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Nikièma AS, Koala L, Unnasch TR, Diendéré J, Compaoré J, Ouédraogo MW, Kafando CM, Bakajika D, Bougouma C, Faye B, Traoré S, Dabiré RK. Field sensitivity and specificity of the SD BIOLINE onchocerciasis IgG4 Rapid Diagnostic Test in children <10 years old from endemic areas in Burkina Faso. Parasite Epidemiol Control 2024; 25:e00352. [PMID: 38708128 PMCID: PMC11066673 DOI: 10.1016/j.parepi.2024.e00352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/04/2024] [Accepted: 04/21/2024] [Indexed: 05/07/2024] Open
Abstract
Skin biopsies (Skin snips) have historically been the gold standard for the diagnosis of onchocerciasis. However, in low prevalence areas and in areas with successful ivermectin mass drug administration (MDA) programs, skin snips are not sensitive enough to decide when to stop MDA; thus, serological diagnostic tools have been recommended for this purpose. This study assessed the sensitivity and specificity of the Ov16 Rapid Diagnostic Test (SD BIOLINE Onchocerciasis RDT) compared to skin snip in endemic areas undergoing ivermectin mass distribution using Community Directed Treatment with Ivermectin (CDTI) strategy. A cross-sectional study was conducted between September and November 2016 in five endemic villages in the Cascades region in Burkina Faso. Children aged 2 to 9-years were examined during the impact epidemiological survey using both the skin snip and Ov16 Rapid Diagnostic Test. The Ov16 Rapid Diagnostic Test sensitivity and specificity were determined with reference to the skin biopsy. Skin snip positivity was 1.25% in this population, while seroprevalence was 6.5%. When compared to the skin snip as the gold standard, the sensitivity of the Ov16 Rapid Diagnostic Test was 60% and the specificity 94%. When the Ov16 Rapid Diagnostic Test was considered as the gold standard, the skin snip exhibited a sensitivity of 11.5% and a specificity of 99.5%. These results are similar to other studies comparing the performance of the Ov16 ELISA to skin snips, suggesting that the Ov16 RDT may be a useful tool for ivermectin STOP MDA and post transmission surveys, assuming that the prevalence of infection is low or close to zero, and the Ov16 RDT detected also pre patent infections.
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Affiliation(s)
- Achille Sindimbasba Nikièma
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest, Ministère de l'Enseignement Supérieur, de la Recherche et de l'Innovation (MESRI), Bobo-Dioulasso, Burkina Faso
- Université Cheikh Anta Diop (UCAD), Dakar, Sénégal
| | - Lassane Koala
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest, Ministère de l'Enseignement Supérieur, de la Recherche et de l'Innovation (MESRI), Bobo-Dioulasso, Burkina Faso
| | - Thomas R. Unnasch
- Center for Global Infectious Disease Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Jeoffray Diendéré
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest, Ministère de l'Enseignement Supérieur, de la Recherche et de l'Innovation (MESRI), Bobo-Dioulasso, Burkina Faso
| | - Justin Compaoré
- Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ministère de la Santé et de l'Hygiène Publique, Ouagadougou, Burkina Faso
| | - Mathias W. Ouédraogo
- Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ministère de la Santé et de l'Hygiène Publique, Ouagadougou, Burkina Faso
| | - Claude Montant Kafando
- Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ministère de la Santé et de l'Hygiène Publique, Ouagadougou, Burkina Faso
| | - Didier Bakajika
- Expanded Special Project for Elimination of Neglected Tropical Diseases, ESPEN, Regional Office for Africa, World Health Organization, Brazzaville, Congo
| | - Clarisse Bougouma
- Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ministère de la Santé et de l'Hygiène Publique, Ouagadougou, Burkina Faso
| | - Babacar Faye
- Université Cheikh Anta Diop (UCAD), Dakar, Sénégal
| | - Soungalo Traoré
- Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ministère de la Santé et de l'Hygiène Publique, Ouagadougou, Burkina Faso
| | - Roch Kounbobr Dabiré
- Institut de Recherche en Sciences de la Santé (IRSS), Direction Régionale de l'Ouest, Ministère de l'Enseignement Supérieur, de la Recherche et de l'Innovation (MESRI), Bobo-Dioulasso, Burkina Faso
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Arndts K, Kegele J, Ritter M, Prazeres da Costa C, Hoerauf A, Winkler AS. Active infection with Onchocerca volvulus and the linkage to epilepsy/nodding syndrome. PLoS Negl Trop Dis 2024; 18:e0012076. [PMID: 38722927 PMCID: PMC11081337 DOI: 10.1371/journal.pntd.0012076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/16/2024] [Indexed: 05/13/2024] Open
Affiliation(s)
- Kathrin Arndts
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Josua Kegele
- Hertie Institute for Clinical Brain Research, Department of Neurology and Epileptology, University of Tübingen, Tübingen, Germany
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Clarissa Prazeres da Costa
- Center for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Institute for Medical Microbiology, Immunology and Hygiene, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany
- German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
| | - Andrea S. Winkler
- Center for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Department of Neurology, Technical University of Munich, Munich, Germany
- Department of Community Medicine and Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
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Street A, Taylor EM. Equivocal diagnostics: Making a 'good' point-of-care test for elimination in global health. SOCIAL STUDIES OF SCIENCE 2024:3063127241246727. [PMID: 38654559 DOI: 10.1177/03063127241246727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
What is a diagnostic test for? We might assume the answer to this question is straightforward. A good test would help identify what disease someone suffers from, assist health providers to determine the correct course of treatment and/or enable public health authorities to know and intervene in health at the level of the population. In this article, we show that what a specific diagnostic test is for, the value it holds for different actors, and what makes it good, or not, is often far from settled. We tell the story of the development and design of a rapid antibody test for onchocerciasis, or river blindness, tracking multiple iterations of the device through three configurational moments in the framing of onchocerciasis disease and reshaping of the global health innovation ecosystem. Efforts to build that ecosystem for diagnostics are often premised on the notion that public health needs for diagnostics are pre-given and stable; the challenge is seen to be how to incentivize investment and find a customer base for diagnostics in under-resourced settings. By contrast, we show that for any disease, diagnostic needs are both multiple and constantly in flux, and are unlikely to be met by a single, stand-alone product. In the case of the onchocerciasis Ov-16 rapid test, the failure to recognize and address the multiplicity and instability of diagnostic needs in the innovation process resulted in the development of a rapid point of care test that might be manufactured, procured and used, but is unloved by public health experts and commercial manufacturers alike. The equivocal value of the onchocerciasis rapid test, we suggest, reveals the inadequacy of the current global health innovation ecosystem for developing diagnostic 'goods'.
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Debrah LB, Gyasi C, Ahiadorme M, Rahamani AA, Opoku VS, Obeng P, Osei-Mensah J, Obeng MA, Mensah DA, Debrah AY. Association of haemato-biochemical indices and blood composite ratios with microfilaridermia in Onchocerciasis patients. BMC Infect Dis 2024; 24:384. [PMID: 38589790 PMCID: PMC11003075 DOI: 10.1186/s12879-024-09278-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 04/01/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Onchocerciasis causes chronic systemic inflammation. Several studies have used markers such as haemato-biochemical indices to predict the occurrence of systemic inflammation. This study assessed the variability and predictability of haemato-biochemical indices and blood composite ratios (BCRs) in microfilariae positive (MF+) and microfilariae negative (MF-) subgroups of onchocercomata participants. METHODS One hundred and five (105) MF + and 34 MF- participants were retrospectively recruited into the study. Screening for the presence of O. volvulus microfilariae was done from skin snips taken from the left and right iliac crests of participants using established and approved protocols. Haematological and biochemical indices were measured using standard laboratory automated analyzers. Blood composite ratios (BCRs) were calculated as ratios of the absolute parameters involved. RESULTS A significantly increased total WBC, absolute eosinophil, eosinophil percent and absolute basophil were observed in the MF + participants compared to MF- participants. Reduced gamma-glutamyl transferase (GGT) with increased estimated glomerular filtration rate (eGFR) was significantly associated with MF + participants compared to MF- participants. BCRs were significantly higher for eosinophil-to-neutrophil ratio (ENR), eosinophil-to-monocyte ratio (EMR), eosinophil-to-basophil ratio (EBR) and eosinophil-to-lymphocyte ratio (ELR) in MF + participants compared to MF- participants. After multivariate adjustment, onchocercomata participants with increased eosinophil counts (aOR = 13.86, 95% CI [2.07-92.90], p = 0.007), ENR x10 (aOR = 1.42, 95% CI [1.05-1.93], p = 0.025), EMR (aOR = 2.64, 95% CI [1.25-5.60], p = 0.011), EBR (aOR = 1.07, 95% CI [1.01-1.10], p = 0.020) and ELR x10 (aOR = 1.69, 95% CI [1.14-2.51], p = 0.009) were more likely to have microfilaridermia. CONCLUSIONS Elevated eosinophil counts with higher ENR, EMR, EBR and ELR levels are significantly associated with microfilaridermia in onchocercomata participants. Combining BCRs with eosinophil count significantly led to an improvement in the conventional model for predicting microfilaridermia.
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Affiliation(s)
- Linda Batsa Debrah
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Charles Gyasi
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Monica Ahiadorme
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Abu Abudu Rahamani
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Vera Serwaa Opoku
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Prince Obeng
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Jubin Osei-Mensah
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Department of Pathobiology, School of Veterinary Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Michael Agyemang Obeng
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Derrick Adu Mensah
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Alexander Yaw Debrah
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
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Nikièma AS, Koala L, Post RJ, Kima A, Compaoré J, Kafando CM, Nana JB, Bougouma C, Faye B, Traoré S, Dabiré RK. Progress towards elimination of onchocerciasis in the Region du Sud-Ouest of Burkina Faso which was previously subject to a recrudescence event after vector control. PLoS Negl Trop Dis 2024; 18:e0012118. [PMID: 38683750 PMCID: PMC11057763 DOI: 10.1371/journal.pntd.0012118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 03/29/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND The Sud-Ouest region of Burkina Faso (especially the Bougouriba valley) has been historically problematic with respect to onchocerciasis control, with a recrudescence of infections after vector control carried out the WHO Onchocerciasis Control Programme was halted in 1989. After 1996, mass drug administration of ivermectin was instigated to control the recrudescence so that it would no longer constitute a public health problem. However, in 2010 WHO changed its recommended policy from control to elimination, and in 2013 biannual Community-Directed Treatment with Ivermectin (CDTI) was instigated. Epidemiological surveys were carried-out in 2011 and 2018 to determine whether CDTI was producing a decline in infection levels and progress towards elimination. METHODOLOGY/PRINCIPAL FINDINGS A cross-sectional study was conducted across 20 villages in four health districts in 2011 and 29 villages in 2018. Individuals aged five years and above were examined by skin-snip, and the prevalence and microfilarial load was determined for each village. In 2011, 75% of villages had some infections and 20% had prevalences >5%, with a mean prevalence across all villages of 2.63% (range 0.0-9.7%), and community microfilarial load ranging from 0 to 0.25 microfilariae per biopsy. In 2018, nine villages (= 31% of total) had some infections, with prevalences ranging from 0.41% to 3.54%, and a mean prevalence across all villages of 0.37%. Community microfilarial load ranged from 0 to 0.1. Amongst those people found to be microfilarial positive, 87% had a history of migration. CONCLUSIONS/SIGNIFICANCE The endemicity of onchocerciasis infection in the Sud-Ouest region has declined to low levels and seems to be progressing towards elimination. Our findings indicated that biannual CDTI is having good effect, but it should continue for a number of years to ensure elimination of transmission. However, progress towards elimination has a troublesome history in this region, and it would be advisable to select more sentinel villages to have confidence in any future epidemiological and entomological surveys, especially Stop-MDA surveys. With positive individuals migrating between countries, cross-border collaboration needs more attention to ensure effective treatment for onchocerciasis elimination.
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Affiliation(s)
- Achille Sindimbasba Nikièma
- Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation, Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest (IRSS/Bobo-Dioulasso), Ouagadougou, Burkina Faso
- Université Cheikh Anta Diop, Dakar, Sénégal
| | - Lassane Koala
- Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation, Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest (IRSS/Bobo-Dioulasso), Ouagadougou, Burkina Faso
| | - Rory J. Post
- School of Biological & Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Appolinaire Kima
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | - Justin Compaoré
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | - Claude M. Kafando
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | - Jean Baptiste Nana
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | - Clarisse Bougouma
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | | | - Soungalo Traoré
- Ministère de la Santé, Direction de la Protection de la Santé de la Population, Programme National de Lutte Contre les Maladies Tropicales Négligées, Ouagadougou, Burkina Faso
| | - Roch Kounbobr Dabiré
- Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation, Institut de Recherche en Sciences de la Santé, Direction Régionale de l’Ouest (IRSS/Bobo-Dioulasso), Ouagadougou, Burkina Faso
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Ambe LA, Limunga E, Mbah CE, Adela N, Eric N, Ngoe M, Sone B, Lochnit G, Tachu JB, Wanji S, Taubert A, Hermosilla C, Kamena F. Identification and Characterization of Onchocerca volvulus Heat Shock Protein 70 ( OvHSP70) as Novel Diagnostic Marker of Onchocerciasis in Human Urine. Pathogens 2024; 13:293. [PMID: 38668248 PMCID: PMC11053476 DOI: 10.3390/pathogens13040293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 04/29/2024] Open
Abstract
Despite several decades of mass drug administration and elimination-related activities, human onchocerciasis still represents a major parasitic threat in endemic regions. Among the challenges encountered by the elimination program is the lack of a suitable diagnostic tool that is accurate and non-invasive. Currently used methods are either invasive or not suitable for monitoring large numbers of patients. Herein, we describe the identification and characterization of Onchocerca volvulus heat shock protein 70 (OvHSP70) as a novel diagnostic biomarker for human onchocerciasis, which can directly be detected in urine samples of infected patients. This nematode-specific antigen was identified through LC-MS after differential SDS-PAGE using urine-derived protein extracts from O. volvulus-infected patients in Cameroon. Polyclonal antibodies generated in rabbits after cloning and expression of OvHSP70 in Escherichia coli reliably differentiated between urine samples from infected- and uninfected patients in a hypoendemic area of human onchocerciasis. These results provide an excellent basis for further development of a non-invasive and scalable diagnostic assay for human onchocerciasis using urine samples. Such a urine-based diagnostic assay will be of major importance for the elimination program of human onchcerciasis in endemic countries.
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Affiliation(s)
- Lum Abienwi Ambe
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
- Centre for Research on Health and Priority Pathologies, Institute of Medical Research and Medicinal Plants Studies (IMPM), Yaounde P.O. Box 13033, Cameroon; (C.E.M.); (N.A.)
| | - Elisabeth Limunga
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
| | - Clarisse Engowei Mbah
- Centre for Research on Health and Priority Pathologies, Institute of Medical Research and Medicinal Plants Studies (IMPM), Yaounde P.O. Box 13033, Cameroon; (C.E.M.); (N.A.)
| | - Ngwewondo Adela
- Centre for Research on Health and Priority Pathologies, Institute of Medical Research and Medicinal Plants Studies (IMPM), Yaounde P.O. Box 13033, Cameroon; (C.E.M.); (N.A.)
| | - Ndumu Eric
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
| | - Martha Ngoe
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
| | - Bertrand Sone
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
| | - Günter Lochnit
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus Liebig University Giessen, 35392 Giessen, Germany;
| | - Julius Babila Tachu
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon;
- Research Foundation in Tropical Disease and Environment (REFOTDE), Buea P.O. Box 474, Cameroon
| | - Anja Taubert
- Biomedical Research Center Seltersberg (BFS), Institute of Parasitology, Justus Liebig University Giessen, 35392 Giessen, Germany; (A.T.); (C.H.)
| | - Carlos Hermosilla
- Biomedical Research Center Seltersberg (BFS), Institute of Parasitology, Justus Liebig University Giessen, 35392 Giessen, Germany; (A.T.); (C.H.)
| | - Faustin Kamena
- Laboratory for Molecular Parasitology, Department of Microbiology and Parasitology, University of Buea, Buea P.O. Box 63, Cameroon; (E.L.); (N.E.); (M.N.); (B.S.); (J.B.T.)
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Crawford KE, Hedtke SM, Doyle SR, Kuesel AC, Armoo S, Osei-Atweneboana MY, Grant WN. Genome-based tools for onchocerciasis elimination: utility of the mitochondrial genome for delineating Onchocerca volvulus transmission zones. Int J Parasitol 2024; 54:171-183. [PMID: 37993016 DOI: 10.1016/j.ijpara.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 09/21/2023] [Accepted: 11/13/2023] [Indexed: 11/24/2023]
Abstract
National programs in Africa have expanded their objectives from control of onchocerciasis (river blindness) as a public health problem to elimination of parasite transmission, motivated by the reduction of Onchocerca volvulus infection prevalence in many African meso- and hyperendemic areas due to mass drug administration of ivermectin (MDAi). Given the large, contiguous hypo-, meso-, and hyperendemic areas, sustainable elimination of onchocerciasis in sub-Saharan Africa requires delineation of geographic boundaries for parasite transmission zones, so that programs can consider the risk of parasite re-introduction through vector or human migration from areas with ongoing transmission when making decisions to stop MDAi. We propose that transmission zone boundaries can be delineated by characterising the parasite genetic population structure within and between potential zones. We analysed whole mitochondrial genome sequences of 189 O. volvulus adults to determine the pattern of genetic similarity across three West African countries: Ghana, Mali, and Côte d'Ivoire. Population genetic structure indicates that parasites from villages near the Pru, Daka, and Black Volta rivers in central Ghana belong to one parasite population, indicating that the assumption that river basins constitute individual transmission zones is not supported by the data. Parasites from Mali and Côte d'Ivoire are genetically distinct from those from Ghana. This research provides the basis for developing tools for elimination programs to delineate transmission zones, to estimate the risk of parasite re-introduction via vector or human movement when intervention is stopped in one area while transmission is ongoing in others, to identify the origin of infections detected post-treatment cessation, and to investigate whether persisting prevalence despite ongoing interventions in one area is due to parasites imported from others.
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Affiliation(s)
- Katie E Crawford
- Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Shannon M Hedtke
- Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, Victoria, Australia; Department of Environment and Genetics, La Trobe University, Bundoora, Victoria, Australia.
| | - Stephen R Doyle
- Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Annette C Kuesel
- UNICEF/UNDP/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | - Samuel Armoo
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research, Council Close, Accra, Ghana
| | - Mike Y Osei-Atweneboana
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research, Council Close, Accra, Ghana
| | - Warwick N Grant
- Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, Victoria, Australia; Department of Environment and Genetics, La Trobe University, Bundoora, Victoria, Australia
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Oyeyemi OT, Ogundahunsi O, Schunk M, Fatem RG, Shollenberger LM. Neglected tropical disease (NTD) diagnostics: current development and operations to advance control. Pathog Glob Health 2024; 118:1-24. [PMID: 37872790 PMCID: PMC10769148 DOI: 10.1080/20477724.2023.2272095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023] Open
Abstract
Neglected tropical diseases (NTDs) have become important public health threats that require multi-faceted control interventions. As late treatment and management of NTDs contribute significantly to the associated burdens, early diagnosis becomes an important component for surveillance and planning effective interventions. This review identifies common NTDs and highlights the progress in the development of diagnostics for these NTDs. Leveraging existing technologies to improve NTD diagnosis and improving current operational approaches for deployment of developed diagnostics are crucial to achieving the 2030 NTD elimination target. Point-of-care NTD (POC-NTD) diagnostic tools are recommended preferred diagnostic options in resource-constrained areas for mapping risk zones and monitoring treatment efficacy. However, few are currently available commercially. Technical training of remote health care workers on the use of POC-NTD diagnostics, and training of health workers on the psychosocial consequences of these diagnostics are critical in harnessing POC-NTD diagnostic potential. While the COVID-19 pandemic has challenged the possibility of achieving NTD elimination in 2030 due to the disruption of healthcare services and dwindling financial support for NTDs, the possible contribution of NTDs in exacerbating COVID-19 pandemic should motivate NTD health system strengthening.
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Affiliation(s)
- Oyetunde T. Oyeyemi
- Department of Biosciences and Biotechnology, University of Medical Sciences, Ondo, Nigeria
- Department of Biological Sciences, Old Dominion University, Virginia, USA
| | - Olumide Ogundahunsi
- The Central Office for Research and Development (CORD), University of Medical Sciences, Ondo, Nigeria
| | - Mirjam Schunk
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU) institution, Munich, Germany
| | - Ramzy G. Fatem
- Schistosome Biological Supply Center, Theodor Bilharz Research Institute, Giza, Egypt
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9
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Doherty M, Grant JR, Pilotte N, Bennuru S, Fischer K, Fischer PU, Lustigman S, Nutman TB, Pfarr K, Hoerauf A, Unnasch TR, Hassan HK, Wanji S, Lammie PJ, Ottesen E, Mackenzie C, Williams SA. Optimized strategy for real-time qPCR detection of Onchocerca volvulus DNA in pooled Simulium sp. blackfly vectors. PLoS Negl Trop Dis 2023; 17:e0011815. [PMID: 38096317 PMCID: PMC10754622 DOI: 10.1371/journal.pntd.0011815] [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: 04/25/2023] [Revised: 12/28/2023] [Accepted: 11/22/2023] [Indexed: 12/30/2023] Open
Abstract
BACKGROUND Onchocerca volvulus is a filarial parasite that is a major cause of dermatitis and blindness in endemic regions primarily in sub-Saharan Africa. Widespread efforts to control the disease caused by O. volvulus infection (onchocerciasis) began in 1974 and in recent years, following successful elimination of transmission in much of the Americas, the focus of efforts in Africa has moved from control to the more challenging goal of elimination of transmission in all endemic countries. Mass drug administration (MDA) with ivermectin has reached more than 150 million people and elimination of transmission has been confirmed in four South American countries, with at least two African countries having now stopped MDA as they approach verification of elimination. It is essential that accurate data for active transmission are used to assist in making the critical decision to stop MDA, since missing low levels of transmission and infection can lead to continued spread or recrudescence of the disease. METHODOLOGY/PRINCIPAL FINDINGS Current World Health Organization guidelines for MDA stopping decisions and post-treatment surveillance include screening pools of the Simulium blackfly vector for the presence of O. volvulus larvae using a PCR-ELISA-based molecular technique. In this study, we address the potential of an updated, practical, standardized molecular diagnostic tool with increased sensitivity and species-specificity by comparing several candidate qPCR assays. When paired with heat-stable reagents, a qPCR assay with a mitochondrial DNA target (OvND5) was found to be more sensitive and species-specific than an O150 qPCR, which targets a non-protein coding repetitive DNA sequence. The OvND5 assay detected 19/20 pools of 100 blackfly heads spiked with a single L3, compared to 16/20 for the O150 qPCR assay. CONCLUSIONS/SIGNIFICANCE Given the improved sensitivity, species-specificity and resistance to PCR inhibitors, we identified OvND5 as the optimal target for field sample detection. All reagents for this assay can be shipped at room temperature with no loss of activity. The qPCR protocol we propose is also simpler, faster, and more cost-effective than the current end-point molecular assays.
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Affiliation(s)
- Mary Doherty
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Jessica R. Grant
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Nils Pilotte
- Department of Biological Sciences, Quinnipiac University, Hamden, Connecticut, United States of America
| | - Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Kerstin Fischer
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Peter U. Fischer
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner-Site Bonn-Cologne, Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Partner-Site Bonn-Cologne, Bonn, Germany
| | - Thomas R. Unnasch
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, Florida, United States of America
| | - Hassan K. Hassan
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, Florida, United States of America
| | - Samuel Wanji
- Parasite and Vectors Research Unit, Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and the Environment, Buea, Cameroon
| | - Patrick J. Lammie
- NTD-SC, Task Force for Global Health, Atlanta, Georgia, United States of America
| | - Eric Ottesen
- NTD-SC, Task Force for Global Health, Atlanta, Georgia, United States of America
| | - Charles Mackenzie
- NTD-SC, Task Force for Global Health, Atlanta, Georgia, United States of America
- RLMF, The END Fund, New York, New York, United States of America
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
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10
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Weppelmann TA, Harvey K, Narain S. Man With Disappearing Subconjunctival Foreign Body. JAMA Ophthalmol 2023; 141:1002-1003. [PMID: 37676654 DOI: 10.1001/jamaophthalmol.2023.4043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
A 33-year-old man reported a “pulling and popping sensation” in his left eye and had a photograph showing an irregular, serpiginous extension that was present during the episode. Examination was unremarkable. What would you do next?
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Affiliation(s)
- Thomas A Weppelmann
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa
- James A. Haley Eye Clinic, Department of Veterans' Affairs, Tampa, Florida
| | - Kevin Harvey
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa
- James A. Haley Eye Clinic, Department of Veterans' Affairs, Tampa, Florida
| | - Sahas Narain
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa
- James A. Haley Eye Clinic, Department of Veterans' Affairs, Tampa, Florida
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11
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Mitra I, Bhattacharya A, Paul J, Anisuzzaman. Present status with impacts and roles of miRNA on Soil Transmitted Helminthiosis control: A review. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2023; 5:100162. [PMID: 37520661 PMCID: PMC10371793 DOI: 10.1016/j.crphar.2023.100162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 06/22/2023] [Accepted: 07/10/2023] [Indexed: 08/01/2023] Open
Abstract
Soil-Transmitted Helminthiasis (STH) is one of the most widespread Neglected Tropical Diseases (NTDs), and almost 1.5 billion of the global population is affected, mostly in the indigent, countryside sectors of tropics/subtropics. STH, commonly caused by various nematodes, adversely affects the hosts' growth, cognatic development, and immunity. Albendazole is most commonly used against STH (Soil-Transmitted Helminths) but resistance has already been reported in different countries. To date, no effective vaccine is present against STH. miRNAs are a unique class of small non-coding RNA, regulating various biological activities indulging host immune responses in host-pathogen interaction of STH. Dysregulation of miRNAs are being considered as one of the most important aspect of host-parasite interactions. Thus, it is the prime importance to identify and characterize parasite-specific as well as host-derived miRNAs to understand the STH infection at the molecular level. Systematic bibliometric analysis reveals a huge knowledge gap in understanding the disease by using both host and parasitic miRNAs as a potential biomarker. In this study, we addressed the present status of the STH prevalence, and therapy under the light of miRNAs. This would further help in designing new inhibitors and therapeutic strategies to control STH.
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Affiliation(s)
- Imon Mitra
- Department of Biological Sciences, School of Life Science and Biotechnology, Adamas University, Kolkata, India
| | - Arijit Bhattacharya
- Department of Biological Sciences, School of Life Science and Biotechnology, Adamas University, Kolkata, India
| | - Joydeep Paul
- Department of Biotechnology, School of Life Science and Biotechnology, Adamas University, Kolkata, India
| | - Anisuzzaman
- Department of Parasitology, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
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12
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Rosa BA, Curtis K, Erdmann Gilmore P, Martin J, Zhang Q, Sprung R, Weil GJ, Townsend RR, Fischer PU, Mitreva M. Direct Proteomic Detection and Prioritization of 19 Onchocerciasis Biomarker Candidates in Humans. Mol Cell Proteomics 2022; 22:100454. [PMID: 36435333 PMCID: PMC9792368 DOI: 10.1016/j.mcpro.2022.100454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/30/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Onchocerca volvulus, the causative agent of onchocerciasis, infects over 20 million people and can cause severe dermatitis and ocular conditions including blindness. Current treatments employed in mass drug administration programs do not kill adult female worms, and common diagnostic tests cannot reliably assess viability of adult worms. There is an urgent need for better diagnostic tests to facilitate monitoring the efficacy of new treatments and disease elimination efforts. Here, eight plasma samples collected from individuals infected with O. volvulus and seven from uninfected individuals were analyzed by MS/MS spectrometry to directly identify O. volvulus proteins present in infected but absent in uninfected control samples. This direct proteomic approach for biomarker discovery had not been previously employed for onchocerciasis. Among all detected proteins, 19 biomarker candidates were supported by two or more unique peptides, identified in the plasma of at least three O. volvulus-infected human samples and absent in all control samples. Comprehensive analysis and ranking of these candidates included detailed functional annotation and a review of RNA-seq gene expression profiles. Isotope-labeled standard peptides were run in parallel and validated MS/MS peptide identifications for 15 peptides from 11 of the 19 proteins, and two infected urine and one uninfected urine sample was used for additional validation. A major antigen/OVOC11613 was identified as the most promising candidate with eight unique peptides across five plasma samples and one urine sample. Additional strong candidates included OVOC1523/ATP synthase, OVOC247/laminin and OVOC11626/PLK5, and along with OVOC11613, and were also detected in urine samples from onchocerciasis patients. This study has identified a promising novel set of proteins that will be carried forward to develop assays that can be used for diagnosis of O. volvulus infections and for monitoring treatment efficacy.
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Affiliation(s)
- Bruce A. Rosa
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Kurt Curtis
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Petra Erdmann Gilmore
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John Martin
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Qiang Zhang
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Robert Sprung
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Gary J. Weil
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - R. Reid Townsend
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Peter U. Fischer
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA,Department of Genetics, Washington University School of Medicine, St Louis, Missouri, USA,McDonnell Genome Institute, Washington University School of Medicine, St Louis, Missouri, USA,For correspondence: Makedonka Mitreva
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13
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Frallonardo L, Di Gennaro F, Panico GG, Novara R, Pallara E, Cotugno S, Guido G, De Vita E, Ricciardi A, Totaro V, Camporeale M, De Iaco G, Bavaro DF, Lattanzio R, Patti G, Brindicci G, Papagni R, Pellegrino C, Santoro CR, Segala FV, Putoto G, Nicastri E, Saracino A. Onchocerciasis: Current knowledge and future goals. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.986884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human Onchocerciasis, caused by infection by the filarial nematode Onchocerca volvulus, is a neglected public health disease that affects millions of people in the endemic regions of sub-Saharan Africa and Latin America. It is also called river blindness because the Blackflies that transmit infection breeds in rapidly flowing fresh water streams and rivers. This review features state-of-the-art data on the parasite, its endobacteria Wolbachia, the prevalence of the infection and its geographical distribution, its diagnostics, the interaction between the parasite and its host, and the pathology of Onchocerciasis. By development and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas (Colombia, Ecuador, Mexico, and Guatemala)and inSudan, followed by Onchocerciasis eliminations. The current state and future perspectives for vector control and elimination strategy are described.
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14
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Yalley AK, Ahiatrogah S, Kafintu-Kwashie AA, Amegatcher G, Prah D, Botwe AK, Adusei-Poku MA, Obodai E, Nii-Trebi NI. A Systematic Review on Suitability of Molecular Techniques for Diagnosis and Research into Infectious Diseases of Concern in Resource-Limited Settings. Curr Issues Mol Biol 2022; 44:4367-4385. [PMID: 36286015 PMCID: PMC9601131 DOI: 10.3390/cimb44100300] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
Infectious diseases significantly impact the health status of developing countries. Historically, infectious diseases of the tropics especially have received insufficient attention in worldwide public health initiatives, resulting in poor preventive and treatment options. Many molecular tests for human infections have been established since the 1980s, when polymerase chain reaction (PCR) testing was introduced. In spite of the substantial innovative advancements in PCR technology, which currently has found wide application in most viral pathogens of global concern, the development and application of molecular diagnostics, particularly in resource-limited settings, poses potential constraints. This review accessed data from sources including PubMed, Google Scholar, the Web of Knowledge, as well as reports from the World Health Organization’s Annual Meeting on infectious diseases and examined these for current molecular approaches used to identify, monitor, or investigate some neglected tropical infectious diseases. This review noted some growth efforts in the development of molecular techniques for diagnosis of pathogens that appear to be common in resource limited settings and identified gaps in the availability and applicability of most of these molecular diagnostics, which need to be addressed if the One Health goal is to be achieved.
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Affiliation(s)
- Akua K. Yalley
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, University of Ghana, Accra P.O. Box KB 143, Ghana
| | - Selasie Ahiatrogah
- Department of Obstetrics and Gynaecology, College of Medicine, Pan African University of Life and Earth Sciences Institute, University of Ibadan, Ibadan P.O. Box 22133, Nigeria
| | - Anna A. Kafintu-Kwashie
- Department of Medical Microbiology, University of Ghana Medical School, Accra GA-221-1570, Ghana
| | - Gloria Amegatcher
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, University of Ghana, Accra P.O. Box KB 143, Ghana
| | - Diana Prah
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra P.O. Box LG 54, Ghana
| | - Akua K. Botwe
- Molecular Biology Unit, Kintampo Health Research Centre, Ghana Health Service, Kintampo P.O. Box 200, Ghana
| | - Mildred A. Adusei-Poku
- Department of Medical Microbiology, University of Ghana Medical School, Accra GA-221-1570, Ghana
| | - Evangeline Obodai
- Department of Virology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra P.O. Box LG 581, Ghana
| | - Nicholas I. Nii-Trebi
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, University of Ghana, Accra P.O. Box KB 143, Ghana
- Correspondence: ; Tel.: +233-54-827-6424
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15
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Otiti-Sengeri J, Omaido BA, Bhwana D, Nakanjako D, Missiru M, Muwonge M, Amaral LJ, Mmbando BP, Colebunders R. High Prevalence of Glaucoma among Patients in an Onchocerciasis Endemic Area (Mahenge, Tanzania). Pathogens 2022; 11:pathogens11091046. [PMID: 36145478 PMCID: PMC9501165 DOI: 10.3390/pathogens11091046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Onchocerciasis is known to cause skin lesions and blindness, but there is also epidemiological evidence that onchocerciasis is associated with epilepsy, including nodding syndrome. We carried out ocular exams in persons with epilepsy in Mahenge, an onchocerciasis endemic area with a high prevalence of epilepsy in Tanzania. We recruited 278 consecutive persons with epilepsy attending the epilepsy clinic at Mahenge hospital and satellite clinics in rural villages. They underwent a general physical and a detailed ocular examination and were tested for onchocerciasis Ov16 IgG4 antibodies. Glaucoma was defined by a raised intraocular pressure above 21 mmHg with evidence of typical glaucomatous disc changes in one or both eyes. Among the 278 participants, median age 27 (IQR 21–38) years, 55.4% were female; 151/210 (71.9%) (95% CI: 65.3–77.9) were Ov16 positive. The most frequent ophthalmic lesions were glaucoma (33.1%), vitreous opacities (6.5%) and cataracts (2.9%). In multivariate analysis, glaucoma (adjusted IRR = 1.46; 95% CI: 1.24–1.70) and age (adjusted IRR = 1.01; 95% CI: 1.01–1.02) were significantly associated with onchocerciasis. In conclusion, a high prevalence of glaucoma was observed among Ov16 positive persons with epilepsy. Persons with epilepsy with O. volvulus infection should undergo screening for glaucoma to prevent one of the causes of preventable blindness.
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Affiliation(s)
- Juliet Otiti-Sengeri
- Department of Ophthalmology, College of Health Sciences, Makerere University, Kampala P.O. Box 7072, Uganda
- Correspondence: ; Tel.: +256-772381162; Fax: +256-41255962
| | - Blair Andrew Omaido
- Department of Ophthalmology, College of Health Sciences, Makerere University, Kampala P.O. Box 7072, Uganda
| | - Dan Bhwana
- National Institute for Medical Research, Tanga Centre, Tanga P.O. Box 5004, Tanzania
| | - Damalie Nakanjako
- Department of Internal Medicine, College of Health Sciences, Makerere University, Kampala P.O. Box 7072, Uganda
| | - Malik Missiru
- Department of Ophthalmology, Mahenge District Hospital, Mahenge P.O. Box 4, Tanzania
| | - Musa Muwonge
- School of Medicine, Soroti University, Soroti P.O. Box 690, Uganda
| | - Luis-Jorge Amaral
- Global Health Institute, University of Antwerp, Kinsbergen Centrum, Doornstraat 331, 2610 Antwerp, Belgium
| | - Bruno P. Mmbando
- National Institute for Medical Research, Tanga Centre, Tanga P.O. Box 5004, Tanzania
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, Kinsbergen Centrum, Doornstraat 331, 2610 Antwerp, Belgium
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Schmidt CA, Cromwell EA, Hill E, Donkers KM, Schipp MF, Johnson KB, Pigott DM, Hay SI. The prevalence of onchocerciasis in Africa and Yemen, 2000-2018: a geospatial analysis. BMC Med 2022; 20:293. [PMID: 36068517 PMCID: PMC9449300 DOI: 10.1186/s12916-022-02486-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 07/14/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Onchocerciasis is a disease caused by infection with Onchocerca volvulus, which is transmitted to humans via the bite of several species of black fly, and is responsible for permanent blindness or vision loss, as well as severe skin disease. Predominantly endemic in parts of Africa and Yemen, preventive chemotherapy with mass drug administration of ivermectin is the primary intervention recommended for the elimination of its transmission. METHODS A dataset of 18,116 geo-referenced prevalence survey datapoints was used to model annual 2000-2018 infection prevalence in Africa and Yemen. Using Bayesian model-based geostatistics, we generated spatially continuous estimates of all-age 2000-2018 onchocerciasis infection prevalence at the 5 × 5-km resolution as well as aggregations to the national level, along with corresponding estimates of the uncertainty in these predictions. RESULTS As of 2018, the prevalence of onchocerciasis infection continues to be concentrated across central and western Africa, with the highest mean estimates at the national level in Ghana (12.2%, 95% uncertainty interval [UI] 5.0-22.7). Mean estimates exceed 5% infection prevalence at the national level for Cameroon, Central African Republic, Democratic Republic of the Congo (DRC), Guinea-Bissau, Sierra Leone, and South Sudan. CONCLUSIONS Our analysis suggests that onchocerciasis infection has declined over the last two decades throughout western and central Africa. Focal areas of Angola, Cameroon, the Democratic Republic of the Congo, Ethiopia, Ghana, Guinea, Mali, Nigeria, South Sudan, and Uganda continue to have mean microfiladermia prevalence estimates exceeding 25%. At and above this level, the continuation or initiation of mass drug administration with ivermectin is supported. If national programs aim to eliminate onchocerciasis infection, additional surveillance or supervision of areas of predicted high prevalence would be warranted to ensure sufficiently high coverage of program interventions.
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Affiliation(s)
- Chris A Schmidt
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA.
| | - Elizabeth A Cromwell
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - Elex Hill
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - Katie M Donkers
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - Megan F Schipp
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - Kimberly B Johnson
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | - David M Pigott
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
| | | | - Simon I Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
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17
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Nana-Djeunga HC, Sicard CM, Mogoung-Wafo AE, Chesnais CB, Deléglise H, Touka-Nounkeu R, Domche A, Golden A, Klion AD, Nutman TB, Boussinesq M, Kamgno J, Pion SD. Changes in Onchocerciasis Ov16 IgG4 Rapid Diagnostic Test Results Over One-Month Follow-up: Lessons for Reading Timeframe and Decision-Making. Am J Trop Med Hyg 2022; 107:tpmd211201. [PMID: 35914689 PMCID: PMC9490668 DOI: 10.4269/ajtmh.21-1201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 04/30/2022] [Indexed: 11/14/2022] Open
Abstract
The SD Bioline® IgG4 rapid diagnostic test (RDT) detects IgG4 antibodies induced by the Onchocerca volvulus-specific antigen Ov16. We evaluated the stability of the RDT results over 1 month, at different time points after completion of each assay, using eluted dried blood spots collected in central Cameroon. Agreement coefficients regarding positivity between 30 minutes and 24 hours, 1, 2, 3, and 4 weeks were, 96.4%, 93.4%, 93.3%, 93.2%, and 93.2%, respectively. Between 30 minutes and 24 hours, 3.6% of the 15,444 tests showed inconsistent results with 81.2% of these tests changing from negative to positive, increasing O. volvulus antibody prevalence from 23.9% to 26.2% (P < 0.0001). This change from negative to positive outcome was confirmed at the subsequent timepoints. Depending on the desired accuracy of prevalence estimates, reading time may have to be redefined more strictly.
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Affiliation(s)
| | - Capucine M. Sicard
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, Montpellier, France
| | - Aude E. Mogoung-Wafo
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon
| | - Cédric B. Chesnais
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, Montpellier, France
| | - Hugo Deléglise
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, Montpellier, France
| | - Rufine Touka-Nounkeu
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon
| | - André Domche
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | | | - Amy D. Klion
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Michel Boussinesq
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, Montpellier, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Sébastien D. Pion
- Institut de Recherche pour le Développement, UMI 233-Inserm U1175-Montpellier University, Montpellier, France
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Djune-Yemeli L, Domché A, Nana-Djeunga HC, Donfo-Azafack C, Lenou-Nanga CG, Masumbe-Netongo P, Kamgno J. Relationship between skin snip and Ov16 ELISA: Two diagnostic tools for onchocerciasis in a focus in Cameroon after two decades of ivermectin-based preventive chemotherapy. PLoS Negl Trop Dis 2022; 16:e0010380. [PMID: 35499993 PMCID: PMC9098087 DOI: 10.1371/journal.pntd.0010380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 05/12/2022] [Accepted: 03/31/2022] [Indexed: 11/28/2022] Open
Abstract
Background Onchocerciasis elimination currently relies on repeated ivermectin-based preventive chemotherapy. Current World Health Organization’s guidelines strongly recommend, though with low evidence of certainty, the use of Ov16 serology testing in children younger than 10 years old to assess whether mass drugs administration can be safely stopped. Therefore, more evidences are needed to support the use of this marker as sero-evaluation tool. This study aimed at determining the relationship between microfilaridermia and anti-Ov16 IgG4, and their variation according to age, gender and ivermectin intake history. Methodology A cross-sectional survey was conducted in an area where ivermectin-based MDA has been implemented since more than 20 years. A questionnaire was used to record ivermectin intake history for the last 5 years. All volunteers aged ≥2 years were tested for microfilaridermia. IgG4 antibodies against Ov16 antigen were determined using the Standard Diagnostic Ov16 IgG4 ELISA kits and the recombinant anti-Ov16 AbD19432 antibodies. Prevalences, microfilaridermia counts and IgG4 concentrations were compared with regards to age, gender and history of ivermectin intake. Principal findings The prevalence of skin microfilariae was 23.4% (95% CI: 23.4–30.8), whereas Ov16 seroprevalence was 53.2% (95% CI: 47.9–58.4). A moderate positive percentage agreement (50.4%) and a high negative percentage agreement (69.2%) was found between skin snip and Ov16 serology in the whole population, while in children aged <10 years, the agreements were higher (positive percentage agreement: 62.6%; negative percentage agreement: 83.5%). In addition, no associations were found between ivermectin intake, Mf counts and estimated IgG4 concentration of participants. Anti-Ov16 IgG4 were higher in individuals harboring microfilariae than their negative counterparts (p<0.0001), though a negative correlation was found between skin microfilarial counts and anti-Ov16 IgG4 levels (r = -0.2400; p = 0.03). No variation in microfilarial counts according to age and gender was observed. Though positively correlated with age (r = 0.4020; p<0.0001), IgG4 was significantly different between the different age classes (p<0.0001). Conclusion/Significance Our results revealed moderate positive and negative agreements between parasitological and immunological parameters of onchocerciasis infection after several rounds MDA. Anti-Ov16 IgG4 levels increased with age but decreased with microfilarial counts, suggesting a variation of anti-Ov16 IgG4 as a result of constant exposure and accumulation of infection. This brings evidence sustaining the use of Ov16 serology in children as evaluation tool. However, additional investigations are needed to further reshape the appropriate age range among children aged <10 years old. The elimination of onchocerciasis places high demands on monitoring and evaluation. The current WHO’s guidelines recommend the use of serological test (ELISA) to determine the presence of IgG4 antibodies to the O. volvulus specific antigen Ov16 among children aged <10 years old, thought with low evidence of certainty. In this paper, we explored the relationship between anti-Ov16 IgG4 antibodies and microfilaridermia counts, and assessed their variation according to age, gender and history of ivermectin intake. Our findings revealed no variation of Mf count and IgG4 with ivermectin intake. However, we observed that anti-Ov16 IgG4 decrease with microfilaridermia counts, but an increasing trend was observed with age. This brings evidence sustaining the use of Ov16 serology testing as exposition marker in children younger than 10 years. However, children age 2 to 4 years seem to have a very low anti-Ov16 IgG4 concentration, this finding should be considered when defining the age class for seroprevalence evaluation.
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Affiliation(s)
- Linda Djune-Yemeli
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
- Molecular Diagnosis Research Group, Biotechnology Centre-University of Yaoundé I (BTC-UY-I), Yaoundé, Cameroon
| | - André Domché
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Hugues C. Nana-Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Cyrille Donfo-Azafack
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Cedric G. Lenou-Nanga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Palmer Masumbe-Netongo
- Molecular Diagnosis Research Group, Biotechnology Centre-University of Yaoundé I (BTC-UY-I), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
- * E-mail:
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Johanns SI, Gantin RG, Wangala B, Komlan K, Halatoko WA, Banla M, Karabou P, Luty AJF, Schulz-Key H, Köhler C, Soboslay PT. Onchocerca volvulus-specific antibody and cellular responses in onchocerciasis patients treated annually with ivermectin for 30 years and exposed to parasite transmission in central Togo. PLoS Negl Trop Dis 2022; 16:e0010340. [PMID: 35503786 PMCID: PMC9064110 DOI: 10.1371/journal.pntd.0010340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 03/20/2022] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Annual mass drug administrations (MDA) of ivermectin will strongly reduce Onchocerca volvulus microfilariae (mf) in the skin and in the onchocerciasis patients' eyes. Ivermectin treatment will also affect the expression of immunity in patients, such that activated immune defenses may help control and contribute to clearance of mf of O. volvulus. Longitudinal surveys are a prerequisite to determining the impact of ivermectin on the status of anti-parasite immunity, notably in risk zones where parasite transmission and active O. volvulus infections persist. METHODOLOGY/PRINCIPAL FINDINGS Onchocerciasis patients were treated annually with ivermectin and their Onchocerca volvulus antigen (OvAg) specific IgG and cellular responses were investigated before and at 30 years post initial ivermectin treatment (30yPT). Repeated annual ivermectin treatments eliminated persisting O. volvulus microfilariae (mf) from the skin of patients and abrogated patent infections. The OvAg-specific IgG1 and IgG4 responses were diminished at 30yPT to the levels observed in endemic controls. Prior to starting ivermectin treatment, OvAg-induced cellular productions of IL-10, IFN-γ, CCL13, CCL17 and CCL18 were low in patients, and at 30yPT, cellular cytokine and chemokine responses increased to the levels observed in endemic controls. In contrast, mitogen(PHA)- induced IL-10, IFN-γ, CCL17 and CCL18 cellular production was diminished. This divergent response profile thus revealed increased parasite antigen-specific but reduced polyclonal cellular responsiveness in patients. The transmission of O. volvulus continued at the patients' location in the Mô river basin in central Togo 2018 and 2019 when 0.58% and 0.45%, respectively, of Simulium damnosum s.l. vector blackflies carried O. volvulus infections. CONCLUSIONS/SIGNIFICANCE Repeated annual ivermectin treatment of onchocerciasis patients durably inhibited their patent O. volvulus infections despite ongoing low-level parasite transmission in the study area. Repeated MDA with ivermectin affects the expression of immunity in patients. O. volvulus parasite-specific antibody levels diminished to levels seen in infection-free endemic controls. With low antibody levels, antibody-dependent cellular cytotoxic responses against tissue-dwelling O. volvulus larvae will weaken. O. volvulus antigen inducible cytokine and chemokine production increased in treated mf-negative patients, while their innate responsiveness to mitogen declined. Such lower innate responsiveness in elderly patients could contribute to reduced adaptive immune responses to parasite infections and vaccines. On the other hand, increased specific cellular chemokine responses in mf-negative onchocerciasis patients could reflect effector cell activation against tissue invasive larval stages of O. volvulus. The annual Simulium damnosum s.l. biting rate observed in the Mô river basin was similar to levels prior to initiation of MDA with ivermectin, and the positive rtPCR results reported here confirm ongoing O. volvulus transmission.
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Affiliation(s)
- Saskia I. Johanns
- University Clinics Tübingen, Institute for Tropical Medicine, Eberhard-Karls University, Tübingen, Germany
| | - Richard G. Gantin
- Onchocerciasis Reference Laboratory, Institut National d’Hygiene, Centre Hospitalier Regional, Sokode, Togo
| | - Bawoubadi Wangala
- Onchocerciasis Reference Laboratory, Institut National d’Hygiene, Centre Hospitalier Regional, Sokode, Togo
| | | | | | - Meba Banla
- Centre Hospitalier Universitaire, Université de Lomé, Lomé, Togo
| | | | - Adrian JF Luty
- Université de Paris, Institut de Recherche pour le Développement, Paris, France
| | - Hartwig Schulz-Key
- University Clinics Tübingen, Institute for Tropical Medicine, Eberhard-Karls University, Tübingen, Germany
| | - Carsten Köhler
- University Clinics Tübingen, Institute for Tropical Medicine, Eberhard-Karls University, Tübingen, Germany
| | - Peter T. Soboslay
- University Clinics Tübingen, Institute for Tropical Medicine, Eberhard-Karls University, Tübingen, Germany
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20
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Rogers MJ, McManus DP, Muhi S, Gordon CA. Membrane Technology for Rapid Point-of-Care Diagnostics for Parasitic Neglected Tropical Diseases. Clin Microbiol Rev 2021; 34:e0032920. [PMID: 34378956 PMCID: PMC8404699 DOI: 10.1128/cmr.00329-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Parasitic neglected tropical diseases (NTDs) affect over one billion people worldwide, with individuals from communities in low-socioeconomic areas being most at risk and suffering the most. Disease management programs are hindered by the lack of infrastructure and resources for clinical sample collection, storage, and transport and a dearth of sensitive diagnostic methods that are inexpensive as well as accurate. Many diagnostic tests and tools have been developed for the parasitic NTDs, but the collection and storage of clinical samples for molecular and immunological diagnosis can be expensive due to storage, transport, and reagent costs, making these procedures untenable in most areas of endemicity. The application of membrane technology, which involves the use of specific membranes for either sample collection and storage or diagnostic procedures, can streamline this process, allowing for long-term sample storage at room temperature. Membrane technology can be used in serology-based diagnostic assays and for nucleic acid purification prior to molecular analysis. This facilitates the development of relatively simple and rapid procedures, although some of these methods, mainly due to costs, lack accessibility in low-socioeconomic regions of endemicity. New immunological procedures and nucleic acid storage, purification, and diagnostics protocols that are simple, rapid, accurate, and cost-effective must be developed as countries progress control efforts toward the elimination of the parasitic NTDs.
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Affiliation(s)
- Madeleine J. Rogers
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Donald P. McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Catherine A. Gordon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
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21
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Tandem Use of OvMANE1 and Ov-16 ELISA Tests Increases the Sensitivity for the Diagnosis of Human Onchocerciasis. Life (Basel) 2021; 11:life11121284. [PMID: 34947815 PMCID: PMC8703281 DOI: 10.3390/life11121284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/15/2021] [Accepted: 11/20/2021] [Indexed: 12/19/2022] Open
Abstract
The current serological test for human onchocerciasis relies on IgG4 reactivity against the parasite Ov-16 antigen, with reported sensitivities of only 60–80%. As control programs move from control to elimination, it is imperative to identify novel molecules that could improve the serodiagnosis reliability of this disease. In this study we compared the sensitivity of total IgG against OvMANE1—a chimeric antigen previously identified as a potential biomarker of human onchocerciasis—with that of an Ov-16 antibody test to detect an Onchocerca volvulus infection in persons presenting with microfilaria in skin snips. One hundred and ninety serum samples were obtained from persons with epilepsy in an onchocerciasis-endemic area at Ituri in the Democratic Republic of Congo where ivermectin has never been distributed. Fifty-nine (31.1%) samples were from individuals with a positive skin snip test; 41 (69.5%) of these 59 samples were positive with the OvMANE1 test and 41 (69.5%) with the Ov-16 test; 30 (50.8%) samples were positive for both tests and in 52 (88.1%) at least one of the tests was positive. Testing the 131 sera from persons with a negative skin snip result revealed that 63 (48.1%) were positive exclusively with the OvMANE1 test, 13 (9.9%) exclusively with the Ov-16 test and 25 (19.1%) with both tests. Nine European samples from individuals without past travel history in onchocerciasis endemic zones and 15 samples from Rwanda, a hypoendemic country for onchocerciasis were all negative for the OvMANE1 and Ov-16 tests. However, the specificity of both tests was difficult to determine due to the lack of a gold standard for antibody tests. In conclusion, the tandem use of OvMANE1 and Ov-16 tests improves the sensitivity of detecting Onchocerca volvulus seropositive individuals but, the OvMANE1 test needs to be further evaluated on samples from a population infected with other helminths to cautiously address its specificity.
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22
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Vengesai A, Naicker T, Kasambala M, Midzi H, Mduluza-Jokonya T, Rusakaniko S, Mduluza T. Clinical utility of peptide microarrays in the serodiagnosis of neglected tropical diseases in sub-Saharan Africa: protocol for a diagnostic test accuracy systematic review. BMJ Open 2021; 11:e042279. [PMID: 34330850 PMCID: PMC8327806 DOI: 10.1136/bmjopen-2020-042279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
INTRODUCTION Neglected tropical diseases tend to cluster in the same poor populations and, to make progress with their control, they will have to be dealt with in an integrated manner. Peptide microarrays may be a solution to these problems, where diagnosis for co-infection can be detected simultaneously using the one tool. A meta-analysis using hierarchical models will be performed to assess the diagnostic accuracy of peptide microarrays for detecting schistosomiasis (Schistosoma mansoni and S. haematobium), soil-transmitted helminths (Trichuris trichiura, Ascaris lumbricoides and Necator americanus), trachoma (Chlamydia trachomatis), lymphatic filariasis (Wuchereria bancrofti) and onchocerciasis (Onchocerca volvulus) in people residing in sub-Saharan Africa. METHODS AND ANALYSIS A comprehensive search of the following databases will be performed: Cochrane Infectious Diseases Group Specialised Register, PubMed, EMBASE and The Web of Science. Studies comparing peptide microarrays with a reference standard from a random or consecutive series of patients will be included in the study. Two review authors will independently screen titles and abstracts for relevance, assess full-text articles for inclusion and carry out data extraction using a tailored data extraction form. The quality Assessment of Diagnostic Accuracy Studies-2 tool will be used to assess the quality of the selected studies. The bivariate model and the hierarchical summary receiver operating characteristic curve model will be performed to evaluate the diagnostic accuracy of the peptide microarrays. Meta-regression analyses will be performed to investigate heterogeneity across studies. ETHICS AND DISSEMINATION There is no requirement for ethical approval because the work will be carried out using previously published data, without human beings involvement. Findings will be disseminated through peer-reviewed publication and in conference presentations. PROSPERO REGISTRATION NUMBER CRD42020175145.
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Affiliation(s)
- Arthur Vengesai
- Biotechnology and Biochemistry, University of Zimbabwe Faculty of Science, Harare, Zimbabwe
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Thajasvarie Naicker
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Maritha Kasambala
- Faculty of Science and Agriculture, University of KwaZulu-Natal, Durban, South Africa
| | - Herald Midzi
- Biotechnology and Biochemistry, University of Zimbabwe Faculty of Science, Harare, Zimbabwe
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | | | | | - Takafira Mduluza
- Biotechnology and Biochemistry, University of Zimbabwe Faculty of Science, Harare, Zimbabwe
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Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning. PLoS Negl Trop Dis 2021; 15:e0008824. [PMID: 34319976 PMCID: PMC8318275 DOI: 10.1371/journal.pntd.0008824] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 05/13/2021] [Indexed: 11/19/2022] Open
Abstract
Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 0·71 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 50·2% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.
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Niamsi-Emalio Y, Nana-Djeunga HC, Chesnais CB, Pion SDS, Tchatchueng-Mbougua JB, Boussinesq M, Basáñez MG, Kamgno J. Unusual Localization of Blood-Borne Loa loa Microfilariae in the Skin Depends on Microfilarial Density in the Blood: Implications for Onchocerciasis Diagnosis in Coendemic Areas. Clin Infect Dis 2021; 72:S158-S164. [PMID: 33909066 PMCID: PMC8201578 DOI: 10.1093/cid/ciab255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background The diagnostic gold standard for onchocerciasis relies on identification and enumeration of (skin-dwelling) Onchocerca volvulus microfilariae (mf) using the skin snip technique (SST). In a recent study, blood-borne Loa loa mf were found by SST in individuals heavily infected with L. loa, and microscopically misidentified as O. volvulus due to their superficially similar morphology. This study investigates the relationship between L. loa microfilarial density (Loa MFD) and the probability of testing SST positive. Methods A total of 1053 participants from the (onchocerciasis and loiasis coendemic) East Region in Cameroon were tested for (1) Loa MFD in blood samples, (2) O. volvulus presence by SST, and (3) Immunoglobulin (Ig) G4 antibody positivity to Ov16 by rapid diagnostic test (RDT). A Classification and Regression Tree (CART) model was used to perform a supervised classification of SST status and identify a Loa MFD threshold above which it is highly likely to find L. loa mf in skin snips. Results Of 1011 Ov16-negative individuals, 28 (2.8%) tested SST positive and 150 (14.8%) were L. loa positive. The range of Loa MFD was 0–85 200 mf/mL. The CART model subdivided the sample into 2 Loa MFD classes with a discrimination threshold of 4080 (95% CI, 2180–12 240) mf/mL. The probability of being SST positive exceeded 27% when Loa MFD was >4080 mf/mL. Conclusions The probability of finding L. loa mf by SST increases significantly with Loa MFD. Skin-snip polymerase chain reaction would be useful when monitoring onchocerciasis prevalence by SST in onchocerciasis–loiasis coendemic areas.
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Affiliation(s)
- Yannick Niamsi-Emalio
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Hugues C Nana-Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Cédric B Chesnais
- Institut de Recherche pour le Développement (IRD), UMI233/INSERM U1175, Université de Montpellier , Montpellier, France
| | - Sébastien D S Pion
- Institut de Recherche pour le Développement (IRD), UMI233/INSERM U1175, Université de Montpellier , Montpellier, France
| | - Jules B Tchatchueng-Mbougua
- Service d'Epidémiologie, Centre Pasteur du Cameroun, Membre du Réseau International des Instituts Pasteur, Yaoundé, Cameroun
| | - Michel Boussinesq
- Institut de Recherche pour le Développement (IRD), UMI233/INSERM U1175, Université de Montpellier , Montpellier, France
| | - María-Gloria Basáñez
- MRC Centre for Global Infectious Disease Analysis and London Centre for Neglected Tropical Disease Research, Dep artment of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé, Cameroon.,Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
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Brattig NW, Cheke RA, Garms R. Onchocerciasis (river blindness) - more than a century of research and control. Acta Trop 2021; 218:105677. [PMID: 32857984 DOI: 10.1016/j.actatropica.2020.105677] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/06/2020] [Accepted: 08/21/2020] [Indexed: 12/14/2022]
Abstract
This review summarises more than a century of research on onchocerciasis, also known as river blindness, and its control. River blindness is an infection caused by the tissue filaria Onchocerca volvulus affecting the skin, subcutaneous tissue and eyes and leading to blindness in a minority of infected persons. The parasite is transmitted by its intermediate hosts Simulium spp. which breed in rivers. Featured are history and milestones in onchocerciasis research and control, state-of-the-art data on the parasite, its endobacteria Wolbachia, on the vectors, previous and current prevalence of the infection, its diagnostics, the interaction between the parasite and its host, immune responses and the pathology of onchocerciasis. Detailed information is documented on the time course of control programmes in the afflicted countries in Africa and the Americas, a long road from previous programmes to current successes in control of the transmission of this infectious disease. By development, adjustment and optimization of the control measures, transmission by the vector has been interrupted in foci of countries in the Americas, in Uganda, in Sudan and elsewhere, followed by onchocerciasis eliminations. The current state and future perspectives for control, elimination and eradication within the next 20-30 years are described and discussed. This review contributes to a deeper comprehension of this disease by a tissue-dwelling filaria and it will be helpful in efforts to control and eliminate other filarial infections.
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Dolo H, Coulibaly YI, Sow M, Dembélé M, Doumbia SS, Coulibaly SY, Sangare MB, Dicko I, Diallo AA, Soumaoro L, Coulibaly ME, Diarra D, Colebunders R, Nutman TB, Walker M, Basáñez MG. Serological Evaluation of Onchocerciasis and Lymphatic Filariasis Elimination in the Bakoye and Falémé Foci, Mali. Clin Infect Dis 2021; 72:1585-1593. [PMID: 32206773 PMCID: PMC8096229 DOI: 10.1093/cid/ciaa318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Indexed: 11/14/2022] Open
Abstract
Background Ivermectin-based onchocerciasis elimination, reported in 2009–2012, for Bakoye and Falémé, Mali, supported policy-shifting from morbidity control to elimination of transmission (EOT). These foci are coendemic with lymphatic filariasis (LF). In 2007–2016 mass ivermectin plus albendazole administration was implemented. We report Ov16 (onchocerciasis) and Wb123 (LF) seroprevalence after 24–25 years of treatment to determine if onchocerciasis EOT and LF elimination as a public health problem (EPHP) have been achieved. Methods The SD Bioline Onchocerciasis/LF Ig[immunoglobulin]G4 biplex rapid diagnostic test (RDT) was used in 2186 children aged 3–10 years in 13 villages (plus 2 hamlets) in Bakoye and in 2270 children in 15 villages (plus 1 hamlet) in Falémé. In Bakoye, all-age serosurveys were conducted in 3 historically hyperendemic villages (1867 individuals aged 3 -78 years). Results In Bakoye, IgG4 seropositivity was 0.27% (95% confidence interval [CI] = .13%–.60%) for both Ov16 and Wb123 antigens. In Falémé, Ov16 and Wb123 seroprevalence was 0.04% (95% CI = .01%–.25%) and 0.09% (95% CI = .02%–.32%), respectively. Ov16-seropositive children were from historically meso/hyperendemic villages. Ov16 positivity was <2% in ≤14 year-olds, and 16% in ≥40 year-olds. Wb123 seropositivity was <2% in ≤39 year-olds, reaching 3% in ≥40 year-olds. Conclusions Notwithstanding uncertainty in the biplex RDT sensitivity, Ov16 and Wb123 seroprevalence among children in Bakoye and Falémé is consistent with EOT (onchocerciasis) and EPHP (LF) since stopping treatment in 2016. The few Ov16-seropositive children should be skin-snip polymerase chain reaction tested and followed up.
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Affiliation(s)
- Housseini Dolo
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali.,Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Yaya I Coulibaly
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali.,Centre National d'Appui à la lutte contre la Maladie, Bamako, Mali
| | - Moussa Sow
- Programme National de Lutte contre l'Onchocercose, Bamako, Mali
| | - Massitan Dembélé
- Programme National d'Elimination de la Filariose Lymphatique, Bamako, Mali
| | - Salif S Doumbia
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Siaka Y Coulibaly
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Moussa B Sangare
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Ilo Dicko
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Abdallah A Diallo
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Lamine Soumaoro
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | - Michel E Coulibaly
- Lymphatic Filariasis Research Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Point G, Bamako, Mali
| | | | | | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Martin Walker
- Department of Pathobiology and Population Sciences and London Centre for Neglected Tropical Disease Research, Royal Veterinary College, Hatfield, United Kingdom
| | - Maria-Gloria Basáñez
- Department of Infectious Disease Epidemiology and London Centre for Neglected Tropical Disease Research, MRC Centre for Global Infectious Disease Analysis, Imperial College London, United Kingdom
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Vlaminck J, Lagatie O, Dana D, Mekonnen Z, Geldhof P, Levecke B, Stuyver LJ. Identification of antigenic linear peptides in the soil-transmitted helminth and Schistosoma mansoni proteome. PLoS Negl Trop Dis 2021; 15:e0009369. [PMID: 33909616 PMCID: PMC8081252 DOI: 10.1371/journal.pntd.0009369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/07/2021] [Indexed: 11/18/2022] Open
Abstract
The scientific community identified non stool-based biomarkers as the way forward to support soil-transmitted helminth (STH; Ascaris lumbricoides, Trichuris trichiura and the hookworms Ancylostoma duodenale and Necator americanus) and schistosome (S. mansoni and S. haematobium) deworming programs. This support is needed in making the decision of whether or not to stop preventive chemotherapy intervention efforts and to ultimately transition towards a post-intervention surveillance phase. We applied a two-step micro-array approach to identify antigenic linear epitopes in the STH and S. mansoni proteomes. In a first experiment, we identified antigenic peptides by applying sera from 24 STH and/or S. mansoni infected Ethiopian children on a high-density peptide microarray containing 3.3 million peptides derived from the complete STH and S. mansoni proteomes. A second array experiment with 170,185 peptides that were recognized in the first array was designed to identify non-specific antibody reactivity by applying sera from 24 healthy individuals from Belgium (a non-endemic country). From this array testing cascade, several peptides were identified for STH but none of them appeared to be unique for one species. We therefore concluded that for STH, none of the peptides revealed to be sufficiently sensitive or species specific. For S. mansoni, some promising peptides were identified prompting future investigation. Based on these results, it is unlikely that linear epitopes would be highly useful in detecting species-specific antibody responses to STH in endemic communities. For S. mansoni, one particular peptide of the micro-exon gene 12 (MEG-12) protein deserves further research. In addition, this study emphasizes the need of well-characterized biobanks for biomarker discovery, particularly when the integration of multiple disease programs is envisioned. Today, infections with intestinal (roundworms, whipworm and hookworms) and blood-dwelling worms (schistosomes) are traditionally diagnosed by demonstrating worm eggs in stool. This current practice comes with some important challenges, including but not limited to the low-throughput and the need of skilled operators. Especially in the context of monitoring and evaluation, there is a need for alternative tools. Therefore, one of the recommendations of the scientific community was to develop tests that are based on the detection of antibodies in blood, which reflect the natural immune response of the host to worm-specific components or antigens. In the present study, we screened the antigenicity of all the peptides that build up the proteome of intestinal and blood-dwelling worms. For intestinal worms, our results revealed that the antibody response to these peptides was either not unique for the worm species or absent in infected subjects. For blood-dwelling worms, the findings were less sobering, with a number of peptides inducing an antibody response that was only observed in infected subjects.
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Affiliation(s)
- Johnny Vlaminck
- Department of Virology, Parasitology, Immunology and Physiology, Ghent University, Merelbeke, Belgium
| | - Ole Lagatie
- Global Public Health R&D, Janssen Pharmaceutica NV, Beerse, Belgium
- * E-mail:
| | - Daniel Dana
- Department of Virology, Parasitology, Immunology and Physiology, Ghent University, Merelbeke, Belgium
- School of Laboratory Science, Faculty of health science, Institute of health, Jimma University, Jimma, Ethiopia
| | - Zeleke Mekonnen
- School of Laboratory Science, Faculty of health science, Institute of health, Jimma University, Jimma, Ethiopia
| | - Peter Geldhof
- Department of Virology, Parasitology, Immunology and Physiology, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Virology, Parasitology, Immunology and Physiology, Ghent University, Merelbeke, Belgium
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Bennuru S, Oduro-Boateng G, Osigwe C, Del Valle P, Golden A, Ogawa GM, Cama V, Lustigman S, Nutman TB. Integrating Multiple Biomarkers to Increase Sensitivity for the Detection of Onchocerca volvulus Infection. J Infect Dis 2021; 221:1805-1815. [PMID: 31201416 DOI: 10.1093/infdis/jiz307] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/13/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Serological assessments for human onchocerciasis are based on IgG4 reactivity against the OV-16 antigen, with sensitivities of 60-80%. We have previously identified 7 novel proteins that could improve serodiagnosis. METHODS IgG4 responses to these 7 proteins were assessed by luciferase immunoprecipitation (LIPS) and enzyme-linked immunosorbent (ELISA) immunoassays. RESULTS OVOC10469 and OVOC3261 were identified as the most promising candidates by IgG4-based immunoassays with sensitivities of 53% for rOVOC10469 and 78% for rOVOC3261 while specificity for each was >99%. These 2 antigens in combination with OV-16 increased the sensitivity for patent infections to 94%. The kinetics of appearance of these IgG4 responses based on experimentally infected non-human primates indicated that they were microfilarial- driven. Further, the IgG4 responses to both OVOC10469 and OVOC3261 (as well as to OV-16) drop significantly (p<0.05) following successful treatment for onchocerciasis. A prototype lateral flow rapid diagnostic test to detect IgG4 to both Ov-16 and OVOC3261 was developed and tested demonstrating an overall 94% sensitivity. CONCLUSION The combined use of rOVOC3261 with OV-16 improved serologic assessment of O. volvulus infection, a current unmet need toward the goal of elimination of transmission of O. volvulus.
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Affiliation(s)
- Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Georgiette Oduro-Boateng
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Chinweoke Osigwe
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Priscilla Del Valle
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | | | - Guilherme Maerschner Ogawa
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Vitaliano Cama
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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29
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Hamley JID, Walker M, Coffeng LE, Milton P, de Vlas SJ, Stolk WA, Basáñez MG. Structural Uncertainty in Onchocerciasis Transmission Models Influences the Estimation of Elimination Thresholds and Selection of Age Groups for Seromonitoring. J Infect Dis 2021; 221:S510-S518. [PMID: 32173745 PMCID: PMC7289547 DOI: 10.1093/infdis/jiz674] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The World Health Organization recommends monitoring Onchocerca volvulus Ov16 serology in children aged <10 years for stopping mass ivermectin administration. Transmission models can help to identify the most informative age groups for serological monitoring and investigate the discriminatory power of serology-based elimination thresholds. Model predictions depend on assumed age-exposure patterns and transmission efficiency at low infection levels. METHODS The individual-based transmission model, EPIONCHO-IBM, was used to assess (1) the most informative age groups for serological monitoring using receiver operating characteristic curves for different elimination thresholds under various age-dependent exposure assumptions, including those of ONCHOSIM (another widely used model), and (2) the influence of within-human density-dependent parasite establishment (included in EPIONCHO-IBM but not ONCHOSIM) on positive predictive values for different serological thresholds. RESULTS When assuming EPIONCHO-IBM exposure patterns, children aged <10 years are the most informative for seromonitoring; when assuming ONCHOSIM exposure patterns, 5-14 year olds are the most informative (as published elsewhere). Omitting density-dependent parasite establishment results in more lenient seroprevalence thresholds, even for higher baseline infection prevalence and shorter treatment durations. CONCLUSIONS Selecting appropriate seromonitoring age groups depends critically on age-dependent exposure patterns. The role of density dependence on elimination thresholds largely explains differing EPIONCHO-IBM and ONCHOSIM elimination predictions.
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Affiliation(s)
- Jonathan I D Hamley
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Martin Walker
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,London Centre for Neglected Tropical Disease Research, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, UK
| | - Luc E Coffeng
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Philip Milton
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Sake J de Vlas
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wilma A Stolk
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Maria-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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30
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Lessons learned for surveillance strategies for trachoma elimination as a public health problem, from the evaluation of approaches utilised by Guinea worm and onchocerciasis programmes: A literature review. PLoS Negl Trop Dis 2021; 15:e0009082. [PMID: 33507903 PMCID: PMC7872237 DOI: 10.1371/journal.pntd.0009082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/09/2021] [Accepted: 12/17/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction A number of neglected tropical diseases are targeted for elimination or eradication. An effective surveillance system is critical to determine if these goals have been achieved and maintained. Trachoma has two related but morphologically different presentations that are monitored for elimination, the active infectious form of trachoma and trachomatous trichiasis (TT), the progression of the disease. There are a number of lessons learnt from the Guinea worm surveillance system that are particularly compatible for TT surveillance and the onchocerciasis surveillance system which can provide insights for surveillance of the infectious form of trachoma. Methods/Principal findings A literature search of peer-reviewed published papers and grey literature was conducted using PUBMED and Google Scholar for articles relating to dracunculiasis or Guinea worm, onchocerciasis and trachoma, along with surveillance or elimination or eradication. The abstracts of relevant papers were read and inclusion was determined based on specified inclusion and exclusion criteria. The credibility and bias of relevant papers were also critically assessed using published criteria. A total of 41 papers were identified that were eligible for inclusion into the review. The Guinea worm programme is designed around a surveillance-containment strategy and combines both active and passive surveillance approaches, with a focus on village-based surveillance and reporting. Although rumour reporting and a monetary incentive for the identification of confirmed Guinea worm cases have been reported as successful for identifying previously unknown transmission there is little unbiased evidence to support this conclusion. More rigorous evidence through a randomised controlled trial, influenced by motivational factors identified through formative research, would be necessary in order to consider applicability for TT case finding in an elimination setting. The onchocerciasis surveillance strategy focuses on active surveillance through sentinel surveillance of villages and breeding sites. It relies on an entomological component, monitoring infectivity rates of black flies and an epidemiological component, tracking exposure to infection in humans. Challenges have included the introduction of relatively complex diagnostics that are not readily available in onchocerciasis endemic countries and target thresholds, which are practically unattainable with current diagnostic tests. Although there is utility in monitoring for infection and serological markers in trachoma surveillance, it is important that adequate considerations are made to ensure evidence-based and achievable guidelines for their utility are put in place. Conclusions/Significance The experiences of both the Guinea worm and onchocerciasis surveillance strategies have very useful lessons for trachoma surveillance, pre- and post-validation. The use of a monetary reward for identification of TT cases and further exploration into the use of infection and serological indicators particularly in a post-validation setting to assist in identifying recrudescence would be of particular relevance. The next step would be a real-world evaluation of their relative applicability for trachoma surveillance. The design of a surveillance system needs to be carefully thought out to ensure it provides sufficient evidence to determine if a disease or infection is eliminated or eradicated. If inappropriate it can lead to on-going transmission and resurgence of infection or disease or the unnecessary continuation of interventions, wasting valuable resources. Guinea worm is a disease that is painful and debilitating, for which there is no drug or vaccine. The aim is to eradicate the disease and as such the Guinea worm programme is designed around a strategy of identification of cases and their containment to prevent onward transmission. Onchocerciasis if left untreated can lead to blindness. The aim is to eliminate the disease through the interruption of transmission. A literature review was conducted to determine available evidence and identify lessons that can be learnt from the surveillance of both diseases for the design of trachoma surveillance strategies in the endgame. The potential utility of rumour reporting and a monetary incentive for the identification of a confirmed case of Guinea worm could be explored for trichiasis case finding. Trichiasis is the progression of trachoma and leads to significant ocular morbidity. The introduction of tests for infection and antibodies and the utility of sentinel surveillance as utilised for onchocerciasis are interesting considerations for active trachoma surveillance post-validation and has potential to identify recrudescence cost-effectively. The experiences of both the Guinea worm and onchocerciasis surveillance strategies have very useful lessons that can be trialled for trachoma surveillance. However, their real-world applicability and implications for trachoma need to be evaluated before any changes in guidelines are proposed.
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The Brief Case: Loa loa in a Patient from Nigeria. J Clin Microbiol 2020; 59:59/1/e01587-20. [PMID: 33335076 DOI: 10.1128/jcm.01587-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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32
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Avendaño C, Patarroyo MA. Loop-Mediated Isothermal Amplification as Point-of-Care Diagnosis for Neglected Parasitic Infections. Int J Mol Sci 2020; 21:ijms21217981. [PMID: 33126446 PMCID: PMC7662217 DOI: 10.3390/ijms21217981] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/13/2022] Open
Abstract
The World Health Organisation (WHO) has placed twenty diseases into a group known as neglected tropical diseases (NTDs), twelve of them being parasitic diseases: Chagas’ disease, cysticercosis/taeniasis, echinococcosis, food-borne trematodiasis, human African trypanosomiasis (sleeping sickness), leishmaniasis, lymphatic filariasis, onchocerciasis (river blindness), schistosomiasis, soil-transmitted helminthiasis (ascariasis, hookworm, trichuriasis), guinea-worm and scabies. Such diseases affect millions of people in developing countries where one of the main problems concerning the control of these diseases is diagnosis-based due to the most affected areas usually being far from laboratories having suitable infrastructure and/or being equipped with sophisticated equipment. Advances have been made during the last two decades regarding standardising and introducing techniques enabling diagnoses to be made in remote places, i.e., the loop-mediated isothermal amplification (LAMP) technique. This technique’s advantages include being able to perform it using simple equipment, diagnosis made directly in the field, low cost of each test and the technique’s high specificity. Using this technique could thus contribute toward neglected parasite infection (NPI) control and eradication programmes. This review describes the advances made to date regarding LAMP tests, as it has been found that even though several studies have been conducted concerning most NPI, information is scarce for others.
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Affiliation(s)
- Catalina Avendaño
- Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A.), Bogotá 111166, Colombia;
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá 111321, Colombia
- Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá 112111, Colombia
- Correspondence: ; Tel.: +57-1-3244672
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Lakwo T, Oguttu D, Ukety T, Post R, Bakajika D. Onchocerciasis Elimination: Progress and Challenges. Res Rep Trop Med 2020; 11:81-95. [PMID: 33117052 PMCID: PMC7548320 DOI: 10.2147/rrtm.s224364] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/16/2020] [Indexed: 01/08/2023] Open
Abstract
Onchocerciasis is a parasitic infection caused by the filarial nematode Onchocerca volvulus and transmitted through the bites of black flies of the genus Similium that breed in rivers and streams. The impact of mass treatment with ivermectin and supplemented by vector control in some countries has changed the global scene of onchocerciasis. There has been reported progress made in elimination of onchocerciasis in central and southern American countries and in some localities in Africa. The target for elimination in the Americas has been set at 2022 while for 12 countries in Africa this is expected in 2030. This review was conducted to examine the current status of onchocerciasis elimination at the global level and report on progress made. Literature searches were made through PubMed, articles in English or English abstracts, reports and any other relevant articles related to the subject. The global burden of onchocerciasis is progressively reducing and is no longer a public health problem in some regions. However, programs are challenged with a range of issues: cross-border transmission, diagnostic tools, Loa loa co-endemicity, limited workforce in entomology and maintaining enthusiasm among community drug distributors. More concerted effort using appropriate tools is required to overcome the challenges.
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Affiliation(s)
- Thomson Lakwo
- Neglected Tropical Disease Control Program, Vector Control Division, Ministry of Health, Kampala, Uganda
| | - David Oguttu
- Neglected Tropical Disease Control Program, Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Tony Ukety
- Centre de Recherche pour les Maladies Tropicales, Rethy, Ituri Province, The Democratic Republic of the Congo
| | - Rory Post
- Disease Control Department, London School of Hygiene & Tropical Medicine, London, UK.,School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Didier Bakajika
- Expanded Special Project for Elimination of Neglected Tropical Diseases, WHO Regional Office for Africa, Brazzaville, Congo
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34
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Geerts M, Van Reet N, Leyten S, Berghmans R, S Rock K, Ht Coetzer T, E-A Eyssen L, Büscher P. Trypanosoma brucei gambiense-iELISA: a promising new test for the post-elimination monitoring of human African trypanosomiasis. Clin Infect Dis 2020; 73:e2477-e2483. [PMID: 32856049 PMCID: PMC8563279 DOI: 10.1093/cid/ciaa1264] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/24/2020] [Indexed: 11/13/2022] Open
Abstract
Background The World Health Organization targeted Trypanosoma brucei gambiense human African trypanosomiasis (gHAT) for elimination as a public health problem and for elimination of transmission. To measure gHAT elimination success with prevalences close to zero, highly specific diagnostics are necessary. Such a test exists in the form of an antibody-mediated complement lysis test, the trypanolysis test, but biosafety issues and technological requirements prevent its large-scale use. We developed an inhibition ELISA with high specificity and sensitivity that is applicable in regional laboratories in gHAT endemic countries. Methods The T. b. gambiense inhibition ELISA (g-iELISA) is based on the principle that binding of monoclonal antibodies to specific epitopes of T. b. gambiense surface glycoproteins can be inhibited by circulating antibodies of gHAT patients directed against the same epitopes. Using trypanolysis as reference test, the diagnostic accuracy of the g-iELISA was evaluated on plasma samples from 739 gHAT patients and 619 endemic controls and on dried blood spots prepared with plasma of 95 gHAT and 37 endemic controls. Results Overall sensitivity and specificity on plasma were, respectively, 98.0% (95% CI 96.7–98.9) and 99.5% (95% CI 98.6–99.9). With dried blood spots, sensitivity was 92.6% (95% CI 85.4–97.0), and specificity was 100% (95% CI 90.5–100.0). The g-iELISA is stable for at least 8 months when stored at 2–8°C. Conclusion The g-iELISA might largely replace trypanolysis for monitoring gHAT elimination and for postelimination surveillance. The g-iELISA kit is available for evaluation in reference laboratories in endemic countries.
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Affiliation(s)
- Manon Geerts
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Belgium
| | - Nick Van Reet
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Belgium
| | - Sander Leyten
- Advanced Practical Diagnostics BVBA, Turnhout, Belgium
| | - Raf Berghmans
- Advanced Practical Diagnostics BVBA, Turnhout, Belgium
| | - Kat S Rock
- Mathematics Institute, University of Warwick, Coventry, United Kingdom
| | - Theresa Ht Coetzer
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Lauren E-A Eyssen
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Belgium
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35
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Taylor EM. NTD Diagnostics for Disease Elimination: A Review. Diagnostics (Basel) 2020; 10:E375. [PMID: 32517108 PMCID: PMC7344624 DOI: 10.3390/diagnostics10060375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022] Open
Abstract
Neglected Tropical Diseases (NTDs) marked out for disease elimination provide a lens through which to explore the changing status of diagnosis in global health. This paper reports on the findings of a scoping review, which set out to explore the main debates around diagnosis for the elimination of NTDs, including the multiple roles diagnostic technologies are being ascribed and the ideal characteristics of tests. It also attempts to summarise the state of diagnosis for three NTDs with elimination goals. The review places special emphasis on point-of-care testing in acknowledgement of the remote and underserved areas where NTDs proliferate. Early NTD campaigns were largely focused on attack phase planning, whereby a similar set of interventions could be transplanted anywhere. Now, with elimination goals in sight, strategies must be tailored to local settings if they are to attain and sustain success. Diagnostic data helps with local adaptation and is increasingly used for programmatic decision-making. The review finds that elimination goals reframe whom diagnosis is for and the myriad roles diagnostics can play. The exigencies of elimination also serve to highlight deficiencies in the current diagnostic arsenal and development pipeline for many NTDs. Moving forward, a guiding framework is needed to drive research and stimulate investment in diagnosis to support NTD goals.
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Affiliation(s)
- Emma Michelle Taylor
- Department of Social Anthropology, University of Edinburgh, Edinburgh EH8 9LD, UK
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36
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Smith ME, Bilal S, Lakwo TL, Habomugisha P, Tukahebwa E, Byamukama E, Katabarwa MN, Richards FO, Cupp EW, Unnasch TR, Michael E. Accelerating river blindness elimination by supplementing MDA with a vegetation "slash and clear" vector control strategy: a data-driven modeling analysis. Sci Rep 2019; 9:15274. [PMID: 31649285 PMCID: PMC6813336 DOI: 10.1038/s41598-019-51835-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 10/09/2019] [Indexed: 01/08/2023] Open
Abstract
Attention is increasingly focusing on how best to accelerate progress toward meeting the WHO's 2030 goals for neglected tropical diseases (NTDs). For river blindness, a major NTD targeted for elimination, there is a long history of using vector control to suppress transmission, but traditional larvicide-based approaches are limited in their utility. One innovative and sustainable approach, "slash and clear", involves clearing vegetation from breeding areas, and recent field trials indicate that this technique very effectively reduces the biting density of Simulium damnosum s.s. In this study, we use a Bayesian data-driven mathematical modeling approach to investigate the potential impact of this intervention on human onchocerciasis infection. We developed a novel "slash and clear" model describing the effect of the intervention on seasonal black fly biting rates and coupled this with our population dynamics model of Onchocerca volvulus transmission. Our results indicate that supplementing annual drug treatments with "slash and clear" can significantly accelerate the achievement of onchocerciasis elimination. The efficacy of the intervention is not very sensitive to the timing of implementation, and the impact is meaningful even if vegetation is cleared only once per year. As such, this community-driven technique will represent an important option for achieving and sustaining O. volvulus elimination.
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Affiliation(s)
- Morgan E Smith
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Shakir Bilal
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Thomson L Lakwo
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | | | | | | | | | | | - Eddie W Cupp
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Thomas R Unnasch
- Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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Xu S, Hazlett LD. MicroRNAs in Ocular Infection. Microorganisms 2019; 7:microorganisms7090359. [PMID: 31533211 PMCID: PMC6780979 DOI: 10.3390/microorganisms7090359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022] Open
Abstract
MicroRNAs (miRNAs) are small, non-coding, regulatory RNA molecules and constitute a newly recognized, important layer of gene-expression regulation at post-transcriptional levels. miRNAs quantitatively fine tune the expression of their downstream genes in a cell type- and developmental stage-specific fashion. miRNAs have been proven to play important roles in the normal development and function as well as in the pathogenesis of diseases in all tissues and organ systems. miRNAs have emerged as new therapeutic targets and biomarkers for treatment and diagnosis of various diseases. Although miRNA research in ocular infection remains in its early stages, a handful of pioneering studies have provided insight into the roles of miRNAs in the pathogenesis of parasitic, fungal, bacterial, and viral ocular infections. Here, we review the current status of research in miRNAs in several major ocular infectious diseases. We predict that the field of miRNAs in ocular infection will greatly expand with the discovery of novel miRNA-involved molecular mechanisms that will inform development of new therapies and identify novel diagnostic biomarkers.
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Affiliation(s)
- Shunbin Xu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
| | - Linda D Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
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Njume FN, Ghogomu SM, Shey RA, Gainkam LOT, Poelvoorde P, Humblet P, Kamgno J, Robert A, Mutesa L, Lelubre C, Edelweiss E, Poterszman A, Anheuser S, Vanhamme L, Souopgui J. Identification and characterization of the Onchocerca volvulus Excretory Secretory Product Ov28CRP, a putative GM2 activator protein. PLoS Negl Trop Dis 2019; 13:e0007591. [PMID: 31329585 PMCID: PMC6675134 DOI: 10.1371/journal.pntd.0007591] [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: 12/22/2018] [Revised: 08/01/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022] Open
Abstract
Onchocerca volvulus is the nematode pathogen responsible for human onchocerciasis also known as "River blindness", a neglected tropical disease that affects up to 18 million people worldwide. Helminths Excretory Secretory Products (ESPs) constitute a rich repertoire of molecules that can be exploited for host-parasite relationship, diagnosis and vaccine studies. Here, we report, using a range of molecular techniques including PCR, western blot, recombinant DNA technology, ELISA, high performance thin-layer chromatography and mass spectrometry that the 28 KDa cysteine-rich protein (Ov28CRP) is a reliable component of the O. volvulus ESPs to address the biology of this parasite. We showed that (1) Ov28CRP is a putative ganglioside GM2 Activator Protein (GM2AP) conserved in nematode; (2) OvGM2AP gene is transcriptionally activated in all investigated stages of the parasitic life cycle, including larval and adult stages; (3) The full-length OvGM2AP was detected in in-vitro O. volvulus ESPs of adult and larval stages; (4) the mass expressed and purified recombinant OvGM2AP purified from insect cell culture medium was found to be glycosylated at asparagine 173 and lacked N-terminal signal peptide sequence; (5) the recombinant OvGM2AP discriminated serum samples of infected and uninfected individuals; (6) OvGM2AP competitively inhibits MUG degradation by recombinant β-hexosaminidase A but not MUGS, and could not hydrolyze the GM2 to GM3; (7) humoral immune responses to the recombinant OvGM2AP revealed a negative correlation with ivermectin treatment. Altogether, our findings suggest for the first time that OvGM2AP is an antigenic molecule whose biochemical and immunological features are important to gain more insight into our understanding of host-parasite relationship, as well as its function in parasite development at large.
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Affiliation(s)
- Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, Yaounde, Cameroon
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB)—Unité 222, CHU Charleroi (Hôpital André Vésale), Rue de Gozée, Montigny-Le-Tilleul, Belgium
| | - Evelina Edelweiss
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Arnaud Poterszman
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Susi Anheuser
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
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Chamnanchanunt S, Svasti S, Fucharoen S, Umemura T. Neglected Tropical Diseases: The Potential Application of microRNAs for Monitoring NTDs in the Real World. Microrna 2019; 9:41-48. [PMID: 31218967 DOI: 10.2174/2211536608666190620104308] [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: 12/25/2018] [Revised: 03/11/2019] [Accepted: 05/20/2019] [Indexed: 11/22/2022]
Abstract
Neglected Tropical Diseases (NTDs) are a common health problem and require an efficient campaign to be eradicated from tropical countries. Almost a million people die of NTDs every year in the world, and almost forty percent of the patients are under 20 years. Mass Drug Administration (MDA) is an effective tool for eradication of this health condition. However, a monitoring system is required to evaluate treatment-response and early detection of the re-emerging NTD. The relevance of current tests depends on good quality of the specimen. Thus, new molecular methods with high sensitivity and specificity are required. In this review, we focus on microRNAs (miRNAs) as biomarkers of NTDs through a narrative review on human research. We searched for reliable search engines using a systematical literature review algorithm and included studies that fit the criterion. Five NTDs (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiases, and trachoma) were set as our target diseases. Later on, the data were extracted and classified as monitoring response and early detection. Four miRNAs were studied in filariasis as a monitoring response. There were 12 miRNAs related to onchocerciasis infection, and 6 miRNAs with schistosomiasis infection. Six miRNAs showed a link to soil-transmitted helminths. Only 3 miRNAs correlated with trachoma infection. In conclusion, circulating miR is a less invasive and promising approach to evaluate NTDs. Further field study may translate those candidate miRs to clinical application of the prevention and control of NTDs.
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Affiliation(s)
- Supat Chamnanchanunt
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Saovaros Svasti
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Suthat Fucharoen
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Tsukuru Umemura
- Department of Medical Technology and Sciences, International University of Health and Welfare, Ohkawa, Japan.,Department of Clinical Laboratory, Kouhoukai Takagi Hospital, Fukuoka, Japan
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40
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Cantey PT, Roy SL, Boakye D, Mwingira U, Ottesen EA, Hopkins AD, Sodahlon YK. Transitioning from river blindness control to elimination: steps toward stopping treatment. Int Health 2019; 10:i7-i13. [PMID: 29471338 PMCID: PMC5881257 DOI: 10.1093/inthealth/ihx049] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/31/2017] [Indexed: 11/18/2022] Open
Abstract
The transition from onchocerciasis control to elimination requires country programmes to rethink their approach to a variety of activities as they move from addressing morbidity to addressing transmission of the parasite. Although the 2016 WHO guidelines provide extensive recommendations, it was beyond the scope of the document to provide guidance on all aspects of the transition. This paper will discuss some of the important issues that programmes are grappling with as they transition to elimination and provide some potential approaches that programmes can use to address them. Although there are some data to support some aspects of the suggested approaches, operational research will be needed to generate data to support these approaches further and to determine how programmes could best tailor them to their own unique epidemiological challenges. Good communication between the national programmes and the broader global programme will facilitate the clear articulation of programmatic challenges and the development of the evidence to support programme decision-making.
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Affiliation(s)
- Paul T Cantey
- Department of Neglected Tropical Diseases, World Health Organization, Geneva 1211, Switzerland
| | - Sharon L Roy
- Division of Parasitic Diseases and Malaria, U.S. Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - Daniel Boakye
- Parasitology Department, Noguchi Memorial Institute for Medical Research, Accra, LG581, Ghana
| | - Upendo Mwingira
- Neglected Tropical Diseases Control Programme, Ministry of Health, Community Development, Gender, Elderly and Children, Dar es Salaam 11478, Tanzania.,National Institute for Medical Research, Dar es Salaam 11101, Tanzania
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41
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Deng MH, Zhong LY, Kamolnetr O, Limpanont Y, Lv ZY. Detection of helminths by loop-mediated isothermal amplification assay: a review of updated technology and future outlook. Infect Dis Poverty 2019; 8:20. [PMID: 30905322 PMCID: PMC6432754 DOI: 10.1186/s40249-019-0530-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 03/07/2019] [Indexed: 02/06/2023] Open
Abstract
Background Helminths are endemic in more than half of the world’s countries, raising serious public health concerns. Accurate diagnosis of helminth infection is crucial to control strategies. Traditional parasitological methods, serological tests and PCR-based assays are the major means of the diagnosis of helminth infection, but they are time-consuming and/or expensive, and sometimes provide inaccurate results. Loop mediated isothermal amplification (LAMP) assay, a sensitive, simple and rapid method was therefore developed for detection of helminths. This study aims to discuss the current status of application of LAMP on helminths detection and to make a comprehensive evaluation about this updated technology and its future outlook by comparing with several other diagnostic methods. Main body This review summarizes LAMP assay applied for helminth detection and helminthiasis surveillance. The basic principle of LAMP is introduced to help better understand its characteristics and each reported assay is assessed mainly based on its detection sensitivity, specificity and limitations, in comparison with other common diagnostic tests. Moreover, we discuss the limitations of the assays so as to clarify some potential ways of improvement. Conclusions Here, we summarize and discuss the advantages, disadvantages and promising future of LAMP in heliminth detection, which is expected to help update current knowledge and future perspectives of LAMP in highly sensitive and specific diagnosis and surveillance of helminthiasis and other parasitic diseases, and can contribute to the elimination of the diseases from endemic areas. Electronic supplementary material The online version of this article (10.1186/s40249-019-0530-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Miao-Han Deng
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China
| | - Lan-Yi Zhong
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China
| | - Okanurak Kamolnetr
- Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Yanin Limpanont
- Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | - Zhi-Yue Lv
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China. .,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, 510080, China. .,Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 519000, China.
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42
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Shey RA, Ghogomu SM, Njume FN, Gainkam LOT, Poelvoorde P, Mutesa L, Robert A, Humblet P, Munyampundu JP, Kamgno J, Lelubre C, Vanhamme L, Souopgui J. Prediction and validation of the structural features of Ov58GPCR, an immunogenic determinant of Onchocerca volvulus. PLoS One 2018; 13:e0202915. [PMID: 30256790 PMCID: PMC6157839 DOI: 10.1371/journal.pone.0202915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/11/2018] [Indexed: 11/18/2022] Open
Abstract
Onchocerciasis is a severely debilitating yet neglected tropical disease (NTD) that creates social stigma, generates and perpetuates poverty, and leads ultimately in some cases to irreversible unilateral or bilateral blindness if untreated. Consequently, the disease is a major impediment to socioeconomic development. Many control programs have been launched for the disease with moderate successes achieved. This mitigated hit is partially due to the lingering need for reliable, non-invasive and easily applicable tools for mapping endemic regions and post-elimination surveillance. In this work, bioinformatics analyses combined with immunological assays were applied in a bid to develop potential tools for diagnosis and assessing the success of drug treatment programs. We report that (i) the O. volvulus antigen, Ov58GPCR is a G-protein coupled receptor (GPCR) conserved in related nematodes, (ii) synthetic peptides predicted to be in the extracellular domain (ECD) of Ov58GPCR are indeed immunogenic epitopes in actively-infected individuals, (iii) synthetic peptide cocktails discriminate between actively-infected individuals, treated individuals and healthy African controls, (iv) polyclonal antibodies against one of the peptides or against the bacterially-expressed ECD reacted specifically with the native antigen of O. volvulus total and surface extracts, (v) Ov58GPCR is transcribed in both larvae and adult parasite stages, (vi) IgG and IgE responses to the recombinant ECD decline with ivermectin treatment. All these findings suggest that the extracellular domain and synthetic peptides of Ov58GPCR, as well as the specific immune response generated could be harnessed in the context of disease diagnosis and surveillance.
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Affiliation(s)
- Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jean-Pierre Munyampundu
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, (CRFilMT), Yaoundé, Cameroon
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB) - Unité 222, CHU Charleroi (Hôpital André Vésale), Montigny-Le-Tilleul, Belgium
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM Universite Libre de Bruxelles, Gosselies Campus, Gosselies, Hainaut, Belgium
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43
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Murdoch ME. Onchodermatitis: Where Are We Now? Trop Med Infect Dis 2018; 3:E94. [PMID: 30274490 PMCID: PMC6160948 DOI: 10.3390/tropicalmed3030094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 02/07/2023] Open
Abstract
Onchocerciasis causes debilitating pruritus and rashes as well as visual impairment and blindness. Prior to control measures, eye disease was particularly prominent in savanna areas of sub-Saharan Africa whilst skin disease was more common across rainforest regions of tropical Africa. Mass drug distribution with ivermectin is changing the global scene of onchocerciasis. There has been successful progressive elimination in Central and Southern American countries and the World Health Organization has set a target for elimination in Africa of 2025. This literature review was conducted to examine progress regarding onchocercal skin disease. PubMed searches were performed using keywords 'onchocerciasis', 'onchodermatitis' and 'onchocercal skin disease' over the past eight years. Articles in English, or with an English abstract, were assessed for relevance, including any pertinent references within the articles. Recent progress in awareness of, understanding and treatment of onchocercal skin disease is reviewed with particular emphasis on publications within the past five years. The global burden of onchodermatitis is progressively reducing and is no longer seen in children in many formerly endemic foci.
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Affiliation(s)
- Michele E Murdoch
- Department of Dermatology, West Herts Hospitals NHS Trust, Vicarage Road, Watford, Hertfordshire WD18 0HB, UK.
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44
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Richards FO, Katabarwa M, Bekele F, Tadesse Z, Mohammed A, Sauerbrey M, Dominguez-Vazquez A, Rodriguez-Perez MA, Fernández-Santos NA, Rizzo N, Schuler Martínez HR, Lovato Silva R, Morales Monroy Z, Habomugisha P, Oguttu DW, Zarroug IMA, Aziz NA, Unnasch TR. Operational Performance of the Onchocerca volvulus "OEPA" Ov16 ELISA Serological Assay in Mapping, Guiding Decisions to Stop Mass Drug Administration, and Posttreatment Surveillance Surveys. Am J Trop Med Hyg 2018; 99:749-752. [PMID: 30014821 DOI: 10.4269/ajtmh.18-0341] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Onchocerciasis is a neglected tropical disease targeted for elimination. The World Health Organization (WHO) has developed guidelines for the verification of onchocerciasis elimination that include entomological and epidemiological criteria. The latter require demonstrating with statistical confidence that the infection prevalence in children is less than 0.1%, necessitating an assay with a high degree of specificity. We present an analysis of the performance of the Onchocerciasis Elimination Program for the Americas (OEPA) version of the Ov16 enzyme-linked immunosorbant assay (ELISA) when used under operational conditions. In Africa and Latin America, the assay demonstrated 99.98% specificity in 69,888 children in 20 foci where transmission was believed to be interrupted. The assay produced a prevalence estimate equal to that of skin snip microscopy when applied in putatively hypo-endemic zones of Ethiopia. The OEPA Ov16 ELISA demonstrated the specificity required to be effectively deployed to verify transmission elimination under the WHO guidelines, while exhibiting a sensitivity equivalent to skin snip microscopy to identify hypo-endemic areas.
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Affiliation(s)
| | | | | | | | | | - Mauricio Sauerbrey
- Onchocerciasis Elimination Program for the Americas, Guatemala City, Guatemala
| | | | | | | | - Nidia Rizzo
- Centro de Estudios en Salud of the Universidad del Valle de, Guatemala (UVG), Guatemala City, Guatemala
| | | | | | | | | | - David W Oguttu
- NTD Control Program, Vector Control Division, Kampala, Uganda
| | | | | | - Thomas R Unnasch
- Center for Global Health Infectious Disease Research, The University of South Florida, Tampa, Florida
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45
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Dadzie Y, Amazigo UV, Boatin BA, Sékétéli A. Is onchocerciasis elimination in Africa feasible by 2025: a perspective based on lessons learnt from the African control programmes. Infect Dis Poverty 2018; 7:63. [PMID: 29966535 PMCID: PMC6029117 DOI: 10.1186/s40249-018-0446-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/31/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Onchocerciasis is found predominantly in Africa where large scale vector control started in 1974. Registration and donation of ivermectin by Merck & Co in 1987 enabled mass treatment with ivermectin in all endemic countries in Africa and the Americas. Although elimination of onchocerciasis with ivermectin was considered feasible only in the Americas, recently it has been shown possible in Africa too, necessitating fundamental changes in technical and operational approaches and procedures. MAIN BODY The American programme(OEPA) operating in onchocerciasis epidemiological settings similar to the mild end of the complex epidemiology of onchocerciasis in Africa, has succeeded in eliminating onchocerciasis from 4 of its 6 endemic countries. This was achieved through biannual mass treatment with ivermectin of 85% of the eligible population, and monitoring and evaluation using serological tests in children and entomological tests. The first African programme(OCP) had a head start of nearly two decades. It employed vector control and accumulated lots of knowledge on the dynamics of onchocerciasis elimination over a wide range of epidemiological settings in the vast expanse of its core area. OCP made extensive use of modelling and operationalised elimination indicators for entomological evaluation and epidemiological evaluation using skin snip procedures. The successor African programme(APOC) employed mainly ivermectin treatment. Initially its objective was to control onchocerciasis as a public health problem but that objective was later expanded to include the elimination of onchocerciasis where feasible. Building on the experience with onchocerciasis elimination of the OCP, APOC has leveraged OCP's vast modelling experience and has developed operational procedures and indicators for evaluating progress towards elimination and stopping ivermectin mass treatment of onchocerciasis in the complex African setting. CONCLUSIONS Following the closure of APOC in 2015, implementation of onchocerciasis elimination in Africa appears to overlook all the experience that has been accumulated by the African programmes. It is employing predominantly American processes that were developed in a dissimilar setting from the complex African onchocerciasis setting. This is impeding progress towards decisions to stop intervention in many areas that have reached the elimination point. This article summarizes lessons learned in Africa and their importance for achieving elimination in Africa by 2025.
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Affiliation(s)
| | - Uche V. Amazigo
- P. O. Box 3397, Main Post Office, Okpara Avenue, Enugu, Nigeria
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46
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Kelly-Hope LA, Blundell HJ, Macfarlane CL, Molyneux DH. Innovative Surveillance Strategies to Support the Elimination of Filariasis in Africa. Trends Parasitol 2018; 34:694-711. [PMID: 29958813 DOI: 10.1016/j.pt.2018.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/18/2018] [Accepted: 05/30/2018] [Indexed: 01/18/2023]
Abstract
Lymphatic filariasis (LF) and onchocerciasis are two neglected tropical diseases (NTDs) of public health significance targeted for global elimination. The World Health Organization (WHO) African Region is a priority region, with the highest collective burden of LF and onchocerciasis globally. Coendemic loiasis further complicates elimination due to the risk of adverse events associated with ivermectin treatment. A public health framework focusing on health-related data, systematic collection of data, and analysis and interpretation of data is used to highlight the range of innovative surveillance strategies required for filariasis elimination. The most recent and significant developments include: rapid point-of-care test (POCT) diagnostics; clinical assessment tools; new WHO guidelines; open-access online data portals; mHealth platforms; large-scale prevalence maps; and the optimisation of mathematical models.
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Affiliation(s)
- Louise A Kelly-Hope
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Harriet J Blundell
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Cara L Macfarlane
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - David H Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
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