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Franco JR, Priotto G, Paone M, Cecchi G, Ebeja AK, Simarro PP, Sankara D, Metwally SBA, Argaw DD. The elimination of human African trypanosomiasis: Monitoring progress towards the 2021-2030 WHO road map targets. PLoS Negl Trop Dis 2024; 18:e0012111. [PMID: 38626188 PMCID: PMC11073784 DOI: 10.1371/journal.pntd.0012111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 05/06/2024] [Accepted: 03/26/2024] [Indexed: 04/18/2024] Open
Abstract
BACKGROUND Human African trypanosomiasis (HAT) is a neglected tropical disease that usually occurs in rural areas in sub-Saharan Africa. It caused devastating epidemics during the 20th century. Sustained, coordinated efforts by different stakeholders working with national sleeping sickness control programmes (NSSCPs) succeeded in controlling the disease and reducing the number of cases to historically low levels. In 2012, WHO targeted the elimination of the disease as a public health problem by 2020. This goal has been reached and a new ambitious target was stated in the WHO road map for NTDs 2021-2030 and endorsed by the 73rd World Health Assembly: the elimination of gambiense HAT transmission (i.e. reducing the number of reported cases to zero). The interruption of transmission was not considered as an achievable goal for rhodesiense HAT, as it would require vast veterinary interventions rather than actions at the public health level. METHODOLOGY/PRINCIPAL FINDINGS Data reported to WHO by NSSCPs were harmonized, verified, georeferenced and included in the atlas of HAT. A total of 802 cases were reported in 2021 and 837 in 2022. This is below the target for elimination as a public health problem at the global level (< 2000 HAT cases/year); 94% of the cases were caused by infection with T. b. gambiense. The areas reporting ≥ 1 HAT case/10 000 inhabitants/year in 2018-2022 cover a surface of 73 134 km2, with only 3013 km2 at very high or high risk. This represents a reduction of 90% from the baseline figure for 2000-2004, the target set for the elimination of HAT as a public health problem. For the surveillance of the disease, 4.5 million people were screened for gambiense HAT with serological tests in 2021-2022, 3.6 million through active screening and 0.9 million by passive screening. In 2021 and 2022 the elimination of HAT as a public health problem was validated in Benin, Uganda, Equatorial Guinea and Ghana for gambiense HAT and in Rwanda for rhodesiense HAT. To reach the next goal of elimination of transmission of gambiense HAT, countries have to report zero cases of human infection with T. b. gambiense for a period of at least 5 consecutive years. The criteria and procedures to verify elimination of transmission have been recently published by WHO. CONCLUSIONS/SIGNIFICANCE HAT elimination as a public health problem has been reached at global level, with seven countries already validated as having reached this goal. This achievement was made possible by the work of NSSCPs, supported by different public and private partners, and coordinated by WHO. The new challenging goal now is to reach zero cases by 2030. To reach this goal is crucial to maintain the engagement and support of donors and stakeholders and to keep the involvement and coordination of all partners. Along with the focus on elimination of transmission of gambiense HAT, it is important not to neglect rhodesiense HAT, which is targeted for elimination as a public health problem in the WHO road map for NTDs 2021-2030.
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Affiliation(s)
- Jose R. Franco
- World Health Organization, Global Neglected Tropical Diseases Programme, Prevention, Treatment and Care Unit, Geneva, Switzerland
| | - Gerardo Priotto
- World Health Organization, Global Neglected Tropical Diseases Programme, Prevention, Treatment and Care Unit, Geneva, Switzerland
| | - Massimo Paone
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Agustin Kadima Ebeja
- World Health Organization, Regional Office for Africa, Communicable Disease Unit, Brazzaville, Congo
| | - Pere P. Simarro
- Consultant, World Health Organization, Global Neglected Tropical Diseases Programme, Innovative and Intensified Disease Management Unit, Geneva, Switzerland
| | - Dieudonne Sankara
- World Health Organization, Global Neglected Tropical Diseases Programme, Prevention, Treatment and Care Unit, Geneva, Switzerland
| | - Samia B. A. Metwally
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Daniel Dagne Argaw
- World Health Organization, Global Neglected Tropical Diseases Programme, Prevention, Treatment and Care Unit, Geneva, Switzerland
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Henríquez AM, Tejedor-Junco MT, González-Martín M, Morales Doreste M, Martín Martel S, Paone M, Cecchi G, Corbera JA. An Atlas of Surra in Spain: A Tool to Support Epidemiological Investigations and Disease Control. Animals (Basel) 2024; 14:243. [PMID: 38254411 PMCID: PMC10812746 DOI: 10.3390/ani14020243] [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: 12/10/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Trypanosomosis is a global animal issue, causing significant economic losses, particularly in Africa. In Spain, only one pathogenic species, Trypanosoma evansi, has been identified so far. It was first detected in a dromedary camel in the Canary Islands in 1997. Since then, numerous cases of the disease, known as Surra, have been diagnosed, prompting various studies and efforts in control and surveillance. Given the lack of a comprehensive database that consolidates the most relevant data in this area, the development of a national atlas, with a focus on the Canary Islands, to incorporate all available information on T. evansi in Spain became a necessity. For the development of the atlas, a repository was constructed, encompassing a range of datasets and documents spanning from 1997 to 2022. Information from each source, and in particular georeferenced locations and results of blood tests on animals, were extracted and integrated into a comprehensive database. A total of 31 sources were analysed, providing a total of 99 georeferenced locations and 12,433 animal samples. Out of these samples, 601 (mostly from dromedaries) were found to be positive for T. evansi. The Card Agglutination Test for T. evansi (CATT/T. evansi), a serological test, was the most commonly used diagnostic method, and it showed a higher prevalence for all tested animal species. Positive cases were mainly concentrated in the Canary Islands, specifically in the eastern islands, with isolated cases found in the province of Alicante (Iberian Peninsula). This atlas provides an overview of the history and occurrence of Surra in Spain, and it represents a valuable tool for future control initiatives and for research. Still, the need for more studies remains, especially for further testing of potential hosts other than camelids and for the examination of their potential transmission vectors.
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Affiliation(s)
- Adrián Melián Henríquez
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria (ULPGC), 35016 Las Palmas, Spain
| | - María Teresa Tejedor-Junco
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria (ULPGC), 35016 Las Palmas, Spain
- Departmento de Ciencias Clínicas, Universidad de Las Palmas de Gran Canaria (ULPGC), Paseo Blas Cabrera Felipe “Físico”, 17, Las Palmas de Gran Canaria, 35016 Las Palmas, Spain
| | - Margarita González-Martín
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria (ULPGC), 35016 Las Palmas, Spain
- Departmento de Ciencias Clínicas, Universidad de Las Palmas de Gran Canaria (ULPGC), Paseo Blas Cabrera Felipe “Físico”, 17, Las Palmas de Gran Canaria, 35016 Las Palmas, Spain
| | - Manuel Morales Doreste
- Hospital Clínico Veterinario-Universidad de Las Palmas de Gran Canaria (HCV-ULPGC), Campus Universitario de Arucas, 35413 Las Palmas, Spain
| | - Sergio Martín Martel
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria (ULPGC), 35016 Las Palmas, Spain
- Hospital Clínico Veterinario-Universidad de Las Palmas de Gran Canaria (HCV-ULPGC), Campus Universitario de Arucas, 35413 Las Palmas, Spain
| | - Massimo Paone
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations (FAO), 00153 Rome, Italy
| | - Giuliano Cecchi
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations (FAO), 00153 Rome, Italy
| | - Juan Alberto Corbera
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria (ULPGC), 35016 Las Palmas, Spain
- Hospital Clínico Veterinario-Universidad de Las Palmas de Gran Canaria (HCV-ULPGC), Campus Universitario de Arucas, 35413 Las Palmas, Spain
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Jobe NB, Huijben S, Paaijmans KP. Non-target effects of chemical malaria vector control on other biological and mechanical infectious disease vectors. Lancet Planet Health 2023; 7:e706-e717. [PMID: 37558351 DOI: 10.1016/s2542-5196(23)00136-5] [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: 07/28/2022] [Revised: 06/09/2023] [Accepted: 06/17/2023] [Indexed: 08/11/2023]
Abstract
Public health insecticides play a crucial role in malaria control and elimination programmes. Many other arthropods, including mechanical and biological vectors of infectious diseases, have similar indoor feeding or resting behaviours, or both, as malaria mosquitoes, and could be exposed to the same insecticides. In this Personal View, we show that little is known about the insecticide susceptibility status and the extent of exposure to malaria interventions of other arthropod species. We highlight that there is an urgent need to better understand the selection pressure for insecticide resistance in those vectors, to ensure current and future active ingredients remain effective in targeting a broad range of arthropod species, allowing us to prevent and control future outbreaks of infectious diseases other than malaria.
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Affiliation(s)
- Ndey Bassin Jobe
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Silvie Huijben
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA; Simon A Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, USA
| | - Krijn P Paaijmans
- The Center for Evolution & Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA; Simon A Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ, USA; The Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ, USA; ISGlobal, Barcelona, Spain; Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
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Gebre T, Kapitano B, Beyene D, Alemu D, Beshir A, Worku Z, Kifle T, Selamu A, Debas E, Kalsa A, Asfaw N, Zhao W, Paone M, Cecchi G. The national atlas of tsetse flies and African animal trypanosomosis in Ethiopia. Parasit Vectors 2022; 15:491. [PMID: 36578020 PMCID: PMC9798648 DOI: 10.1186/s13071-022-05617-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/13/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND With the largest cattle population in Africa and vast swathes of fertile lands infested by tsetse flies, trypanosomosis is a major challenge for Ethiopian farmers. Managing the problem strategically and rationally requires comprehensive and detailed information on disease and vector distribution at the national level. To this end, the National Institute for Control and Eradication of Tsetse and Trypanosomosis (NICETT) developed a national atlas of tsetse and African animal trypanosomosis (AAT) for Ethiopia. METHODS This first edition of the atlas focused on the tsetse-infested areas in western Ethiopia. Data were collected between 2010 and 2019 in the framework of national surveillance and control activities. Over 88,000 animals, mostly cattle, were tested with the buffy-coat technique (BCT). Odour-enhanced traps were deployed in approximately 14,500 locations for the entomological surveys. Animal- and trap-level data were geo-referenced, harmonized and centralized in a single database. RESULTS AAT occurrence was confirmed in 86% of the districts surveyed (107/124). An overall prevalence of 4.8% was detected by BCT in cattle. The mean packed cell volume (PCV) of positive animals was 22.4, compared to 26.1 of the negative. Trypanosoma congolense was responsible for 61.9% of infections, T. vivax for 35.9% and T. brucei for 1.7%. Four tsetse species were found to have a wide geographic distribution. The highest apparent density (AD) was reported for Glossina pallidipes in the Southern Nations, Nationalities and People's Region (SNNPR) (3.57 flies/trap/day). Glossina tachinoides was the most abundant in Amhara (AD 2.39), Benishangul-Gumuz (2.38), Gambela (1.16) and Oromia (0.94) regions. Glossina fuscipes fuscipes and G. morsitans submorsitans were detected at lower densities (0.19 and 0.42 respectively). Only one specimen of G. longipennis was captured. CONCLUSIONS The atlas establishes a reference for the distribution of tsetse and AAT in Ethiopia. It also provides crucial evidence to plan surveillance and monitor control activities at the national level. Future work on the atlas will focus on the inclusion of data collected by other stakeholders, the broadening of the coverage to tsetse-free areas and continuous updates. The extension of the atlas to data on control activities is also envisaged.
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Affiliation(s)
| | - Berisha Kapitano
- Food and Agriculture Organization of the United Nations, Ethiopia Country Office, Addis Ababa, Ethiopia
| | | | - Dereje Alemu
- Animal Health Institute, Bedelle Animal Health Centre, Bedelle, Ethiopia
| | - Ahimedin Beshir
- Animal Health Institute, Bedelle Animal Health Centre, Bedelle, Ethiopia
| | - Zelalem Worku
- Animal Health Institute, Asossa Animal Health Centre, Asossa, Ethiopia
| | - Teshome Kifle
- Animal Health Institute, Asossa Animal Health Centre, Asossa, Ethiopia
| | - Ayana Selamu
- Animal Health Institute, Finote Selam Animal Health Centre, Finote Selam, Ethiopia
| | - Endalew Debas
- Animal Health Institute, Finote Selam Animal Health Centre, Finote Selam, Ethiopia
| | - Aschenaki Kalsa
- Animal Health Institute, Arba Minch Animal Health Centre, Arba Minch, Ethiopia
| | - Netsanet Asfaw
- Animal Health Institute, Arba Minch Animal Health Centre, Arba Minch, Ethiopia
| | - Weining Zhao
- grid.420153.10000 0004 1937 0300Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Massimo Paone
- grid.420153.10000 0004 1937 0300Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Giuliano Cecchi
- grid.420153.10000 0004 1937 0300Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
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Medicinal plants as potential therapeutic agents for trypanosomosis: a systematic review. ADVANCES IN TRADITIONAL MEDICINE 2022. [DOI: 10.1007/s13596-022-00662-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Boulangé A, Lejon V, Berthier D, Thévenon S, Gimonneau G, Desquesnes M, Abah S, Agboho P, Chilongo K, Gebre T, Fall AG, Kaba D, Magez S, Masiga D, Matovu E, Moukhtar A, Neves L, Olet PA, Pagabeleguem S, Shereni W, Sorli B, Taioe MO, Tejedor Junco MT, Yagi R, Solano P, Cecchi G. The COMBAT project: controlling and progressively minimizing the burden of vector-borne animal trypanosomosis in Africa. OPEN RESEARCH EUROPE 2022; 2:67. [PMID: 37645305 PMCID: PMC10445831 DOI: 10.12688/openreseurope.14759.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/02/2022] [Indexed: 11/23/2023]
Abstract
Vector-borne diseases affecting livestock have serious impacts in Africa. Trypanosomosis is caused by parasites transmitted by tsetse flies and other blood-sucking Diptera. The animal form of the disease is a scourge for African livestock keepers, is already present in Latin America and Asia, and has the potential to spread further. A human form of the disease also exists, known as human African trypanosomosis or sleeping sickness. Controlling and progressively minimizing the burden of animal trypanosomosis (COMBAT) is a four-year research and innovation project funded by the European Commission, whose ultimate goal is to reduce the burden of animal trypanosomosis (AT) in Africa. The project builds on the progressive control pathway (PCP), a risk-based, step-wise approach to disease reduction or elimination. COMBAT will strengthen AT control and prevention by improving basic knowledge of AT, developing innovative control tools, reinforcing surveillance, rationalizing control strategies, building capacity, and raising awareness. Knowledge gaps on disease epidemiology, vector ecology and competence, and biological aspects of trypanotolerant livestock will be addressed. Environmentally friendly vector control technologies and more effective and adapted diagnostic tools will be developed. Surveillance will be enhanced by developing information systems, strengthening reporting, and mapping and modelling disease risk in Africa and beyond. The socio-economic burden of AT will be assessed at a range of geographical scales. Guidelines for the PCP and harmonized national control strategies and roadmaps will be developed. Gender equality and ethics will be pivotal in all project activities. The COMBAT project benefits from the expertise of African and European research institutions, national veterinary authorities, and international organizations. The project consortium comprises 21 participants, including a geographically balanced representation from 13 African countries, and it will engage a larger number of AT-affected countries through regional initiatives.
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Affiliation(s)
- Alain Boulangé
- CIRAD, UMR INTERTRYP, Bouaké, 01 BP 1500, Cote d'Ivoire
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - Veerle Lejon
- CIRAD, IRD, UMR INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - David Berthier
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Montpellier, F-34398, France
| | - Sophie Thévenon
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Montpellier, F-34398, France
| | - Geoffrey Gimonneau
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Dakar-Hann, BP 2057, Senegal
| | - Marc Desquesnes
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Toulouse, F-31076, France
| | - Samuel Abah
- Mission Spéciale D'Eradication des Glossines (MSEG), Ministère de l'Elevage, des Pêches et des Industries Animales, Ngaoundéré, BP 263, Cameroon
| | - Prudenciène Agboho
- Centre International de Recherche-Développement sur l’Elevage en zone Subhumide (CIRDES), Bobo-Dioulasso, 01 BP 454, Burkina Faso
| | - Kalinga Chilongo
- Tsetse and Trypanosomosis Control Unit (TTCU), Ministry of Fisheries and Livestock, P.O Box 50197, Lusaka, 10101, Zambia
| | - Tsegaye Gebre
- National Institute for Control and Eradication of Tsetse and Trypanosomosis (NICETT), P.O Box 19917, Addis Ababa, Ethiopia
| | - Assane Gueye Fall
- Institut Sénégalais de Recherches Agricoles (ISRA), Dakar-Hann, BP 2057, Senegal
| | - Dramane Kaba
- Institut Pierre Richet (IPR), Institut National de Santé Publique, Bouaké, 01 BP 1500, Cote d'Ivoire
| | - Stefan Magez
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, B-1050, Belgium
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, 00100, Kenya
| | | | - Aldjibert Moukhtar
- Institut de Recherche en Elevage pour le Développement (IRED), N'Djamena, Route de Farcha, BP 433, Chad
| | - Luis Neves
- Centro de Biotecnologia, Universidade Eduardo Mondlane, Maputo, 00200, Mozambique
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Sciences, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Pamela A. Olet
- Kenya Tsetse and Trypanosomosis Eradication Council (KENTTEC), Nairobi, 00800, Kenya
| | - Soumaïla Pagabeleguem
- Insectarium de Bobo-Dioulasso – Campagne d'Eradication de la mouche Tsé-tsé et de la Trypanosomose (IBD-CETT), Ministère des ressources animales et halieutiques, Bobo-Dioulasso, 01 BP 1087, Burkina Faso
| | - William Shereni
- Division of Tsetse Control Services (TCD), Ministry of Lands, Agriculture, Fisheries, Water and Rural Development, P.O Box CY52, Harare, Zimbabwe
| | - Brice Sorli
- Institut d'Electronique et des Systèmes (IES), Université de Montpellier, Montpellier, F-34090, France
| | - Moeti O. Taioe
- Onderstepoort Veterinary Research, Agricultural Research Council (ARC), Pretoria, 0110, South Africa
| | | | - Rehab Yagi
- Central Veterinary Research Laboratory (CVRL), Animal Resources Research Corporation, Khartoum, 12217, Sudan
| | - Philippe Solano
- CIRAD, IRD, UMR INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - Giuliano Cecchi
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations (FAO), Rome, 00153, Italy
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Boulangé A, Lejon V, Berthier D, Thévenon S, Gimonneau G, Desquesnes M, Abah S, Agboho P, Chilongo K, Gebre T, Fall AG, Kaba D, Magez S, Masiga D, Matovu E, Moukhtar A, Neves L, Olet PA, Pagabeleguem S, Shereni W, Sorli B, Taioe MO, Tejedor Junco MT, Yagi R, Solano P, Cecchi G. The COMBAT project: controlling and progressively minimizing the burden of vector-borne animal trypanosomosis in Africa. OPEN RESEARCH EUROPE 2022; 2:67. [PMID: 37645305 PMCID: PMC10445831 DOI: 10.12688/openreseurope.14759.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/02/2022] [Indexed: 08/31/2023]
Abstract
Vector-borne diseases affecting livestock have serious impacts in Africa. Trypanosomosis is caused by parasites transmitted by tsetse flies and other blood-sucking Diptera. The animal form of the disease is a scourge for African livestock keepers, is already present in Latin America and Asia, and has the potential to spread further. A human form of the disease also exists, known as human African trypanosomosis or sleeping sickness. Controlling and progressively minimizing the burden of animal trypanosomosis (COMBAT) is a four-year research and innovation project funded by the European Commission, whose ultimate goal is to reduce the burden of animal trypanosomosis (AT) in Africa. The project builds on the progressive control pathway (PCP), a risk-based, step-wise approach to disease reduction or elimination. COMBAT will strengthen AT control and prevention by improving basic knowledge of AT, developing innovative control tools, reinforcing surveillance, rationalizing control strategies, building capacity, and raising awareness. Knowledge gaps on disease epidemiology, vector ecology and competence, and biological aspects of trypanotolerant livestock will be addressed. Environmentally friendly vector control technologies and more effective and adapted diagnostic tools will be developed. Surveillance will be enhanced by developing information systems, strengthening reporting, and mapping and modelling disease risk in Africa and beyond. The socio-economic burden of AT will be assessed at a range of geographical scales. Guidelines for the PCP and harmonized national control strategies and roadmaps will be developed. Gender equality and ethics will be pivotal in all project activities. The COMBAT project benefits from the expertise of African and European research institutions, national veterinary authorities, and international organizations. The project consortium comprises 21 participants, including a geographically balanced representation from 13 African countries, and it will engage a larger number of AT-affected countries through regional initiatives.
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Affiliation(s)
- Alain Boulangé
- CIRAD, UMR INTERTRYP, Bouaké, 01 BP 1500, Cote d'Ivoire
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - Veerle Lejon
- CIRAD, IRD, UMR INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - David Berthier
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Montpellier, F-34398, France
| | - Sophie Thévenon
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Montpellier, F-34398, France
| | - Geoffrey Gimonneau
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Dakar-Hann, BP 2057, Senegal
| | - Marc Desquesnes
- CIRAD, IRD, INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
- CIRAD, UMR INTERTRYP, Toulouse, F-31076, France
| | - Samuel Abah
- Mission Spéciale D'Eradication des Glossines (MSEG), Ministère de l'Elevage, des Pêches et des Industries Animales, Ngaoundéré, BP 263, Cameroon
| | - Prudenciène Agboho
- Centre International de Recherche-Développement sur l’Elevage en zone Subhumide (CIRDES), Bobo-Dioulasso, 01 BP 454, Burkina Faso
| | - Kalinga Chilongo
- Tsetse and Trypanosomosis Control Unit (TTCU), Ministry of Fisheries and Livestock, P.O Box 50197, Lusaka, 10101, Zambia
| | - Tsegaye Gebre
- National Institute for Control and Eradication of Tsetse and Trypanosomosis (NICETT), P.O Box 19917, Addis Ababa, Ethiopia
| | - Assane Gueye Fall
- Institut Sénégalais de Recherches Agricoles (ISRA), Dakar-Hann, BP 2057, Senegal
| | - Dramane Kaba
- Institut Pierre Richet (IPR), Institut National de Santé Publique, Bouaké, 01 BP 1500, Cote d'Ivoire
| | - Stefan Magez
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, B-1050, Belgium
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, 00100, Kenya
| | | | - Aldjibert Moukhtar
- Institut de Recherche en Elevage pour le Développement (IRED), N'Djamena, Route de Farcha, BP 433, Chad
| | - Luis Neves
- Centro de Biotecnologia, Universidade Eduardo Mondlane, Maputo, 00200, Mozambique
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Sciences, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Pamela A. Olet
- Kenya Tsetse and Trypanosomosis Eradication Council (KENTTEC), Nairobi, 00800, Kenya
| | - Soumaïla Pagabeleguem
- Insectarium de Bobo-Dioulasso – Campagne d'Eradication de la mouche Tsé-tsé et de la Trypanosomose (IBD-CETT), Ministère des ressources animales et halieutiques, Bobo-Dioulasso, 01 BP 1087, Burkina Faso
| | - William Shereni
- Division of Tsetse Control Services (TCD), Ministry of Lands, Agriculture, Fisheries, Water and Rural Development, P.O Box CY52, Harare, Zimbabwe
| | - Brice Sorli
- Institut d'Electronique et des Systèmes (IES), Université de Montpellier, Montpellier, F-34090, France
| | - Moeti O. Taioe
- Onderstepoort Veterinary Research, Agricultural Research Council (ARC), Pretoria, 0110, South Africa
| | | | - Rehab Yagi
- Central Veterinary Research Laboratory (CVRL), Animal Resources Research Corporation, Khartoum, 12217, Sudan
| | - Philippe Solano
- CIRAD, IRD, UMR INTERTRYP, Univ of Montpellier, Montpellier, F-34398, France
| | - Giuliano Cecchi
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations (FAO), Rome, 00153, Italy
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8
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Lendzele SS, Abah S, Nguetoum C, Burinyuy KA, Koumba AA, Mavoungou JF. Tabanid-transmitted animal trypanosomiasis in Cameroon: Evidence from a study in the tsetse free pastoral zone of Galim. Parasite Epidemiol Control 2022; 18:e00253. [PMID: 36926001 PMCID: PMC10011870 DOI: 10.1016/j.parepi.2022.e00253] [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: 11/09/2021] [Revised: 04/19/2022] [Accepted: 05/22/2022] [Indexed: 10/18/2022] Open
Abstract
The role of tabanids as potential transmitters of animal trypanosomiasis (AAT) has not yet been established in Cameroon. The objectives of this study were: (i) to trap and determine the species richness and abundance of tabanids, (ii) to identify circulating trypansomes in cattle and tabanids in a tsetse free area. A three year (2015 to 2017) tabanid survey in six regions of Cameroon was conducted. In Galim village, which is in a tsetse free area, both tabanids and cattle blood samples were screened by PCR for the presence of trypanosome DNA. Tabanids were diverse in Littoral (13 species) and in Adamawa (13 species), but were abundant in the Far North region (36.37 to 145.58 tabanids per trap per day (t/t/d)). In Galim, the tabanid trypanosomal DNA presence was 24.4% (95% CI: 11.25-37.53), while the bovine trypanosomal DNA presence was 4.8% (95% CI: 1.68-11.20). In this village, the Trypanosoma spp. identified in tabanids were T. theileri, T. vivax and T. evansi, while those in cattle were T. theileri and T. vivax. The control of tabanids is required to stop the mechanical spread of AAT in tsetse free areas.
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Affiliation(s)
- Sevidzem Silas Lendzele
- Organisation Pour la Production Laitière et d'Embouche Bovine (PLEB), Adamawa, Cameroon.,Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET/CENAREST), Libreville, Gabon.,Laboratoire d'Ecologie Vectorielle (LEV), Libreville, Gabon
| | - Samuel Abah
- Special Mission for Tse-tse fly Eradication, Ngaoundéré, Cameroon
| | - Cyrille Nguetoum
- Institute of Agricultural Research for Development (IRAD), Bangangté Multipurpose Station, Cameroon
| | - Kong Anita Burinyuy
- School of Veterinary Medicine and Sciences, University of Ngaoundere, Cameroon
| | - Armel Aubin Koumba
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET/CENAREST), Libreville, Gabon.,Laboratoire d'Ecologie Vectorielle (LEV), Libreville, Gabon
| | - Jacques François Mavoungou
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET/CENAREST), Libreville, Gabon.,Laboratoire d'Ecologie Vectorielle (LEV), Libreville, Gabon.,Université des Sciences et Techniques (USTM), Franceville, Gabon.,Université Internationale de Libreville (UIL), Gabon
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9
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Sevidzem SL, Koumba AA, Mavoungou JF, Windsor PA. Spatial meta-analysis of the occurrence and distribution of tsetse-transmitted animal trypanosomiasis in Cameroon over the last 30 years. Epidemiol Infect 2022; 150:1-38. [PMID: 35473820 PMCID: PMC9128350 DOI: 10.1017/s0950268822000772] [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: 11/04/2021] [Revised: 04/10/2022] [Accepted: 04/17/2022] [Indexed: 11/19/2022] Open
Abstract
In Cameroon, >90% of cattle are considered exposed to African animal trypanosomiasis (AAT) infection, with the presence of tsetse rendering cattle husbandry as a very difficult proposition. A systematic review of data on AAT and tsetse from 1990 to 2021 was conducted to develop a national atlas. The review identified 74 relevant scientific documents, with three pathogenic Trypanosoma species (Trypanosoma vivax , T. congolense and T. brucei s.l.) most frequently identified as causing AAT. Trypanosoma grayi , T. theileri , T. simiae and the human African trypanosomiasis causative agent T. brucei gambiense were also identified in a wide range of hosts. The tsetse fly fauna of Cameroon comprises nine species, with Glossina palpalis palpalis and G. fuscipes fuscipes the most widely distributed following their identification in seven and five of the 10 regions, respectively. Two species, Glossina nigrofusca and G. pallicera pallicera appeared to be rare and were restricted to both forest and protected areas. The presence of AAT is associated with the presence of tsetse in the livestock–human–wildlife interface of Cameroon. AAT occurs beyond the tsetse belts of the country where mechanical vectors are abundant. This study provides AAT and tsetse maps to support ongoing interventions in Cameroon.
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Affiliation(s)
- Silas Lendzele Sevidzem
- Programme Onchocercoses Field Station Laboratory, Ngaoundéré, Cameroon
- Organisation Pour la Production Laitière et d'Embouche Bovine (PLEB), Adamawa, Cameroon
- Laboratoire d'Ecologie Vectorielle, Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale, Libreville, Gabon
- Université Internationale de Libreville, Libreville, Gabon
| | - Aubin Armel Koumba
- Laboratoire d'Ecologie Vectorielle, Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale, Libreville, Gabon
- Université Internationale de Libreville, Libreville, Gabon
| | - Jacques François Mavoungou
- Laboratoire d'Ecologie Vectorielle, Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale, Libreville, Gabon
- Université Internationale de Libreville, Libreville, Gabon
- Université des Sciences et Techniques, Franceville, Gabon
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10
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Contreras Garcia M, Walshe E, Steketee PC, Paxton E, Lopez-Vidal J, Pearce MC, Matthews KR, Ezzahra-Akki F, Evans A, Fairlie-Clark K, Matthews JB, Grey F, Morrison LJ. Comparative Sensitivity and Specificity of the 7SL sRNA Diagnostic Test for Animal Trypanosomiasis. Front Vet Sci 2022; 9:868912. [PMID: 35450136 PMCID: PMC9017285 DOI: 10.3389/fvets.2022.868912] [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: 02/03/2022] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
Animal trypanosomiasis (AT) is a significant livestock disease, affecting millions of animals across Sub-Saharan Africa, Central and South America, and Asia, and is caused by the protozoan parasites Trypanosoma brucei, Trypanosoma vivax, and Trypanosoma congolense, with the largest economic impact in cattle. There is over-reliance on presumptive chemotherapy due to inadequate existing diagnostic tests, highlighting the need for improved AT diagnostics. A small RNA species, the 7SL sRNA, is excreted/secreted by trypanosomes in infected animals, and has been previously shown to reliably diagnose active infection. We sought to explore key properties of 7SL sRNA RT-qPCR assays; namely, assessing the potential for cross-reaction with the widespread and benign Trypanosoma theileri, directly comparing assay performance against currently available diagnostic methods, quantitatively assessing specificity and sensitivity, and assessing the rate of decay of 7SL sRNA post-treatment. Results showed that the 7SL sRNA RT-qPCR assays specific for T. brucei, T. vivax, and T. congolense performed better than microscopy and DNA PCR in detecting infection. The 7SL sRNA signal was undetectable or significantly reduced by 96-h post treatment; at 1 × curative dose there was no detectable signal in 5/5 cattle infected with T. congolense, and in 3/5 cattle infected with T. vivax, with the signal being reduced 14,630-fold in the remaining two T. vivax cattle. Additionally, the assays did not cross-react with T. theileri. Finally, by using a large panel of validated infected and uninfected samples, the species-specific assays are shown to be highly sensitive and specific by receiver operating characteristic (ROC) analysis, with 100% sensitivity (95% CI, 96.44-100%) and 100% specificity (95% CI, 96.53-100%), 96.73% (95% CI, 95.54-99.96%) and 99.19% specificity (95% CI, 92.58-99.60%), and 93.42% (95% CI, 85.51-97.16% %) and 82.43% specificity (95% CI, 72.23-89.44% %) for the T brucei, T. congolense and T. vivax assays, respectively, under the conditions used. These findings indicate that the 7SL sRNA has many attributes that would be required for a potential diagnostic marker of AT: no cross-reaction with T. theileri, high specificity and sensitivity, early infection detection, continued signal even in the absence of detectable parasitaemia in blood, and clear discrimination between infected and treated animals.
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Affiliation(s)
- Maria Contreras Garcia
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Emily Walshe
- Roslin Technologies Limited, Roslin Innovation Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Pieter C Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Edith Paxton
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Javier Lopez-Vidal
- Ashworth Laboratories, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael C Pearce
- Global Alliance for Livestock Veterinary Medicines, Edinburgh, United Kingdom
| | - Keith R Matthews
- Ashworth Laboratories, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | | | - Karen Fairlie-Clark
- Roslin Technologies Limited, Roslin Innovation Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Jacqueline B Matthews
- Roslin Technologies Limited, Roslin Innovation Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Finn Grey
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
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11
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Percoma L, Rayaissé JB, Gimonneau G, Bengaly Z, Pooda SH, Pagabeleguem S, Ganaba R, Sow A, Argilés R, Bouyer J, Ouedraogo M, Zhao W, Paone M, Sidibé I, Gisele O, Cecchi G. An atlas to support the progressive control of tsetse-transmitted animal trypanosomosis in Burkina Faso. Parasit Vectors 2022; 15:72. [PMID: 35246216 PMCID: PMC8895521 DOI: 10.1186/s13071-021-05131-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/13/2021] [Indexed: 12/01/2023] Open
Abstract
Background African animal trypanosomosis (AAT), transmitted by tsetse flies, is arguably the main disease constraint to integrated crop-livestock agriculture in sub-Saharan Africa, and African heads of state and governments adopted a resolution to rid the continent of this scourge. In order to sustainably reduce or eliminate the burden of AAT, a progressive and evidence-based approach is needed, which must hinge on harmonized, spatially explicit information on the occurrence of AAT and its vectors. Methods A digital repository was assembled, containing tsetse and AAT data collected in Burkina Faso between 1990 and 2019. Data were collected either in the framework of control activities or for research purposes. Data were systematically verified, harmonized, georeferenced and integrated into a database (PostgreSQL). Entomological data on tsetse were mapped at the level of individual monitoring traps. When this was not possible, mapping was done at the level of site or location. Epidemiological data on AAT were mapped at the level of location or village. Results Entomological data showed the presence of four tsetse species in Burkina Faso. Glossina tachinoides, present from the eastern to the western part of the country, was the most widespread and abundant species (56.35% of the catches). Glossina palpalis gambiensis was the second most abundant species (35.56%), and it was mainly found in the west. Glossina morsitans submorsitans was found at lower densities (6.51%), with a patchy distribution in the southern parts of the country. A single cluster of G. medicorum was detected (less than 0.25%), located in the south-west. Unidentified tsetse flies accounted for 1.33%. For the AAT component, data for 54,948 animal blood samples were assembled from 218 geographic locations. The samples were tested with a variety of diagnostic methods. AAT was found in all surveyed departments, including the tsetse-free areas in the north. Trypanosoma vivax and T. congolense infections were the dominant ones, with a prevalence of 5.19 ± 18.97% and 6.11 ± 21.56%, respectively. Trypanosoma brucei infections were detected at a much lower rate (0.00 ± 0.10%). Conclusions The atlas provides a synoptic view of the available information on tsetse and AAT distribution in Burkina Faso. Data are very scanty for most of the tsetse-free areas in the northern part of the country. Despite this limitation, this study generated a robust tool for targeting future surveillance and control activities. The development of the atlas also strengthened the collaboration between the different institutions involved in tsetse and AAT research and control in Burkina Faso, which will be crucial for future updates and the sustainability of the initiative. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05131-4.
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Affiliation(s)
- Lassane Percoma
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso. .,Ecole de Lutte Anti-Tsétsé, Bobo-Dioulasso, Burkina Faso.
| | - Jean Baptiste Rayaissé
- Centre International de Recherche-Développement sur l'Elevage en zone subhumide, Bobo-Dioulasso, Burkina Faso
| | - Geoffrey Gimonneau
- Centre International de Recherche-Développement sur l'Elevage en zone subhumide, Bobo-Dioulasso, Burkina Faso.,CIRAD, UMR INTERTRYP, Montpellier, France.,INTERTRYP, Univ Montpellier, CIRAD, IRD, Montpellier, France
| | - Zakaria Bengaly
- Centre International de Recherche-Développement sur l'Elevage en zone subhumide, Bobo-Dioulasso, Burkina Faso
| | - Sié Hermann Pooda
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso.,Université de Dédougou (UDDG), BP 176, Dédougou, Burkina Faso
| | - Soumaïla Pagabeleguem
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso.,Université de Dédougou (UDDG), BP 176, Dédougou, Burkina Faso
| | - Rasmané Ganaba
- Agence de Formation, de Recherche et d'Expertise en Santé pour l'Afrique (AFRICSanté), 01 BP 298, Bobo-Dioulasso 01, Burkina Faso
| | - Adama Sow
- Food and Agriculture Organization of the United Nations, Emergency Centre for Transboundary Animal Diseases (ECTAD), Conakry, Guinea
| | - Rafael Argilés
- Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Vienna, Austria
| | - Jérémy Bouyer
- CIRAD, UMR INTERTRYP, Montpellier, France.,Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Vienna, Austria.,CIRAD, UMR, ASTRE, Montpellier, France
| | - Moussa Ouedraogo
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso
| | - Weining Zhao
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Massimo Paone
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Issa Sidibé
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso.,Centre International de Recherche-Développement sur l'Elevage en zone subhumide, Bobo-Dioulasso, Burkina Faso
| | - Ouedraogo/Sanon Gisele
- Insectarium de Bobo-Dioulasso-Campagne Panafricaine d'Eradication de la Tsé-tsé et de la Trypanosomose, Bobo-Dioulasso, Burkina Faso
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
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12
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Li M, Gaussmann S, Tippler B, Ott J, Popowicz GM, Schliebs W, Sattler M, Erdmann R, Kalel VC. Novel Trypanocidal Inhibitors that Block Glycosome Biogenesis by Targeting PEX3-PEX19 Interaction. Front Cell Dev Biol 2022; 9:737159. [PMID: 34988071 PMCID: PMC8721105 DOI: 10.3389/fcell.2021.737159] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 11/15/2021] [Indexed: 12/02/2022] Open
Abstract
Human pathogenic trypanosomatid parasites harbor a unique form of peroxisomes termed glycosomes that are essential for parasite viability. We and others previously identified and characterized the essential Trypanosoma brucei ortholog TbPEX3, which is the membrane-docking factor for the cytosolic receptor PEX19 bound to the glycosomal membrane proteins. Knockdown of TbPEX3 expression leads to mislocalization of glycosomal membrane and matrix proteins, and subsequent cell death. As an early step in glycosome biogenesis, the PEX3–PEX19 interaction is an attractive drug target. We established a high-throughput assay for TbPEX3–TbPEX19 interaction and screened a compound library for small-molecule inhibitors. Hits from the screen were further validated using an in vitro ELISA assay. We identified three compounds, which exhibit significant trypanocidal activity but show no apparent toxicity to human cells. Furthermore, we show that these compounds lead to mislocalization of glycosomal proteins, which is toxic to the trypanosomes. Moreover, NMR-based experiments indicate that the inhibitors bind to PEX3. The inhibitors interfering with glycosomal biogenesis by targeting the TbPEX3–TbPEX19 interaction serve as starting points for further optimization and anti-trypanosomal drug development.
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Affiliation(s)
- Mengqiao Li
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Stefan Gaussmann
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Department of Chemistry, Bavarian NMR Center, Technical University of Munich, Garching, Germany
| | - Bettina Tippler
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Julia Ott
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Grzegorz M Popowicz
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Department of Chemistry, Bavarian NMR Center, Technical University of Munich, Garching, Germany
| | - Wolfgang Schliebs
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Department of Chemistry, Bavarian NMR Center, Technical University of Munich, Garching, Germany
| | - Ralf Erdmann
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Vishal C Kalel
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
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13
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Franco JR, Cecchi G, Paone M, Diarra A, Grout L, Kadima Ebeja A, Simarro PP, Zhao W, Argaw D. The elimination of human African trypanosomiasis: Achievements in relation to WHO road map targets for 2020. PLoS Negl Trop Dis 2022; 16:e0010047. [PMID: 35041668 PMCID: PMC8765662 DOI: 10.1371/journal.pntd.0010047] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/02/2021] [Indexed: 11/19/2022] Open
Abstract
Background In the 20th century, epidemics of human African trypanosomiasis (HAT) ravaged communities in a number of African countries. The latest surge in disease transmission was recorded in the late 1990s, with more than 35,000 cases reported annually in 1997 and 1998. In 2013, after more than a decade of sustained control efforts and steady progress, the World Health Assembly resolved to target the elimination of HAT as a public health problem by 2020. We report here on recent progress towards this goal. Methodology/principal findings With 992 and 663 cases reported in 2019 and 2020 respectively, the first global target was amply achieved (i.e. fewer than 2,000 HAT cases/year). Areas at moderate or higher risk of HAT, where more than 1 case/10,000 people/year are reported, shrunk to 120,000 km2 for the five-year period 2016–2020. This reduction of 83% from the 2000–2004 baseline (i.e. 709,000 km2) is slightly below the target (i.e. 90% reduction). As a result, the second global target for HAT elimination as a public health problem cannot be considered fully achieved yet. The number of health facilities able to diagnose and treat HAT expanded (+9.6% compared to a 2019 survey), thus reinforcing the capacity for passive detection and improving epidemiological knowledge of the disease. Active surveillance for gambiense HAT was sustained. In particular, 2.8 million people were actively screened in 2019 and 1.6 million in 2020, the decrease in 2020 being mainly caused by COVID-19-related restrictions. Togo and Côte d’Ivoire were the first countries to be validated for achieving elimination of HAT as a public health problem at the national level; applications from three additional countries are under review by the World Health Organization (WHO). Conclusions/significance The steady progress towards the elimination of HAT is a testament to the power of multi-stakeholder commitment and coordination. At the end of 2020, the World Health Assembly endorsed a new road map for 2021–2030 that set new bold targets for neglected tropical diseases. While rhodesiense HAT remains among the diseases targeted for elimination as a public health problem, gambiense HAT is targeted for elimination of transmission. The goal for gambiense HAT is expected to be particularly arduous, as it might be hindered by cryptic reservoirs and a number of other challenges (e.g. further integration of HAT surveillance and control into national health systems, availability of skilled health care workers, development of more effective and adapted tools, and funding for and coordination of elimination efforts). Human African trypanosomiasis (HAT) is a lethal neglected tropical disease (NTD) transmitted by the bite of infected tsetse flies. The disease is also known as “sleeping sickness”. During the 20th century it caused enormous suffering in the endemic areas in sub-Saharan Africa. HAT transmission last soared in the late 1990s, triggering a renewed, coordinated and very successful control effort. In this paper, we present achievements towards HAT elimination, with a focus on the WHO road map targets for 2020. In particular, reported cases continue to decline, from over 30,000 cases per year at the turn of the century to 663 cases in 2020. Despite the impact of the COVID-19 pandemic, HAT surveillance was largely sustained, and the network of health facilities able to diagnose and treat the disease further expanded. Looking to the future, the World Health Organization (WHO) set bold new targets for HAT in its 2021–2030 road map for NTDs, namely: the elimination of transmission of gambiense HAT, which occurs in western and central Africa, and the elimination as a public health problem of rhodesiense HAT, which is found in eastern and southern Africa. The strong commitment of national health authorities and the international community will be essential if these goals are to be achieved.
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Affiliation(s)
- Jose R. Franco
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
- * E-mail:
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Massimo Paone
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Abdoulaye Diarra
- World Health Organization, Regional Office for Africa, Communicable Disease Unit, Brazzaville, Congo
| | - Lise Grout
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
| | - Augustin Kadima Ebeja
- World Health Organization, Regional Office for Africa, Communicable Disease Unit, Brazzaville, Congo
| | - Pere P. Simarro
- Consultant, World Health Organization, Control of Neglected Tropical Diseases, Innovative and Intensified Disease Management, Geneva, Switzerland
| | - Weining Zhao
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Daniel Argaw
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
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14
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Hidalgo J, Ortiz JF, Fabara SP, Eissa-Garcés A, Reddy D, Collins KD, Tirupathi R. Efficacy and Toxicity of Fexinidazole and Nifurtimox Plus Eflornithine in the Treatment of African Trypanosomiasis: A Systematic Review. Cureus 2021; 13:e16881. [PMID: 34513456 PMCID: PMC8411996 DOI: 10.7759/cureus.16881] [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] [Accepted: 08/04/2021] [Indexed: 11/29/2022] Open
Abstract
Human African trypanosomiasis (HAT), or sleeping sickness disease, is an infection caused mainly by Trypanosoma brucei gambiense-human African trypanosomiasis (g-HAT) and is transmitted by tsetse flies. The disease goes through two stages: hemolymphatic and meningo-encephalic phases. The treatment for the second stage has changed from melarsoprol or eflornithine to nifurtimox-eflornithine combination therapy (NECT) and fexinidazole. We aimed to systematically review the literature on the efficacy and toxicity of fexinidazole and NECT. We used PubMed advanced strategy and Google Scholar databases, including clinical trials and observational studies on humans in the last 20 years in the English literature. Applying the inclusion/exclusion criteria, we reviewed eight studies. We used Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) protocol. For assessing bias, we used the Cochrane Collaboration’s tool for risk assessment of the clinical trials and the Robins-I tool for the observational studies. Overall, the clinical trials showed that NECT was non-inferior to eflornithine. The proportion of patients discharged alive is higher in patients treated with NECT vs. patients treated with eflornithine. Gastrointestinal complaints are a common side effect of NECT therapy, while fearful but relatively rare convulsions can also occur. The main limitation among the studies of NECT was the lack of blinding because most of them were open-label. Fexinidazole, the new oral medication showed is effective and safe for the treatment of g-HAT infection. Because of their convenience, fexinidazole is preferred over NECT therapy, oral vs. IV infusion in the first and second stages of the disease. Compared to older therapies, fexinidazole and NECT are more effective and safer than eflornithine and melarsoprol monotherapy.
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Affiliation(s)
- Jessica Hidalgo
- Internal Medicine, San Francisco de Quito University, Quito, ECU
| | | | - Stephanie P Fabara
- Internal Medicine, Santiago de Guayaquil Catholic University, Guayaquil, ECU
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15
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Richards S, Morrison LJ, Torr SJ, Barrett MP, Manangwa O, Mramba F, Auty H. Pharma to farmer: field challenges of optimizing trypanocide use in African animal trypanosomiasis. Trends Parasitol 2021; 37:831-843. [PMID: 33962879 DOI: 10.1016/j.pt.2021.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 01/07/2023]
Abstract
Trypanocides are a key control component of African animal trypanosomiasis (AAT) in tsetse-infested areas of sub-Saharan Africa. While farmers are dependent upon trypanocides, recent research highlights their inappropriate and ineffective use, problems with drug quality, and treatment failure. There are currently gaps in knowledge and investment in inexpensive AAT diagnostics, understanding of drug resistance, and the effective use of trypanocides in the field. Without this important knowledge it is difficult to develop best practice and policy for existing drugs or to inform development and use of new drugs. There needs to be better understanding of the drivers and behavioural practices around trypanocide use so that they can be incorporated into sustainable solutions needed for the development of effective control of AAT.
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Affiliation(s)
- Shauna Richards
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK.
| | - Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Steve J Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Michael P Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Inflammation & Immunity, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Furaha Mramba
- Tanzania Veterinary Laboratory Agency, Dar Es Salaam, Tanzania
| | - Harriet Auty
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
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Hargrove JW, Van Sickle J, Vale GA, Lucas ER. Negative density-dependent dispersal in tsetse (Glossina spp): An artefact of inappropriate analysis. PLoS Negl Trop Dis 2021; 15:e0009026. [PMID: 33764969 PMCID: PMC8023489 DOI: 10.1371/journal.pntd.0009026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/06/2021] [Accepted: 02/24/2021] [Indexed: 11/18/2022] Open
Abstract
Published analysis of genetic material from field-collected tsetse (Glossina spp, primarily from the Palpalis group) has been used to predict that the distance (δ) dispersed per generation increases as effective population densities (De) decrease, displaying negative density-dependent dispersal (NDDD). Using the published data we show this result is an artefact arising primarily from errors in estimates of S, the area occupied by a subpopulation, and thereby in De. The errors arise from the assumption that S can be estimated as the area ( S^) regarded as being covered by traps. We use modelling to show that such errors result in anomalously high correlations between δ^ and S^ and the appearance of NDDD, with a slope of -0.5 for the regressions of log( δ^) on log( D^e), even in simulations where we specifically assume density-independent dispersal (DID). A complementary mathematical analysis confirms our findings. Modelling of field results shows, similarly, that the false signal of NDDD can be produced by varying trap deployment patterns. Errors in the estimates of δ in the published analysis were magnified because variation in estimates of S were greater than for all other variables measured, and accounted for the greatest proportion of variation in δ^. Errors in census population estimates result from an erroneous understanding of the relationship between trap placement and expected tsetse catch, exacerbated through failure to adjust for variations in trapping intensity, trap performance, and in capture probabilities between geographical situations and between tsetse species. Claims of support in the literature for NDDD are spurious. There is no suggested explanation for how NDDD might have evolved. We reject the NDDD hypothesis and caution that the idea should not be allowed to influence policy on tsetse and trypanosomiasis control. Published analysis of genetic material from field-sampled tsetse (Glossina spp) has been used to suggest that, as tsetse population densities decrease, rates of dispersal increase–displaying negative density-dependent dispersal (NDDD), perhaps in all tsetse species. It is further suggested that tsetse control operations might, as a consequence of NDDD, unleash enhanced invasion of areas cleared of tsetse, prejudicing the long-term success of control campaigns. We demonstrate that NDDD in tsetse is an artefact consequent on multiple errors of analysis and interpretation. The most serious of these errors stems from a misunderstanding of the way in which traps sample tsetse, resulting in large errors in estimates of the areas covered by the traps, and occupied by the subpopulations being sampled. Our modelling studies show that these errors can produce the false signal of NDDD, even in situations where DID is assumed. Errors in census population estimates are made worse through failure to adjust for variations in trapping intensity, trap performance, and in capture probabilities between geographical situations, and between tsetse species. We reject the NDDD hypothesis and caution that the idea should not be allowed to influence policy on tsetse and trypanosomiasis control.
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Affiliation(s)
- John W. Hargrove
- SACEMA, University of Stellenbosch, Stellenbosch, South Africa
- * E-mail:
| | - John Van Sickle
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Glyn A. Vale
- SACEMA, University of Stellenbosch, Stellenbosch, South Africa
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
| | - Eric R. Lucas
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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