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Mutono N, Basáñez MG, James A, Stolk WA, Makori A, Kimani TN, Hollingsworth TD, Vasconcelos A, Dixon MA, de Vlas SJ, Thumbi SM. Elimination of transmission of onchocerciasis (river blindness) with long-term ivermectin mass drug administration with or without vector control in sub-Saharan Africa: a systematic review and meta-analysis. Lancet Glob Health 2024; 12:e771-e782. [PMID: 38484745 PMCID: PMC11009120 DOI: 10.1016/s2214-109x(24)00043-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 01/11/2024] [Accepted: 01/19/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND WHO has proposed elimination of transmission of onchocerciasis (river blindness) by 2030. More than 99% of cases of onchocerciasis are in sub-Saharan Africa. Vector control and mass drug administration of ivermectin have been the main interventions for many years, with varying success. We aimed to identify factors associated with elimination of onchocerciasis transmission in sub-Saharan Africa. METHODS For this systematic review and meta-analysis we searched for published articles reporting epidemiological or entomological assessments of onchocerciasis transmission status in sub-Saharan Africa, with or without vector control. We searched MEDLINE, PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, African Index Medicus, and Google Scholar databases for all articles published from database inception to Aug 19, 2023, without language restrictions. The search terms used were "onchocerciasis" AND "ivermectin" AND "mass drug administration". The three inclusion criteria were (1) focus or foci located in Africa, (2) reporting of elimination of transmission or at least 10 years of ivermectin mass drug administration in the focus or foci, and (3) inclusion of at least one of the following assessments: microfilarial prevalence, nodule prevalence, Ov16 antibody seroprevalence, and blackfly infectivity prevalence. Epidemiological modelling studies and reviews were excluded. Four reviewers (NM, AJ, AM, and TNK) extracted data in duplicate from the full-text articles using a data extraction tool developed in Excel with columns recording the data of interest to be extracted, and a column where important comments for each study could be highlighted. We did not request any individual-level data from authors. Foci were classified as achieving elimination of transmission, being close to elimination of transmission, or with ongoing transmission. We used mixed-effects meta-regression models to identify factors associated with transmission status. This study is registered in PROSPERO, CRD42022338986. FINDINGS Of 1525 articles screened after the removal of duplicates, 75 provided 282 records from 238 distinct foci in 19 (70%) of the 27 onchocerciasis-endemic countries in sub-Saharan Africa. Elimination of transmission was reported in 24 (9%) records, being close to elimination of transmission in 86 (30%) records, and ongoing transmission in 172 (61%) records. I2 was 83·3% (95% CI 79·7 to 86·3). Records reporting 10 or more years of continuous mass drug administration with 80% or more therapeutic coverage of the eligible population yielded significantly higher odds of achieving elimination of transmission (log-odds 8·5 [95% CI 3·5 to 13·5]) or elimination and being close to elimination of transmission (42·4 [18·7 to 66·1]) than those with no years achieving 80% coverage or more. Reporting 15-19 years of ivermectin mass drug administration (22·7 [17·2 to 28·2]) and biannual treatment (43·3 [27·2 to 59·3]) were positively associated with elimination and being close to elimination of transmission compared with less than 15 years and no biannual mass drug administration, respectively. Having had vector control without vector elimination (-42·8 [-59·1 to -26·5]) and baseline holoendemicity (-41·97 [-60·6 to -23·2]) were associated with increased risk of ongoing transmission compared with no vector control and hypoendemicity, respectively. Blackfly disappearance due to vector control or environmental change contributed to elimination of transmission. INTERPRETATION Mass drug administration duration, frequency, and coverage; baseline endemicity; and vector elimination or disappearance are important determinants of elimination of onchocerciasis transmission in sub-Saharan Africa. Our findings underscore the importance of improving and sustaining high therapeutic coverage and increasing treatment frequency if countries are to achieve elimination of onchocerciasis transmission. FUNDING The Bill & Melinda Gates Foundation and Neglected Tropical Diseases Modelling Consortium, UK Medical Research Council, and Global Health EDCTP3 Joint Undertaking. TRANSLATIONS For the Swahili, French, Spanish and Portuguese translations of the abstract see Supplementary Materials section.
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Affiliation(s)
- Nyamai Mutono
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA.
| | - Maria-Gloria Basáñez
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Ananthu James
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Anita Makori
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Teresia Njoki Kimani
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA; Ministry of Health Kenya, Kiambu Town, Kenya
| | | | | | - Matthew A Dixon
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - S M Thumbi
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA; Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK
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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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Domche A, Nana Djeunga HC, Nwane PB, Njitchouang GR, Nono Fesuh B, Njiokou F, Jacob B, Pion SD, Kamgno J. Significant reduction of blackfly densities in persistent onchocerciasis area following pilot implementation of an environment friendly approach (Slash and Clear). Sci Rep 2024; 14:408. [PMID: 38172522 PMCID: PMC10764779 DOI: 10.1038/s41598-023-50747-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/24/2023] [Indexed: 01/05/2024] Open
Abstract
The effectiveness of the "Slash and Clear" method in reducing blackfly populations in low transmission areas is established, but its impact in high transmission settings with large rivers and dense vectors is yet to be proven. A community-based intervention study was conducted in the Mbam Valley, Centre Cameroon, involving two sites: Bayomen (control) and Biatsota (intervention). In each arm, baseline blackfly densities were collected over one year using the human landing method. The intervention consisted of destroying the trailing vegetation where blackflies breed. Blackfly densities were collected post-intervention to assess the impact of the intervention. Post-intervention data showed a 50.8% reduction in blackfly density in Biatsota (mean number of collected blackflies from 1936 to 953), while a reduction of 26.7% was observed in Bayomen (mean number of collected blackflies from 2418 to 1774). The reduction rate attributable to the intervention was 32.9%. Statistical analysis confirmed that the reduction in blackfly density was significantly greater in the intervention site. This study demonstrates the feasibility and significant impact of the "Slash and Clear" method in high transmission areas. However, further research is required to assess its long-term effects and determine how this strategy can be scaled up and sustained until onchocerciasis elimination is achieved.
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Affiliation(s)
- André Domche
- Higher Institute of Scientific and Medical Research (ISM), Yaoundé, Cameroon.
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon.
| | | | - Philippe B Nwane
- Higher Institute of Scientific and Medical Research (ISM), Yaoundé, Cameroon
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Guy R Njitchouang
- Higher Institute of Scientific and Medical Research (ISM), Yaoundé, Cameroon
| | - Betrand Nono Fesuh
- Higher Institute of Scientific and Medical Research (ISM), Yaoundé, Cameroon
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Benjamin Jacob
- Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Sébastien D Pion
- UMI 233 TransVIH MI, University of Montpellier, Institut de Recherche pour le Développement (IRD), Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Joseph Kamgno
- Higher Institute of Scientific and Medical Research (ISM), Yaoundé, Cameroon
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Marques LLM, Beneti SC, Pinzon C, Cardoso FAR. Ivermectin as a possible treatment for COVID-19: a review of the 2022 protocols. BRAZ J BIOL 2024; 84:e258325. [DOI: 10.1590/1519-6984.258325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/16/2022] [Indexed: 11/22/2022] Open
Abstract
Abstract Ivermectin is a safe and effective drug in humans and has been approved for use in numerous parasitic infections for over 50 years. In addition, many studies have already shown its antiviral activity. Ivermectin is generally well tolerated, with no indication of central nervous system-associated toxicity at doses up to 10 times the highest FDA-approved dose of 200 µg/kg. The in vitro results of ivermectin for reducing SARS-CoV-2 viral load are promising and show that Ivermectin kills SARS-CoV-2 within 48 hours. A hypothesized mechanism of action for this drug is a likely inhibition of IMPα/β1-mediated nuclear import of viral proteins as demonstrated for other RNA viruses. However, controlled and randomized studies are needed to prove its effectiveness in COVID-19 in humans. In a single in vivo study with published results, patients confirmed to be infected with SARS-CoV-2 received at least one dose of ivermectin at any time during hospitalization. The use of ivermectin was associated with lower mortality during treatment with COVID-19, especially in patients who required increased inspired oxygen or ventilatory support. Additionally, 81 studies with the clinical use of ivermectin in humans are being carried out worldwide according to ClinicalTrials.gov. However, none of these data has been published so far. However, private and public entities in Brazil have been adopting this drug in their protocols as prophylaxis and in the initial phase of the disease. In addition, ivermectin has been used in mass treatment to prevent onchocerciasis and lymphatic filariasis in sub-Saharan Africa for many years. Surprisingly, this region has the lowest proportional mortality rate among the continents, despite the increasing numbers of infected people released by the World Health Organization.
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Affiliation(s)
| | - S. C. Beneti
- Universidade Tecnológica Federal do Paraná, Brasil
| | - C. Pinzon
- Universidade Tecnológica Federal do Paraná, Brasil
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Rehborg EG, Wheeler NJ, Zamanian M. Mapping resistance-associated anthelmintic interactions in the model nematode Caenorhabditis elegans. PLoS Negl Trop Dis 2023; 17:e0011705. [PMID: 37883578 PMCID: PMC10629664 DOI: 10.1371/journal.pntd.0011705] [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: 04/28/2023] [Revised: 11/07/2023] [Accepted: 10/07/2023] [Indexed: 10/28/2023] Open
Abstract
Parasitic nematodes infect billions of people and are mainly controlled by anthelmintic mass drug administration (MDA). While there are growing efforts to better understand mechanisms of anthelmintic resistance in human and animal populations, it is unclear how resistance mechanisms that alter susceptibility to one drug affect the interactions and efficacy of drugs used in combination. Mutations that alter drug permeability across primary nematode barriers have been identified as potential resistance mechanisms using the model nematode Caenorhabditis elegans. We leveraged high-throughput assays in this model system to measure altered anthelmintic susceptibility in response to genetic perturbations of potential cuticular, amphidial, and alimentary routes of drug entry. Mutations in genes associated with these tissue barriers differentially altered susceptibility to the major anthelmintic classes (macrocyclic lactones, benzimidazoles, and nicotinic acetylcholine receptor agonists) as measured by animal development. We investigated two-way anthelmintic interactions across C. elegans genetic backgrounds that confer resistance or hypersensitivity to one or more drugs. We observe that genetic perturbations that alter susceptibility to a single drug can shift the drug interaction landscape and lead to the appearance of novel synergistic and antagonistic interactions. This work establishes a framework for investigating combinatorial therapies in model nematodes that can potentially be translated to amenable parasite species.
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Affiliation(s)
- Elena G. Rehborg
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nicolas J. Wheeler
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mostafa Zamanian
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Rehborg EG, Wheeler NJ, Zamanian M. Mapping resistance-associated anthelmintic interactions in the model nematode Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538424. [PMID: 37163071 PMCID: PMC10168335 DOI: 10.1101/2023.04.26.538424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Parasitic nematodes infect billions of people and are mainly controlled by anthelmintic mass drug administration (MDA). While there are growing efforts to better understand mechanisms of anthelmintic resistance in human and animal populations, it is unclear how resistance mechanisms that alter susceptibility to one drug affect the interactions and efficacy of drugs used in combination. Mutations that alter drug permeability across primary nematode barriers have been identified as potential resistance mechanisms using the model nematode Caenorhabditis elegans. We leveraged high-throughput assays in this model system to measure altered anthelmintic susceptibility in response to genetic perturbations of potential cuticular, amphidial, and alimentary routes of drug entry. Mutations in genes associated with these tissue barriers differentially altered susceptibility to the major anthelmintic classes (macrocyclic lactones, benzimidazoles, and nicotinic acetylcholine receptor agonists) as measured by animal development. We investigated two-way anthelmintic interactions across C. elegans genetic backgrounds that confer resistance or hypersensitivity to one or more drugs. We observe that genetic perturbations that alter susceptibility to a single drug can shift the drug interaction landscape and lead to the appearance of novel synergistic and antagonistic interactions. This work establishes a framework for investigating combinatorial therapies in model nematodes that can potentially be translated to amenable parasite species.
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Affiliation(s)
- Elena G. Rehborg
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI USA
| | - Nicolas J Wheeler
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI USA
| | - Mostafa Zamanian
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI USA
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Olamiju FO, Mogaji HO, Bjørn MT, Marcus AJ, Oduwa V, Olamiju OJ, Nzunde M, Ikyerga DK, Hopkins A. Preliminary assessment of Onchocerca-induced visual impairment using clinical fundus camera in Gashaka local government area of Taraba state, north eastern Nigeria. Parasite Epidemiol Control 2023; 21:e00296. [PMID: 36969391 PMCID: PMC10034485 DOI: 10.1016/j.parepi.2023.e00296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 01/30/2023] [Accepted: 03/09/2023] [Indexed: 03/13/2023] Open
Abstract
Introduction Onchocerciasis is the world's second leading cause of infectious blindness and remains a major problem in parts of Africa. In light of the efforts targeted towards improving ongoing elimination program, this study assessed onchocerca-induced visual impairments in Gashaka local government areas (LGA) in Taraba State, north-eastern Nigeria. Methods In 2019, we recruited 158 consenting visually impaired persons across three communities in Garbabi ward of Gashaka LGA. To avoid confusion with co-endemic trachoma, the integrity of the tarsal conjunctiva, eyelashes were assessed using direct light. The anterior segment of the eye was also examined using a torchlight with oblique illumination. However, the posterior segment of the eye was assessed using a fundus camera. Two photographic images for the left and right eye of each participant were captured using the clinical fundus camera. The photographic eye images that were too dark were discarded, and only clear images were analyzed by two ophthalmologists. An ocular manifestation report was recorded for each participant following consensus between the ophthalmologists. Results Of the 316 photographic eye images, almost half 146 (46.2%) from 73 participants were just too destroyed for light to penetrate and was not included in the analysis. Only 170 from 85 participants were clear and examinable. A total of 33 (39%) participants had chorioretinitis suggestive of onchocerciasis, including 22(25.9%) with chorio-retinal atrophy, 7(8.2%) and 4(4.7%) had chorioretinal atrophy in combination with early cataract and signs of trachoma respectively. In addition, 3(3.5%) of the participant had eye images which showed lens opacities, 1(1.2%) showed signs of keratoconus and 1(1.2%) showed a scared and pigmented cornea, possibly due to onchocerciasis. Furthermore, 28 (32.9%) had some ill-defined changes and 19 (22.4%) showed poorly defined chorio-retinal atrophy. Conclusion In a bid to sustain MDA gains towards elimination of onchocerciasis, this work highlights the need for continuous assessment of onchocerciasis induced visual impairment, strengthening of ivermectin delivery and optimizing compliance and patient care among affected populations. These would require resource acquisition and local capacity building. Our preliminary findings call for further operational research on ocular morbidity as well as future stakeholders' consultations in this important and understudied area.
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Affiliation(s)
| | - Hammed O. Mogaji
- Mission To Save The Helpless (MITOSATH), Jos, Nigeria
- Parasitology and Epidemiology Unit, Department of Animal and Environmental Biology, Federal University Oye-Ekiti, Nigeria
- Corresponding author at: Mission To Save The Helpless (MITOSATH), Jos, Nigeria.
| | | | | | - Vera Oduwa
- Smiley Optical Services Limited, Abuja, Nigeria
| | | | - Markus Nzunde
- Neglected Tropical Disease Unit, State Ministry of Health, Taraba, Nigeria
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Miri ES, Eigege A, Kahansim B, Nwodu K, Sambo Y, Mancha B, Adelamo S, Umaru J, Kadimbo J, Danboyi J, Mafuyai H, Makata E, Akpan N, Akilah J, Igbe M, Coalson J, Rakers L, Griswold E, Unnasch TR, Nwoke BEB, Noland GS, Richards FO. Two Nigerian States (Plateau and Nasarawa) Have Eliminated Transmission of Human Onchocerciasis-A Report of Post-Ivermectin Mass Drug Administration Surveillance. Am J Trop Med Hyg 2023; 108:37-40. [PMID: 36450227 PMCID: PMC9833078 DOI: 10.4269/ajtmh.22-0491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/02/2022] [Indexed: 12/02/2022] Open
Abstract
Transmission of Onchocerca volvulus (causing "river blindness") was interrupted in two states of Nigeria (Plateau and Nasarawa) in 2017 in accordance with 2016 WHO guidelines. Ivermectin mass drug administration was halted in January 2018, and posttreatment surveillance activities were conducted over a 3-year period. Vector Simulium damnosum s.l. flies were collected during the 2019 (39 sites) and 2020 (42 sites) transmission seasons. Head pools were tested by polymerase chain reaction for the presence of third-stage O. volvulus larvae; 15,585 flies were all negative, demonstrating an infective rate of < 1/2,000 with 95% confidence. In 2021, the Nigerian Federal Ministry of Health declared the two-state area as having eliminated transmission. Plateau and Nasarawa states are the first of 30 endemic states in Nigeria to have met the WHO criteria for onchocerciasis elimination. Post-elimination surveillance will need to continue given the risk of reintroduction of transmission from neighboring states.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Emeka Makata
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
| | - Nse Akpan
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
| | - Joel Akilah
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
| | - Michael Igbe
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
| | | | | | | | | | | | | | - Frank O. Richards
- The Carter Center, Atlanta, Georgia;,Address correspondence to Frank O. Richards, Jr., The Carter Center, 1 Copenhill, Atlanta, GA 30307. E-mail:
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Domche A, Nwane PB, Nana Djeunga HC, Njitchouang GR, Pion SD, Boussinesq M, Njiokou F, Kamgno J. Status of Onchocerca volvulus (Spirurida: Onchocercidae) Transmission and Effect of Climatic Variables on the Vector Population Dynamics After Two Decades of Ivermectin-based Preventive Chemotherapy in the Mbam Valley (Centre Region, Cameroon). JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:2130-2138. [PMID: 36111691 DOI: 10.1093/jme/tjac133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Entomological indicators of onchocerciasis transmission and the effect of climatic variables on the vector population dynamics were investigated in two first-line villages after more than two decades of mass drug administration with ivermectin. Female blackflies were collected in two villages (Bayomen and Biatsota) using human landing method for a period of 12 months. Blackflies were dissected and entomological indices were computed. Monthly temperature, precipitation, and humidity were collected and the Spearman correlation rank test was used to assess the relationship between biting rates and climatic variables. The highest biting rates (62,280 bites/human/month in Bayomen and 42,090 bites/human/month in Biatsota) were recorded during the long rainy season (November). The Onchocerca volvulus transmission was greater during the long dry season in both villages, with a peak at the beginning of the long dry season in Biatsota (100 infective larvae/human/month), and at the middle of the long dry season in Bayomen (92 infective larvae/human/month). No correlation was found between biting rates and selected climatic variables in the two villages. This study revealed that onchocerciasis transmission is ongoing in the study area despite almost 25 years of Community-Directed Treatment with Ivermectin. In accordance with WHO recommendations, vector control should be used in combination with mass drug administration to accelerate transmission interruption of onchocerciasis. To be optimal, this vector control should be implemented during the long dry season (November to March) when water volumes are low and transmission potentials are high.
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Affiliation(s)
- André Domche
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Philippe B Nwane
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Hugues C Nana Djeunga
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Guy R Njitchouang
- Centre for Research on Filariasis and Other Tropical Diseases (CRFilMT), Yaoundé, Cameroon
| | - Sébastien D Pion
- TransVIHMI, University of Montpellier, Institut de Recherche pour le Développement (IRD), Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Michel Boussinesq
- TransVIHMI, University of Montpellier, Institut de Recherche pour le Développement (IRD), Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Joseph Kamgno
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
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10
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Isiyaku S, Igbe M, Madaki S, Hamill LC, Ndongmo P, Adamani W, Bush S, Shu'aibu J, Elhassan E, Saka Y, Anyaike C, Akpan NM, Joel A, Nyior A, Abdullahi A, Aleiro A, Labbo A, Mafuyai HB, Nwoke BEB. The interruption of transmission of onchocerciasis in Kaduna, Kebbi and Zamfara states, Nigeria: another milestone achievement. Int Health 2022; 14:ii43-ii54. [PMID: 36130252 PMCID: PMC9492257 DOI: 10.1093/inthealth/ihac036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/02/2022] [Accepted: 05/12/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND More than 40 million people live in onchocerciasis-endemic areas in Nigeria. For at least 19 y, mass drug administration (MDA) with ivermectin was implemented with at least 65% total population coverage in Kaduna, Kebbi and Zamfara states. Impact surveys done using skin biopsies yielded no infections. Serological and entomological assessments were undertaken to determine if onchocerciasis transmission had been interrupted and MDA could be stopped. METHODS The presence of onchocerciasis-specific immunoglobulin G4 antibody was measured by enzyme=linked immunosorbent assay conducted on dried blood spots collected from 5- to 9-year-old children resident in each state. O-150 polymerase chain reaction testing of Simulium damnosum s.l. heads for Onchocerca volvulus DNA was done on black flies collected by human landing capture and Esperanza window traps. RESULTS A total of 9078 children were surveyed across the three states. A total of 6139 vectors were collected from Kaduna state, 129 from Kebbi state and 2 from Zamfara state; all were negative. Kebbi and Zamfara states did thousands of hours of black fly catching and intensive river prospecting. The resulting low fly catch was due to a low fly population incapable of sustaining transmission. CONCLUSION Onchocerciasis transmission has been interrupted and the three states meet World Health Organization thresholds: seropositivity in children <0.1% and <1/2000 infective black flies with 95% confidence. The 2.2 million people in Kaduna state and 4 million in Kebbi and Zamfara states no longer need ivermectin for onchocerciasis.
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Affiliation(s)
- Sunday Isiyaku
- Sightsavers, Golf Course Road, P.O. Box 503, Kaduna, Nigeria
| | - Michael Igbe
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
| | - Suzie Madaki
- Sightsavers, Golf Course Road, P.O. Box 503, Kaduna, Nigeria
| | - Louise C Hamill
- Sightsavers, 35 Perrymount Road, Haywards Heath, RH16 3BZ, UK
| | - Patrick Ndongmo
- Sightsavers, Derriere Laboratoire Meka, Bastos, Yaoundé, BP 4484, Cameroon
| | - William Adamani
- Sightsavers, Golf Course Road, P.O. Box 503, Kaduna, Nigeria
| | - Simon Bush
- Sightsavers, 35 Perrymount Road, Haywards Heath, RH16 3BZ, UK
| | - Joy Shu'aibu
- Sightsavers, Golf Course Road, P.O. Box 503, Kaduna, Nigeria
| | | | - Yisa Saka
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
| | - Chukwuma Anyaike
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
| | - Nse Michael Akpan
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
| | - Akilah Joel
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
| | - Audrey Nyior
- Federal Ministry of Health, Abuja, FCT, Nigeria, P.M.B. 083, Garki Abuja, Nigeria
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11
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Griswold E, Eigege A, Adelamo S, Mancha B, Kenrick N, Sambo Y, Ajiji J, Zam G, Solomon J, O. Urude R, Kadimbo J, Danboyi J, Miri E, Nute AW, Rakers L, Nebe O, Anyaike C, Weiss P, S. Noland G, Richards F. Impact of Three to Five Rounds of Mass Drug Administration on Schistosomiasis and Soil-Transmitted Helminths in School-Aged Children in North-Central Nigeria. Am J Trop Med Hyg 2022; 107:tpmd211207. [PMID: 35576949 PMCID: PMC9294711 DOI: 10.4269/ajtmh.21-1207] [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: 11/19/2021] [Accepted: 02/04/2022] [Indexed: 11/25/2022] Open
Abstract
Nasarawa and Plateau states of north-central Nigeria have implemented programs to control schistosomiasis (SCH) and soil-transmitted helminths (STH) in children since the 1990s. Statewide mapping surveys were conducted in 2013, when 11,332 school-aged children were sampled from 226 schools. The local government areas (LGAs) then received varying combinations of mass drug administration (MDA) for the next 5 years. We revisited 196 (87%) schools in 2018 plus an additional six (202 schools in total), sampling 9,660 children. We calculated overall prevalence and intensity of infection and evaluated associations with gender; age; behaviors; water, sanitation, and hygiene (WASH); and treatment regimen. Urine heme detection dipsticks were used for Schistosoma hematobium in both surveys, with egg counts added in 2018. Stool samples were examined by Kato-Katz for Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, and hookworm. Schistosomiasis prevalence among sampled students dropped from 12.9% (95% confidence interval [CI]: 11.1-14.9%) to 9.0% (95% CI: 7.5-10.9%), a statistically significant change (P < 0.05). In 2018, eight LGAs still had > 1% of children with heavy-intensity schistosome infections. Prevalence of STH infection did not significantly change, with 10.8% (95% CI: 9.36-12.5%) of children positive in 2013 and 9.4% (95% CI: 8.0-10.9%) in 2018 (P = 0.182). Heavy-intensity STH infections were found in < 1% of children with hookworm, and none in children with A. lumbricoides or T. trichiura in either study. The WASH data were collected in 2018, indicating 43.6% of schools had a latrine and 14.4% had handwashing facilities. Although progress is evident, SCH remains a public health problem in Nasarawa and Plateau states.
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Affiliation(s)
| | | | | | | | | | | | | | - Gideon Zam
- Nasarawa State Ministry of Health, Lafia, Nigeria
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12
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Stolk WA, Blok DJ, Hamley JID, Cantey PT, de Vlas SJ, Walker M, Basáñez MG. Scaling-Down Mass Ivermectin Treatment for Onchocerciasis Elimination: Modeling the Impact of the Geographical Unit for Decision Making. Clin Infect Dis 2021; 72:S165-S171. [PMID: 33909070 PMCID: PMC8201558 DOI: 10.1093/cid/ciab238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background Due to spatial heterogeneity in onchocerciasis transmission, the duration of ivermectin mass drug administration (MDA) required for eliminating onchocerciasis will vary within endemic areas and the occurrence of transmission “hotspots” is inevitable. The geographical scale at which stop-MDA decisions are made will be a key driver in how rapidly national programs can scale down active intervention upon achieving the epidemiological targets for elimination. Methods We used 2 onchocerciasis models (EPIONCHO-IBM and ONCHOSIM) to predict the likelihood of achieving elimination by 2030 in Africa, accounting for variation in preintervention endemicity levels and histories of ivermectin treatment. We explore how decision making at contrasting geographical scales (community vs larger scale “project”) changes projections on populations still requiring MDA or transitioning to post-treatment surveillance. Results The total population considered grows from 118 million people in 2020 to 136 million in 2030. If stop-MDA decisions are made at project level, the number of people requiring treatment declines from 69–118 million in 2020 to 59–118 million in 2030. If stop-MDA decisions are made at community level, the numbers decline from 23–81 million in 2020 to 15–63 million in 2030. The lower estimates in these prediction intervals are based on ONCHOSIM, the upper limits on EPIONCHO-IBM. Conclusions The geographical scale at which stop-MDA decisions are made strongly determines how rapidly national onchocerciasis programs can scale down MDA programs. Stopping in portions of project areas or transmission zones would free up human and economic resources.
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Affiliation(s)
- Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - David J Blok
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jonathan I D Hamley
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, United Kingdom.,MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, United Kingdom
| | - Paul T Cantey
- Division of Parasitic Diseases and Malaria, US Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martin Walker
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, United Kingdom.,London Centre for Neglected Tropical Disease Research, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, United Kingdom
| | - María-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, United Kingdom.,MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, United Kingdom
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13
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Mabey D, Agler E, Amuasi JH, Hernandez L, Hollingsworth TD, Hotez PJ, Lammie PJ, Malecela MN, Matendechero SH, Ottesen E, Phillips RO, Reeder JC, Szwarcwald CL, Shott JP, Solomon AW, Steer A, Swaminathan S. Towards a comprehensive research and development plan to support the control, elimination and eradication of neglected tropical diseases. Trans R Soc Trop Med Hyg 2021; 115:196-199. [PMID: 33179054 PMCID: PMC7842110 DOI: 10.1093/trstmh/traa114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/06/2020] [Indexed: 12/14/2022] Open
Abstract
To maximise the likelihood of success, global health programmes need repeated, honest appraisal of their own weaknesses, with research undertaken to address any identified gaps. There is still much to be learned to optimise work against neglected tropical diseases. To facilitate that learning, a comprehensive research and development plan is required. Here, we discuss how such a plan might be developed.
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Affiliation(s)
- David Mabey
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | | | - John H Amuasi
- African Research Network for Neglected Tropical Diseases, Kumasi AK-039-5028, Ghana
| | - Leda Hernandez
- Department of Health, Infectious Disease Office, National Center for Disease Prevention and Control, Manila 1003, Philippines
| | - T Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford OX3 7LF, UK
| | - Peter J Hotez
- Departments of Pediatrics and Molecular Virology & Microbiology, Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030s, USA.,Hagler Institute for Advanced Study at Texas A & M University, College Station, TX 77843, USA.,Department of Biology, Baylor University, Waco, TX 76706, USA.,James A. Baker III Institute of Public Policy, Rice University, Houston, TX 77005, USA.,Scowcroft Institute of International Affairs, Bush School of Government and Public Service, Texas A & M University, College Station, TX 77845, USA
| | - Patrick J Lammie
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, GA 30030, USA
| | - Mwelecele N Malecela
- Department of Control of Neglected Tropical Diseases, WHO 1211, Geneva, Switzerland
| | - Sultani H Matendechero
- Division of Communicable Disease Prevention and Control, Neglected Tropical Diseases Unit, Ministry of Health, Nairobi, Kenya
| | - Eric Ottesen
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, GA 30030, USA
| | - Richard O Phillips
- Kumasi Center for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi AK-039-5028, Ghana
| | - John C Reeder
- UNICEF, UNDP, World Bank, WHO Special Programme for Research and Training in Tropical Disease (TDR), 1211 Geneva 21040-900, Switzerland
| | - Célia Landmann Szwarcwald
- Instituto de Comunicação e Informação Científica e Tecnológica em Saúde, Fundação Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brasil
| | - Joseph P Shott
- Division of Neglected Tropical Diseases, Office of Infectious Diseases, Bureau for Global Health, USAID, Washington, DC 20004, USA
| | - Anthony W Solomon
- Department of Control of Neglected Tropical Diseases, WHO 1211, Geneva, Switzerland
| | - Andrew Steer
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3010, Australia.,Department of General Medicine, Royal Children's Hospital, Melbourne, Victoria 3052, Australia.,Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria 3052, Australia
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14
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Emodepside targets SLO-1 channels of Onchocerca ochengi and induces broad anthelmintic effects in a bovine model of onchocerciasis. PLoS Pathog 2021; 17:e1009601. [PMID: 34077488 PMCID: PMC8202924 DOI: 10.1371/journal.ppat.1009601] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/14/2021] [Accepted: 05/01/2021] [Indexed: 12/14/2022] Open
Abstract
Onchocerciasis (river blindness), caused by the filarial worm Onchocerca volvulus, is a neglected tropical disease mostly affecting sub-Saharan Africa and is responsible for >1.3 million years lived with disability. Current control relies almost entirely on ivermectin, which suppresses symptoms caused by the first-stage larvae (microfilariae) but does not kill the long-lived adults. Here, we evaluated emodepside, a semi-synthetic cyclooctadepsipeptide registered for deworming applications in companion animals, for activity against adult filariae (i.e., as a macrofilaricide). We demonstrate the equivalence of emodepside activity on SLO-1 potassium channels in Onchocerca volvulus and Onchocerca ochengi, its sister species from cattle. Evaluation of emodepside in cattle as single or 7-day treatments at two doses (0.15 and 0.75 mg/kg) revealed rapid activity against microfilariae, prolonged suppression of female worm fecundity, and macrofilaricidal effects by 18 months post treatment. The drug was well tolerated, causing only transiently increased blood glucose. Female adult worms were mostly paralyzed; however, some retained metabolic activity even in the multiple high-dose group. These data support ongoing clinical development of emodepside to treat river blindness.
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15
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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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16
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Eigege A, Noland GS, Adelamo SE, Nwodu K, Sallau A, Umaru J, Mancha BS, Davies E, Danboyi J, Kadimbo JA, Saka YA, Anagbogu I, Miri ES, Richards FO. Post-Treatment Surveillance for Lymphatic Filariasis in Plateau and Nasarawa States, Nigeria: Results of Transmission Assessment Surveys. Am J Trop Med Hyg 2020; 102:1404-1410. [PMID: 32228796 PMCID: PMC7253131 DOI: 10.4269/ajtmh.20-0020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Following the halt of mass drug administration (MDA) for lymphatic filariasis (LF), the WHO recommends at least 4 years of post-treatment surveillance (PTS) to confirm that transmission recrudescence or importation does not occur. The primary means of evaluation during PTS is repeated transmission assessment surveys (TASs) conducted at 2- to 3-year intervals after TAS-1 stop-MDA surveys. This study reports the results of TAS-2 and TAS-3 surveys in Plateau and Nasarawa states (pop. 6.9 million) of Nigeria divided into a minimum of seven evaluation units (EUs) per TAS. A total of 26,536 first- and second-year primary school children (approximately 6–7 years old) were tested for circulating filarial antigen (CFA) between 2014 and 2017. Of 12,313 children tested in TAS-2 surveys, only five (0.04%) were CFA positive, with no more than two positive samples from any one EU, which was below the critical value of 20 per EU. Of 14,240 children tested in TAS-3 surveys, none (0%) were CFA positive. These results indicate that LF transmission remains below sustainable transmission levels and suggest that elimination of transmission has been achieved in Plateau and Nasarawa, Nigeria.
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17
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Evans DS. Challenges to Making the Decision to Stop Mass Drug Administration for Onchocerciasis: Lessons Learned from Nigeria. Am J Trop Med Hyg 2020; 102:485-486. [PMID: 32043450 PMCID: PMC7056426 DOI: 10.4269/ajtmh.19-0951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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