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Van Cutsem G, Siewe Fodjo JN, Hadermann A, Amaral LJ, Trevisan C, Pion S, Colebunders R. Onchocerciasis-associated epilepsy: Charting a path forward. Seizure 2024:S1059-1311(24)00123-7. [PMID: 38677953 DOI: 10.1016/j.seizure.2024.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024] Open
Abstract
This narrative review intends to inform neurologists and public health professionals about Onchocerciasis-Associated Epilepsy (OAE), a neglected public health problem in many remote onchocerciasis-endemic areas. For epidemiological purposes, we define OAE as sudden-onset of convulsive and non-convulsive seizure types, including head nodding seizures (nodding syndrome) in a previously healthy child aged 3 to 18 years in the absence of any other obvious cause for epilepsy, all happening within an area with high ongoing Onchocerca volvulus transmission. Several OAE pathophysiological mechanisms have been proposed, but none has been proven yet. Recent population-based studies showed that strengthening onchocerciasis elimination programs was followed by a significant reduction in the incidence of OAE and nodding syndrome. Treating epilepsy in onchocerciasis-endemic regions is challenging. More advocacy is needed to provide uninterrupted, free access to anti-seizure medication to persons with epilepsy in these remote, impoverished areas. It is crucial todevelop policies and increase funding for the prevention and treatment of OAE to reduce the associated burden of disease, notably via the establishment of morbidity management and disability prevention programs (MMDP). Moreover, effective collaboration between onchocerciasis elimination and mental health programs is imperative to alleviate the burden of OAE. This synergy promises reciprocal advantages and underscores the need for a comprehensive approach to address this multifaceted challenge.
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Affiliation(s)
- G Van Cutsem
- Department of Neurology, Centre Hospitalier de Luxembourg, Luxembourg; Faculty of Science, Technology and Medicine, University of Luxembourg, Luxembourg; Centre for Infectious Disease Epidemiology and Research, University of Cape Town, South Africa
| | - J N Siewe Fodjo
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - A Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - L-J Amaral
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - C Trevisan
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - S Pion
- Institute of Research for Sustainable Development, Montpelier, France
| | - R Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Belgium.
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Metanmo S, Winkler AS. Response to "Nodding Syndrome Associated with Onchocerciasis". Neuroepidemiology 2024:1-4. [PMID: 38631300 DOI: 10.1159/000538697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024] Open
Affiliation(s)
- Salvatore Metanmo
- Inserm U1094, IRD U270, University of Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, Omega Health, Limoges, France
| | - Andrea Sylvia Winkler
- Department of Neurology, Center for Global Health, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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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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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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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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6
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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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7
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Hadermann A, Amaral LJ, Van Cutsem G, Siewe Fodjo JN, Colebunders R. Onchocerciasis-associated epilepsy: an update and future perspectives. Trends Parasitol 2023; 39:126-138. [PMID: 36528471 DOI: 10.1016/j.pt.2022.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
Abstract
Onchocerciasis-associated epilepsy (OAE) is an important neglected public health problem in areas with high ongoing onchocerciasis transmission. The risk that children in such areas develop epilepsy is related to their Onchocerca volvulus microfilarial (mf) load. Before the implementation of mass treatment with ivermectin, microfilariae were detected in cerebrospinal fluid (CSF). More recently, neither O. volvulus microfilariae nor DNA were detected in CSF or brain tissue; however, these samples were obtained years after seizure onset. It is possible that during fever-induced increased blood-brain barrier permeability, microfilariae enter the brain and, upon dying, cause an inflammatory reaction inducing seizures. Including OAE in the onchocerciasis disease burden estimation may mobilise extra resources for onchocerciasis disease elimination and treatment/care of OAE-affected persons/families.
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Affiliation(s)
- Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, Belgium
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8
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Wu Y, Duffey M, Alex SE, Suarez-Reyes C, Clark EH, Weatherhead JE. The role of helminths in the development of non-communicable diseases. Front Immunol 2022; 13:941977. [PMID: 36119098 PMCID: PMC9473640 DOI: 10.3389/fimmu.2022.941977] [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: 05/12/2022] [Accepted: 08/01/2022] [Indexed: 12/15/2022] Open
Abstract
Non-communicable diseases (NCDs) like cardiovascular disease, chronic respiratory diseases, cancers, diabetes, and neuropsychiatric diseases cause significant global morbidity and mortality which disproportionately affect those living in low resource regions including low- and middle-income countries (LMICs). In order to reduce NCD morbidity and mortality in LMIC it is imperative to understand risk factors associated with the development of NCDs. Certain infections are known risk factors for many NCDs. Several parasitic helminth infections, which occur most commonly in LMICs, have been identified as potential drivers of NCDs in parasite-endemic regions. Though understudied, the impact of helminth infections on the development of NCDs is likely related to helminth-specific factors, including species, developmental stage and disease burden. Mechanical and chemical damage induced by the helminth in combination with pathologic host immune responses contribute to the long-term inflammation that increases risk for NCD development. Robust studies from animal models and human clinical trials are needed to understand the immunologic mechanisms of helminth-induced NCDs. Understanding the complex connection between helminths and NCDs will aid in targeted public health programs to reduce helminth-induced NCDs and reduce the high rates of morbidity that affects millions of people living in parasite-endemic, LMICs globally.
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Affiliation(s)
- Yifan Wu
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Megan Duffey
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States
| | - Saira Elizabeth Alex
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Charlie Suarez-Reyes
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Eva H. Clark
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States,National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Jill E. Weatherhead
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States,National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,*Correspondence: Jill E. Weatherhead,
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9
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Ndondo AP, Eley B, Wilmshurst JM, Kakooza-Mwesige A, Giannoccaro MP, Willison HJ, Cruz PMR, Heckmann JM, Bateman K, Vincent A. Post-Infectious Autoimmunity in the Central (CNS) and Peripheral (PNS) Nervous Systems: An African Perspective. Front Immunol 2022; 13:833548. [PMID: 35356001 PMCID: PMC8959857 DOI: 10.3389/fimmu.2022.833548] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
The direct impact and sequelae of infections in children and adults result in significant morbidity and mortality especially when they involve the central (CNS) or peripheral nervous system (PNS). The historical understanding of the pathophysiology has been mostly focused on the direct impact of the various pathogens through neural tissue invasion. However, with the better understanding of neuroimmunology, there is a rapidly growing realization of the contribution of the innate and adaptive host immune responses in the pathogenesis of many CNS and PNS diseases. The balance between the protective and pathologic sequelae of immunity is fragile and can easily be tipped towards harm for the host. The matter of immune privilege and surveillance of the CNS/PNS compartments and the role of the blood-brain barrier (BBB) and blood nerve barrier (BNB) makes this even more complex. Our understanding of the pathogenesis of many post-infectious manifestations of various microbial agents remains elusive, especially in the diverse African setting. Our exploration and better understanding of the neuroimmunology of some of the infectious diseases that we encounter in the continent will go a long way into helping us to improve their management and therefore lessen the burden. Africa is diverse and uniquely poised because of the mix of the classic, well described, autoimmune disease entities and the specifically "tropical" conditions. This review explores the current understanding of some of the para- and post-infectious autoimmune manifestations of CNS and PNS diseases in the African context. We highlight the clinical presentations, diagnosis and treatment of these neurological disorders and underscore the knowledge gaps and perspectives for future research using disease models of conditions that we see in the continent, some of which are not uniquely African and, where relevant, include discussion of the proposed mechanisms underlying pathogen-induced autoimmunity. This review covers the following conditions as models and highlight those in which a relationship with COVID-19 infection has been reported: a) Acute Necrotizing Encephalopathy; b) Measles-associated encephalopathies; c) Human Immunodeficiency Virus (HIV) neuroimmune disorders, and particularly the difficulties associated with classical post-infectious autoimmune disorders such as the Guillain-Barré syndrome in the context of HIV and other infections. Finally, we describe NMDA-R encephalitis, which can be post-HSV encephalitis, summarise other antibody-mediated CNS diseases and describe myasthenia gravis as the classic antibody-mediated disease but with special features in Africa.
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Affiliation(s)
- Alvin Pumelele Ndondo
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | - Brian Eley
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa.,Paediatric Infectious Diseases Unit, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - Jo Madeleine Wilmshurst
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa.,Department of Paediatric Neurology, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Angelina Kakooza-Mwesige
- Department of Pediatrics and Child Health, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Maria Pia Giannoccaro
- Laboratory of Neuromuscular Pathology and Neuroimmunology, Istituto di Ricovero e Cura a CarattereScientifico (IRCCS) Instiuto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Hugh J Willison
- Institute of Infection, Immunity and Inflammation (3I), University of Glasgow, Glasgow, United Kingdom
| | - Pedro M Rodríguez Cruz
- Centro Nacional de Analisis Genomico - Centre for Genomic Regulation (CNAG-CRG ), Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Department of Neuromuscular Disease, University College London (UCL) Queen Square Institute of Neurology, London, United Kingdom.,Faculté de Médecine, de Pharmacie et d'Odontologie, Université Cheikh Anta Diop, Dakar, Senegal
| | - Jeannine M Heckmann
- Neurology Division, Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa.,The University of Cape Town (UCT) Neurosciences Institute, University of Cape Town, Cape Town, South Africa
| | - Kathleen Bateman
- Neurology Division, Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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10
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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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Vieri MK, Hotterbeekx A, Raimon S, Abd-Elfarag G, Mukendi D, Carter JY, Kumar-Singh S, Colebunders R. Cytokines and Onchocerciasis-Associated Epilepsy, a Pilot Study and Review of the Literature. Pathogens 2021; 10:310. [PMID: 33799934 PMCID: PMC7998365 DOI: 10.3390/pathogens10030310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 12/03/2022] Open
Abstract
Neuro-inflammation may be associated with onchocerciasis-associated epilepsy (OAE) but thus far very few immunological studies have been performed in children with this form of epilepsy. In a pilot study we measured the cytokine levels in cerebrospinal fluid (CSF) of persons with OAE from Maridi, South Sudan, and from Mosango, Democratic Republic of the Congo (DRC) and compared these results with cytokine levels in CSF of Africans with non-OAE neurological disorders, and Europeans with epilepsy or other neurological conditions. The following cytokines were studied: IL-6, TNF-α, IL1-β, IL-5, IL-4, IL-13, CCL3 (Mip-1α), VEGF-C, VCAM-1. No cytokine was significantly associated with OAE, although a lower IL-13 level was observed in CSF of persons with OAE compared to African controls. Observed cytokine profiles and neuro-inflammation may be the consequence of long-standing epilepsy, concomitant infections and malnutrition. Ideally cytokine levels should be determined in a prospective study in serum and CSF collected at the time of onset of the first seizures.
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Affiliation(s)
| | - An Hotterbeekx
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium;
- Molecular Pathology Group, Laboratory of Cell Biology & Histology, Faculty of Medical and Health Sciences, University of Antwerp, 20610 Antwerp, Belgium;
| | | | - Gasim Abd-Elfarag
- Academic Medical Center, Global Child Health Group, Department of Paediatrics and Department of Global Health, University of Amsterdam, 1105 Amsterdam, The Netherlands;
- Amsterdam Institute for Global Health and Development, 1105 Amsterdam, The Netherlands
| | - Deby Mukendi
- Institut National de Recherche Biomédicale, Av. De la Démocratie N°5345, Kinshasa 1197, Congo;
- Centre Neuro-Psycho Pathologique, Universite’ de Kinshasa, Kinshasa P.O. Box 127, Congo
| | - Jane Y. Carter
- Amref International Headquarters, Nairobi P.O. Box 27691−00506, Kenya;
| | - Samir Kumar-Singh
- Molecular Pathology Group, Laboratory of Cell Biology & Histology, Faculty of Medical and Health Sciences, University of Antwerp, 20610 Antwerp, Belgium;
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Luna J, Metanmo S, Boumediene F, Mbelesso P, Auditeau E, Ajzenberg D, Preux PM. Onchocerciasis in tropical neurology: A scoping review. J Neurol Sci 2021; 421:117314. [PMID: 33493958 DOI: 10.1016/j.jns.2021.117314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Onchocerciasis is a serious problem in tropical areas. The role of the parasite as a factor associated with neurological diseases needs to be addressed because it might involve a reduction of the risk via elimination strategies. We performed a systematic scoping review to identify available studies on this association and put into perspective the different methodological approaches for interpreting the evidence. METHODOLOGY A literature search was conducted using MEDLINE (Pubmed) through October 1, 2020. We included all the studies evaluating the association between onchocerciasis and four neurological diseases (epilepsy, nodding syndrome, Nakalanga syndrome, and encephalitis) in tropical countries. A descriptive and critical summary of the results was conducted to provide an overview of the findings. RESULTS Overall, 161 articles were identified in the literature search. After full-length examination, we included twelve articles for epilepsy and three for nodding syndrome. Two meta-analyses of case-control studies found a modest strength of the association between O. volvulus and epilepsy. Recent meta-analyses and original studies support a significant association. Epidemiological studies suggest an association between onchocerciasis and nodding syndrome, however, the level of evidence from case-control studies was relatively low. No measure of association was reported for Nakalanga syndrome. There was no specific study on the association between O. volvulus and encephalitis. CONCLUSION The association between onchocerciasis and epilepsy seems increasingly likely. However, there are still many unanswered questions about the different clinical presentations of this epilepsy. Strong international collaboration is essential to improve our understanding of risk factors and physiopathological mechanisms of these intriguing conditions.
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Affiliation(s)
- Jaime Luna
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Salvatore Metanmo
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Farid Boumediene
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Pascal Mbelesso
- Department of Neurology, Amitié Hospital, Bangui, Central African Republic
| | - Emilie Auditeau
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Daniel Ajzenberg
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France
| | - Pierre-Marie Preux
- INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France.
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Colebunders R, Njamnshi AK, Menon S, Newton CR, Hotterbeekx A, Preux PM, Hopkins A, Vaillant M, Siewe Fodjo JN. Onchocerca volvulus and epilepsy: A comprehensive review using the Bradford Hill criteria for causation. PLoS Negl Trop Dis 2021; 15:e0008965. [PMID: 33411705 PMCID: PMC7790236 DOI: 10.1371/journal.pntd.0008965] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The possibility that onchocerciasis may cause epilepsy has been suggested for a long time, but thus far, an etiological link has not been universally accepted. The objective of this review is to critically appraise the relationship between Onchocerca volvulus and epilepsy and subsequently apply the Bradford Hill criteria to further evaluate the likelihood of a causal association. METHODS PubMed and gray literature published until September 15, 2020, were searched and findings from original research were synthesized. Adherence to the 9 Bradford Hill criteria in the context of onchocerciasis and epilepsy was determined to assess whether the criteria are met to strengthen the evidence base for a causal link between infection with O. volvulus and epilepsy, including the nodding syndrome. RESULTS Onchocerciasis as a risk factor for epilepsy meets the following Bradford Hill criteria for causality: strength of the association, consistency, temporality, and biological gradient. There is weaker evidence supporting causality based on the specificity, plausibility, coherence, and analogy criteria. There is little experimental evidence. Considering the Bradford Hill criteria, available data suggest that under certain conditions (high microfilarial load, timing of infection, and perhaps genetic predisposition), onchocerciasis is likely to cause epilepsy including nodding and Nakalanga syndromes. CONCLUSION Applying the Bradford Hill criteria suggests consistent epidemiological evidence that O. volvulus infection is a trigger of epilepsy. However, the pathophysiological mechanisms responsible for seizure induction still need to be elucidated.
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Affiliation(s)
- Robert Colebunders
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- * E-mail:
| | - Alfred K. Njamnshi
- Neurology Department, Yaoundé Central Hospital, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé Cameroon
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
| | - Sonia Menon
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Charles R. Newton
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - An Hotterbeekx
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Pierre-Marie Preux
- Institute of Epidemiology and Tropical Neurology, INSERM UMR1094, University of Limoges, Limoges, France
| | - Adrian Hopkins
- Neglected and Disabling Diseases of Poverty Consultant, Kent, United Kingdom
| | - Michel Vaillant
- Competence Center in Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
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Putative Autoantigen Leiomodin-1 Is Expressed in the Human Brain and in the Membrane Fraction of Newly Formed Neurons. Pathogens 2020; 9:pathogens9121036. [PMID: 33321732 PMCID: PMC7763904 DOI: 10.3390/pathogens9121036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/21/2022] Open
Abstract
Nodding syndrome is a pediatric epilepsy disorder associated with Onchocerca volvulus infection, but the mechanism driving this relationship is unclear. One hypothesis proposes that parasite-induced immune responses cross-react with human leiomodin-1 resulting in immune-mediated central nervous system (CNS) damage. However, as leiomodin-1 expression and epitope availability in human neurons remains uncharacterized, the relevance of leiomodin-1 autoimmunity is unknown. Leiomodin-1 transcript expression was assessed in silico using publicly available ribonucleic acid (RNA) sequencing databases and in tissue by in situ hybridization and quantitative polymerase chain reaction. Abundance and subcellular localization were examined by cell fractionation and immunoblotting. Leiomodin-1 transcripts were expressed in cells of the CNS, including neurons and astrocytes. Protein was detectable from all brain regions examined as well as from representative cell lines and in vitro differentiated neurons and astrocytes. Leiomodin-1 was expressed on the membrane of newly formed neurons, but not neural progenitor cells or mature neurons. Importantly, leiomodin-1 antibodies were only toxic to cells expressing leiomodin-1 on the membrane. Our findings provide evidence that leiomodin-1 is expressed in human neurons and glia. Furthermore, we show membrane expression mediates leiomodin-1 antibody toxicity, suggesting these antibodies may play a role in pathogenesis.
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Vanhamme L, Souopgui J, Ghogomu S, Ngale Njume F. The Functional Parasitic Worm Secretome: Mapping the Place of Onchocerca volvulus Excretory Secretory Products. Pathogens 2020; 9:pathogens9110975. [PMID: 33238479 PMCID: PMC7709020 DOI: 10.3390/pathogens9110975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 01/15/2023] Open
Abstract
Nematodes constitute a very successful phylum, especially in terms of parasitism. Inside their mammalian hosts, parasitic nematodes mainly dwell in the digestive tract (geohelminths) or in the vascular system (filariae). One of their main characteristics is their long sojourn inside the body where they are accessible to the immune system. Several strategies are used by parasites in order to counteract the immune attacks. One of them is the expression of molecules interfering with the function of the immune system. Excretory-secretory products (ESPs) pertain to this category. This is, however, not their only biological function, as they seem also involved in other mechanisms such as pathogenicity or parasitic cycle (molting, for example). We will mainly focus on filariae ESPs with an emphasis on data available regarding Onchocerca volvulus, but we will also refer to a few relevant/illustrative examples related to other worm categories when necessary (geohelminth nematodes, trematodes or cestodes). We first present Onchocerca volvulus, mainly focusing on the aspects of this organism that seem relevant when it comes to ESPs: life cycle, manifestations of the sickness, immunosuppression, diagnosis and treatment. We then elaborate on the function and use of ESPs in these aspects.
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Affiliation(s)
- Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium; (J.S.); (F.N.N.)
- Correspondence:
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium; (J.S.); (F.N.N.)
| | - Stephen Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea P.O Box 63, Cameroon;
| | - Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Rue des Professeurs Jeener et Brachet 12, 6041 Gosselies, Belgium; (J.S.); (F.N.N.)
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea P.O Box 63, Cameroon;
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Zoonotic Implications of Onchocerca Species on Human Health. Pathogens 2020; 9:pathogens9090761. [PMID: 32957647 PMCID: PMC7560048 DOI: 10.3390/pathogens9090761] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/10/2020] [Accepted: 09/15/2020] [Indexed: 12/14/2022] Open
Abstract
The genus Onchocerca includes several species associated with ungulates as hosts, although some have been identified in canids, felids, and humans. Onchocerca species have a wide geographical distribution, and the disease they produce, onchocerciasis, is generally seen in adult individuals because of its large prepatency period. In recent years, Onchocerca species infecting animals have been found as subcutaneous nodules or invading the ocular tissues of humans; the species involved are O. lupi, O. dewittei japonica, O. jakutensis, O. gutturosa, and O. cervicalis. These findings generally involve immature adult female worms, with no evidence of being fertile. However, a few cases with fertile O. lupi, O. dewittei japonica, and O. jakutensis worms have been identified recently in humans. These are relevant because they indicate that the parasite’s life cycle was completed in the new host—humans. In this work, we discuss the establishment of zoonotic Onchocerca infections in humans, and the possibility of these infections to produce symptoms similar to human onchocerciasis, such as dermatitis, ocular damage, and epilepsy. Zoonotic onchocerciasis is thought to be an emerging human parasitic disease, with the need to take measures such as One Health Strategies, in order to identify and control new cases in humans.
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Johnson TP, Sejvar J, Nutman TB, Nath A. The Pathogenesis of Nodding Syndrome. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2020; 15:395-417. [PMID: 31977293 DOI: 10.1146/annurev-pathmechdis-012419-032748] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nodding syndrome is a rare, enigmatic form of pediatric epilepsy that has occurred in an epidemic fashion beginning in the early 2000s in geographically distinct regions of Africa. Despite extensive investigation, the etiology of nodding syndrome remains unclear, although much progress has been made in understanding the pathogenesis of the disease, as well as in treatment and prevention. Nodding syndrome is recognized as a defined disease entity, but it is likely one manifestation along a continuum of Onchocerca volvulus-associated neurological complications. This review examines the epidemiology of nodding syndrome and its association with environmental factors. It provides a critical analysis of the data that support or contradict the leading hypotheses of the etiologies underlying the pathogenesis of the syndrome. It also highlights the important progress made in treating and preventing this devastating neurological disease and prioritizes important areas for future research.
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Affiliation(s)
- Tory P Johnson
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | - James Sejvar
- Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30329-4027, USA
| | - Thomas B Nutman
- Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA;
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Zoonotic and vector-borne parasites and epilepsy in low-income and middle-income countries. Nat Rev Neurol 2020; 16:333-345. [PMID: 32427939 DOI: 10.1038/s41582-020-0361-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2020] [Indexed: 12/22/2022]
Abstract
Zoonotic and vector-borne parasites are important preventable risk factors for epilepsy. Three parasitic infections - cerebral malaria, Taenia solium cysticercosis and onchocerciasis - have an established association with epilepsy. Parasitoses are widely prevalent in low-income and middle-income countries, which are home to 80% of the people with epilepsy in the world. Once a parasitic infection has taken hold in the brain, therapeutic measures do not seem to influence the development of epilepsy in the long term. Consequently, strategies to control, eliminate and eradicate parasites represent the most feasible way to reduce the epilepsy burden at present. The elucidation of immune mechanisms underpinning the parasitic infections, some of which are parasite-specific, opens up new therapeutic possibilities. In this Review, we explore the pathophysiological basis of the link between parasitic infections and epilepsy, and we consider preventive and therapeutic approaches to reduce the burden of epilepsy attributable to parasitic disorders. We conclude that a concerted approach involving medical, veterinary, parasitological and ecological experts, backed by robust political support and sustainable funding, is the key to reducing this burden.
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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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Hotterbeekx A, Raimon S, Abd-Elfarag G, Carter JY, Sebit W, Suliman A, Siewe Fodjo JN, De Witte P, Logora MY, Colebunders R, Kumar-Singh S. Onchocerca volvulus is not detected in the cerebrospinal fluid of persons with onchocerciasis-associated epilepsy. Int J Infect Dis 2019; 91:119-123. [PMID: 31786246 PMCID: PMC6996151 DOI: 10.1016/j.ijid.2019.11.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES Epidemiological evidence links onchocerciasis with the development of epilepsy. The aim of this study was to detect Onchocerca volvulus microfilariae or its bacterial endosymbiont, Wolbachia, in the cerebrospinal fluid (CSF) of persons with onchocerciasis-associated epilepsy (OAE). METHODS Thirteen persons with OAE and O. volvulus skin snip densities of >80 microfilariae were recruited in Maridi County (South Sudan) and their CSF obtained. Cytospin centrifuged preparations of CSF were examined by light microscopy for the presence of O. volvulus microfilariae. DNA was extracted from CSF to detect O. volvulus (O-150 repeat) by quantitative real-time PCR, and Wolbachia (FtsZ gene) by standard PCR. To further investigate whether CSF from onchocerciasis-infected participants could induce seizures, 3- and 7-day old zebrafish larvae were injected with the CSF intracardially and intraperitoneally, respectively. For other zebrafish larvae, CSF was added directly to the larval medium. RESULTS No microfilariae, parasite DNA, or Wolbachia DNA were detected in any of the CSF samples by light microscopy or PCR. All zebrafish survived the procedures and none developed seizures. CONCLUSIONS The absence of O. volvulus in the CSF suggests that OAE is likely not caused by direct parasite invasion into the central nervous system, but by another phenomenon triggered by O. volvulus infection.
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Affiliation(s)
- An Hotterbeekx
- Global Health Institute, University of Antwerp, Antwerp, Belgium.
| | | | - Gasim Abd-Elfarag
- Global Child Health Group, Department of Paediatrics and Department of Global Health, Academic Medical Center, University of Amsterdam, The Netherlands; Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands.
| | | | - Wilson Sebit
- National Public Health Laboratory, Juba, South Sudan.
| | | | | | - Peter De Witte
- Moleculaire bio-ontdekking, Katholieke Universiteit Leuven, Leuven, Belgium.
| | - Makoy Yibi Logora
- Neglected Tropical Diseases Unit, Ministry of Health, Juba, South Sudan.
| | | | - Samir Kumar-Singh
- Molecular Pathology Group, Laboratory of Cell Biology and Histology, Faculty of Medical and Health Sciences, University of Antwerp, Antwerp, Belgium.
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Irani J, Rujumba J, Mwaka AD, Arach J, Lanyuru D, Idro R, Gerrets R, Grietens KP, O’Neill S. "Those who died are the ones that are cured". Walking the political tightrope of Nodding Syndrome in northern Uganda: Emerging challenges for research and policy. PLoS Negl Trop Dis 2019; 13:e0007344. [PMID: 31220081 PMCID: PMC6605670 DOI: 10.1371/journal.pntd.0007344] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/02/2019] [Accepted: 03/28/2019] [Indexed: 11/19/2022] Open
Abstract
Background Nodding Syndrome was first reported from Tanzania in the 1960s but appeared as an epidemic in Northern Uganda in the 1990s during the LRA civil war. It is characterized by repetitive head nodding, often followed by other types of seizures, developmental retardation and growth faltering with onset occurring in children aged 5–15 years. More than 50 years after the first reports, the aetiology remains unknown and there is still no cure. The recent hypothesis that Nodding Syndrome is caused by onchocerciasis also increases the relevance of onchocerciasis control. Northern Uganda, with its unique socio-political history, adds challenges to the prevention and treatment for Nodding Syndrome. This article aims to show how and why Nodding Syndrome has been politicised in Uganda; how this politicisation has affected health interventions including research and dissemination; and, the possible implications this can have for disease prevention and treatment. Methodology Ethnographic research methods were used triangulating in-depth interviews, focus group discussions, informal conversations and participant observation, for an understanding of the various stakeholders’ perceptions of Nodding Syndrome and how these perceptions impact future interventions for prevention, treatment and disease control. Principal findings Distrust towards the government was a sentiment that had developed in Northern Uganda over several decades of war and was particularly linked to the political control and ethnic divisions between the north and south. This coincided with the sudden appearance of Nodding Syndrome, an unknown epidemic disease of which the cause could not be clearly identified and optimal treatment had not clearly been established. Additionally, the dissemination of the inconclusive results of research conducted in the area lacked sufficient community involvement which further fueled this political distrust. Disease perceptions revolved around rumours that the entire Acholi ethnic group of the north would be annihilated, or that international researchers were making money by stealing study samples. This discouraged some community members from participating in research or from accepting the mass drug administration of ivermectin for prevention and treatment of onchocerciasis. Such rumour and distrust led to suspicions concerning the integrity of the disseminated results, which may negatively impact future disease management and control interventions. Conclusions and recommendations Trust must be built up gradually through transparency and by de-politicising interventions. This can be done by engaging the community at regular intervals during research and data collection and the dissemination of results in addition to involvement during service delivery for prevention and treatment. Maintaining a regular feedback loop with the community will help control rumours, build trust, and improve the preparations for adequate dissemination. Nodding Syndrome, a form of epilepsy that occurs in onchocerciasis-endemic areas has affected about 3000 children in Northern Uganda where the epidemic emerged at the time of the civil war. Although an association with onchocerciasis has been established, the disease etiology has not yet been identified. In conjunction with the area’s history of war, political conflict and ethnic divides, many affected people were suspicious of government health interventions and scientific studies. Furthermore, ambiguities around the disease etiology leaves room for several interpretations, which in addition to distrust leads to rumours, that may hinder future interventions. In view of improving adherence to health interventions, this article explains the socio-political nature of Nodding Syndrome in Northern Uganda. We show how and why this disease has been politicised in Uganda; how this politicisation has affected research and dissemination; and, the implications this has for disease control. The insights presented will be critical for reducing resistance to research, to treatment and to the dissemination of knowledge which is necessary for the prevention and control of Nodding Syndrome and onchocerciasis in Northern Uganda.
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Affiliation(s)
- Julia Irani
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | - Joseph Rujumba
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Amos Deogratius Mwaka
- Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
- The Ugandan Ministry of Health, Kampala, Uganda
| | - Jesca Arach
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Denis Lanyuru
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Richard Idro
- Department of Pediatrics and Child Health, College of Health Sciences, Makerere University, Kampala, Uganda
- The Ugandan Ministry of Health, Kampala, Uganda
| | - Rene Gerrets
- The Amsterdam Institute for Social Science Research, University of Amsterdam, Amsterdam, Netherlands
| | | | - Sarah O’Neill
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- CRISS, Ecole de Santé Publique and LAMC, Faculté de Philosophie et Sciences Sociales, Université Libre de Bruxelles, Brussels, Belgium
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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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Boullé C, Njamnshi AK, Dema F, Mengnjo MK, Siewe Fodjo JN, Bissek ACZK, Suykerbuyk P, Lenou-Nanga CG, Nana-Djeunga HC, Kamgno J, Chesnais CB, Boussinesq M, Colebunders R. Impact of 19 years of mass drug administration with ivermectin on epilepsy burden in a hyperendemic onchocerciasis area in Cameroon. Parasit Vectors 2019; 12:114. [PMID: 30890155 PMCID: PMC6423875 DOI: 10.1186/s13071-019-3345-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/26/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Surveys conducted in 1991-1992 in the Mbam Valley (Cameroon) revealed that onchocerciasis was highly endemic, with community microfilarial loads (CMFL) > 100 microfilariae/snip in some villages. Also in 1991-1992, a survey of suspected cases of epilepsy (SCE) found 746 SCE using a questionnaire administered to individuals identified by key informants, with prevalences reaching 13.6% in some communities. From 1998, annual community-directed treatment with ivermectin (CDTI) was implemented to control onchocerciasis. In 2017, a door-to-door household survey was conducted in three of the villages visited in 1991-1992, using a standardized 5-item epilepsy screening questionnaire. RESULTS In 2017, a total of 2286 individuals living in 324 households were screened (582 in Bayomen, 553 in Ngongol and 1151 in Nyamongo) and 112 SCE were identified (4.9%). Neurologists examined 92 of these SCE and confirmed the diagnosis of epilepsy for 81 of them (3.5%). Between the surveys in 1991-1992 and 2017, the prevalence of SCE decreased from 13.6% to 2.5% in Bayomen (P = 0.001), from 8.7% to 6.6% in Ngongol (P = 0.205) and from 6.4% to 5.4% in Nyamongo (P = 0.282). The median age of SCE shifted from 20 (IQR: 12-23) to 29 years (IQR: 18-33; P = 0.018) in Bayomen, from 16 (IQR: 12-21) to 26 years (IQR: 21-39; P < 0.001) in Ngongol and from 16 (IQR: 13-19) to 24 years (IQR: 19-32; P < 0.001) in Nyamongo. The proportions of SCE aged < 10, 10-19, 20-29 and ≥ 30 years shifted from 9.5, 58.3, 25.0 and 7.1% in 1991-1992 to 2.7, 20.5, 39.3 and 37.5% in 2017, respectively. CONCLUSIONS SCE prevalence decreased overall between 1991-1992 and 2017. The age shift observed is probably due to a decrease in the number of new cases of epilepsy resulting from the dramatic reduction of Onchocerca volvulus transmission after 19 years of CDTI.
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Affiliation(s)
- Charlotte Boullé
- TransVIHMI, University of Montpellier, Inserm, IRD, Montpellier, France
- Infectious and Tropical Diseases Department, University Hospital, Nîmes, France
| | - Alfred K. Njamnshi
- Neurology Department, Central Hospital of Yaoundé, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
- Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
| | | | - Michel K. Mengnjo
- Neurology Department, Central Hospital of Yaoundé, Yaoundé, Cameroon
| | - Joseph Nelson Siewe Fodjo
- Subdivisonal hospital of Mbangassina, Mbangassina, Cameroon
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Anne-Cécile Zoung-Kanyi Bissek
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
- Ministry of Public Health, Yaoundé, Cameroon
- Dermatology Department, Chantal Biya Mother-Child Center, Yaoundé, Cameroon
| | | | | | | | - Joseph Kamgno
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon
| | | | - Michel Boussinesq
- TransVIHMI, University of Montpellier, Inserm, IRD, Montpellier, France
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Angwafor SA, Bell GS, Njamnshi AK, Singh G, Sander JW. Parasites and epilepsy: Understanding the determinants of epileptogenesis. Epilepsy Behav 2019; 92:235-244. [PMID: 30711777 DOI: 10.1016/j.yebeh.2018.11.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 11/25/2018] [Accepted: 11/26/2018] [Indexed: 12/25/2022]
Abstract
There is a large body of evidence suggesting that parasites could be a major preventable risk factor for epilepsy in low- and middle-income countries. We review potentially important substrates for epileptogenesis in parasitic diseases. Taenia solium is the most widely known parasite associated with epilepsy, and the risk seems determined mainly by the extent of cortical involvement and the evolution of the primary cortical lesion to gliosis or to a calcified granuloma. For most parasites, however, epileptogenesis is more complex, and other favorable host genetic factors and parasite-specific characteristics may be critical. In situations where cortical involvement by the parasite is either absent or minimal, parasite-induced epileptogenesis through an autoimmune process seems plausible. Further research to identify important markers of epileptogenesis in parasitic diseases will have huge implications for the development of trials to halt or delay onset of epilepsy.
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Affiliation(s)
- Samuel A Angwafor
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom; Chalfont Centre for Epilepsy, Buckinghamshire, United Kingdom
| | - Gail S Bell
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom; Chalfont Centre for Epilepsy, Buckinghamshire, United Kingdom
| | - Alfred K Njamnshi
- Neurology Department, Central Hospital Yaoundé/Faculty of Medicine and Biomedical Sciences (FMBS), The University of Yaoundé 1, Cameroon; Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon
| | - Gagandeep Singh
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom; Chalfont Centre for Epilepsy, Buckinghamshire, United Kingdom; Department of Neurology, Dayanand Medical College, Ludhiana, India
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, United Kingdom; Chalfont Centre for Epilepsy, Buckinghamshire, United Kingdom; Stichting Epilepsie Instelligen Nederland (SEIN), the Netherlands.
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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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Hotterbeekx A, Namale Ssonko V, Oyet W, Lakwo T, Idro R. Neurological manifestations in Onchocerca volvulus infection: A review. Brain Res Bull 2018; 145:39-44. [PMID: 30458251 PMCID: PMC6382410 DOI: 10.1016/j.brainresbull.2018.08.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/22/2018] [Accepted: 08/25/2018] [Indexed: 11/17/2022]
Abstract
Human onchocerciasis, caused by infection by the filarial nematode Onchocerca volvulus, is a major neglected public health problem that affects millions of people in the endemic regions of sub-Saharan Africa and Latin America. Onchocerciasis is known to be associated with skin and eye disease and more recently, neurological features have been recognized as a major manifestation. Especially the latter poses a severe burden on affected individuals and their families. Although definite studies are awaited, preliminary evidence suggests that neurological disease may include the nodding syndrome, Nakalanga syndrome and epilepsy but to date, the exact pathophysiological mechanisms remain unclear. Currently, the only way to prevent Onchocera volvulus associated disease is through interventions that target the elimination of onchocerciasis through community distribution of ivermectin and larviciding the breeding sites of the Similium or blackfly vector in rivers. In this review, we discuss the epidemiology, potential pathological mechanisms as well as prevention and treatment strategies of onchocerciasis, focusing on the neurological disease.
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Affiliation(s)
- An Hotterbeekx
- University of Antwerp, Global Health Institute, Antwerp, Belgium
| | | | | | - Thomson Lakwo
- Ministry of Health, Division of Vector Control, Kampala, Uganda
| | - Richard Idro
- Makerere University College of Health Sciences, Kampala, Uganda; Centre for Tropical Neuroscience, Kampala, Uganda; University of Oxford, Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford, UK.
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Kaiser C, Asaba G, Rubaale T, Tukesiga E, Kipp W. Onchocerciasis-Associated Epilepsy with Head Nodding Seizures-Nodding Syndrome: A Case Series of 15 Patients from Western Uganda, 1994. Am J Trop Med Hyg 2018; 99:1211-1218. [PMID: 30226148 PMCID: PMC6221207 DOI: 10.4269/ajtmh.18-0511] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 08/05/2018] [Indexed: 11/07/2022] Open
Abstract
Nodding syndrome (NS) is an encephalopathy characterized by the core symptom of epileptic head nodding seizures, affecting children at the age between 3 and 18 years in distinct areas of tropical Africa. A consistent correlation with onchocerciasis was found, but so far, the causation of NS has not been fully clarified. With a systematic analysis of features of a cohort of epilepsy patients examined in the Itwara onchocerciasis focus of western Uganda in 1994, we provide evidence that NS actually occurred in this area at this time, and we demonstrate a correlation between prevalence of NS and that of onchocerciasis in different villages. Following the elimination of onchocerciasis by community-directed treatment with ivermectin and ground larviciding, our data provide a baseline to examine the question whether NS will disappear once its putative cause has been removed.
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Affiliation(s)
- Christoph Kaiser
- Basic Health Services Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - George Asaba
- Basic Health Services Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Tom Rubaale
- Basic Health Services Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Ephraim Tukesiga
- Basic Health Services Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Walter Kipp
- Basic Health Services Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
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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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30
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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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Greter H, Mmbando B, Makunde W, Mnacho M, Matuja W, Kakorozya A, Suykerbuyk P, Colebunders R. Evolution of epilepsy prevalence and incidence in a Tanzanian area endemic for onchocerciasis and the potential impact of community-directed treatment with ivermectin: a cross-sectional study and comparison over 28 years. BMJ Open 2018; 8:e017188. [PMID: 29605818 PMCID: PMC5884367 DOI: 10.1136/bmjopen-2017-017188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
INTRODUCTION Worldwide, there are an estimated 50 million people affected by epilepsy. Its aetiology is manifold, and parasitic infections play an important role, specifically onchocerciasis. In onchocerciasis endemic areas, a distinctive form of epilepsy has been described as nodding syndrome, affecting children and causing nodding seizures, mental retardation and debilitating physical development. Onchocerciasis control programmes using community-directed treatment with ivermectin (CDTI) are implemented in endemic countries. This study is designed to contribute to a better understanding of the linkage between the onset of epilepsy, onchocerciasis and CDTI. Comparing the epidemiological data on epilepsy and onchocerciasis from pre-CDTI and 20 years after its introduction will allow identifying a potential impact of ivermectin on the onset of epilepsy. METHODS AND ANALYSIS The study will be conducted in the Mahenge highlands in Tanzania. Study site selection is based on an in-depth study on epilepsy in that area dating from 1989. CDTI was introduced in 1997. By a door-to-door approach, the population will be screened for epilepsy using a validated questionnaire. Suspected cases will be invited for a neurological examination for case verification. Onchocerciasis prevalence will be assessed by a rapid epidemiological assessment. As an indicator for ongoing transmission, children younger than 10 years of age will be tested for Ov16 antibodies. Ivermectin use will be assessed at household level. Epilepsy data will be analysed in comparison with the 1989 data to reveal pre-CDTI and post-CDTI prevalence and incidence. ETHICS AND DISSEMINATION The protocol has received ethical approval from the ethics committees of the University of Antwerp, Belgium, and of the National Institut of Medical Research, Dar es Salaam, Tanzania. The findings will be published in peer-reviewed journals, and presented to the health authorities in Tanzania, at national, regional and village level.
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Affiliation(s)
- Helena Greter
- Global Health Institute, University of Antwerp, Wilrijk, Belgium
| | - Bruno Mmbando
- National Institute of Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Williams Makunde
- National Institute of Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Mohamed Mnacho
- Department of Neurology, Muhimbili University of Health Sciences, Dar es Salaam, Tanzania
| | - William Matuja
- Department of Neurology, Muhimbili University of Health Sciences, Dar es Salaam, Tanzania
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Johnson TP, Tyagi R, Lee PR, Lee MH, Johnson KR, Kowalak J, Elkahloun A, Medynets M, Hategan A, Kubofcik J, Sejvar J, Ratto J, Bunga S, Makumbi I, Aceng JR, Nutman TB, Dowell SF, Nath A. Nodding syndrome may be an autoimmune reaction to the parasitic worm Onchocerca volvulus. Sci Transl Med 2017; 9:9/377/eaaf6953. [PMID: 28202777 DOI: 10.1126/scitranslmed.aaf6953] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 11/17/2016] [Indexed: 12/16/2022]
Abstract
Nodding syndrome is an epileptic disorder of unknown etiology that occurs in children in East Africa. There is an epidemiological association with Onchocerca volvulus, the parasitic worm that causes onchocerciasis (river blindness), but there is limited evidence that the parasite itself is neuroinvasive. We hypothesized that nodding syndrome may be an autoimmune-mediated disease. Using protein chip methodology, we detected autoantibodies to leiomodin-1 more abundantly in patients with nodding syndrome compared to unaffected controls from the same village. Leiomodin-1 autoantibodies were found in both the sera and cerebrospinal fluid of patients with nodding syndrome. Leiomodin-1 was found to be expressed in mature and developing human neurons in vitro and was localized in mouse brain to the CA3 region of the hippocampus, Purkinje cells in the cerebellum, and cortical neurons, structures that also appear to be affected in patients with nodding syndrome. Antibodies targeting leiomodin-1 were neurotoxic in vitro, and leiomodin-1 antibodies purified from patients with nodding syndrome were cross-reactive with O. volvulus antigens. This study provides initial evidence supporting the hypothesis that nodding syndrome is an autoimmune epileptic disorder caused by molecular mimicry with O. volvulus antigens and suggests that patients may benefit from immunomodulatory therapies.
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Affiliation(s)
- Tory P Johnson
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Richa Tyagi
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul R Lee
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Myoung-Hwa Lee
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeffrey Kowalak
- Clinical Proteomics Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Abdel Elkahloun
- Microarray Core Facility, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marie Medynets
- Neural Differentiation Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alina Hategan
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joseph Kubofcik
- Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Sejvar
- Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Jeffrey Ratto
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Sudhir Bunga
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
| | | | | | - Thomas B Nutman
- Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Kaiser C, Pion SDS. River blindness goes beyond the eye: autoimmune antibodies, cross-reactive with Onchocerca volvulus antigen, detected in brain of patients with Nodding syndrome. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:459. [PMID: 29285492 DOI: 10.21037/atm.2017.08.35] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Sébastien D S Pion
- UMI 233, Institut de Recherche pour le Développement (IRD) and University of Montpellier 1, Montpellier, France
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O-5S quantitative real-time PCR: a new diagnostic tool for laboratory confirmation of human onchocerciasis. Parasit Vectors 2017; 10:451. [PMID: 28969662 PMCID: PMC5625774 DOI: 10.1186/s13071-017-2382-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 09/17/2017] [Indexed: 12/01/2022] Open
Abstract
Background Onchocerciasis is a parasitic disease caused by the filarial nematode Onchocerca volvulus. In endemic areas, the diagnosis is commonly confirmed by microscopic examination of skin snip samples, though this technique is considered to have low sensitivity. The available melting-curve based quantitative real-time PCR (qPCR) using degenerated primers targeting the O-150 repeat of O. volvulus was considered insufficient for confirming the individual diagnosis, especially in elimination studies. This study aimed to improve detection of O. volvulus DNA in clinical samples through the development of a highly sensitive qPCR assay. Methods A novel hydrolysis probe based qPCR assay was designed targeting the specific sequence of the O. volvulus O-5S rRNA gene. A total of 200 clinically suspected onchocerciasis cases were included from Goma district in South-west Ethiopia, from October 2012 through May 2013. Skin snip samples were collected and subjected to microscopy, O-150 qPCR, and the novel O-5S qPCR. Results Among the 200 individuals, 133 patients tested positive (positivity rate of 66.5%) and 67 negative by O-5S qPCR, 74 tested positive by microscopy (37.0%) and 78 tested positive by O-150 qPCR (39.0%). Among the 133 O-5S qPCR positive individuals, microscopy and O-150 qPCR detected 55.6 and 59.4% patients, respectively, implying a higher sensitivity of O-5S qPCR than microscopy and O-150 qPCR. None of the 67 individuals who tested negative by O-5S qPCR tested positive by microscopy or O-150 qPCR, implying 100% specificity of the newly designed O-5S qPCR assay. Conclusions The novel O-5S qPCR assay is more sensitive than both microscopic examination and the existing O-150 qPCR for the detection of O. volvulus from skin snip samples. The newly designed assay is an important step towards appropriate individual diagnosis and control of onchocerciasis. Electronic supplementary material The online version of this article (10.1186/s13071-017-2382-3) contains supplementary material, which is available to authorized users.
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Spencer PS, Schmutzhard E, Winkler AS. Nodding Syndrome in the Spotlight - Placing Recent Findings in Perspective. Trends Parasitol 2017; 33:490-492. [PMID: 28596064 DOI: 10.1016/j.pt.2017.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 05/01/2017] [Indexed: 11/24/2022]
Abstract
Nodding syndrome (NS) is a debated scientific topic. A recently published study suggests that NS is an autoimmune disorder based on findings of cross-reacting antibodies between neuronal structures and a protein present in Onchocerca volvulus (OV). In our opinion, the proposed causal relationship between OV infection and NS has yet to be demonstrated and, instead, OV infection in NS may be opportunistic.
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Affiliation(s)
- Peter S Spencer
- Department of Neurology, School of Medicine, and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA.
| | - Erich Schmutzhard
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Andrea S Winkler
- Centre for Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway; Centre for Global Health, Department of Neurology, Technical University of Munich, Munich, Germany
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Colebunders R, Njamnshi AK, van Oijen M, Mukendi D, Kashama JM, Mandro M, Gumisiriza N, Preux PM, Suykerbuyk P, Idro R. Onchocerciasis-associated epilepsy: From recent epidemiological and clinical findings to policy implications. Epilepsia Open 2017; 2:145-152. [PMID: 29588943 PMCID: PMC5719844 DOI: 10.1002/epi4.12054] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2017] [Indexed: 11/12/2022] Open
Abstract
A high prevalence of epilepsy is reported in many onchocerciasis‐endemic regions. In this paper we discuss recent epidemiological and clinical aspects as well as public health implications of onchocerciasis‐associated epilepsy (OAE) and propose a strategy to reduce the burden of disease. OAE probably presents in a variety of clinical manifestations, including the nodding syndrome and the Nakalanga syndrome. The most common clinical presentation, however, is generalized (primarily tonic‐clonic) seizures. A characteristic of OAE is the onset of seizures between the ages of 3 and 18 years and clustering in certain families and villages close to rapid‐flowing black‐fly‐infested rivers. A strategy combining active surveillance for epilepsy with early treatment with antiepileptic drugs and prevention of onchocerciasis by increasing the geographical and therapeutic coverage of community‐directed treatment with ivermectin (CDTi) may considerably decrease the burden of disease.
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Affiliation(s)
| | - Alfred K Njamnshi
- Neurology Department Central Hospital Yaoundé Faculty of Medicine and Biomedical Sciences the University of Yaoundé IYaoundé IRepublic of Cameroon
| | - Marieke van Oijen
- Global Health Institute University of Antwerp Antwerp Belgium.,Department of Neurology Academic Medical Center Amsterdam the Netherlands
| | - Deby Mukendi
- Neuro-psycho-pathological Centre University of Kinshasa Kinshasa Democratic Republic of the Congo
| | - Jean Marie Kashama
- Neuro-psycho-pathological Centre University of Kinshasa Kinshasa Democratic Republic of the Congo
| | - Michel Mandro
- Provincial division of Health of Ituri Ministery of Health Bunia Democratic Republic of the Congo
| | | | | | | | - Richard Idro
- College of Health Sciences Makerere University Kampala Uganda.,Nuffield Department of Medicine Centre for Tropical Medicine and Global Health University of Oxford Oxford United Kingdom
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Föger K, Gora-Stahlberg G, Sejvar J, Ovuga E, Jilek-Aall L, Schmutzhard E, Kaiser C, Winkler AS. Nakalanga Syndrome: Clinical Characteristics, Potential Causes, and Its Relationship with Recently Described Nodding Syndrome. PLoS Negl Trop Dis 2017; 11:e0005201. [PMID: 28182652 PMCID: PMC5300103 DOI: 10.1371/journal.pntd.0005201] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Nakalanga syndrome is a condition that was described in Uganda and various other African countries decades ago. Its features include growth retardation, physical deformities, endocrine dysfunction, mental impairment, and epilepsy, amongst others. Its cause remains obscure. Nodding syndrome is a neurological disorder with some features in common with Nakalanga syndrome, which has been described mainly in Uganda, South Sudan, and Tanzania. It has been considered an encephalopathy affecting children who, besides head nodding attacks, can also present with stunted growth, delayed puberty, and mental impairment, amongst other symptoms. Despite active research over the last years on the pathogenesis of Nodding syndrome, to date, no convincing single cause of Nodding syndrome has been reported. In this review, by means of a thorough literature search, we compare features of both disorders. We conclude that Nakalanga and Nodding syndromes are closely related and may represent the same condition. Our findings may provide new directions in research on the cause underlying this neurological disorder.
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Affiliation(s)
- Kathrin Föger
- Department of Neurology, Technical University of Munich, Munich, Germany
| | | | - James Sejvar
- Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Emilio Ovuga
- Department of Psychiatry and Mental Health, Gulu University, Gulu, Uganda
| | - Louise Jilek-Aall
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Erich Schmutzhard
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Andrea S. Winkler
- Department of Neurology, Technical University of Munich, Munich, Germany
- Centre for Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
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Colebunders R, Mandro M, Mokili JL, Mucinya G, Mambandu G, Pfarr K, Reiter-Owona I, Hoerauf A, Tepage F, Levick B, Begon M, Laudisoit A. Risk factors for epilepsy in Bas-Uélé Province, Democratic Republic of the Congo: a case-control study. Int J Infect Dis 2016; 49:1-8. [PMID: 27210267 PMCID: PMC4973807 DOI: 10.1016/j.ijid.2016.05.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND The reason for the high prevalence of epilepsy in onchocerciasis endemic areas remains unknown. The aim of this study was to detect risk factors associated with epilepsy in a region endemic for onchocerciasis. METHODS In June 2014, a case-control study was performed in Titule, Bas-Uélé Province in the Democratic Republic of the Congo. Individuals with unprovoked convulsive epilepsy of unknown aetiology were enrolled as cases (n=59). Healthy members of families without cases of epilepsy in the same village were recruited as controls (n=61). A multivariate binomial logistic regression analysis was performed to identify potential risk factors associated with epilepsy. To evaluate the potential protective effect of ivermectin treatment on the development of epilepsy, a nested age-matched case-control study was performed including only those who were eligible for ivermectin treatment in the year before they developed epilepsy. RESULTS Suspected onchocerciasis skin lesions were more often present in cases than in controls: 12/41 (29%) vs. 1/56 (2%), respectively (odds ratio (OR) 20.26, 95% confidence interval (CI) 2.42-170; p<0.01). Ivermectin had been taken 7 months earlier in 29/59 (49%) cases and 29/61 (48%) controls. Onchocerca volvulus (OV) DNA was detected by PCR in skin snips in 26/34 cases (76%) and 10/14 controls (71%) (p=0.7), and there was presence of OV IgG4 antibodies in 35/48 (73%) cases and 15/18 (83%) controls (p=0.5). OV DNA was not detected in the cerebrospinal fluid of cases (controls not tested). Both cases and controls reported frequent bites by blackflies (Diptera, Simuliidae). Bathing daily as opposed to less often (OR 16.7, 95% CI 2.2-125.8; p<0.01), bathing between 11 a.m. and 4 p.m. (OR 12.7, 95% CI 1.6-103.7; p=0.02), and washing clothes between 11 a.m. and 4 p.m. (OR 10.9, 95% CI 1.5-77.3; p=0.02) were all independently associated with epilepsy. Blood screening by specific PCR tests for Toxoplasma and Wuchereria bancrofti was negative in all cases and controls. A Loa loa infestation was found in only one case and one control by PCR and Giemsa smear. Antibodies to Taenia solium, Toxocara, and Trypanosoma sp were not detected in any of the participants. In an age-matched case-control analysis, 16/18 (89%) cases had not taken ivermectin the year before they developed epilepsy, compared to 7/18 (39%) controls that same year (p=0.002). CONCLUSIONS These data suggest that frequent activities at rivers known to be blackfly breeding sites and a historical lack of ivermectin treatment were risk factors for epilepsy in this onchocerciasis endemic area.
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Affiliation(s)
| | - Michel Mandro
- Provincial Health Division Ituri, Ministry of Health, Bunia, Democratic Republic of the Congo
| | - John L Mokili
- Biology Department, San Diego State University, San Diego, USA
| | - Gisele Mucinya
- Medical Doctor Bunia, Bunia, Democratic Republic of the Congo
| | - Germain Mambandu
- Provincial Ministry of Public Health, Ministry of Health, Kisangani, Democratic Republic of the Congo
| | - Kenneth Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Ingrid Reiter-Owona
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Floribert Tepage
- National Onchocerciasis Control Program, Ministry of Health, Kisangani, Democratic Republic of the Congo
| | - Bethanie Levick
- Institute of Integrative Biology, School of Biological Sciences, University of Liverpool, Liverpool, UK
| | - Michael Begon
- Institute of Integrative Biology, School of Biological Sciences, University of Liverpool, Liverpool, UK
| | - Anne Laudisoit
- Global Health Institute, University of Antwerp, Antwerp, Belgium; Institute of Integrative Biology, School of Biological Sciences, University of Liverpool, Liverpool, UK
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Wamala JF, Malimbo M, Tepage F, Lukwago L, Okot CL, Cannon RO, Laudisoit A, Colebunders R. Nodding Syndrome May Be Only the Ears of the Hippo. PLoS Negl Trop Dis 2015; 9:e0003880. [PMID: 26270048 PMCID: PMC4535877 DOI: 10.1371/journal.pntd.0003880] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
| | - Mugagga Malimbo
- National Disease Control, Ministry of Health, Kampala, Uganda
| | - Floribert Tepage
- National Onchocerciasis Control Program, Ministry of Health, Kisangani, Democratic Republic of the Congo
| | - Luswa Lukwago
- National Disease Control, Ministry of Health, Kampala, Uganda
| | - Charles Lukoya Okot
- Disease Prevention and Control Cluster, World Health Organization, Kampala, Uganda
| | | | - Anne Laudisoit
- Evolutionary Biology Group, University of Antwerp, Antwerp, Belgium
- Institute of Integrative Ecology, University of Liverpool, Liverpool, United Kingdom
| | - Robert Colebunders
- Department of Epidemiology and Social Medicine, University of Antwerp, Antwerp, Belgium
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
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Kaiser C, Rubaale T, Tukesiga E, Kipp W, Asaba G. Nodding syndrome, western Uganda, 1994. Am J Trop Med Hyg 2015; 93:198-202. [PMID: 25918208 PMCID: PMC4497897 DOI: 10.4269/ajtmh.14-0838] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/15/2015] [Indexed: 11/07/2022] Open
Abstract
Nodding syndrome (NS) is a poorly understood condition, which was delineated in 2008 as a new epilepsy syndrome. So far, confirmed cases of NS have been observed in three circumscribed African areas: southern Tanzania, southern Sudan, and northern Uganda. Case-control studies have provided evidence of an association between NS and infection with Onchocerca volvulus, but the causation of NS is still not fully clarified. We report a case of a 15-year old boy with head nodding seizures and other characteristic features of NS from an onchocerciasis endemic area in western Uganda, with no contiguity to the hitherto known areas. We suggest that the existence of NS should be systematically investigated in other areas.
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Affiliation(s)
- Christoph Kaiser
- Basic Health Services, Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Tom Rubaale
- Basic Health Services, Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Ephraim Tukesiga
- Basic Health Services, Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - Walter Kipp
- Basic Health Services, Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
| | - George Asaba
- Basic Health Services, Kabarole and Bundibugyo Districts, Fort Portal, Uganda; Vector Control Unit, Ministry of Health, Fort Portal, Uganda; Department of Public Health Sciences, University of Alberta, Edmonton, Canada
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Sebera F, Munyandamutsa N, Teuwen DE, Ndiaye IP, Diop AG, Tofighy A, Boon P, Dedeken P. Addressing the treatment gap and societal impact of epilepsy in Rwanda--Results of a survey conducted in 2005 and subsequent actions. Epilepsy Behav 2015; 46:126-32. [PMID: 25936276 PMCID: PMC4464509 DOI: 10.1016/j.yebeh.2015.03.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 02/23/2015] [Accepted: 03/27/2015] [Indexed: 01/03/2023]
Abstract
This study, supported by the Rwandan Ministry of Health and the World Health Organization, was conducted in 2005 to determine the prevalence of epilepsy and its sociocultural perception in Rwanda, as well as epilepsy-related knowledge and practices of health-care professionals (HCPs). A cross-sectional, nationally representative survey was conducted throughout Rwanda by trained investigators. Participants were recruited by random cluster sampling based on the organization of administrative units in the country. Overall, 1137 individuals (62% from rural areas) were interviewed. The prevalence of epilepsy was estimated to be 49 per 1000 people or 41 per 1000 for active epilepsy. Onset of epilepsy before the age of 2years was reported in 32% of the cases. Family history of epilepsy, head trauma, and premature delivery were reported in 53%, 50%, and 68% of the cases, respectively. Most (68%) patients did not receive any medical treatment for epilepsy; 21.5% had received some form of traditional treatment. According to responses from the general population, people with epilepsy should not be entitled to schooling (according to 66%), to work (according to 72%), to the use of public places (according to 69%), or to marriage (according to 66%). Furthermore, 50% believed that epilepsy was untreatable, and 40% thought that it was transmissible. Of the 29 HCPs interviewed, the majority knew the definition of epilepsy and status epilepticus, as well as basic treatment options and side effects. However, 90% believed that treatment was only necessary in the first week after a seizure. Living with epilepsy was associated heavily with stigma, and a significant treatment gap (68%) was identified. Following this study, numerous actions have been taken by the Rwandan government, the Rwandan League Against Epilepsy, and several nongovernmental organizations to increase awareness about epilepsy and to close the treatment gap. An overview of these activities is provided.
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Affiliation(s)
- Fidèle Sebera
- Hôpital Neuro-Psychiatrique, Fracarita Ndera, Kigali, Rwanda.
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Buchmann K. 'These nodding people': Experiences of having a child with nodding syndrome in postconflict Northern Uganda. Epilepsy Behav 2015; 42:71-7. [PMID: 25500358 DOI: 10.1016/j.yebeh.2014.10.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 10/20/2014] [Accepted: 10/23/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Nodding syndrome, an epidemic epileptic encephalopathy of unknown etiology, has affected an estimated 1834 children in Northern Uganda. Children are being treated symptomatically but inconsistently with antiepileptic drugs. DESIGN Ten semistructured interviews with caregivers of affected children and five focus group discussions with 23 relatives, teachers, and religious leaders were conducted to examine the experiences of affected families and communities in Kitgum and Pader districts. The researcher also did participant observation during MoH outreach clinics. Data collection was carried out from July to September 2012, and data were analyzed through inductive thematic analysis. RESULTS Nodding syndrome severely affects the children's ability to participate in daily life activities. Daily seizures and physical features such as salivating and stunting make them unable to pass as normal, and mood changes make it difficult for some to interact with others. Caregivers of children with nodding syndrome feel confined to their homes, and economic activities are reduced, which affects entire families, especially the education of healthy siblings. The familial clustering and the unknown etiology made many separate from the affected children when eating, sleeping, and having seizures because of a fear of transmission through saliva. Families struggle to provide care with minimal resources and have experienced a reduction in visitors since their children were affected by nodding syndrome. There were signs of apathy in patterns of care, and, generally, parents felt that antiepileptic medicine had brought only slight improvement in their child's condition because many had begun treatment when developmental milestones had already been lost. CONCLUSIONS A consistent supply of antiepileptic medication is likely to reduce the stigma and fear of transmission, as the affected children's acceptance among others was greatly compromised whenever they had seizures. The loss and suffering involved with nodding syndrome are seen as a continuation of the confinement and trauma once caused by war, and a good regimen of medication is not the whole answer.
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Schmutzhard E, Winkler AS. Nodding syndrome--a critical note and a plea to join forces. Trop Med Int Health 2014; 20:201-4. [PMID: 25418025 DOI: 10.1111/tmi.12417] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Erich Schmutzhard
- Department of Neurology, Neurocritical Care Unit, Medical University Innsbruck, Innsbruck, Austria
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Buchmann K. 'You sit in fear': understanding perceptions of nodding syndrome in post-conflict northern Uganda. Glob Health Action 2014; 7:25069. [PMID: 25361725 PMCID: PMC4212077 DOI: 10.3402/gha.v7.25069] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/21/2014] [Accepted: 09/22/2014] [Indexed: 12/04/2022] Open
Abstract
Background Nodding syndrome, a disabling epidemic epileptic encephalopathy, has affected an estimated 1,834 children in northern Uganda, with reports of as many as 3,000. Etiology is unknown and children are being treated symptomatically but inconsistently with anti-epileptic drugs. Design This qualitative study comprised 10 semi-structured interviews with caregivers of affected children and five focus group discussions with 23 participants; relatives, teachers, and religious leaders. Data collection and participant observation were carried out from July to September 2012 in Kitgum and Pader districts. The material was coded through inductive thematic analysis. Results Nodding syndrome has brought signs of discrimination in school admission procedures, founded in a fear of transmission. The suffering and loss caused by nodding syndrome is collective, and participants felt that nodding syndrome was viewed as a threat to the Acholi only, and that interventions had therefore been delayed. Multiple theories of causation exist, most commonly that the disease is caused by chemicals from bombs or that food aid distributed in IDP camps had expired or been poisoned. A feeling of uncertainty was present in all focus group discussions, fueled by the fact that results of investigations were not being shared with the communities. It was especially agonizing that CDC results had been given to the Ugandan government in 2010 but not to the public. The definitive fear is that the disease will be the end of the Acholi. Conclusions This study provided insight into the perceptions of communities affected by an unknown emerging disease. Families of affected children are grieving not only their child's illness; it is a loss of social value and of lineage. The loss and suffering involved with nodding syndrome should be seen in the context of the wider suffering of a society disrupted by violent conflict. The memory of war is omnipresent and is also how nodding syndrome is understood.
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Ba-Diop A, Marin B, Druet-Cabanac M, Ngoungou EB, Newton CR, Preux PM. Epidemiology, causes, and treatment of epilepsy in sub-Saharan Africa. Lancet Neurol 2014; 13:1029-44. [PMID: 25231525 PMCID: PMC5497080 DOI: 10.1016/s1474-4422(14)70114-0] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
SUMMARY Epilepsy is a common neurological disease in tropical countries, particularly in sub-Saharan Africa. Previous work on epilepsy in sub-Saharan Africa has shown that many cases are severe, partly a result of some specific causes, that it carries a stigma, and that it is not adequately treated in many cases. Many studies on the epidemiology, aetiology, and management of epilepsy in sub-Saharan Africa have been reported in the past 10 years. The prevalence estimated from door-to-door studies is almost double that in Asia, Europe, and North America. The most commonly implicated risk factors are birth trauma, CNS infections, and traumatic brain injury. About 60% of patients with epilepsy receive no antiepileptic treatment, largely for economic and social reasons. Further epidemiological studies should be a priority to improve understanding of possible risk factors and thereby the prevention of epilepsy in Africa, and action should be taken to improve access to treatment.
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Affiliation(s)
- Awa Ba-Diop
- INSERM UMR1094, Tropical Neuroepidemiology, and Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France
| | - Benoît Marin
- INSERM UMR1094, Tropical Neuroepidemiology, and Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France; CEBIMER: Center of Epidemiology, Biostatitics, and Research Methodology, CHU Limoges, France
| | - Michel Druet-Cabanac
- INSERM UMR1094, Tropical Neuroepidemiology, and Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France
| | - Edgard B Ngoungou
- INSERM UMR1094, Tropical Neuroepidemiology, and Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France; Unit of Neuroepidemiology and Tropical Infectious Diseases, Department of Epidemiology, Biostatistics, University of Health Sciences, Libreville, Gabon
| | - Charles R Newton
- KEMRI/Wellcome Trust Collaborative Programme, Centre for Geographical Medicine, Kilifi, Kenya; Department of Psychiatry, University of Oxford, Oxford, UK
| | - Pierre-Marie Preux
- INSERM UMR1094, Tropical Neuroepidemiology, and Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France; CEBIMER: Center of Epidemiology, Biostatitics, and Research Methodology, CHU Limoges, France.
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Colebunders R, Hendy A, Nanyunja M, Wamala JF, van Oijen M. Nodding syndrome-a new hypothesis and new direction for research. Int J Infect Dis 2014; 27:74-7. [PMID: 25181949 DOI: 10.1016/j.ijid.2014.08.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 08/04/2014] [Accepted: 08/08/2014] [Indexed: 11/26/2022] Open
Abstract
Nodding syndrome (NS) is an unexplained neurological illness that mainly affects children aged between 5 and 15 years. NS has so far been reported from South Sudan, northern Uganda, and Tanzania, but in spite of extensive investigations, the aetiology remains unknown. We hypothesize that blackflies (Diptera: Simuliidae) infected with Onchocerca volvulus microfilariae may also transmit another pathogen. This may be a novel neurotropic virus or an endosymbiont of the microfilariae, which causes not only NS, but also epilepsy without nodding. This hypothesis addresses many of the questions about NS that researchers have previously been unable to answer. An argument in favour of the hypothesis is the fact that in Uganda, the number of new NS cases decreased (with no new cases reported since 2013) after ivermectin coverage was increased and with the implementation of a programme of aerial spraying and larviciding of the large rivers where blackflies were breeding. If confirmed, our hypothesis will enable new strategies to control NS outbreaks.
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Affiliation(s)
- Robert Colebunders
- Department of Epidemiology and Social Medicine, University of Antwerp, Antwerp, Belgium; Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
| | - Adam Hendy
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | | | - Marieke van Oijen
- Department of Neurology, Epidemiology and Biostatistics, Erasmus Medical Centre, Rotterdam, Netherlands
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Dietmann A, Wallner B, König R, Friedrich K, Pfausler B, Deisenhammer F, Griesmacher A, Seger C, Matuja W, JilekAall L, Winkler AS, Schmutzhard E. Nodding syndrome in Tanzania may not be associated with circulating anti-NMDA-and anti-VGKC receptor antibodies or decreased pyridoxal phosphate serum levels-a pilot study. Afr Health Sci 2014; 14:434-8. [PMID: 25320594 DOI: 10.4314/ahs.v14i2.20] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Nodding syndrome (NS) is a seemingly progressive epilepsy disorder of unknown underlying cause. We investigated association of pyridoxal-phosphate serum levels and occurrence of anti-neuronal antibodies against N-methyl-D-aspartate (NMDA) receptor and voltage gated potassium channel (VGKC) complex in NS patients. METHODS Sera of a Tanzanian cohort of epilepsy and NS patients and community controls were tested for the presence of anti-NMDA-receptor and anti-VGKC complex antibodies by indirect immunofluorescence assay. Furthermore pyridoxal-phosphate levels were measured. RESULTS Auto-antibodies against NMDA receptor or VGKC (LG1 or Caspr2) complex were not detected in sera of patients suffering from NS (n=6), NS plus other seizure types (n=16), primary generalized epilepsy (n=1) and community controls without epilepsy (n=7). Median Pyridoxal-phosphate levels in patients with NS compared to patients with primary generalized seizures and community controls were not significantly different. However, these median pyridoxal-phosphate levels are significantly lower compared to the range considered normal in Europeans. CONCLUSIONS In this pilot study NS was not associated with serum anti-NMDA receptor or anti-VGKC complex antibodies and no association to pyridoxal-phosphate serum levels was found.
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Kamuyu G, Bottomley C, Mageto J, Lowe B, Wilkins PP, Noh JC, Nutman TB, Ngugi AK, Odhiambo R, Wagner RG, Kakooza-Mwesige A, Owusu-Agyei S, Ae-Ngibise K, Masanja H, Osier FHA, Odermatt P, Newton CR. Exposure to multiple parasites is associated with the prevalence of active convulsive epilepsy in sub-Saharan Africa. PLoS Negl Trop Dis 2014; 8:e2908. [PMID: 24875312 PMCID: PMC4038481 DOI: 10.1371/journal.pntd.0002908] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 04/16/2014] [Indexed: 11/21/2022] Open
Abstract
Background Epilepsy is common in developing countries, and it is often associated with parasitic infections. We investigated the relationship between exposure to parasitic infections, particularly multiple infections and active convulsive epilepsy (ACE), in five sites across sub-Saharan Africa. Methods and Findings A case-control design that matched on age and location was used. Blood samples were collected from 986 prevalent cases and 1,313 age-matched community controls and tested for presence of antibodies to Onchocerca volvulus, Toxocara canis, Toxoplasma gondii, Plasmodium falciparum, Taenia solium and HIV. Exposure (seropositivity) to Onchocerca volvulus (OR = 1.98; 95%CI: 1.52–2.58, p<0.001), Toxocara canis (OR = 1.52; 95%CI: 1.23–1.87, p<0.001), Toxoplasma gondii (OR = 1.28; 95%CI: 1.04–1.56, p = 0.018) and higher antibody levels (top tertile) to Toxocara canis (OR = 1.70; 95%CI: 1.30–2.24, p<0.001) were associated with an increased prevalence of ACE. Exposure to multiple infections was common (73.8% of cases and 65.5% of controls had been exposed to two or more infections), and for T. gondii and O. volvulus co-infection, their combined effect on the prevalence of ACE, as determined by the relative excess risk due to interaction (RERI), was more than additive (T. gondii and O. volvulus, RERI = 1.19). The prevalence of T. solium antibodies was low (2.8% of cases and 2.2% of controls) and was not associated with ACE in the study areas. Conclusion This study investigates how the degree of exposure to parasites and multiple parasitic infections are associated with ACE and may explain conflicting results obtained when only seropositivity is considered. The findings from this study should be further validated. The prevalence of epilepsy is greater in developing countries compared to developed countries, and parasitic infestations are thought to contribute to this increased burden. We conducted a case-control study across five sites in sub-Saharan Africa to investigate the relationship between epilepsy and exposure to parasitic infections, and the association between epilepsy and multiple co-incidental infections. Exposure to Onchocerca volvulus, Toxocara canis and Toxoplasma gondii as well as high antibody levels (top tertile) to Toxocara canis was positively associated with the prevalence of active convulsive epilepsy (ACE). Multiple co-incidental parasitic infections were common, and the combined effect of T. gondii and O. volvulus co-infection on ACE was greater than the sum of the individual effects. The contribution of each of these parasitic infections on the burden of epilepsy in sub-Saharan Africa should be explored.
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Affiliation(s)
- Gathoni Kamuyu
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- * E-mail:
| | - Christian Bottomley
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- MRC Tropical Epidemiology Group, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - James Mageto
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Egerton University, Nakuru, Kenya
| | - Brett Lowe
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Patricia P. Wilkins
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - John C. Noh
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases. National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Anthony K. Ngugi
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Research Support Unit, Faculty of Health Sciences, Aga Khan University (East Africa), Nairobi, Kenya
| | - Rachael Odhiambo
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
| | - Ryan G. Wagner
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Epidemiology and Public Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Angelina Kakooza-Mwesige
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Iganga-Mayuge Health and Demographic Surveillance System, Iganga, Uganda
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | | | | | | | - Faith H. A. Osier
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- Unversity of Basel, Basel, Switzerland
| | - Charles R. Newton
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Neurosciences Unit, UCL Institute of Child Health, London, United Kingdom
- Clinical Research Unit, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
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Dowell SF, Sejvar JJ, Riek L, Vandemaele KAH, Lamunu M, Kuesel AC, Schmutzhard E, Matuja W, Bunga S, Foltz J, Nutman TB, Winkler AS, Mbonye AK. Nodding syndrome. Emerg Infect Dis 2014; 19:1374-84. [PMID: 23965548 PMCID: PMC3810928 DOI: 10.3201/eid1909.130401] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An epidemic illness characterized by head nodding associated with onchocerciasis has been described in eastern Africa since the early 1960s; we summarize published reports and recent studies. Onset of nodding occurs in previously healthy 5-15-year-old children and is often triggered by eating or cold temperatures and accompanied by cognitive impairment. Its incidence has increased in Uganda and South Sudan over the past 10 years. Four case-control studies identified modest and inconsistent associations. There were nonspecific lesions seen by magnetic resonance imaging, no cerebrospinal fluid inflammation, and markedly abnormal electroencephalography results. Nodding episodes are atonic seizures. Testing has failed to demonstrate associations with trypanosomiasis, cysticercosis, loiasis, lymphatic filariasis, cerebral malaria, measles, prion disease, or novel pathogens; or deficiencies of folate, cobalamin, pyridoxine, retinol, or zinc; or toxicity from mercury, copper, or homocysteine. There is a consistent enigmatic association with onchocerciasis detected by skin snip or serologic analysis. Nodding syndrome is an unexplained epidemic epilepsy.
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Affiliation(s)
- Scott F Dowell
- Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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