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Melachio Tanekou TT, Bouaka Tsakeng CU, Tirados I, Acho A, Bigoga J, Wondji CS, Njiokou F. Impact of a small-scale tsetse fly control operation with deltamethrin impregnated "Tiny Targets" on tsetse density and trypanosomes' circulation in the Campo sleeping sickness focus of South Cameroon. PLoS Negl Trop Dis 2023; 17:e0011802. [PMID: 38011275 PMCID: PMC10732512 DOI: 10.1371/journal.pntd.0011802] [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: 08/06/2023] [Revised: 12/07/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND Significant progress has been made towards African sleeping sickness elimination in the last decade. Indeed, the World Health Organization (WHO) global goal of eliminating the chronic form of the disease as a public health problem was achieved in 2020 (i.e., < 2,000 new cases per year). Vector control has played an important role in achieving this goal. In this study, we evaluated the impact of the insecticide impregnated Tiny Targets on tsetse fly densities and their infection rates with Trypanosoma spp in the Campo sleeping sickness focus of South Cameroon. METHODS The study site was divided into two areas: (i) the south-west experimental area, which included vector control, and (ii) the eastern part as the non-intervention area. After compiling the baseline entomological data (tsetse densities and trypanosome infection rates), around 2000 Tiny Targets were deployed in the South-West area and replaced every six months for two years. Post-intervention surveys were conducted every six months to determine tsetse densities and levels of trypanosome infections with PCR-based methods. RESULTS Following the intervention, tsetse mean catches decreased by 61% after six months, and up to 73% after twelve months (pre-intervention: 2.48 flies/trap/day, 95%CI [1.92-3.14]; 12-months post-intervention: 0.66 tsetse/trap/day, 95%CI [0.42-0.94]). This decrease was not sustained after 18 months, and the mean catch doubled compared to that after 12 months. After 24 months, the mean catches still increased by 17% (18 months: 1.45 tsetse/trap/day, 95%CI [1.07-1.90] and 24 months: 1.71 tsetse/trap/day, 95%CI [1.27-2.24]). In the non-intervention area, a variation in tsetse catches was observed during the two years, with a general increase from 2.43 [0.73-5.77] to 3.64 [1.47-7.70] tsetse/trap/day. In addition, trypanosome infection rates dropped by 75% in both areas (P-value < 0.001) from 21.20% to 5.06% and from 13.14% to 3.45% in intervention and control areas respectively. CONCLUSION Tiny targets have proven useful in reducing tsetse population densities and trypanosome infection rates, providing evidence for the integration of this tool in current strategies towards trypanosomiasis elimination in Campo. The non-sustained decrease of tsetse densities after one year may indicate reinvasions from neighbouring breeding sites or that the intervention area was not large enough. Our results show the need to scale up by accessing difficult breeding sites and extend the tiny targets to the whole transborder focus.
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Affiliation(s)
- Tito Tresor Melachio Tanekou
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Microbiology and Parasitology, Faculty of Science, University of Bamenda, Bamenda, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Calmes Ursain Bouaka Tsakeng
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Inaki Tirados
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Alphonse Acho
- Programme National de Lutte contre la Trypanosomose Humaine Africaine (PNLTHA), Ministère de la Santé Publique, Cameroon
| | - Jude Bigoga
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- Laboratory for Vector Biology and Control, National Reference Unit for Vector Control, The Biotechnology Centre, Nkolbisson, Yaoundé, Cameroon
| | - Charles Sinclair Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Flobert Njiokou
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
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Abstract
PURPOSE OF REVIEW Gambiense human African trypanosomiasis (gHAT), a disease that has killed hundreds of thousands as recently as the 1990s, could be on the verge of elimination or even eradication. This review describes recent developments that give us reasons for optimism as well as some caveats. RECENT FINDINGS New developments in diagnostic and vector control tools, and especially in treatment, make it possible to strive for elimination of transmission of gHAT by 2030, perhaps even eradication. SUMMARY Gambiense human African trypanosomiasis is a deadly infectious disease affecting West and Central Africa, South Sudan and Uganda, and transmitted between humans by tsetse flies. The disease has caused several major epidemics, the latest one in the 1990s. Thanks to recent innovations such as rapid diagnostic tests for population screening, a single-dose oral treatment and a highly efficient vector control strategy, interruption of transmission of the causative parasite is now within reach. If indeed gHAT has an exclusively human reservoir, this could even result in eradication of the disease. Even if there were an animal reservoir, on the basis of epidemiological data, it plays a limited role. Maintaining adequate postelimination surveillance in known historic foci, using the newly developed tools, should be sufficient to prevent any future resurgence.
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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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Bessell PR, Esterhuizen J, Lehane MJ, Longbottom J, Mugenyi A, Selby R, Tirados I, Torr SJ, Waiswa C, Wamboga C, Hope A. Estimating the impact of Tiny Targets in reducing the incidence of Gambian sleeping sickness in the North-west Uganda focus. Parasit Vectors 2021; 14:410. [PMID: 34407867 PMCID: PMC8371857 DOI: 10.1186/s13071-021-04889-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/22/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Riverine species of tsetse (Glossina) transmit Trypanosoma brucei gambiense, which causes Gambian human African trypanosomiasis (gHAT), a neglected tropical disease. Uganda aims to eliminate gHAT as a public health problem through detection and treatment of human cases and vector control. The latter is being achieved through the deployment of 'Tiny Targets', insecticide-impregnated panels of material which attract and kill tsetse. We analysed the spatial and temporal distribution of cases of gHAT in Uganda during the period 2010-2019 to assess whether Tiny Targets have had an impact on disease incidence. METHODS To quantify the deployment of Tiny Targets, we mapped the rivers and their associated watersheds in the intervention area. We then categorised each of these on a scale of 0-3 according to whether Tiny Targets were absent (0), present only in neighbouring watersheds (1), present in the watersheds but not all neighbours (2), or present in the watershed and all neighbours (3). We overlaid all cases that were diagnosed between 2000 and 2020 and assessed whether the probability of finding cases in a watershed changed following the deployment of targets. We also estimated the number of cases averted through tsetse control. RESULTS We found that following the deployment of Tiny Targets in a watershed, there were fewer cases of HAT, with a sampled error probability of 0.007. We estimate that during the intervention period 2012-2019 we should have expected 48 cases (95% confidence intervals = 40-57) compared to the 36 cases observed. The results are robust to a range of sensitivity analyses. CONCLUSIONS Tiny Targets have reduced the incidence of gHAT by 25% in north-western Uganda.
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Affiliation(s)
| | - Johan Esterhuizen
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Michael J. Lehane
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Joshua Longbottom
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Albert Mugenyi
- Coordinating Office for Control of Trypanosomiasis in Uganda (COCTU), Kampala, Uganda
| | - Richard Selby
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Inaki Tirados
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Steve J. Torr
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
| | - Charles Waiswa
- Coordinating Office for Control of Trypanosomiasis in Uganda (COCTU), Kampala, Uganda
| | | | - Andrew Hope
- Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, UK
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Koné M, N’Gouan EK, Kaba D, Koffi M, Kouakou L, N’Dri L, Kouamé CM, Nanan VK, Tapé GA, Coulibaly B, Courtin F, Ahouty B, Djohan V, Bucheton B, Solano P, Büscher P, Lejon V, Jamonneau V. The complex health seeking pathway of a human African trypanosomiasis patient in Côte d'Ivoire underlines the need of setting up passive surveillance systems. PLoS Negl Trop Dis 2020; 14:e0008588. [PMID: 32925917 PMCID: PMC7515183 DOI: 10.1371/journal.pntd.0008588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/24/2020] [Accepted: 07/13/2020] [Indexed: 11/25/2022] Open
Abstract
Background Significant efforts to control human African trypanosomiasis (HAT) over the two past decades have resulted in drastic decrease of its prevalence in Côte d’Ivoire. In this context, passive surveillance, integrated in the national health system and based on clinical suspicion, was reinforced. We describe here the health-seeking pathway of a girl who was the first HAT patient diagnosed through this strategy in August 2017. Methods After definitive diagnosis of this patient, epidemiological investigations were carried out into the clinical evolution and the health and therapeutic itinerary of the patient before diagnosis. Results At the time of diagnosis, the patient was positive in both serological and molecular tests and trypanosomes were detected in blood and cerebrospinal fluid. She suffered from important neurological disorders. The first disease symptoms had appeared three years earlier, and the patient had visited several public and private peripheral health care centres and hospitals in different cities. The failure to diagnose HAT for such a long time caused significant health deterioration and was an important financial burden for the family. Conclusion This description illustrates the complexity of detecting the last HAT cases due to complex diagnosis and the progressive disinterest and unawareness by both health professionals and the population. It confirms the need of implementing passive surveillance in combination with continued sensitization and health staff training. Human African trypanosomiasis (HAT) or sleeping sickness is a parasitic disease caused by Trypanosoma brucei that is transmitted by tsetse flies. In 2012, HAT was included in the World Health Organization roadmap for the control of neglected tropical diseases with the objective of elimination as a public health problem by 2020. In Côte d’Ivoire, HAT prevalence has dropped sharply the last decade. A passive HAT surveillance was therefore integrated in the national health system, which allowed to detect a first patient in 2017. This article describes the complex health seeking pathway and suffering before diagnosis of this patient, an 11 years old girl, and illustrates the challenge when health agents and population no longer consider HAT as a threat in an elimination context. Our results show the need to install a solid surveillance system, in combination with continued sensitization and repeated health staff training.
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Affiliation(s)
- Minayégninrin Koné
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | | | - Dramane Kaba
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Mathurin Koffi
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | - Lingué Kouakou
- Programme National d’Élimination de la Trypanosomose Humaine Africaine, Abidjan, Côte d’Ivoire
| | - Louis N’Dri
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Cyrille Mambo Kouamé
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Valentin Kouassi Nanan
- Direction Départementale de la Marahoué, District sanitaire de Sinfra, Ministère de la Santé et de l’Hygiène Publique, Abidjan, Côte d’Ivoire
| | - Gossé Apollinaire Tapé
- Direction départementale de la santé de la Marahoué, Centre de Santé Urbain de Bonon, Ministère de la Santé et de l’Hygiène Publique, Abidjan Côte d’Ivoire
| | - Bamoro Coulibaly
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Fabrice Courtin
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Bernardin Ahouty
- Laboratoire de Biodiversité et Gestion des Ecosystèmes Tropicaux, Unité de Recherche en Génétique et Epidémiologie Moléculaire, Université Jean Lorougnon Guédé, UFR Environnement, Daloa, Côte d’Ivoire
| | - Vincent Djohan
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
| | - Bruno Bucheton
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Philippe Solano
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Veerle Lejon
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
| | - Vincent Jamonneau
- Unité de Recherche « Trypanosomoses », Institut Pierre Richet, Bouaké, Côte d’Ivoire
- Unité Mixte de Recherche IRD-CIRAD 177, INTERTRYP, Institut de Recherche pour le Développement (IRD) Université de Montpellier, Montpellier, France
- * E-mail:
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Ravel S, Séré M, Manangwa O, Kagbadouno M, Mahamat MH, Shereni W, Okeyo WA, Argiles-Herrero R, De Meeûs T. Developing and quality testing of microsatellite loci for four species of Glossina. INFECTION GENETICS AND EVOLUTION 2020; 85:104515. [PMID: 32861909 DOI: 10.1016/j.meegid.2020.104515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/29/2020] [Accepted: 08/24/2020] [Indexed: 11/15/2022]
Abstract
Microsatellite loci still represent valuable resources for the study of the population biology of non-model organisms. Discovering or adapting new suitable microsatellite markers in species of interest still represents a useful task, especially so for non-model organisms as tsetse flies (genus Glossina), which remain a serious threat to the health of humans and animals in sub-Saharan Africa. In this paper, we present the development of new microsatellite loci for four species of Glossina: two from the Morsitans group, G. morsitans morsitans (Gmm) from Zimbabwe, G. pallidipes (Gpalli) from Tanzania; and the other two from the Palpalis group, G. fuscipes fuscipes (Gff) from Chad, and G. palpalis gambiensis (Gpg) from Guinea. We found frequent short allele dominance and null alleles. Stuttering could also be found and amended when possible. Cryptic species seemed to occur frequently in all taxa but Gff. This explains why it may be difficult finding ecumenical primers, which thus need adaptation according to each taxonomic and geographic context. Amplification problems occurred more often in published old markers, and Gmm and Gpg were the most affected (stronger heterozygote deficits). Trinucleotide markers displayed selection signature in some instances (Gmm). Combining old and new loci, for Gmm, eight loci can be safely used (with correction for null alleles); and five seem particularly promising; for Gpalli, only five to three loci worked well, depending on the clade, which means that the use of loci from other species (four morsitans loci seemed to work well), or other new primers will need to be used; for Gff, 14 loci behaved well, but with null alleles, seven of which worked very well; and for G. palpalis sl, only four loci, needing null allele and stuttering corrections seem to work well, and other loci from the literature are thus needed, including X-linked markers, five of which seem to work rather well (in females only), but new markers will probably be needed. Finally, the high proportion of X-linked markers (around 30%) was explained by the non-Y DNA quantity and chromosome structure of tsetse flies studied so far.
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Affiliation(s)
- Sophie Ravel
- Intertryp, IRD, Cirad, Univ Montpellier, Montpellier, France
| | - Modou Séré
- University of Dédougou, Dédougou B.P. 176, Burkina Faso
| | - Oliver Manangwa
- Vector and Vector Borne Disease Research Institute, P.O.Box 1026, Tanga, Tanzania
| | - Moise Kagbadouno
- Programme National de Lutte contre la THA (PNLTHA), Conakry, Guinea
| | | | - William Shereni
- Ministry of Lands, Agriculture, Water and Rural Resettlement, Harare, Zimbabwe
| | | | - Rafael Argiles-Herrero
- Insect Pest Control Sub-Programme, Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency Programme of Nuclear Techniques in Food and Agriculture, Vienna A-1400, Austria
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De Meeûs T, Ravel S, Solano P, Bouyer J. Response to the Comments of J.S. Lord. Trends Parasitol 2019; 35:742-743. [PMID: 31431328 DOI: 10.1016/j.pt.2019.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 07/26/2019] [Indexed: 01/30/2023]
Affiliation(s)
| | - Sophie Ravel
- Intertryp, IRD, Cirad, Univ Montpellier, Montpellier, France
| | - Philippe Solano
- Intertryp, IRD, Cirad, Univ Montpellier, Montpellier, France
| | - Jérémy Bouyer
- Intertryp, IRD, Cirad, Univ Montpellier, Montpellier, France; Astre, Cirad, Inra, Montpellier, France; Insect Pest Control Laboratory, Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency Program of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria
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