. Effectively tackling these interrelated challenges requires a multifaceted approach, including conducting research into region-specific factors contributing to epilepsy, increasing healthcare funding, subsidizing the costs of treatment, deploying mobile tools for extensive screening, launching awareness campaigns to dispel myths and reduce stigma, and promoting collaborations between traditional healers and medical practitioners to enhance local understanding and epilepsy management. Despite the difficulties, significant progress can be achieved through sustained and compassionate efforts to understand and eliminate the barriers faced by epilepsy patients in the region. This review outlines essential steps for alleviating the epilepsy burden in the DRC. PLAIN LANGUAGE SUMMARY: There are not enough resources to treat epilepsy in the DRC. PWEs struggle with stigma and the lack of money. Many of them still use traditional medicine for treatment and hold wrong beliefs about epilepsy. That is why there is a need for more resources to make the lives of PWEs better in the DRC.
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Affiliation(s)
| | | | - Thomas Thesen
- Geisel School of Medicine at DartmouthHanoverNew HampshireUSA
| | - Luabeya Mesu’a Kabwa
- Department of Neurology and Neuropsychiatry, Center for Neuro‐Psycho‐Pathology of Mont‐Amba, Faculty of MedicineUniversity of KinshasaKinshasaDemocratic Republic of Congo
- Centre Hospitalier ValisanaBrusselsBelgium
| | - Karen Blackmon
- Department of Psychiatry and PsychologyMayo ClinicJacksonvilleFloridaUSA
| | - Jean Marie Kashama wa Kashama
- Department of Neurology and Neuropsychiatry, Center for Neuro‐Psycho‐Pathology of Mont‐Amba, Faculty of MedicineUniversity of KinshasaKinshasaDemocratic Republic of Congo
| | - Barbara C. Jobst
- Department of Neurology, Geisel School of Medicine at DartmouthDartmouth‐Hitchcock Medical CenterLebanonNew HampshireUSA
| | | | - Immanuel Olarinde
- Richmond Gabriel University College of MedicineBelairSaint Vincent and the Grenadines
| | - Daniel Okitundu‐Luwa E‐Andjafono
- Department of Neurology and Neuropsychiatry, Center for Neuro‐Psycho‐Pathology of Mont‐Amba, Faculty of MedicineUniversity of KinshasaKinshasaDemocratic Republic of Congo
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Otiti-Sengeri J, Sube KLL, Siewe Fodjo JN, Otabil KB, Colebunders R. Chorioretinitis among Immigrant and Travellers. Comment on Mansour et al. Presumed Onchocerciasis Chorioretinitis Spilling over into North America, Europe and Middle East. Diagnostics 2023, 13, 3626. Diagnostics (Basel) 2024; 14:478. [PMID: 38472950 DOI: 10.3390/diagnostics14050478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/08/2024] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
We read, with interest, the paper by Mansour et al [...].
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Affiliation(s)
| | | | | | - Kenneth Bentum Otabil
- Department of Biological Science, University of Energy and Natural Resources, Sunyani P.O. Box 214, Ghana
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
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Metanmo S, Dossa D, Ahmat DN, Winkler AS, Boumediene F. Mapping, Associated Factors, and Pathophysiology of Nodding Syndrome in Africa: A Systematic Review. Neuroepidemiology 2024; 58:92-119. [PMID: 38171341 DOI: 10.1159/000536013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/08/2023] [Indexed: 01/05/2024] Open
Abstract
INTRODUCTION Nodding syndrome (NS) remains a poorly understood disorder. For a long time, it has been thought to be restricted to East Africa; however, cases in Central Africa have been increasing over time. The objective of this systematic review (SR) was to provide a summary of the state of knowledge on NS to date. METHODS All original articles published on NS up to November 2021 were searched in four major databases and in the gray literature. Commentaries, editorials, book chapters, books, conference paper, qualitative studies that mentioned NS cases were also included. Data retrieved included study location (with GPS coordinates searched), year of study and publication, population characteristics, definition and diagnosis of NS, associated factors, and treatment if applicable. A meta-analysis of associated factors was performed where possible, and results were presented as odds ratios (ORs) and visualized as forest plots. Geographic information systems were used for cartographic representations. The quality of the articles included was assessed. RESULTS Of the 876 articles initially identified, 67 (corresponding to 59 studies) were included in the SR. NS is only present in Central and East Africa. Interestingly, there were reports of NS in Central Africa prior to 2010, earlier than previously thought. The way NS diagnosis was established varies according to studies, and the 2012 WHO classification was used in only 60% of the studies. Approximately 11% of the articles did not meet the quality requirements set for this review. In our meta-analysis, the main factor associated with NS was onchocerciasis (OR = 8.8 [4.8, 15.9]). However, the pathophysiology of the disease remains poorly understood. The lack of common anti-epileptic drugs is a significant barrier to the management of head nodding and associated epileptic seizures. DISCUSSION/CONCLUSION The lack of an operational definition of NS is an obstacle to its diagnosis and, thus, to its appropriate treatment. Indeed, diagnostic difficulties might have led to false positives and false negatives which could have altered the picture of NS presented in this article. Treatment should take into account nutritional and psychological factors, as well as associated infections. Some risk factors deserve further investigation; therefore, we suggest a multicentric study with an etiological focus using a more operational definition of NS.
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Affiliation(s)
- Salvatore Metanmo
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, Omega Health, Limoges, France
| | - Djamirou Dossa
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, Omega Health, Limoges, France
| | - Djibrine Nassir Ahmat
- Inserm U1094, IRD U270, Univ. 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
- Centre for Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
| | - Farid Boumediene
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, Omega Health, Limoges, France,
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Hedtke SM, Post RJ, Feleke SM, Gebretsadik FS, Boakye DA, Krueger A, Grant WN, Wilding CS. Cytotaxonomic characterization and estimation of migration patterns of onchocerciasis vectors (Simulium damnosum sensu lato) in northwestern Ethiopia based on RADSeq data. PLoS Negl Trop Dis 2024; 18:e0011868. [PMID: 38175836 DOI: 10.1371/journal.pntd.0011868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 01/17/2024] [Accepted: 12/17/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND While much progress has been made in the control and elimination of onchocerciasis across Africa, the extent to which vector migration might confound progress towards elimination or result in re-establishment of endemism in areas where transmission has been eliminated remains unclear. In Northern Ethiopia, Metema and Metekel-two foci located near the Sudan border-exhibit continuing transmission. While progress towards elimination has been faster in Metema, there remains a problematic hotspot of transmission. Whether migration from Metekel contributes to this is currently unknown. METHODOLOGY/PRINCIPLE FINDINGS To assess the role of vector migration from Metekel into Metema, we present a population genomics study of 151 adult female vectors using 47,638 RADseq markers and mtDNA CoI sequencing. From additional cytotaxonomy data we identified a new cytoform in Metema, closely related to S. damnosum s.str, here called the Gondar form. RADseq data strongly indicate the existence of two distinctly differentiated clusters within S. damnosum s.l.: one genotypic cluster found only in Metema, and the second found predominantly in Metekel. Because blackflies from both clusters were found in sympatry (in all four collection sites in Metema), but hybrid genotypes were not detected, there may be reproductive barriers preventing interbreeding. The dominant genotype in Metema was not found in Metekel while the dominant genotype in Metekel was found in Metema, indicating that (at the time of sampling) migration is primarily unidirectional, with flies moving from Metekel to Metema. There was strong differentiation between clusters but little genetic differentiation within clusters, suggesting migration and gene flow of flies within the same genetic cluster are sufficient to prevent genetic divergence between sites. CONCLUSIONS/SIGNIFICANCE Our results confirm that Metekel and Metema represent different transmission foci, but also indicate a northward movement of vectors between foci that may have epidemiological importance, although its significance requires further study.
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Affiliation(s)
- Shannon M Hedtke
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Victoria, Australia
| | - Rory J Post
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
- Disease Control Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Fikre Seife Gebretsadik
- Neglected Tropical Disease Prevention and Control Program, Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Daniel A Boakye
- Parasitology Department, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Andreas Krueger
- Military Hospital Hamburg, Department Tropical Medicine, Hamburg, Germany
| | - Warwick N Grant
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Victoria, Australia
| | - Craig S Wilding
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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7
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Arndts K, Kegele J, Massarani AS, Ritter M, Wagner T, Pfarr K, Lämmer C, Dörmann P, Peisker H, Menche D, Al-Bahra M, Prazeres da Costa C, Schmutzhard E, Matuja W, Hoerauf A, Layland-Heni LE, Winkler AS. Epilepsy and nodding syndrome in association with an Onchocerca volvulus infection drive distinct immune profile patterns. PLoS Negl Trop Dis 2023; 17:e0011503. [PMID: 37535695 PMCID: PMC10426931 DOI: 10.1371/journal.pntd.0011503] [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: 01/09/2023] [Revised: 08/15/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023] Open
Abstract
Previous studies have described the association of onchocerciasis (caused by Onchocerca volvulus) with epilepsy, including nodding syndrome, although a clear etiological link is still missing. Cases are found in different African countries (Tanzania, South Sudan, Uganda, Democratic Republic of the Congo, Central African Republic and Cameroon). In our study we investigated immunological parameters (cytokine, chemokine, immunoglobulin levels) in individuals from the Mahenge area, Tanzania, presenting with either epilepsy or nodding syndrome with or without O. volvulus infection and compared them to O. volvulus negative individuals from the same endemic area lacking neurological disorders. Additionally, cell differentiation was performed using blood smears and systemic levels of neurodegeneration markers, leiomodin-1 and N-acetyltyramine-O, β-glucuronide (NATOG) were determined. Our findings revealed that cytokines, most chemokines and neurodegeneration markers were comparable between both groups presenting with epilepsy or nodding syndrome. However, we observed elevated eosinophil percentages within the O. volvulus positive epilepsy/nodding syndrome patients accompanied with increased eosinophilic cationic protein (ECP) and antigen-specific IgG levels in comparison to those without an O. volvulus infection. Furthermore, highest levels of NATOG were found in O. volvulus positive nodding syndrome patients. These findings highlight that the detection of distinct biomarkers might be useful for a differential diagnosis of epilepsy and nodding syndrome in O. volvulus endemic areas. Trial-registration: NCT03653975.
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Affiliation(s)
- Kathrin Arndts
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
| | - Josua Kegele
- Hertie Institute for Clinical Brain Research, Department of Neurology and Epileptology, University of Tübingen, Tübingen, Germany
| | - Alain S. Massarani
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
| | - Thomas Wagner
- Center for Pediatric and Adolescent Medicine, University Heidelberg, Heidelberg, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Germany
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Christine Lämmer
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, Germany
| | - Helga Peisker
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, Germany
| | - Dirk Menche
- Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, Bonn, Germany
| | - Mazen Al-Bahra
- Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, Bonn, Germany
| | - Clarissa Prazeres da Costa
- German Center for Infection Research (DZIF), Partner Site Munich, Germany
- Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Munich, Germany
- Center for Global Health, School of Medicine, Technical University of Munich, Munich, Germany
| | - Erich Schmutzhard
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - William Matuja
- Department of Neurology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Laura E. Layland-Heni
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, German
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Andrea S. Winkler
- Center for Global Health, School of Medicine, Technical University of Munich, Munich, Germany
- Department of Neurology, Technical University of Munich, Munich, Germany
- Department of Community Medicine and Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA
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Hedtke SM, Choi YJ, Kode A, Chalasani GC, Sirwani N, Jada SR, Hotterbeekx A, Mandro M, Siewe Fodjo JN, Amambo GN, Abong RA, Wanji S, Kuesel AC, Colebunders R, Mitreva M, Grant WN. Assessing Onchocerca volvulus Intensity of Infection and Genetic Diversity Using Mitochondrial Genome Sequencing of Single Microfilariae Obtained before and after Ivermectin Treatment. Pathogens 2023; 12:971. [PMID: 37513818 PMCID: PMC10385737 DOI: 10.3390/pathogens12070971] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/16/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Onchocerciasis is a neglected tropical disease targeted for elimination using ivermectin mass administration. Ivermectin kills the microfilariae and temporarily arrests microfilariae production by the macrofilariae. We genotyped 436 microfilariae from 10 people each in Ituri, Democratic Republic of the Congo (DRC), and Maridi County, South Sudan, collected before and 4-5 months after ivermectin treatment. Population genetic analyses identified 52 and 103 mitochondrial DNA haplotypes among the microfilariae from DRC and South Sudan, respectively, with few haplotypes shared between people. The percentage of genotype-based correct assignment to person within DRC was ~88% and within South Sudan ~64%. Rarefaction and extrapolation analysis showed that the genetic diversity in DRC, and even more so in South Sudan, was captured incompletely. The results indicate that the per-person adult worm burden is likely higher in South Sudan than DRC. Analyses of haplotype data from a subsample (n = 4) did not discriminate genetically between pre- and post-treatment microfilariae, confirming that post-treatment microfilariae are not the result of new infections. With appropriate sampling, mitochondrial haplotype analysis could help monitor changes in the number of macrofilariae in a population as a result of treatment, identify cases of potential treatment failure, and detect new infections as an indicator of continuing transmission.
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Affiliation(s)
- Shannon M. Hedtke
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, VIC 3086, Australia; (A.K.); (G.C.C.); (N.S.); (W.N.G.)
| | - Young-Jun Choi
- Department of Medicine, Washington University in St. Louis and McDonnell Genome Institute, St. Louis, MO 63108, USA; (Y.-J.C.); (M.M.)
| | - Anusha Kode
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, VIC 3086, Australia; (A.K.); (G.C.C.); (N.S.); (W.N.G.)
| | - Gowtam C. Chalasani
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, VIC 3086, Australia; (A.K.); (G.C.C.); (N.S.); (W.N.G.)
| | - Neha Sirwani
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, VIC 3086, Australia; (A.K.); (G.C.C.); (N.S.); (W.N.G.)
| | | | - An Hotterbeekx
- Global Health Institute, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium; (A.H.); (J.N.S.F.); (R.C.)
| | - Michel Mandro
- Provincial Health Division Ituri, Ministry of Health, Bunia P.O. Box 57, Democratic Republic of the Congo;
| | - Joseph N. Siewe Fodjo
- Global Health Institute, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium; (A.H.); (J.N.S.F.); (R.C.)
| | - Glory Ngongeh Amambo
- Parasites and Vectors Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (G.N.A.); (R.A.A.); (S.W.)
| | - Raphael A. Abong
- Parasites and Vectors Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (G.N.A.); (R.A.A.); (S.W.)
- Research Foundation for Tropical Diseases and Environment (REFOTDE), Buea P.O. Box 474, Cameroon
| | - Samuel Wanji
- Parasites and Vectors Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (G.N.A.); (R.A.A.); (S.W.)
- Research Foundation for Tropical Diseases and Environment (REFOTDE), Buea P.O. Box 474, Cameroon
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, 1202 Geneva, Switzerland;
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium; (A.H.); (J.N.S.F.); (R.C.)
| | - Makedonka Mitreva
- Department of Medicine, Washington University in St. Louis and McDonnell Genome Institute, St. Louis, MO 63108, USA; (Y.-J.C.); (M.M.)
| | - Warwick N. Grant
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, VIC 3086, Australia; (A.K.); (G.C.C.); (N.S.); (W.N.G.)
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Amaral LJ, Bhwana D, Mhina AD, Mmbando BP, Colebunders R. Nodding syndrome, a case-control study in Mahenge, Tanzania: Onchocerca volvulus and not Mansonella perstans as a risk factor. PLoS Negl Trop Dis 2023; 17:e0011434. [PMID: 37339148 DOI: 10.1371/journal.pntd.0011434] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/05/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Nodding syndrome (NS) has been consistently associated with onchocerciasis. Nevertheless, a positive association between NS and a Mansonella perstans infection was found in South Sudan. We aimed to determine whether the latter parasite could be a risk factor for NS in Mahenge. METHODS Cases of epilepsy were identified in villages affected by NS in Mahenge, Tanzania, and matched with controls without epilepsy of the same sex, age and village. We examined blood films of cases and controls to identify M. perstans infections. The participants were also asked for sociodemographic and epilepsy information, examined for palpable onchocercal nodules and onchocerciasis-related skin lesions and tested for anti-Onchocerca volvulus antibodies (Ov16 IgG4) by ELISA. Clinical characteristics of cases and controls, O. volvulus exposure status and relevant sociodemographic variables were assessed by a conditional logistic regression model for NS and epilepsy status matched for age, sex and village. RESULTS A total of 113 epilepsy cases and 132 controls were enrolled, of which, respectively, 56 (49.6%) and 64 (48.5%) were men. The median age in cases and controls was 28.0 (IQR: 22.0-35.0) and 27.0 (IQR: 21.0-33.3) years. Of the persons with epilepsy, 43 (38.1%) met the probable NS criteria and 106 (93.8%) had onchocerciasis-associated epilepsy (OAE). M. perstans infection was absent in all participants, while Ov16 seroprevalence was positively associated with probable NS (odds ratio (OR): 5.05, 95%CI: 1.79-14.27) and overall epilepsy (OR: 2.03, 95%CI: 1-07-3.86). Moreover, onchocerciasis-related skin manifestations were only found in the cases (n = 7, p = 0.0040), including persons with probable NS (n = 4, p = 0.0033). Residing longer in the village and having a family history of seizures were positively correlated with Ov16 status and made persons at higher odds for epilepsy, including probable NS. CONCLUSION In contrast to O. volvulus, M. perstans is most likely not endemic to Mahenge and, therefore, cannot be a co-factor for NS in the area. Hence, this filaria is unlikely to be the primary and sole causal factor in the development of NS. The main risk factor for NS remains onchocerciasis.
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Affiliation(s)
| | - Dan Bhwana
- National Institute of Medical Research, Tanga, Tanzania
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Amaral LJ, Bhwana D, Fomo MF, Mmbando BP, Chigoho CN, Colebunders R. Quality of life of persons with epilepsy in Mahenge, an onchocerciasis-endemic area in Tanzania: A cross-sectional study. Epilepsy Behav 2023; 145:109302. [PMID: 37336132 DOI: 10.1016/j.yebeh.2023.109302] [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: 04/19/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
OBJECTIVE This study investigated the quality of life (QoL) of adults with epilepsy living in Mahenge, an onchocerciasis-endemic area in Tanzania with a high prevalence of onchocerciasis-associated epilepsy (OAE). METHODS Between February and December 2020, persons with epilepsy (PWE) were recruited from four rural villages in Mahenge: Mdindo, Msogezi, Mzelezi, and Sali. For PWE who could not answer the questionnaire due to their mental or physical disability, a family member was asked to answer the questions instead. The Quality of Life in Epilepsy Inventory-31 (QOLIE-31) questionnaire used contained seven domains. The raw domain scores were transformed to 0-100% subscales, with higher scores indicating better QoL. The global QoL was calculated from the subscales using the overall QOLIE-31 score formula. RESULTS In total, 96 PWE were enrolled in the study with a median age of 28 (range: 18-60) years, of whom 45 (47%) were male. The questionnaires were answered by PWE (54.8%) or one of their family members (45.2%). Most PWE were single (81%), and half never attended school. About two-thirds (65%) of PWE were suspected of having OAE, and a third (31%) had a history of head nodding seizures. Most PWE were treated with phenobarbital (85.4%) and had high treatment adherence (96.9%). Still, the number of seizures per week ranged from 0 to 7, with a median of one. The mean global QOLIE-31 score was 66.9 (range: 38.3-92.1) out of 100.0. Predictors of lower QoL were living in Sali Village and experiencing seizures the week before the interview. In contrast, completing primary school and switching to second-line anti-seizure medication were predictors of higher QoL. CONCLUSION In order to improve the QoL of PWE in Mahenge, it is vital to optimize anti-seizure medication regimens to decrease the frequency of seizures and to increase the schooling of PWE.
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Affiliation(s)
| | - Dan Bhwana
- National Institute of Medical Research, Tanga, P.O. Box 5004, Tanzania
| | - Messaline F Fomo
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Bruno P Mmbando
- National Institute of Medical Research, Tanga, P.O. Box 5004, Tanzania
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Van Cutsem G, Siewe Fodjo JN, Dekker MCJ, Amaral LJ, Njamnshi AK, Colebunders R. Case definitions for onchocerciasis-associated epilepsy and nodding syndrome: A focused review. Seizure 2023; 107:132-135. [PMID: 37023626 DOI: 10.1016/j.seizure.2023.03.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/03/2023] Open
Abstract
Onchocerciasis-associated epilepsy (OAE) is an important but neglected public health problem in onchocerciasis-endemic areas with insufficient or inadequate onchocerciasis control. Hence, there is a need for an internationally accepted, easy-to-use epidemiological case definition of OAE to identify areas of high Onchocerca volvulus transmission and disease burden requiring treatment and prevention interventions. By including OAE as a manifestation of onchocerciasis, we will considerably improve the accuracy of the overall onchocerciasis disease burden, which is currently underestimated. Hopefully, this will lead to increased interest and funding for onchocerciasis research and control interventions, notably the implementation of more effective elimination measures and treatment and support for affected individuals and their families.
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Mazumder R, Lubowa SK, Salamon N, Jackson NJ, Kawooya M, Akun PR, Anguzu R, Ogwang RJ, Kubofcik J, Nutman T, Marsh K, Newton C, Vincent A, Idro R. Comparison of Structural Changes in Nodding Syndrome and Other Epilepsies Associated With Onchocerca volvulus. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2022; 10:10/2/e200074. [PMID: 36543539 PMCID: PMC9773419 DOI: 10.1212/nxi.0000000000200074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/18/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Nodding syndrome (NS) is a unique childhood-onset epileptic disorder that occurs predominantly in several regions of sub-Saharan Africa. The disease has been associated with Onchocerca volvulus (Ov)-induced immune responses and possible cross-reactivity with host proteins. The aim of this study was to compare structural changes in the brain on MRI between NS and other forms of onchocerciasis-associated epilepsies (OAEs) and to relate structural changes to the Ov-induced immune responses and level of disability. METHODS Thirty-nine children with NS and 14 age-matched participants with other forms of OAE from an endemic region in Uganda underwent detailed clinical examination, serologic evaluation (including Ov-associated antibodies to Ov-16 and Hu-leiomodin-1) and quantitative volumetric analysis of brain MRIs (1.5 T scanner) using Neuroreader, a cloud-based software. RESULTS Cerebral and cerebellar atrophy were the predominant features in both NS and OAE. On quantitative volumetric analysis, participants with NS had larger ventricular volumes compared with participants with OAE, indicative of increased global cortical atrophy (pcorr = 0.036). Among children with NS, severe disability correlated with higher degree of atrophy in the gray matter volume (pcorr = 0.009) and cerebellar volume (pcorr = 0.009). NS cases had lower anti-Ov-16 IgG signal-to-noise ratios than the OAE cases (p < 0.01), but no difference in the levels of the Hu-leiomodin-1 antibodies (p = 0.64). The levels of Ov-associated antibodies did not relate to the degree of cerebral or cerebellar atrophy in either NS or OAE cases. DISCUSSION This is the first study to show that cerebral and cerebellar atrophy correlated with the severity of NS disability, providing an imaging marker for these endemic epileptic disorders that until now have remained poorly characterized. Both NS and OAE have cerebral and cerebellar atrophy, and the levels of Ov-associated antibodies do not seem to be related to the structural changes on MRI.
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Affiliation(s)
- Rajarshi Mazumder
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Samson Kamya Lubowa
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Noriko Salamon
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Nicholas J Jackson
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Michael Kawooya
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Pamela Rosemary Akun
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Ronald Anguzu
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Rodney J Ogwang
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Joseph Kubofcik
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Thomas Nutman
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Kevin Marsh
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Charles Newton
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Angela Vincent
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom
| | - Richard Idro
- From the Department of Neurology (R.M.), David Geffen School of Medicine at University of California Los Angeles; Kampala MRI Centre (S.K.L., M.K.), Uganda; Department of Radiological Sciences (N.S.), David Geffen School of Medicine, University of California Los Angeles, CA; Division of General Internal Medicine and Health Services Research (N.J.J.), David Geffen School of Medicine at UCLA; Centre of Tropical Neuroscience (P.R.A., R.A., R.I.), Kitgum Site, Uganda; Makerere University (R.A., R.J.O., R.I.), College of Health Sciences, Kampala, Uganda; Laboratory of Parasitic Diseases (J.K., T.N.), National Institutes of Health, Bethesda, MD; Centre for Tropical Medicine and Global Health (K.M., R.I.), Nuffield Department of Medicine, University of Oxford, United Kingdom; Department of Psychiatry (C.N.), University of Oxford, United Kingdom; and Nuffield Department of Clinical Neurosciences (A.V.), University of Oxford, United Kingdom.
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Efon-Ekangouo A, Nana-Djeunga HC, Nwane P, Lisongue-Tonga E, Domche A, Sumo L, Osei-Atweneboana MY, Geiger A, Kamgno J. Prevalence of epilepsy in Ndom Health District (Littoral Region, Cameroon) after long-term ivermectin-based preventive chemotherapy for the control of onchocerciasis. Epilepsy Behav 2022; 136:108939. [PMID: 36252289 DOI: 10.1016/j.yebeh.2022.108939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 12/14/2022]
Abstract
Assuming the causality relationship between Onchocerca volvulus infection and epilepsy onset, preventive chemotherapy for the control onchocerciasis can result to a significant impact on epilepsy burden. This study aimed at assessing the prevalence of epilepsy in an onchocerciasis endemic area under annual CDTI for 16 years. A cross-sectional survey was conducted in two communities (Kelleng and Nkonkwalla) located in the Ndom Health District (Littoral Region, Cameroon) to assess the prevalence of epilepsy using a standardized questionnaire for non-specialists in tropical areas. Data on the nuisance of onchocerciasis vector and distance of surveyed households to the river were also collected. Epilepsy status was collected from 367 participants (sex ratio (M/F): 1.13). The crude prevalence of epilepsy was estimated at 8.4 % (95 % CI: 5.8-11.8); the highest prevalence was found in females (13.8 %; 95 % CI: 8.8-20.3) compared to males (5.0 %; 95 % CI: 2.4-9.04)) (p-value = 0.02) and in Nkonkwalla (9.0 %; 95 % CI: 5.5-13.6) (p-value = 0.82) compared to Kelleng (7.7 %; 95 % CI: 4.06-13.13). After 16 years of CDTI in Kelleng, crude prevalence of epilepsy decreased from 10.2 % to 7.2 % (p-value = 0.19), whereas the age sex-standardized prevalence dropped from 13.5 % to 7.7 % between 2004 and 2020 (p-value = 0.05). The median age of epilepsy cases shifted from 24 (IQR: 20-30) in 2004 to 28 years (IQR: 23-34) in 2020. The shift in age-specific prevalence over the years suggests a decreasing incidence of epilepsy in areas under long-term CDTI and a significant impact of onchocerciasis control on the prevalence of epilepsy.
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Affiliation(s)
- Arnauld Efon-Ekangouo
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon; INTERTRYP, Institut de Recherche pour le Développement (IRD), University of Montpellier, TA A-17/G Campus International de Baillarguet, 34398 Montpellier cedex 5, France
| | - Hugues C Nana-Djeunga
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon.
| | - Philippe Nwane
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon; Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon
| | - Elvis Lisongue-Tonga
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon
| | - André Domche
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon; Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon
| | - Laurentine Sumo
- Department of Biological Sciences, Faculty of Science, University of Bamenda, PO Box 39, Bambili, Cameroon
| | - Mike Yaw Osei-Atweneboana
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research (CSIR), Ghana; CSIR-College of Science and Technology, Accra, Ghana
| | - Anne Geiger
- INTERTRYP, Institut de Recherche pour le Développement (IRD), University of Montpellier, TA A-17/G Campus International de Baillarguet, 34398 Montpellier cedex 5, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), PO Box 5797, Yaoundé, Cameroon; Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, PO Box 1364, Yaoundé, Cameroon
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Bhwana D, Mmbando BP, Dusabimana A, Mhina A, Challe DP, Fodjo JNS, Makunde WH, Colebunders R. Ivermectin treatment response in two rural villages with a high prevalence of onchocerciasis and epilepsy, Mahenge Tanzania. Afr Health Sci 2022; 22:607-616. [PMID: 36910370 PMCID: PMC9993262 DOI: 10.4314/ahs.v22i3.65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background Despite 20 years of ivermectin mass distribution in the Mahenge area, Tanzania, the prevalence of onchocerciasis and epilepsy has remained high in rural villages. Objectives We investigated the efficacy of ivermectin in reducing Onchocerca volvulus microfilariae and predictors for parasitic load following ivermectin treatment in persons with (PWE) and without epilepsy (PWOE). Methods Between April and September 2019, 50 PWE and 160 randomly selected PWOE from Msogezi and Mdindo villages participated in a follow-up study. Skin snips were obtained pre (baseline) and three months post-ivermectin treatment. Results The overall prevalence of O. volvulus positive skin snips at baseline was 49% (103/210), with no significant difference between PWE (58.0%) and PWOE (46.3%); p=0.197. The overall mean microfilarial density was significantly higher at baseline 1.45(95%CI:0.98-2.04)) than three-month post-ivermectin treatment (0.23(95%CI:0.11-0.37), p<0.001. Three months after ivermectin, the microfilarial density had decreased by ≥80% in 54 (81.8%, 95%CI: 72.3-91.4) of the 66 individuals with positive skin snips at baseline. High microfilarial density at baseline was the only significant predictor associated with higher microfilarial density in the post-ivermectin skin snips. Conclusion Our study reports a decrease in microfilarial density following ivermectin treatment in most individuals. Optimizing ivermectin coverage will address the ongoing onchocerciasis transmission in Mahenge.
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Affiliation(s)
- Dan Bhwana
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Bruno P Mmbando
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | | | - Athanas Mhina
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Daniel P Challe
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | | | - Williams H Makunde
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
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15
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Shrestha H, McCulloch K, Hedtke SM, Grant WN. Geospatial modeling of pre-intervention nodule prevalence of Onchocerca volvulus in Ethiopia as an aid to onchocerciasis elimination. PLoS Negl Trop Dis 2022; 16:e0010620. [PMID: 35849615 PMCID: PMC9333447 DOI: 10.1371/journal.pntd.0010620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 07/28/2022] [Accepted: 06/28/2022] [Indexed: 11/19/2022] Open
Abstract
Background Onchocerciasis is a neglected tropical filarial disease transmitted by the bites of blackflies, causing blindness and severe skin lesions. The change in focus for onchocerciasis management from control to elimination requires thorough mapping of pre-control endemicity to identify areas requiring interventions and to monitor progress. Onchocerca volvulus nodule prevalence in sub-Saharan Africa is spatially continuous and heterogeneous, and highly endemic areas may contribute to transmission in areas of low endemicity or vice-versa. Ethiopia is one such onchocerciasis-endemic country with heterogeneous O. volvulus nodule prevalence, and many districts are still unmapped despite their potential for onchocerciasis transmission. Methodology/Principle findings A Bayesian geostatistical model was fitted for retrospective pre-intervention nodule prevalence data collected from 916 unique sites and 35,077 people across Ethiopia. We used multiple environmental, socio-demographic, and climate variables to estimate the pre-intervention prevalence of O. volvulus nodules across Ethiopia and to explore their relationship with prevalence. Prevalence was high in southern and northwestern Ethiopia and low in Ethiopia’s central and eastern parts. Distance to the nearest river (RR: 0.9850, 95% BCI: 0.9751–0.995), precipitation seasonality (RR: 0.9837, 95% BCI: 0.9681–0.9995), and flow accumulation (RR: 0.9586, 95% BCI: 0.9321–0.9816) were negatively associated with O. volvulus nodule prevalence, while soil moisture (RR: 1.0218, 95% BCI: 1.0135–1.0302) was positively associated. The model estimated the number of pre-intervention cases of O. volvulus nodules in Ethiopia to be around 6.48 million (95% BCI: 3.53–13.04 million). Conclusions/Significance Nodule prevalence distribution was correlated with habitat suitability for vector breeding and associated biting behavior. The modeled pre-intervention prevalence can be used as a guide for determining priorities for elimination mapping in regions of Ethiopia that are currently unmapped, most of which have comparatively low infection prevalence. Areas with unknown onchocerciasis endemicity may pose a threat to eliminating transmission because they may re-introduce onchocerciasis to areas where interventions have been successful. Additionally, because vectors (and thus Onchocerca volvulus transmission) have specific ecological requirements for growth and development, changes in these ecological factors due to human activities (deforestation, modification of river flows by dam construction, climate change) might change patterns of parasite transmission and endemicity. To estimate the impact of environmental changes, we must first identify ecological factors determining prevalence. We have employed Bayesian geostatistical modeling to create a nationwide O. volvulus nodule prevalence map for Ethiopia based on pre-intervention nodule prevalence data and have explored the effect of environmental variables on nodule prevalence. We estimated the number of pre-intervention cases of nodules and associated uncertainty in previously unmapped areas of Ethiopia to identify areas that need additional data to increase the prediction accuracy. Hydrological variables such as distance to the nearest river, precipitation seasonality, soil moisture, and flow accumulation are associated significantly with O. volvulus nodule prevalence. We show that the spatial distribution of nodule prevalence can be estimated based on ecological data and that predicted prevalence can be used as a guide to prioritize pre-intervention mapping.
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Affiliation(s)
- Himal Shrestha
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Australia
| | - Karen McCulloch
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Australia
- WHO Collaborating Centre for Viral Hepatitis, Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital, and Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Shannon M. Hedtke
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Australia
- * E-mail:
| | - Warwick N. Grant
- Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora, Australia
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16
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Idro R, Ogwang R, Barragan A, Raimondo JV, Masocha W. Neuroimmunology of Common Parasitic Infections in Africa. Front Immunol 2022; 13:791488. [PMID: 35222377 PMCID: PMC8866860 DOI: 10.3389/fimmu.2022.791488] [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: 10/08/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Parasitic infections of the central nervous system are an important cause of morbidity and mortality in Africa. The neurological, cognitive, and psychiatric sequelae of these infections result from a complex interplay between the parasites and the host inflammatory response. Here we review some of the diseases caused by selected parasitic organisms known to infect the nervous system including Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei spp., and Taenia solium species. For each parasite, we describe the geographical distribution, prevalence, life cycle, and typical clinical symptoms of infection and pathogenesis. We pay particular attention to how the parasites infect the brain and the interaction between each organism and the host immune system. We describe how an understanding of these processes may guide optimal diagnostic and therapeutic strategies to treat these disorders. Finally, we highlight current gaps in our understanding of disease pathophysiology and call for increased interrogation of these often-neglected disorders of the nervous system.
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Affiliation(s)
- Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Rodney Ogwang
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Nairobi, Kenya
| | - Antonio Barragan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Joseph Valentino Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Willias Masocha
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
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17
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Community knowledge, attitudes, and practices regarding epilepsy in Mahenge, Tanzania: A socio-anthropological study in an onchocerciasis-endemic area with a high prevalence of epilepsy. Epilepsy Behav 2022; 128:108568. [PMID: 35101841 DOI: 10.1016/j.yebeh.2022.108568] [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: 11/01/2021] [Revised: 01/09/2022] [Accepted: 01/09/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Throughout Africa, epilepsy is a highly stigmatized condition. It is often considered to be contagious. This study aimed to assess community knowledge, attitude, and practices toward epilepsy in four villages namely Mdindo, Msogezi, Mzelezi, and Sali within Mahenge division, in Morogoro region, Tanzania. These villages are located in an onchocerciasis-endemic area with a high prevalence of epilepsy. METHODS A qualitative cross-sectional study was conducted between June and July 2019 within the framework of a multi-disciplinary research project investigating the association between onchocerciasis and epilepsy. Focus group discussions (FGDs) and in-depth interviews (IDIs) were held with persons with epilepsy (PWE) and their caretakers, community resource persons, and program coordinators of the neglected tropical diseases program. RESULTS The main symptoms of epilepsy were well described by all participants in all villages. PWE and caretakers in all villages considered epilepsy to be a major health problem and some participants ranked it second in importance after malaria. The reported perceived causes of epilepsy included febrile seizures during childhood (locally known as degedege), heredity, evil spirits, and inhaling flatus or touching secretions from PWE, especially during seizures. Knowledge about the association between epilepsy and onchocerciasis was low. People with epilepsy are disregarded, stigmatized, and marginalized from various opportunities such as conjugal rights, schooling, leadership roles, and property inheritance. Traditional healers are often the first contact when seeking care after a person develops epilepsy. CONCLUSION Epilepsy is a major health burden and public health concern in the Mahenge area. The negative attitudes toward PWE and misconceptions about the causes of epilepsy contribute to delays in seeking care at health facilities. Findings from this study will be used to optimize the comprehensive community-based epilepsy treatment program that was recently initiated in the area.
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18
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Ojekunle OZ, Esan RO, Balogun MA, Ademolu KO, Adegoke KA, Taiwo AM. Ecological assessment of Black Fly (Simuliumdamnosum, Sensulato) breeding sites in two tributaries of Ogun river, Ogun state, Nigeria. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:220. [PMID: 35201429 DOI: 10.1007/s10661-022-09770-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Onchocerciasis is a disease transmitted by blackfly vector of the genus Simuliumdamnosum complex having public and socio-economic consequences. The abundance of blackfly is directly linked to fluvial ecosystems in both tropical and non-tropical countries of the world. This study assessed the ecology of blackfly breeding sites in two tributaries of River Ogun located in Olokemeji and Lisa villages, Ogun State. A total of eighteen water samples were collected for physicochemical analysis during high rainfall (May, June and July), low rainfall (August, September and October) and dry season (November and December) with mean rainfall values of 163.17, 88.03 and 8.95 mm, respectively, in both tributaries. Physicochemical parameters such as temperature (oC), electrical conductivity (EC), pH, total solids (TS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), hardness (H), sulphate (SO4), phosphate (PO4), alkalinity, acidity, nitrate (NO3) and total dissolved solids (TDS) were analysed using standard laboratory methods. Digestive enzymes were analysed using 1 g of frozen gut of Simulium larvae grounded with 20 ml of 0.067 g of potassium hydrogen and 20 ml of 0.1 M sodium reagent. A total of 766 and 482 samples of Simulium larvae were collected from Olokemeji and Lisa tributaries using Eppendorf tubes. The zooplanktons collected from Olokemeji and Lisa tributary were 904 and 802, while phytoplanktons collected from Olokemeji and Lisa tributary were 635 and 582 during the study period. Data obtained were analysed using both descriptive analysis and T-test. The results obtained for the physicochemical parameters were 28.7 °C, 137.5 µS/cm, 6.3, 248.1 mg/L, 58 mg/L, 108.8 mg/L, 90.8 mg/L, 2.24 mg/L, 2.24 mg/L, 30.76 mg/L, 42.35 mg/L, 1.99 mg/L, 2.07 mg/L and 2.55 mg/L for Temperature, EC, pH, TS, DO, BOD, TSS, H, SO4, PO4, alkalinity, acidity, NO3 and TDS, respectively. There were significant (p < 0.05) differences between the means of EC, pH, TS, TDS, TSS and hardness of Lisa tributary, and water samples were also viewed under an electron microscope for zooplanktons and phytoplanktons. The values of species diversity which were greater than 0.5 indicated that the species were abundant and evenly distributed. There were significant (p < 0.05) differences between the tributaries in all the digestive enzymes except amylase content. The regression analysis between TSS, nitrate, sulphate, phosphate, acidity, hardness, TS, pH and Simulium larvae abundance showed a positive correlation, R2 with values of 0.828, 0.994, 0.948, 0.933, 0.986, 0.997, 0.889 and 0.981, respectively. The R2 values between Simulium larvae abundance with phytoplanktons and rainfall have values of 0.868 at p < 0.01 and 0.911 at p < 0.05.
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Affiliation(s)
- Olusheyi Zaccheaus Ojekunle
- Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Rotimi Olabode Esan
- Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Mujeeb Adeyemi Balogun
- Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
- Faculty of Science and Technology, University of the Basque Country, Basque, Spain
- College of Science and Technology, University of Bordeaux, Bordeaux, France
- Faculty of Sciences, University of Liège, Liège, Belgium
| | - Kehinde O Ademolu
- Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Kayode Adesina Adegoke
- Department of Chemical Sciences, University of Johannesburg, Johannesburg, South Africa.
| | - Adewale Matthew Taiwo
- Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
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19
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Efon Ekangouo A, Nana Djeunga HC, Sempere G, Kamgno J, Njiokou F, Moundipa Fewou P, Geiger A. Bacteriome Diversity of Blackflies' Gut and Association with Onchocerca volvulus, the Causative Agent of Onchocerciasis in Mbam Valley (Center Region, Cameroon). Pathogens 2021; 11:pathogens11010044. [PMID: 35055992 PMCID: PMC8779297 DOI: 10.3390/pathogens11010044] [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: 10/15/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 11/19/2022] Open
Abstract
Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin for the control of onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and the resistance of vector populations. Therefore, efficient and environmentally safe alternative control strategies are still needed. This study explores the composition of the blackfly bacteriome and its variability in the presence of Onchocerca volvulus infection, in order to determine their potential as a novel vector control-based approach to fight onchocerciasis. An entomological survey of a collection of samples was performed in the Bafia health district, a historical endemic focus for onchocerciasis in Cameroon. A total of 1270 blackflies were dissected and the infection rate was 10.1%, indicative of ongoing transmission of onchocerciasis in the surveyed communities. Sequencing process of blackflies’ gut DNA for bacteria screening revealed 14 phyla and 123 genera, highlighting the diversity of gut blackflies bacterial communities. Eight bacteria formed the core of blackfly bacteriome and Wolbachia was the predominant genus with 73.4% of relative abundance of blackflies’ gut bacterial communities. Acidomonas and Roseanomas genera were significantly abundant among infected blackflies (p = 0.01), whereas other genera such as Brevibacterium and Fructobacillus were associated with the absence of infection (p = 0.0009). Differences in gut bacterial distribution of blackflies according to their infection status by the parasite suggest a causal relationship between the bacteriome composition and the onset of blackflies’ infection by O. volvulus or vice versa. Blackfly native bacteria are then potentially involved in infection by O. volvulus, either by facilitating or preventing the parasite infestation of the vector. These bacteria represent an interesting potential as a biological tool/target for a novel approach of vector control to fight onchocerciasis.
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Affiliation(s)
- Arnauld Efon Ekangouo
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Hugues C. Nana Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- Correspondence: ; Tel.: +237-699-076-499
| | - Guilhem Sempere
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- South Green Bioinformatics Platform, Biodiversity, F-34934 Montpellier, France
- UMR InterTryp, CIRAD (Centre de Coopération Internationale en Recherche Agronomique Pour le Développement), Campus International de Baillarguet, F-34398 Montpellier, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Paul Moundipa Fewou
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Anne Geiger
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
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20
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Tandem Use of OvMANE1 and Ov-16 ELISA Tests Increases the Sensitivity for the Diagnosis of Human Onchocerciasis. Life (Basel) 2021; 11:life11121284. [PMID: 34947815 PMCID: PMC8703281 DOI: 10.3390/life11121284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/15/2021] [Accepted: 11/20/2021] [Indexed: 12/19/2022] Open
Abstract
The current serological test for human onchocerciasis relies on IgG4 reactivity against the parasite Ov-16 antigen, with reported sensitivities of only 60–80%. As control programs move from control to elimination, it is imperative to identify novel molecules that could improve the serodiagnosis reliability of this disease. In this study we compared the sensitivity of total IgG against OvMANE1—a chimeric antigen previously identified as a potential biomarker of human onchocerciasis—with that of an Ov-16 antibody test to detect an Onchocerca volvulus infection in persons presenting with microfilaria in skin snips. One hundred and ninety serum samples were obtained from persons with epilepsy in an onchocerciasis-endemic area at Ituri in the Democratic Republic of Congo where ivermectin has never been distributed. Fifty-nine (31.1%) samples were from individuals with a positive skin snip test; 41 (69.5%) of these 59 samples were positive with the OvMANE1 test and 41 (69.5%) with the Ov-16 test; 30 (50.8%) samples were positive for both tests and in 52 (88.1%) at least one of the tests was positive. Testing the 131 sera from persons with a negative skin snip result revealed that 63 (48.1%) were positive exclusively with the OvMANE1 test, 13 (9.9%) exclusively with the Ov-16 test and 25 (19.1%) with both tests. Nine European samples from individuals without past travel history in onchocerciasis endemic zones and 15 samples from Rwanda, a hypoendemic country for onchocerciasis were all negative for the OvMANE1 and Ov-16 tests. However, the specificity of both tests was difficult to determine due to the lack of a gold standard for antibody tests. In conclusion, the tandem use of OvMANE1 and Ov-16 tests improves the sensitivity of detecting Onchocerca volvulus seropositive individuals but, the OvMANE1 test needs to be further evaluated on samples from a population infected with other helminths to cautiously address its specificity.
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21
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Alizadeh Khatir A, Sepidarkish M, Rajabalizadeh MR, Alizadeh Moghaddam S, Aghapour S, Mehravar S, Hotez PJ, Gasser RB, Rostami A. Case-Control Study to Assess the Association between Epilepsy and Toxocara Infection/Exposure. Microorganisms 2021; 9:microorganisms9102091. [PMID: 34683412 PMCID: PMC8537584 DOI: 10.3390/microorganisms9102091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022] Open
Abstract
Although causes and etiology of epilepsy are mostly obscure, some zoonotic parasites, such as Toxocara species, have been proposed as a risk factor for this disease. Here, we conducted an age-matched case-control study to evaluate whether there is an association between epilepsy and the presence of serum antibodies to Toxocara in incident cases. We included 94 idiopathic epileptic patients as cases, and—from the same geographical region—88 people with no own history of epilepsy or neurological disease as control subjects. Epilepsy was confirmed by a physician using the International League Against Epilepsy (ILAE) definition. All participants were screened for the anti-Toxocara IgG serum antibody by enzyme-linked immunosorbent assay (ELISA). Univariate and mutltivariate statistical analyses were applied to calculate the crude and adjusted odds ratios (OR) and 95% confidence intervals (CIs). Anti-Toxocara serum antibody was detected in 37 epileptic patients and in 23 control subjects, giving respective seroprevalences of 39.3% (95% CI, 29.4–49.9%) and 26.1% (95% CI, 17.3–36.5%), respectively. Adjusted multivariate logistic regression analysis estimated an OR of 2.38 (95% CI, 1.25–4.63), indicating a significant association between epilepsy and Toxocara seropositivity. There was also a significant association between seropositivity to Toxocara and partial (OR, 2.60; 95% CI, 1.14–6.04) or generalized (OR, 2.17; 95% CI, 1.09–4.40%) seizures. Findings from the present study of incident epileptic cases support previous studies proposing that Toxocara infection/exposure is a risk factor for epilepsy. However, further well-designed population-based surveys and mechanistic/experimental studies in animal models are required to better understand the reason(s) for this association.
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Affiliation(s)
- Ali Alizadeh Khatir
- Mobility Impairment Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 4714871167, Iran;
| | - Mahdi Sepidarkish
- Department of Biostatistics and Epidemiology, School of Public Health, Babol University of Medical Sciences, Babol 4714871167, Iran;
| | - Mohammad Reza Rajabalizadeh
- Student Research Committee, Babol University of Medical Sciences, Babol 4714871167, Iran; (M.R.R.); (S.A.M.)
| | - Solmaz Alizadeh Moghaddam
- Student Research Committee, Babol University of Medical Sciences, Babol 4714871167, Iran; (M.R.R.); (S.A.M.)
| | - Saeed Aghapour
- Department of Neurosurgery, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari 1353447416, Iran;
| | - Saeed Mehravar
- Department of Epidemiology and Statistics, School of Public Health, Tehran University of Medical Science, Tehran 1666663111, Iran;
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Department of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Robin B. Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence: (R.B.G.); (A.R.); Tel.: +98-11-32190557 (A.R.)
| | - Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 4714871167, Iran
- Correspondence: (R.B.G.); (A.R.); Tel.: +98-11-32190557 (A.R.)
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22
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Ogwang R, Ningwa A, Akun P, Bangirana P, Anguzu R, Mazumder R, Salamon N, Henning OJ, Newton CR, Abbo C, Mwaka AD, Marsh K, Idro R. Epilepsy in Onchocerca volvulus Sero-Positive Patients From Northern Uganda-Clinical, EEG and Brain Imaging Features. Front Neurol 2021; 12:687281. [PMID: 34149607 PMCID: PMC8209377 DOI: 10.3389/fneur.2021.687281] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/12/2021] [Indexed: 01/08/2023] Open
Abstract
Globally, epilepsy is the most common chronic neurological disorder. The incidence in sub-Saharan Africa is 2-3 times higher than that in high income countries. Infection by Onchocerca volvulus may be an underlying risk factor for the high burden and based upon epidemiological associations, has been proposed to cause a group of disorders—Onchocerca associated epilepsies (OAE) like nodding syndrome (NS). To improve our understanding of the disease spectrum, we described the clinical, electroencephalographic (EEG) and magnetic resonance imaging (MRI) features of children with epilepsy and sero-positive for Onchocerca volvulus (possible OAEs other than nodding syndrome). Twenty-nine children and adolescents with non-nodding syndrome OAE in northern Uganda were enrolled. A diagnosis of OAE was made in patients with epilepsy and seizure onset after age 3 years, no reported exposure to perinatal severe febrile illness or traumatic brain injury, no syndromic epilepsy diagnosis and a positive Ov-16 ELISA test. Detailed clinical evaluation including psychiatric, diagnostic EEG, a diagnostic brain MRI (in 10 patients) and laboratory testing were performed. Twenty participants (69%) were male. The mean age was 15.9 (standard deviation [SD] 1.9) years while the mean age at seizure onset was 9.8 (SD 2.9) years. All reported normal early childhood development. The most common clinical presentation was a tonic-clonic seizure. The median number of seizures was 2 (IQR 1–4) in the previous month. No specific musculoskeletal changes, or cranial nerve palsies were reported, neither were any vision, hearing and speech difficulties observed. The interictal EEG was abnormal in the majority with slow wave background activity in 52% (15/29) while 41% (12/29) had focal epileptiform activity. The brain MRI showed mild to moderate cerebellar atrophy and varying degrees of atrophy of the frontal, parietal and occipital lobes. The clinical spectrum of epilepsies associated with Onchocerca may be broader than previously described. In addition, focal onset tonic-clonic seizures, cortical and cerebellar atrophy may be important brain imaging and clinical features.
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Affiliation(s)
- Rodney Ogwang
- College of Health Sciences, Makerere University, Kampala, Uganda.,KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya.,Centre of Tropical Neuroscience, Kitgum, Uganda
| | - Albert Ningwa
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda
| | - Pamela Akun
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda
| | - Paul Bangirana
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Ronald Anguzu
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Division of Epidemiology, Medical College of Wisconsin, Institute for Health and Equity, Milwaukee, WI, United States
| | - Rajarshi Mazumder
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Noriko Salamon
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Oliver Johannes Henning
- Division of Clinical Neuroscience, The National Centre for Epilepsy, Oslo University Hospital, Oslo, Norway
| | - Charles R Newton
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya.,Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Catherine Abbo
- College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Kevin Marsh
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda.,Centre of Tropical Neuroscience, Kitgum, Uganda.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
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A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication? PLoS Negl Trop Dis 2021; 15:e0009144. [PMID: 33730099 PMCID: PMC7968658 DOI: 10.1371/journal.pntd.0009144] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/13/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. METHODOLOGY/PRINCIPAL FINDINGS A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. CONCLUSIONS/SIGNIFICANCE Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance.
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Ogwang R, Muhanguzi D, Mwikali K, Anguzu R, Kubofcik J, Nutman TB, Taylor M, Newton CR, Vincent A, Conroy AL, Marsh K, Idro R. Systemic and cerebrospinal fluid immune and complement activation in Ugandan children and adolescents with long-standing nodding syndrome: A case-control study. Epilepsia Open 2021; 6:297-309. [PMID: 34033255 PMCID: PMC8166803 DOI: 10.1002/epi4.12463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/03/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Nodding syndrome is a poorly understood epileptic encephalopathy characterized by a unique seizure type-head nodding-and associated with Onchocerca volvulus infection. We hypothesized that altered immune activation in the cerebrospinal fluid (CSF) and plasma of children with nodding syndrome may yield insights into the pathophysiology and progression of this seizure disorder. METHOD We conducted a case-control study of 154 children (8 years or older) with long-standing nodding syndrome and 154 healthy age-matched community controls in 3 districts of northern Uganda affected by nodding syndrome. Control CSF samples were obtained from Ugandan children in remission from hematological malignancy during routine follow-up. Markers of immune activation and inflammation (cytokines and chemokines) and complement activation (C5a) were measured in plasma and CSF using ELISA or Multiplex Luminex assays. O volvulus infection was assessed by serology for anti-OV-16 IgG levels. RESULTS The mean (SD) age of the population was 15.1 (SD: 1.9) years, and the mean duration of nodding syndrome from diagnosis to enrollment was 8.3 (SD: 2.7) years. The majority with nodding syndrome had been exposed to O volvulus (147/154 (95.4%)) compared with community children (86/154 (55.8%)), with an OR of 17.04 (95% CI: 7.33, 45.58), P < .001. C5a was elevated in CSF of children with nodding syndrome compared to controls (P < .0001). The levels of other CSF markers tested were comparable between cases and controls after adjusting for multiple comparisons. Children with nodding syndrome had lower plasma levels of IL-10, APRIL, CCL5 (RANTES), CCL2, CXCL13, and MMP-9 compared with community controls (P < .05 for all; multiple comparisons). Plasma CRP was elevated in children with nodding syndrome compared to community children and correlated with disease severity. SIGNIFICANCE Nodding syndrome is associated with exposure to O. volvulus. Compared to controls, children with long-standing symptoms of nodding syndrome show evidence of complement activation in CSF and altered immune activation in plasma.
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Affiliation(s)
- Rodney Ogwang
- Makerere University College of Health Sciences, Kampala, Uganda.,Centre of Tropical Neuroscience (CTN), Kitgum Site, Uganda.,KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Dennis Muhanguzi
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Kioko Mwikali
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya
| | - Ronald Anguzu
- Centre of Tropical Neuroscience (CTN), Kitgum Site, Uganda.,Division of Epidemiology, Institute of Health and Equity, Medical College of Wisconsin, Wisconsin, WI, USA
| | - Joe Kubofcik
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Mark Taylor
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Charles R Newton
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Coast, Kilifi, Kenya.,Department of Psychiatry, University of Oxford, Oxford, UK
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Andrea L Conroy
- Indiana University School of Medicine, Ryan White Center for Pediatric Infectious Disease & Global Health, Indianapolis, IN, USA
| | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard Idro
- Makerere University College of Health Sciences, Kampala, Uganda.,Centre of Tropical Neuroscience (CTN), Kitgum Site, Uganda.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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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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Olum S, Scolding P, Hardy C, Obol J, Scolding NJ. Response to: 'Nodding syndrome, many questions remain but we can prevent it by eliminating onchocerciasis'. Brain Commun 2021; 3:fcaa229. [PMID: 33502386 PMCID: PMC7811753 DOI: 10.1093/braincomms/fcaa229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2020] [Indexed: 11/15/2022] Open
Affiliation(s)
- Sam Olum
- Faculty of Medicine, Gulu University, Uganda
| | | | - Charlotte Hardy
- Faculty of Medicine, Gulu University, Uganda
- Royal United Hospital, Bath, UK
| | - James Obol
- Faculty of Medicine, Gulu University, Uganda
| | - Neil J Scolding
- Faculty of Medicine, Gulu University, Uganda
- Institute of Clinical Neurosciences, University of Bristol, Bristol, UK
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Identifying areas for improvement in epilepsy management in developing countries: an experience of neurocooperation in Cameroon. NEUROLOGÍA (ENGLISH EDITION) 2021. [DOI: 10.1016/j.nrleng.2019.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Siewe Fodjo JN, Remme JHF, Preux PM, Colebunders R. Meta-analysis of epilepsy prevalence in West Africa and its relationship with onchocerciasis endemicity and control. Int Health 2020; 12:192-202. [PMID: 32141502 PMCID: PMC7320426 DOI: 10.1093/inthealth/ihaa012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/04/2020] [Accepted: 02/19/2020] [Indexed: 01/28/2023] Open
Abstract
Background A high prevalence and incidence of epilepsy has been reported in onchocerciasis-endemic regions in Central and East Africa. There is compelling epidemiological evidence suggesting that this high burden is caused by onchocerciasis-associated epilepsy (OAE). We hypothesized that OAE had also occured in West African onchocerciasis foci. Methods We searched PubMed, the African Journals Online platform and grey literature for population-based epilepsy studies in West African countries. Epilepsy and onchocerciasis prevalence data were extracted. The pre-control onchocerciasis endemicity in the study sites was estimated from historical data of onchocerciasis control programmes. The prevalence of epilepsy in different sites was analysed, taking into account onchocerciasis endemicity and the duration of control. Results The pooled prevalence of epilepsy in the West African study sites was 13.14 per 1000 (95% confidence interval 11.28–15.00). Higher pre-control endemicity and a shorter duration of onchocerciasis control were both associated with increased epilepsy prevalence (p<0.001). Two studies in Ivory Coast that provided detailed descriptions of persons with epilepsy in onchocerciasis-endemic settings revealed that most of them had features of OAE (73.7% and 83.3%, respectively). Conclusions Our findings suggest that before and during the early years of implementing onchocerciasis control in West Africa, high onchocerciasis endemicity resulted in a high prevalence of OAE and that subsequent control efforts significantly reduced the prevalence of OAE.
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Affiliation(s)
| | | | - Pierre-Marie Preux
- INSERM, University of Limoges, CHU Limoges, UMR 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, GEIST, 87000 Limoges, France
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, Doornstraat 331, 2610 Antwerp, Belgium
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Epilepsy-associated neurocognitive disorders (EAND) in an onchocerciasis-endemic rural community in Cameroon: A population-based case-control study. Epilepsy Behav 2020; 112:107437. [PMID: 32920377 DOI: 10.1016/j.yebeh.2020.107437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/16/2020] [Accepted: 08/16/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND Epilepsy affects at least 50 million individuals worldwide, especially in sub-Saharan Africa (sSA). Cognitive impairment is common in people with epilepsy (PWE) yet, little is known on the burden of cognitive impairment in people with epilepsy in sSA. This study was thus designed to assess cognitive impairment in PWE or epilepsy-associated neurocognitive disorders (EAND) in a rural population in Cameroon. METHODS This was a case-control study including PWE and age/sex-matched healthy controls from July to September 2017 in Bilomo, a village in the Mbam and Kim Division. The Montreal Cognitive Assessment (MoCA), International HIV Dementia Scale (IHDS), Dubois' Five Word testing, Frontal Assessment Battery (FAB), Isaac's Set Test and the Clock drawing test were administered to the study participants to evaluate global and specific cognitive functions. RESULTS Eighty participants were included (40 cases and 40 controls) with a mean age of 25.78 years. Using the MoCA, 87.5% of cases had cognitive impairment, against 37.5% of controls (p < 0.001; OR 11.67; CI 3.40-45.09). Using the IHDS, the prevalence of global cognitive impairment was 84.6% among the cases against 40% for the controls (p = <0.001; OR 7.07; CI 2.29-29.19). Specifically, executive function deficits (92.5% of cases vs 40.0% of controls p = <0.001 OR = 18.50 CI; 4.48-105.08) and decreased verbal fluency (100% of cases against 45% of controls p < 0.001) were the most affected cognitive domains. Longer duration of epilepsy and higher seizure frequency were associated with global cognitive impairment. Low level of education was associated with both decreased verbal fluency and executive dysfunction while a longer stay in Bilomo correlated with poor results on the Isaac's Set Test. CONCLUSION The prevalence of cognitive impairment appears to be much higher in PWE in the Mbam valley, particularly decreased executive function and verbal fluency, than in people without epilepsy. Longer disease duration, higher seizure frequency, low level of education and length of stay in Bilomo are associated with poorer cognitive performance. More studies are needed to refine evaluation tools to better characterize and manage EAND in sSA.
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De Castro AC, Ortega-Deballon I. Nodding syndrome: bridging the gap-a scoping review protocol. BMJ Open 2020; 10:e035269. [PMID: 33082177 PMCID: PMC7577026 DOI: 10.1136/bmjopen-2019-035269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION Nodding syndrome (NS) is an encephalopathy of unknown origin that affects children aged between 3 and 15 years old. Cases have been reported since the 1950 in Tanzania and South Sudan, the most heavily affected population is the Acholi community in Uganda. In response to the high incidence of the disease, the Ugandan Government has developed a management algorithm, but access to such measures in affected communities is limited. There is little funding for research on the disease, consequently, few studies have been conducted to date. Nevertheless, the number of scientific publications on NS has increased since 2013, reporting several aetiological hypotheses, management algorithms and cases of stigmatisation; however, none has obtained conclusive results.This document describes a protocol for a scoping review of NS to date aimed at obtaining a broad overview of the disease. The results will identify gaps in knowledge in order to better guide future research, intervention strategies, health policies in areas at risk and cooperation and development programmes. METHODS AND ANALYSIS To identify the relevant data, we will conduct a literature search using the electronic databases PubMed/Medline, Embase, Social Science Citation Index Scopus, Scientific Electronic Library Online (SciELO), Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS), Social Science Citation Index Expanded and The Cochrane Library. We will also include grey literature. The search strategy will be designed by a librarian.Two members of the team will work independently to identify studies for inclusion and perform data extraction. The search results will be assessed by two independent reviewers and data from the included studies will be charted and summarised in duplicate. The data will be summarised in tables and figures to present the research landscape and describe and map gaps. ETHICS AND DISSEMINATION Ethical approval is not required. The scoping review will adhere to the Preferred Reporting Items for Systematic Reviews andMeta-Analyses-ScR guidelines. The results will be disseminated at scientific congresses and meetings.
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Affiliation(s)
- Ana Cristina De Castro
- Facultad de Medicina y Ciencias de la Salud. Departamento de Enfermería, Universidad de Alcala, Alcala de Henares, Madrid, Spain
| | - Ivan Ortega-Deballon
- Facultad de Medicina y Ciencias de la Salud. Departamento de Enfermería, Universidad de Alcala, Alcala de Henares, Madrid, Spain
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Latio LSY, Nam NH, Shah J, Smith C, Sakai K, Stonewall Shaban K, Idro R, Makoto N, Huy NT, Hamano S, Moji K. Economic burden of the persistent morbidity of nodding syndrome on caregivers in affected households in Northern Uganda. PLoS One 2020; 15:e0238643. [PMID: 32991607 PMCID: PMC7523991 DOI: 10.1371/journal.pone.0238643] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 08/20/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Nodding syndrome (NS), is an unexplained form of epilepsy which leads to stunted growth, cognitive decline, and a characteristic nodding of the head. Current data about its impact on households in Uganda is scarce. Therefore, this study aims to assess the economic burden of the persistent morbidity of NS on caregivers in affected households in Northern Uganda. METHODS A cross-sectional cost-of-care study was conducted from January 2019 to February 2019 in Lakwela village-Northern Uganda in 14 households, who are members of a community-based organization (CBO) established in the village with the support of a Japanese research team, (Uganda-Japan Nodding Syndrome Network). Data was collected through questionnaires. Both direct (medical and non-medical) and indirect (informal care) costs of caregiving were assessed. Indirect costs were valued using the human-capital method as loss of production. RESULTS Direct costs constituted a higher proportion of costs for NS households, accounting for on average 7.7% of household expenditure. The annual weighted mean cost per NS patient was estimated at 27.6 USD (26.4 USD direct costs, 96.2% and 1.2 USD indirect cost, 3.8%). Average time spent on informal caregiving was 4.4 ±1.7 (standard deviation) hours/week with an estimated annual informal caregiving cost of 24.85 USD and gross domestic product (GDP) loss of 412.40 USD. CONCLUSION Direct costs due to NS are still high among households in this study. More studies are needed to investigate measures that could help bring down these costs and equally reduce the day-to-day disruption of caregiver's activities; consequently, improving the lives of these affected households and communities.
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Affiliation(s)
| | - Nguyen Hai Nam
- Online Research Club (http://www.onlineresearchclub.org), Nagasaki, Japan
- Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Jaffer Shah
- Online Research Club (http://www.onlineresearchclub.org), Nagasaki, Japan
- Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Chris Smith
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kikuko Sakai
- Liberal Arts and Science, Kanazawa Seiryo University, Kanazawa, Japan
| | - Kato Stonewall Shaban
- Department of Environment and Natural Resources, Faculty of Agriculture and Environment Gulu University, Gulu, Uganda
| | - Richard Idro
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Nishi Makoto
- Graduate School of Asian and African Area Studies, Kyoto University, Kyoto, Japan
| | - Nguyen Tien Huy
- Department of Clinical Product Development, Institute of Tropical Medicine (NEKKEN), School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- * E-mail: (KM); (NTH)
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Kazuhiko Moji
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- * E-mail: (KM); (NTH)
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Prevalence and incidence of nodding syndrome and other forms of epilepsy in onchocerciasis-endemic areas in northern Uganda after the implementation of onchocerciasis control measures. Infect Dis Poverty 2020; 9:12. [PMID: 32114979 PMCID: PMC7050130 DOI: 10.1186/s40249-020-0628-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 01/14/2020] [Indexed: 12/20/2022] Open
Abstract
Background Around 2007, a nodding syndrome (NS) epidemic appeared in onchocerciasis-endemic districts of northern Uganda, where ivermectin mass distribution had never been implemented. This study evaluated the effect of community-directed treatment with ivermectin (CDTI) and ground larviciding of rivers initiated after 2009 and 2012 respectively, on the epidemiology of NS and other forms of epilepsy (OFE) in some districts of northern Uganda. Methods In 2012, a population-based community survey of NS/epilepsy was carried out by the Ugandan Ministry of Health in Kitgum and Pader districts. In August 2017, we conducted a new survey in selected villages of these districts and compared our findings with the 2012 data. In addition, two villages in Moyo district (where CDTI was ongoing since 1993) served as comparative onchocerciasis-endemic sites in which larviciding had never been implemented. The comparison between 2012 and 2017 prevalence and cumulative incidence were done using the Fisher’s and Pearson’s Chi-square tests at 95% level of significance. Results A total of 2138 individuals in 390 households were interviewed. In the selected villages of Kitgum and Pader, there was no significant decrease in prevalence of NS and OFE between 2012 and 2017. However, the cumulative incidence of all forms of epilepsy decreased from 1165 to 130 per 100 000 persons per year (P = 0.002); that of NS decreased from 490 to 43 per 100 000 persons per year (P = 0.037); and for OFE from 675 to 87 per 100 000 persons per year (P = 0.024). The median age of affected persons (NS and OFE) shifted from 13.5 (IQR: 11.0–15.0) years in 2012 to 18.0 (IQR: 15.0–20.3) years in 2017; P < 0.001. The age-standardized prevalence of OFE in Moyo in 2017 was 4.6%, similar to 4.5% in Kitgum and Pader. Conclusions Our findings support the growing evidence of a relationship between infection by Onchocerca volvulus and some types of childhood epilepsy, and suggest that a combination of bi-annual mass distribution of ivermectin and ground larviciding of rivers is an effective strategy to prevent NS and OFE in onchocerciasis-hyperendemic areas.
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Stacey HJ, Woodhouse L, Welburn SC, Jones JD. Aetiologies and therapies of nodding syndrome: a systematic review and meta-analysis. JOURNAL OF GLOBAL HEALTH REPORTS 2019. [DOI: 10.29392/joghr.3.e2019066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Kaiser C, Mmbando BP, Siewe Fodjo JN, Suykerbuyk P, Mnacho M, Kakorozya A, Matuja W, Hendy A, Greter H, Makunde WH, Colebunders R. Onchocerciasis-associated epilepsy: another piece in the puzzle from the Mahenge mountains, southern Tanzania. Infect Dis Poverty 2019; 8:35. [PMID: 31122275 PMCID: PMC6533739 DOI: 10.1186/s40249-019-0545-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 04/29/2019] [Indexed: 11/10/2022] Open
Abstract
In a study from the onchocerciasis-endemic area of Mahenge in southern Tanzania, Mmbando et al. [Inf Dis Poverty. 2018;7:64] demonstrate that in four selected villages the overall epilepsy prevalence was high, and significantly more elevated in the two villages of higher onchocerciasis endemicity compared to those of lower endemicity. This is replicating earlier findings from many other areas of tropical Africa. The authors are also providing data indicating that in the Mahenge focus, the prevalence of nodding syndrome may be related to that of onchocerciasis in the same way as epilepsy in general. The application of a clinical case definition for onchocerciasis-associated epilepsy (OAE) as used in the study of Mmbando et al. [Inf Dis Poverty. 2018;7:64] faces some difficulties; indeed, its precision in discerning cases of OAE from epilepsy due to other etiologies is not known, and it does not allow for a specific diagnosis in the individual patient. Because an operational surveillance tool for assessing the number of patients in the population could mean substantial advance for better estimating the burden of OAE, the proposed definition should be tried in different settings and its performance reviewed in the process.
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Affiliation(s)
- Christoph Kaiser
- Pediatric Practice, Balzenbergstrasse 73, 76530, Baden-Baden, Germany.
| | - Bruno P Mmbando
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania.
| | | | | | | | | | - William Matuja
- Muhimbili University of Health and allied Sciences, Dar es Salaam, Tanzania
| | - Adam Hendy
- University of Texas Medical Branch,, Galveston, TX, USA
| | - Helena Greter
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Williams H Makunde
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
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Stigma and epilepsy in onchocerciasis-endemic regions in Africa: a review and recommendations from the onchocerciasis-associated epilepsy working group. Infect Dis Poverty 2019; 8:34. [PMID: 31109376 PMCID: PMC6526597 DOI: 10.1186/s40249-019-0544-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/21/2019] [Indexed: 01/24/2023] Open
Abstract
Background In onchocerciasis-endemic areas, particularly in those with a sub-optimal onchocerciasis control programme, a high prevalence of epilepsy is observed. Both onchocerciasis and epilepsy are stigmatizing conditions. The first international workshop on onchocerciasis-associated epilepsy (OAE) was held in Antwerp, Belgium (12–14 October 2017) and during this meeting, an OAE alliance was established. In this paper, we review what is known about epilepsy-associated stigma in onchocerciasis-endemic regions, and present the recommendations of the OAE alliance working group on stigma. Main body For this scoping review, literature searches were performed on the electronic databases PubMed, Scopus and Science Direct using the search terms “epilepsy AND onchocerciasis AND stigma”. Hand searches were also undertaken using Google Scholar, and in total seven papers were identified that addressed epilepsy-related stigma in an onchocercisasis-endemic area. Due to the limited number of published research papers on epilepsy-associated stigma in onchocerciasis-endemic areas, other relevant literature that describes important aspects related to stigma is discussed. The thematic presentation of this scoping review follows key insights on the barriers to alleviating the social consequences of stigma in highly affected onchocerciasis-endemic areas, which were established by experts during the working group on stigma and discrimination at the first international workshop on OAE. These themes are: knowledge gaps, perceived disease aetiology, access to education, marriage restrictions, psycho-social well-being, burden on the care-giver and treatment seeking behaviour. Based on the literature and expert discussions during the OAE working group on stigma, this paper describes important issues regarding epilepsy-related stigma in onchocerciasis-endemic regions and recommends interventions that are needed to reduce stigma and discrimination for the improvement of the psycho-social well-being of persons with epilepsy. Conclusions Educating healthcare workers and communities about OAE, strengthening onchocerciasis elimination programs, decreasing the anti-epileptic treatment gap, improving the care of epilepsy-related injuries, and prioritising epilepsy research is the way forward to decreasing the stigma associated with epilepsy in onchocerciasis-endemic regions. Electronic supplementary material The online version of this article (10.1186/s40249-019-0544-6) contains supplementary material, which is available to authorized users.
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Identifying areas for improvement in epilepsy management in developing countries: An experience of neurocooperation in Cameroon. Neurologia 2019; 36:29-33. [PMID: 31064664 DOI: 10.1016/j.nrl.2019.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 02/14/2019] [Accepted: 02/25/2019] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Epilepsy is especially prevalent in developing countries: incidence and prevalence rates are at least twice as high as in our setting. Epilepsy is also highly stigmatised, and few resources are available for its management. MATERIAL AND METHODS We performed a descriptive observational study in December 2016, distributing a questionnaire on epilepsy management to healthcare professionals from 3 different hospitals in Cameroon. Data are presented as means or percentages. RESULTS Thirty-eight healthcare providers participated in the survey; 42.1% were female and mean age was 40.1 years (range, 22-62). Regarding the causes of epilepsy, 68.4% considered it a psychiatric condition, 34.2% a degenerative disease, 28.9% a hereditary condition, and 21.1% secondary to infection. In terms of management, 23.7% considered that thorough clinical history is sufficient to establish a diagnosis. Only 60.5% considered the clinical interview to be important for diagnosis, 52.6% considered EEG to be necessary, and 28.9% considered laboratory analyses to be important. Only 13.2% mentioned neuroimaging. In the treatment of pregnant women, 36.8% recommended folic acid supplementation, 65.8% believed antiepileptic treatment should be maintained, and only 39.5% recommended breastfeeding. Concerning treatment, the participants knew a mean of 2 antiepileptic drugs: phenobarbital was the best known (81.6%), followed by carbamazepine (55.3%) and valproic acid (28.9%). CONCLUSIONS There is a need among healthcare professionals for education and information on the disease, its diagnosis, and management options, in order to optimise management and consequently improve patients' quality of life.
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Siewe Fodjo JN, Dekker MCJ, Idro R, Mandro MN, Preux PM, Njamnshi AK, Colebunders R. Comprehensive management of epilepsy in onchocerciasis-endemic areas: lessons learnt from community-based surveys. Infect Dis Poverty 2019; 8:11. [PMID: 30738437 PMCID: PMC6368958 DOI: 10.1186/s40249-019-0523-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 01/23/2019] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Onchocerciasis-endemic regions are known to have a high epilepsy prevalence. Limited resources in these areas and poor access to healthcare by persons with epilepsy (PWE) result in a wide anti-epileptic treatment gap, poor seizure control and a high burden of seizure-related complications. Recent community-based surveys highlight the need for epilepsy management strategies suitable for remote onchocerciasis-endemic villages to ensure better health outcomes for PWE. In this paper, we propose a feasible approach to manage PWE in such settings. MAIN TEXT Improved management of PWE in onchocerciasis-endemic areas may be achieved by decentralizing epilepsy care. Simplified approaches for the diagnosis and treatment of epilepsy may be used by non-physicians, under the supervision of physicians or specialists. To reduce the treatment gap, a regular supply of subsidized anti-epileptic drugs (AED) appropriate for different types of onchocerciasis-associated epilepsy should be instituted. Setting up a community-based epilepsy surveillance system will enable early diagnosis and treatment of PWE thereby preventing complications. Community awareness programs on epilepsy must be implemented to reduce stigma and facilitate the social rehabilitation of PWE. Finally, strengthening onchocerciasis elimination programs by optimizing community-directed treatment with ivermectin (CDTI) and considering alternative treatment strategies might reduce the incidence of epilepsy. CONCLUSIONS A community-based approach with task-shifting of epilepsy care from specialists to non-physician health workers will reduce epilepsy-associated morbidity. Increased advocacy and collaboration with various stakeholders is needed to establish a sustainable, cost-effective chronic care model for epilepsy that will significantly improve the quality of life of PWE in onchocerciasis-endemic regions.
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Affiliation(s)
| | - Marieke C. J. Dekker
- Department of Internal Medicine and Pediatrics, Kilimanjaro Christian Medical Centre, Moshi, Tanzania
- Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Richard Idro
- Department of Paediatrics and Child Health, Makerere University, College of Health Sciences, Kampala, Uganda
| | - Michel Ndahura Mandro
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- Provincial Health Division Ituri, Ministry of Health, Bunia, Democratic Republic of the Congo
| | - Pierre-Marie Preux
- INSERM, Univ. Limoges, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, GEIST, 87000, Limoges, CHU, UMR 1094 Limoges, France
| | - Alfred K. Njamnshi
- Department of Neurology, Yaoundé Central Hospital / FMBS, The University of Yaoundé 1, Yaoundé, Cameroon
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
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Siewe JNF, Ukaga CN, Nwazor EO, Nwoke MO, Nwokeji MC, Onuoha BC, Nwanjor SO, Okeke J, Osahor K, Chimechefulam L, Ogomaka AI, Amaechi AA, Ezenwa CI, Ezike MN, Ikpeama C, Nwachukwu O, Eriama-Joseph AI, Nwoke BEB, Colebunders R. Low prevalence of epilepsy and onchocerciasis after more than 20 years of ivermectin treatment in the Imo River Basin in Nigeria. Infect Dis Poverty 2019; 8:8. [PMID: 30670093 PMCID: PMC6343278 DOI: 10.1186/s40249-019-0517-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/06/2019] [Indexed: 12/02/2022] Open
Abstract
Background High epilepsy prevalence and incidence have been reported in areas with high onchocerciasis transmission. Recent findings suggest that proper community-directed treatment with ivermectin (CDTI) is potentially able to prevent onchocerciasis-associated epilepsy (OAE). We assessed the epilepsy prevalence and onchocerciasis transmission in two Nigerian villages following more than 20 years of CDTI. Methods A cross-sectional door-to-door survey was performed in two villages in the Imo River Basin reported to be mesoendomic for onchocerciasis (Umuoparaodu and Umuezeala). Individuals were screened for epilepsy using a validated 5-item questionnaire. Persons suspected to have epilepsy were examined by a neurologist or a physician with training in epilepsy for confirmation. Onchocerciasis was investigated via skin snip microscopy and rapid diagnostic tests for Ov16 antibodies. Results were compared with previous findings from the Imo river basin. Results A total of 843 individuals from 257 households in the two villages were encountered. We detected four persons with epilepsy (PWE) giving a crude epilepsy prevalence of 0.5%. This finding differs from observations reported 14 years ago which showed an epilepsy prevalence of 2.8% in the neighbouring village of Umulolo (P = 0.0001), and 1.2% from 13 villages in the Imo river basin (P = 0.07). The seroprevalence of Ov16 antibodies was found to be 0%. Only 4.6% of skin snips were positive compared to 26.8% in previous surveys (P < 0.0001). Ivermectin mass distribution coverage in the study sites in 2017 was 79.7%. Conclusions A low epilepsy and onchocerciasis prevalence was observed following more than 20 years of CDTI in the Imo River Basin. Absence of Ov16 antibodies indicates minimal transmission of onchocerciasis. These results contrast with observations from areas of high onchocerciasis transmission, where epilepsy prevalence and incidence remain high. Findings from this study suggest that sustained efforts could eventually achieve elimination of onchocerciasis in these villages. Electronic supplementary material The online version of this article (10.1186/s40249-019-0517-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joseph N F Siewe
- Global Health Institute, University of Antwerp, Campus Drie Eiken, Doornstraat 331, 2610 Wilrijk, Antwerp, Belgium.
| | | | - Ernest O Nwazor
- Federal Medical Centre, Owerri, Nigeria.,Madonna University Teaching Hospital, Elele, Nigeria
| | | | | | | | | | - Joel Okeke
- Imo State Ministry of Health, Owerri, Nigeria
| | | | | | | | | | | | | | | | | | | | | | - Robert Colebunders
- Global Health Institute, University of Antwerp, Campus Drie Eiken, Doornstraat 331, 2610 Wilrijk, Antwerp, Belgium
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Siewe JFN, Ngarka L, Tatah G, Mengnjo MK, Nfor LN, Chokote ES, Boullé C, Nkouonlack C, Dema F, Nkoro GA, Njamnshi WY, Tabah EN, Zoung-Kanyi Bissek AC, Colebunders R, Njamnshi AK. Clinical presentations of onchocerciasis-associated epilepsy (OAE) in Cameroon. Epilepsy Behav 2019; 90:70-78. [PMID: 30513438 DOI: 10.1016/j.yebeh.2018.11.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/16/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND A high prevalence of epilepsy has been observed in several onchocerciasis-endemic countries, including Cameroon. However, little is known on the clinical presentations of the affected persons with epilepsy (PWE). A community-based study was conducted with the aim of describing the spectrum of seizures in selected onchocerciasis-endemic villages in Cameroon and documenting relevant medical history in patients with onchocerciasis-associated epilepsy (OAE). METHODS We carried out door-to-door surveys in 5 onchocerciasis-endemic villages in Cameroon and recruited all consenting PWE. Epilepsy was diagnosed using a 2-step approach consisting of the administration of a standardized 5-item questionnaire followed by confirmation of the suspected cases by a neurologist. Onchocerciasis-associated epilepsy was defined as ≥2 seizures without an obvious cause, starting between the ages of 3-18 years in previously healthy persons having resided for at least 3 years in an onchocerciasis-endemic area. Ivermectin use by PWE was verified. Seizure history, relevant past medical, and family history, as well as neurological findings, were noted. RESULTS In all, 156 PWE were recruited in the 5 villages. The modal age group for epilepsy onset was 10-14 years. The diagnostic criteria for OAE were met by 93.2% of the PWE. Participants had one or more of the following seizure types: generalized tonic-clonic seizures (89.1%), absences (38.5%), nodding (21.8%), focal nonmotor (7.7%), and focal motor seizures (1.9%). One case (0.6%) with the "Nakalanga syndrome" was identified. More than half (56.4%) of PWE had at least one seizure per month. In one village, 56.2% of PWE had onchocercal skin lesions. CONCLUSION People with epilepsy in onchocerciasis-endemic villages in Cameroon present with a wide clinical spectrum including nodding seizures and Nakalanga features. A great majority of participants met the diagnostic criteria for OAE, suggesting that better onchocerciasis control could prevent new cases. Epilepsy management algorithms in these areas must be adjusted to reflect the varied seizure types.
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Affiliation(s)
| | - Leonard Ngarka
- Neurology Department, Yaoundé Central Hospital, Cameroon; Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon
| | - Godwin Tatah
- Neurology Department, Yaoundé Central Hospital, Cameroon; Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon; Neurology Department, CH Saint Nazaire, France
| | - Michel K Mengnjo
- Neurology Department, Yaoundé Central Hospital, Cameroon; Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon
| | - Leonard N Nfor
- Neurology Department, Yaoundé Central Hospital, Cameroon; Neurology Department, CHU Brugmann, Belgium
| | - Eric S Chokote
- Neurology Department, Yaoundé Central Hospital, Cameroon; Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon
| | - Charlotte Boullé
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, France
| | | | | | - Grace A Nkoro
- Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon
| | - Wepnyu Y Njamnshi
- Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon; Faculty of Science and Medicine, University of Fribourg, Switzerland
| | | | | | | | - Alfred K Njamnshi
- Neurology Department, Yaoundé Central Hospital, Cameroon; Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Cameroon; Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon.
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Nodding syndrome research, lessons learned from the NSETHIO project. Glob Ment Health (Camb) 2019; 6:e26. [PMID: 31807310 PMCID: PMC6880249 DOI: 10.1017/gmh.2019.24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 09/04/2019] [Accepted: 09/19/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Until recently, nodding syndrome (NS) was considered as a mysterious disease of unknown etiology. A link between onchocerciasis and epilepsy was suspected for a long time. However, onchocerciasis was not considered as the cause of NS because NS was believed to occur only in onchocerciasis-endemic regions in Uganda, South Sudan, and Tanzania. In October 2015, with funding from the European Research Council, the NSETHIO group launched a trans-disciplinary, multi-country research project to identify the cause of NS and to study the link between onchocerciasis and epilepsy. METHODS We reviewed NSETHIO activities as well as all published papers, and compared project findings with results of previous research on NS. RESULTS Findings from the NSETHIO project showed that NS is only one of the clinical manifestations in the wide spectrum of onchocerciasis-associated epilepsy (OAE) that could be prevented by strengthening onchocerciasis elimination programs. NSETHIO demonstrated that OAE is an important neglected public health problem in onchocerciasis-endemic areas with no or a sub-optimally functioning onchocerciasis control strategies. CONCLUSIONS Today there is overwhelming evidence that NS together with the Nakalanga syndrome is clinical presentations of OAE, a condition that could be prevented by strengthening onchocerciasis elimination programs. While research needs to continue to elucidate the pathophysiological mechanisms causing NS, new strategies to accelerate onchocerciasis elimination coupled with community-based surveillance and treatment programs for epilepsy are urgently needed in areas of high Onchocerca volvulus transmission.
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Siewe Fodjo JN, Tatah G, Tabah EN, Ngarka L, Nfor LN, Chokote SE, Mengnjo MK, Dema F, Sitouok AT, Nkoro G, Ntone FE, Bissek ACZK, Chesnais CB, Boussinesq M, Colebunders R, Njamnshi AK. Epidemiology of onchocerciasis-associated epilepsy in the Mbam and Sanaga river valleys of Cameroon: impact of more than 13 years of ivermectin. Infect Dis Poverty 2018; 7:114. [PMID: 30501640 DOI: 10.1186/s40249-018-0497-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/18/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A high epilepsy prevalence has been reported in several onchocerciasis-endemic villages along the Mbam and Sanaga river valleys in Cameroon, including Bilomo and Kelleng. We sought to determine the prevalence of epilepsy in these two villages following more than 13 years of community-directed treatment with ivermectin (CDTI). METHODS Door-to-door surveys were performed on the entire resident population in the villages in August 2017 and January 2018. Epilepsy was diagnosed using a 2-step approach: administration of a standardized 5-item questionnaire followed by confirmation by a neurologist. Previously published diagnostic criteria for onchocerciasis-associated epilepsy (OAE) were used. Ov16 serology was done for children aged 7-10 years to assess onchocerciasis transmission. Findings were compared with previous data from these two villages. RESULTS A total of 1525 individuals (1321 in Bilomo and 204 in Kelleng) in 233 households were surveyed in both villages. The crude prevalence of epilepsy was 4.6% in Bilomo (2017) and 7.8% in Kelleng (2018), including 12 (15.6% of cases) persons with epilepsy (PWE) with nodding seizures. The age and sex-standardized prevalence in Kelleng decreased from 13.5% in 2004 to 9.3% in 2018 (P < 0.001). The median age of PWE shifted from 17 (IQR: 12-22) years to 24 (IQR: 20-30) years in Bilomo (P < 0.001); and slightly from 24 (IQR: 14-34) years to 28 (IQR: 21.25-36.75) years in Kelleng (P = 0.112). Furthermore, 47.6% of all tested children between 7 and 10 years had Ov16 antibodies. CONCLUSIONS There is a decrease in epilepsy prevalence after 13 years and more of CDTI in both villages. The age-shift observed in PWE suggests that ivermectin may prevent OAE in younger residents. Ov16 seropositivity in children indicates ongoing onchocerciasis transmission possibly due to suboptimal control measures. Our findings support the existence of OAE in Cameroon and highlight the need to strengthen onchocerciasis elimination programs.
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Affiliation(s)
| | - Godwin Tatah
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neurology Department, CH Saint-Nazaire, Saint-Nazaire, France.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Earnest Njih Tabah
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Ministry of Public Health, Yaoundé, Cameroon
| | - Leonard Ngarka
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Leonard Njamnshi Nfor
- Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon.,Neurology Department, CHU Brugman, Brussels, Belgium
| | - Samuel Eric Chokote
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Michel K Mengnjo
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Fidèle Dema
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Yoko District Hospital, Yaoundé, Cameroon
| | - Aurélien Tele Sitouok
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Grace Nkoro
- Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Félicien E Ntone
- Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon
| | - Anne-Cécile Zoung-Kanyi Bissek
- Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon.,Ministry of Public Health, Yaoundé, Cameroon
| | - Cédric B Chesnais
- UMI 233, Institut de Recherche pour le Développement (IRD), Montpellier, France.,Université Montpellier, Montpellier, France.,INSERM Unité 1175, Montpellier, France
| | - Michel Boussinesq
- UMI 233, Institut de Recherche pour le Développement (IRD), Montpellier, France.,Université Montpellier, Montpellier, France.,INSERM Unité 1175, Montpellier, France
| | | | - Alfred K Njamnshi
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon.,Neuroscience Laboratory, FMBS, The University of Yaoundé I, Yaoundé, Cameroon.,Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
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Baseline characterization of epilepsy in an onchocerciasis endemic area of the Democratic Republic of Congo. Brain Res Bull 2018; 145:45-52. [PMID: 30468846 DOI: 10.1016/j.brainresbull.2018.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 11/03/2018] [Accepted: 11/13/2018] [Indexed: 11/22/2022]
Abstract
Increased epilepsy prevalence is reported in onchocerciasis (OC) endemic areas and is associated with the occurrence of distinct syndromes such as nodding disease and Nakalanga syndrome. To date, a causal relationship between OC and epilepsy is still a matter of controversy. We conducted a case-control study of participants with epilepsy and age- and gender-matched presumably healthy controls to elucidate the relationships between OC and epilepsy and explore the role of inflammation and growth factors in an OC endemic area in the Democratic Republic of Congo (DRC). Eighty-two participants with epilepsy (mean age ± SD: 23.2 ± 8.7 years) and 27 controls (mean age ± SD: 22.3 ± 12.0 years) underwent snip skin biopsies to determine Onchocerca volvulus infection status. Serum concentrations of cytokines, chemokines, and growth factors were measured using a Luminex Multiplex Assay kit. Children <19 years of age underwent neurocognitive assessments using the Kaufman Assessment Battery for Children, 2nd edition (KABC-II). Overall, epilepsy was associated with OC (OR = 4.51, z = 3.11, p = 0.0019), and children with OC were more likely to be severely stunted (OR = 11.67, z = 2.62, p = 0.0087). The relationship between epilepsy and OC was no longer significant (z = 1.27, p = 0.20) when stunting was included as a correcting covariate. Epilepsy was associated with poor KABC-II test scores, high serum levels of IL-17, and low levels of IL-1RA, IL-8, and EGF. KABC-II testing scores correlated with serum levels of IL-10, MCP-1 and HGF. Familial history of epilepsy occurred frequently. Future studies should consider cytokines and/or growth factors when assessing susceptibility to epilepsy in OC endemic areas. Additional investigations, preferentially in low-prevalence OC areas, may provide further insights into the concept, risk, and burden of river epilepsy.
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Colebunders R, Abd-Elfarag G, Carter JY, Olore PC, Puok K, Menon S, Fodjo Siewe JN, Bhattacharyya S, Ojok M, Lako R, Logora MY. Clinical characteristics of onchocerciasis-associated epilepsy in villages in Maridi County, Republic of South Sudan. Seizure 2018; 62:108-115. [PMID: 30340162 DOI: 10.1016/j.seizure.2018.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 09/30/2018] [Accepted: 10/04/2018] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To describe the clinical manifestations of persons with epilepsy (PWE) in onchocerciasis endemic villages in South Sudan. METHODS During a survey in Maridi County in May 2018, PWE were interviewed and examined in their households by a clinical officer or medical doctor. Onchocerciasis-associated epilepsy (OAE) was defined as ≥2 seizures without any obvious cause, starting between the ages of 3-18 years in previously healthy persons who had resided for at least 3 years in the onchocerciasis endemic area. RESULTS Seven hundred and thirty-six PWE were included in the study; 315 (42.8%) were females; median age was 18 years. A variety of seizure types were reported: generalized tonic-clonic seizures in 511 PWE (69.4%), absences in 15 (2.0%), focal motor seizures with full awareness in 7 (1.0%), focal motor seizures with impaired awareness in 25 (3.4%), brief episodes of hallucinations in 316 (43.9%) and nodding seizures in 335 (45.5%). The median age of onset of all seizures was 10 years, and 8 years for nodding seizures. PWE with nodding seizures presented with more cognitive disabilities. The diagnostic criteria for OAE were met by 414 (85.2%) of the 486 PWE with complete information. Eighty (11.0%) PWE presented with Nakalanga features. Only 378 (51.4%) PWE were taking anti-epileptic treatment. CONCLUSION PWE presented with a wide spectrum of seizures. The high percentage of PWE who met the diagnostic criteria for OAE suggests that better onchocerciasis control could prevent new cases. Urgent action is needed to close the anti-epileptic treatment gap.
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Affiliation(s)
| | - Gasim Abd-Elfarag
- Department of Global Health, Academic Medical Center, University of Amsterdam, the Netherlands; Amsterdam Institute for Global Health and Development, Amsterdam, the Netherlands.
| | | | | | - Kai Puok
- Maridi Health Sciences Institute, Maridi, Sudan.
| | - Sonia Menon
- Global Health Institute, University of Antwerp, Belgium.
| | | | - Samit Bhattacharyya
- Department of Mathematics, School of Natural Sciences, Shiv Nadar University, Dadri, Uttar Pradesh, India.
| | | | - Richard Lako
- Policy, Planning, Budgeting and Research, Ministry of Health, Juba, Sudan.
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Romo ML, Nash D. Onchocerciasis and epilepsy: a causal relationship? THE LANCET. INFECTIOUS DISEASES 2018; 18:1172-1174. [PMID: 30268644 DOI: 10.1016/s1473-3099(18)30488-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
Affiliation(s)
- Matthew L Romo
- CUNY Institute for Implementation Science in Population Health & Department of Epidemiology and Biostatistics, CUNY Graduate School of Public Health and Health Policy, City University of New York, New York, NY 10027, USA.
| | - Denis Nash
- CUNY Institute for Implementation Science in Population Health & Department of Epidemiology and Biostatistics, CUNY Graduate School of Public Health and Health Policy, City University of New York, New York, NY 10027, USA
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Chesnais CB, Nana-Djeunga HC, Njamnshi AK, Lenou-Nanga CG, Boullé C, Bissek ACZK, Kamgno J, Colebunders R, Boussinesq M. The temporal relationship between onchocerciasis and epilepsy: a population-based cohort study. THE LANCET. INFECTIOUS DISEASES 2018; 18:1278-1286. [PMID: 30268645 DOI: 10.1016/s1473-3099(18)30425-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/13/2018] [Accepted: 07/04/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND Many studies have suggested that onchocerciasis might be associated with epilepsy. Therefore, we did a cohort study to assess the incidence of epilepsy relative to Onchocerca volvulus skin microfilarial density (MFD) measured during childhood and to assess the possibility of a temporal relationship. METHODS During onchocerciasis surveys undertaken in 25 villages in Cameroon during 1991-93, we measured MFD in individuals aged 5 years or older. In 2017, we revisited seven of these villages. With a standardised five-item questionnaire, we collected information on the occurrence of epilepsy in 856 individuals who were aged 5-10 years in 1991-93, and had MFD determined during the original surveys. We did multivariable analyses to assess the overall incidence and incidence ratios taking into account age, sex, individual MFD in 1991-93, and onchocerciasis endemicity level in the village. FINDINGS In 2017, we obtained data on the history of epilepsy for 85% (729 of 856) of individuals. Among these individuals, we classified 60 as being suspected cases of epilepsy. The overall incidence of epilepsy was 350 per 100 000 person-years (95% CI 270-450). The adjusted incidence ratio for developing epilepsy was 7·07 (95% CI 0·98-51·26; p=0·0530) in individuals with initial MFD of one to five microfilariae per skin snip (mf per snip), 11·26 (2·73-46·43) in individuals with six to 20 mf per snip, 12·90 (4·40-37·83) in individuals with 21-50 mf per snip, 20·00 (3·71-108·00) in individuals with 51-100 mf per snip, 22·58 (3·21-158·56) in individuals with 101-200 mf per snip, and 28·50 (95% CI 3·84-211·27; p=0·0010) in individuals with more than 200 mf per snip, compared with that of individuals without detectable densities of skin microfilariae. INTERPRETATION Individual O volvulus MFD in childhood was associated with the risk of either seizures or epilepsy in an onchocerciasis focus in Cameroon. This temporal relationship suggests a potential causal link between onchocerciasis and epilepsy. FUNDING European Research Council, NSETHIO Project.
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Affiliation(s)
- Cédric B Chesnais
- UMI 233, Institut de Recherche pour le Développement, Montpellier, France; Université Montpellier, Montpellier, France; INSERM Unité 1175, Montpellier, France
| | | | - Alfred K Njamnshi
- Neurology Department, University of Yaoundé I, Yaounde, Cameroon; Brain Research Africa Initiative, Yaounde, Cameroon
| | - Cédric G Lenou-Nanga
- Centre for Research on Filariasis and other Tropical Diseases, Yaounde, Cameroon
| | - Charlotte Boullé
- UMI 233, Institut de Recherche pour le Développement, Montpellier, France; Université Montpellier, Montpellier, France; INSERM Unité 1175, Montpellier, France; Centre Hospitalier Universitaire Nîmes, Nîmes, France
| | - Anne-Cécile Zoung-Kanyi Bissek
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaounde, Cameroon; Division of Health Operations Research, Ministry of Public Health, Yaoundé, Cameroon
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases, Yaounde, Cameroon; Public Health Department, University of Yaoundé I, Yaounde, Cameroon
| | | | - Michel Boussinesq
- UMI 233, Institut de Recherche pour le Développement, Montpellier, France; Université Montpellier, Montpellier, France; INSERM Unité 1175, Montpellier, France.
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48
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Vinkeles Melchers NVS, Mollenkopf S, Colebunders R, Edlinger M, Coffeng LE, Irani J, Zola T, Siewe JN, de Vlas SJ, Winkler AS, Stolk WA. Burden of onchocerciasis-associated epilepsy: first estimates and research priorities. Infect Dis Poverty 2018; 7:101. [PMID: 30253788 PMCID: PMC6156959 DOI: 10.1186/s40249-018-0481-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/30/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Since the 1990s, evidence has accumulated of an increased prevalence of epilepsy in onchocerciasis-endemic areas in Africa as compared to onchocerciasis-free areas. Although the causal relationship between onchocerciasis and epilepsy has yet to be proven, there is likely an association. Here we discuss the need for disease burden estimates of onchocerciasis-associated epilepsy (OAE), provide them, detail how such estimates should be refined, and discuss the socioeconomic impact of OAE, including a cost-estimate for anti-epileptic drugs. MAIN BODY Providing OAE burden estimates may aid prevention of epilepsy in onchocerciasis- endemic areas by inciting and informing collaboration between onchocerciasis control programmes and mental health services. Epilepsy not only massively impacts the health of those affected, but it also carries a high socioeconomic burden for the households and communities involved. We used previously published geospatial estimates of onchocerciasis in Africa and a separately published logistic regression model quantifying the association between onchocerciasis and epilepsy to estimate the number of OAE cases. We then applied disability weights for epilepsy to quantify the burden in terms of years of life lived with disability (YLD) and estimate the cost of treatment. We estimate that in 2015 roughly 117 000 people were affected by OAE across onchocerciasis-endemic areas previously under the African Programme for Onchocerciases control (APOC) mandate where OAE has ever been reported or suspected, and another 264 000 persons in onchocerciasis-endemic areas where OAE has never been investigated before. The total number of YLDs due to OAE was 39 300 and 88 700 in these areas respectively, based on a weighted mean disability weight of 0.336. The burden of OAE is approximately 13% of the total YLDs attributable to onchocerciasis and 10% of total YLDs attributable to epilepsy. We estimated that by 2015 the total costs of treatment with anti-epileptic drug for OAE cases would have been a minimum of 12.4 million US$. CONCLUSIONS These estimates suggest a considerable health, social and economic burden of OAE in Africa. The treatment and care for people with epilepsy, especially in hyperendemic onchocerciasis areas with high epilepsy prevalence thus requires more financial and human resources.
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Affiliation(s)
- Natalie V S Vinkeles Melchers
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. box 2040, 3000, CA, Rotterdam, The Netherlands.
| | - Sarah Mollenkopf
- Institute for Health Metrics and Evaluation, University of Washington, 2301 5th Avenue, Suite 600, Seattle, WA, 98121, USA
| | | | - Michael Edlinger
- Department of Medical Statistics, Informatics, and Health Economics, Medical University Innsbruck, Vienna, Austria
| | - Luc E Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. box 2040, 3000, CA, Rotterdam, The Netherlands
| | - Julia Irani
- Department of Public Health, Institute of Tropical Medicine Antwerp, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Trésor Zola
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Joseph N Siewe
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. box 2040, 3000, CA, Rotterdam, The Netherlands
| | - Andrea S Winkler
- Centre for Global Health, Institute for Health and Society, Oslo, Norway.,Center for Global Health, Department of Neurology, Technical University of Munich, Munich, Germany
| | - Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. box 2040, 3000, CA, Rotterdam, The Netherlands
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49
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Mmbando BP, Suykerbuyk P, Mnacho M, Kakorozya A, Matuja W, Hendy A, Greter H, Makunde WH, Colebunders R. High prevalence of epilepsy in two rural onchocerciasis endemic villages in the Mahenge area, Tanzania, after 20 years of community directed treatment with ivermectin. Infect Dis Poverty 2018; 7:64. [PMID: 29921319 PMCID: PMC6009039 DOI: 10.1186/s40249-018-0450-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/07/2018] [Indexed: 11/10/2022] Open
Abstract
Background Epilepsy is a neurological disorder with a multitude of underlying causes, which may include infection with Onchocerca volvulus, the parasitic worm that causes human onchocerciasis. A survey carried out in 1989 revealed a high prevalence of epilepsy (1.02% overall, ranging from 0.51 to 3.71% in ten villages) in the Mahenge area of Ulanga district, an onchocerciasis endemic region in south eastern Tanzania. This study aimed to determine the prevalence and incidence of epilepsy following 20 years of onchocerciasis control through annual community directed treatment with ivermectin (CDTI). Methods The study was conducted in January 2017 in two suburban and two rural villages in the Mahenge area. Door-to-door household visits were carried out by trained community health workers and data assistants to screen for persons suspected of having epilepsy, using a standardised questionnaire. Persons with suspected epilepsy were then interviewed and examined by a neurologist for case verification. Onchocerciasis associated epilepsy was defined as epilepsy without an obvious cause, with an onset of seizures between the ages of 3–18 years in previously healthy children. In each village, fifty males aged ≥20 years were tested for onchocerciasis antibodies using an OV16 rapid test and were examined for presence of onchocerciasis nodules. Children aged 6–10 years were also tested using OV16 tests. Results 5117 individuals (median age 18.5 years, 53.2% female) from 1168 households were screened. 244 (4.8%) were suspected of having epilepsy and invited for neurological assessment. Prevalence of epilepsy was 2.5%, with the rural villages having the highest rate (3.5% vs 1.5%), P < 0.001. Overall incidence of epilepsy was 111 cases (95% CI: 73–161) per 100 000 person-years, while that of onchocerciasis associated epilepsy was 131 (95% CI: 70–223). Prevalence of OV16 antibodies in adult males and among children 6–10 years old was higher in rural villages than in suburban villages (76.5% vs 50.6, and 42.6% vs 4.7% respectively), (P < 0.001), while overall prevalence of onchocerciasis nodules was 1.8%. Conclusions This survey revealed a high prevalence and incidence of epilepsy in two rural onchocerciasis endemic villages in the Mahenge area. Despite 20 years of CDTI, a high prevalence of OV16 antibodies in children aged 6–10 years suggests on-going O. volvulus transmission. Reasons for the persistence of on-going parasite transmission in the Mahenge area need to be investigated. Electronic supplementary material The online version of this article (10.1186/s40249-018-0450-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bruno P Mmbando
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania.
| | | | | | | | - William Matuja
- Muhimbili University of Health and allied Sciences, Dar es Salaam, Tanzania
| | - Adam Hendy
- University of Texas Medical Branch, Galveston, TX, USA
| | - Helena Greter
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Williams H Makunde
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
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50
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Mwaka AD, Semakula JR, Abbo C, Idro R. Nodding syndrome: recent insights into etiology, pathophysiology, and treatment. Res Rep Trop Med 2018; 9:89-93. [PMID: 30050359 PMCID: PMC6049047 DOI: 10.2147/rrtm.s145209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nodding syndrome is an enigmatic neuropsychiatric and epileptiform disorder associated with psychomotor, mental, and physical growth retardation. The disorder affects otherwise previously normal children aged 3-18 years, with a slight preponderance for the male child. Nodding syndrome has been described in rural regions of some low-income countries in sub-Saharan Africa including northern Uganda, South Sudan, and a mountainous region of southern Tanzania. The cause of the disorder has hitherto eluded scientists. Neuroimaging studies show involvement of the nervous system with associated severe cortical atrophy in the affected children. The affected communities have generated a number of perceived causes including some conspiracy theories related to intentional poisoning of water sources and foods, and causes related to fumes and chemicals from ammunitions used during civil wars in the affected regions. From biomedical perspectives, the treatment of the affected children is geared towards symptoms control and rehabilitation. There is evidence that seizures and behavioral problems including wandering and episodes of aggressions are controllable with anticonvulsants, especially sodium valproate and antipsychotics. No treatments have proven effective in reversing the course of the disorder, and cure remains a distant goal. Community members have used indigenous medicines, cleansing rituals, and prayer interventions, but have not perceived any reasonable improvements. A randomized controlled clinical trial is ongoing in northern Uganda to test the efficacy and effectiveness of doxycycline in the treatment of nodding syndrome. The hypothesis underlying the doxycycline trial underscores the role of antigenic mimicry: that antibodies generated against an antigen of a microorganism that resides inside the black fly-transmitted parasite, Onchocerca volvulus becomes directed against nervous tissue in the brain. This paper reviews some of the recent advances in researches on the etiologies, pathophysiology, and treatment of nodding syndrome.
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Affiliation(s)
- Amos Deogratius Mwaka
- Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda,
| | - Jerome Roy Semakula
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda
| | - Catherine Abbo
- Department of Psychiatry, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Richard Idro
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
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