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Morrison LJ, Barrett MP, Steketee PC, Cecchi G, Kijanga O, Mramba F, Auty HK. What is needed to achieve effective and sustainable control of African animal trypanosomosis? Trends Parasitol 2024; 40:679-686. [PMID: 39048503 DOI: 10.1016/j.pt.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/14/2024] [Accepted: 06/20/2024] [Indexed: 07/27/2024]
Abstract
A welcome resurgence in African animal trypanosomosis (AAT) research has resulted in advances in capabilities, foundational datasets, and understanding. Additionally, there is the prospect of the first new trypanocide in >60 years. However, it is vital to ensure that advances translate to improved and sustainable control in the field. A recent meeting, the Symposium on African Livestock Trypanosomes - Tanzania, convened stakeholders from across the spectrum of AAT research and control to ask how this can be achieved. Current constraints on progress were defined, as were critical gaps and opportunities that need addressing. There is a requirement and opportunity for the AAT research community to communicate, collaborate, and coordinate to maintain momentum and achieve the ultimate goal of sustainable AAT control.
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Affiliation(s)
| | | | | | - Giuliano Cecchi
- Animal Production and Health Division (NSA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy
| | - Oliver Kijanga
- Vector and Vector-Borne Diseases Institute, Tanga, Tanzania
| | | | - Harriet K Auty
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
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Ungogo MA, de Koning HP. Drug resistance in animal trypanosomiases: Epidemiology, mechanisms and control strategies. Int J Parasitol Drugs Drug Resist 2024; 25:100533. [PMID: 38555795 PMCID: PMC10990905 DOI: 10.1016/j.ijpddr.2024.100533] [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: 12/18/2023] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 04/02/2024]
Abstract
Animal trypanosomiasis (AT) is a complex of veterinary diseases known under various names such as nagana, surra, dourine and mal de caderas, depending on the country, the infecting trypanosome species and the host. AT is caused by parasites of the genus Trypanosoma, and the main species infecting domesticated animals are T. brucei brucei, T. b. rhodesiense, T. congolense, T. simiae, T. vivax, T. evansi and T. equiperdum. AT transmission, again depending on species, is through tsetse flies or common Stomoxys and tabanid flies or through copulation. Therefore, the geographical spread of all forms of AT together is not restricted to the habitat of a single vector like the tsetse fly and currently includes almost all of Africa, and most of South America and Asia. The disease is a threat to millions of companion and farm animals in these regions, creating a financial burden in the billions of dollars to developing economies as well as serious impacts on livestock rearing and food production. Despite the scale of these impacts, control of AT is neglected and under-resourced, with diagnosis and treatments being woefully inadequate and not improving for decades. As a result, neither the incidence of the disease, nor the effectiveness of treatment is documented in most endemic countries, although it is clear that there are serious issues of resistance to the few old drugs that are available. In this review we particularly look at the drugs, their application to the various forms of AT, and their mechanisms of action and resistance. We also discuss the spread of veterinary trypanocide resistance and its drivers, and highlight current and future strategies to combat it.
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Affiliation(s)
- Marzuq A Ungogo
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom; School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Harry P de Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
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Yamazaki A, Tanaka Y, Watanabe K, Sato M, Kawazu SI, Kita K, Inoue N, van Rensburg HDJ, N'Da DD, Suganuma K. Prophylactic activity of orally administered dry-heat-sterilized Acremonium egyptiacum against Trypanosoma congolense-induced animal African trypanosomosis. Acta Trop 2024; 254:107185. [PMID: 38494059 DOI: 10.1016/j.actatropica.2024.107185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/08/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
Animal African trypanosomosis (AAT) is an important global disease of livestock that causes economic losses of up to 4.5 billion US dollars per year. Thus, eliminating AAT in endemic countries will improve agricultural productivity and economic growth. To prevent AAT, vector control and the development of prophylactic drugs are crucial. Ascofuranone (AF) is a bioactive fungal compound with proven in vitro trypanocidal potency and in vivo treatment efficacy. However, the complex stereoselective synthesis of AF has prevented its cost-effective industrial production. Recently, a genetically modified strain of Acremonium egyptiacum fungus that produces a high yield of AF was developed. Therefore, we hypothesized that the oral administration of the AF-producing fungus itself may be effective against AAT. Hence, this study aimed to evaluate the prophylactic activity of orally administered dry-heat-sterilized A. egyptiacum against Trypanosoma congolense IL3000 infection using a mouse model. The survival rate was significantly prolonged (p = 0.009), and parasitemia was suppressed in all AF-fungus-treated groups (Group 1-9) compared with that in the untreated control group (Group 10). Hence, the trypanocidal activity of AF was retained after dry-heat-sterilization of the AF-producing fungus and that its oral administration effectively prevented AAT. Since AAT is endemic to rural areas with underdeveloped veterinary infrastructure, dry-heat-sterilized A. egyptiacum would be the most cost-effective potential treatment for AAT.
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Affiliation(s)
- Ai Yamazaki
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido, 080-8555, Japan
| | - Yusuke Tanaka
- Department of Functional Anatomy and Neuroscience, Asahikawa Medical University, Asahikawa, Hokkaido, 078-8510, Japan
| | - Kenichi Watanabe
- Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan; Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Mayu Sato
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Shin-Ichiro Kawazu
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido, 080-8555, Japan
| | - Kiyoshi Kita
- School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto, Nagasaki 852-8523, Japan
| | - Noboru Inoue
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido, 080-8555, Japan
| | - Helena D Janse van Rensburg
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom 2520, South Africa
| | - David D N'Da
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom 2520, South Africa
| | - Keisuke Suganuma
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido, 080-8555, Japan; Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan.
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Iwaka C, Azando EVB, Houehanou TD, Kora S, Idrissou Y, Olounlade PA, Hounzangbe-Adote SM. Ethnoveterinary survey of trypanocidal medicinal plants of the beninese pharmacopoeia in the management of bovine trypanosomosis in North Benin (West Africa). Heliyon 2023; 9:e17697. [PMID: 37496927 PMCID: PMC10366400 DOI: 10.1016/j.heliyon.2023.e17697] [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: 11/06/2022] [Revised: 06/20/2023] [Accepted: 06/26/2023] [Indexed: 07/28/2023] Open
Abstract
Cattle breeding is of great socio-economic importance for Benin's cattle farmers in general and those of North Benin in particular. The objective of this study is to inventory the natural products of medicinal plants of the Beninese pharmacopoeia for the management of trypanosomes in cattle in North Benin. The methodology consisted of individual and semi-structured interviews with cattle farmers on the use of medicinal plants. A total of 360 cattle farmers were selected and interviewed in twelve villages in four municipalities (Tchaourou, N'dali, Bembèrèkè and Gogounou) in northern Benin. Different quantitative ethnobotanical indices were calculated to determine the level of use of plant species. The Relative Frequency of Citation (RFC), the Informant Consensus Factor (ICF = 0.918) and the Generic Coefficient (Rg = 1.04) were evaluated. The knowledge of medicinal plants was influenced by the level of education and the main activity of those who practiced animal husbandry. The results yielded 48 medicinal plants for veterinary use belonging to 46 genera and 28 families. The Leguminosae family (12.50%) was the most represented. The most cited plants with a RFC above 10% were K. senegalensis, P. africana, K. africana, M. inermis, S. latifolius, M. polyandra. The parts used were leaves (46.15%); barks (24.62%) and roots (15.38%). Decoction (53.23%), plundering (32.26%) and maceration (11.26%) were the main methods of preparation. The administration was mainly by oral route. The calculated indices show a high diversity of medicinal plants with trypanocidal properties in the control of cattle trypanosomosis in the Sudanese and Sudano-Guinean zones of northern Benin. Plant species with high citation and RFC values should be selected for comprehensive pharmacological and phytochemical research to validate this ethnomedical knowledge in the management of cattle trypanosomosis.
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Affiliation(s)
- Christophe Iwaka
- Laboratoire d’Ecologie, de Santé et de Production Animales (LESPA), Faculté d’Agronomie (FA), Université de Parakou (UP), 01 BP 123, Parakou, Benin
- Laboratoire d’Ecologie, de Botanique et de Biologie Végétale, Faculté d’Agronomie, Université de Parakou, 03 BP 125, Parakou, Benin
- Laboratoire d’Ethnopharmacologie et de Santé Animale, Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, 01 BP 526, Cotonou, Benin
| | - Erick Virgile Bertrand Azando
- Laboratoire d’Ecologie, de Santé et de Production Animales (LESPA), Faculté d’Agronomie (FA), Université de Parakou (UP), 01 BP 123, Parakou, Benin
- Laboratoire de Biotechnologie et d’Amélioration Animale, Faculté des Sciences Agronomiques, Institut des Sciences Biomédicales Appliquées (ISBA), Université d’Abomey Calavi, 01 BP 526, Cotonou, Benin
- Laboratoire d’Ethnopharmacologie et de Santé Animale, Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, 01 BP 526, Cotonou, Benin
| | - Thierry Dehouegnon Houehanou
- Laboratoire d’Ecologie, de Botanique et de Biologie Végétale, Faculté d’Agronomie, Université de Parakou, 03 BP 125, Parakou, Benin
- Laboratoire de Biomathématiques et d’Estimations Forestières, Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, 04 BP 1525, Cotonou, Benin
| | - Sabi Kora
- Laboratoire d’Ecologie, de Santé et de Production Animales (LESPA), Faculté d’Agronomie (FA), Université de Parakou (UP), 01 BP 123, Parakou, Benin
| | - Yaya Idrissou
- Laboratoire d’Ecologie, de Santé et de Production Animales (LESPA), Faculté d’Agronomie (FA), Université de Parakou (UP), 01 BP 123, Parakou, Benin
| | - Pascal Abiodoun Olounlade
- Laboratoire de Biotechnologie et d’Amélioration Animale, Faculté des Sciences Agronomiques, Institut des Sciences Biomédicales Appliquées (ISBA), Université d’Abomey Calavi, 01 BP 526, Cotonou, Benin
- Laboratoire des Sciences Animale et Halieutique (LaSAH), Unité de Recherches Zootechnique et Système d’élevage, Ecole Doctorale des Sciences Agronomiques et de l’Eau, Université Nationale d’Agriculture, 01 BP 55, Porto Novo, Benin
- Laboratoire d’Ethnopharmacologie et de Santé Animale, Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, 01 BP 526, Cotonou, Benin
| | - Sylvie Mawulé Hounzangbe-Adote
- Laboratoire d’Ethnopharmacologie et de Santé Animale, Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, 01 BP 526, Cotonou, Benin
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Okello I, Mafie E, Nzalawahe J, Eastwood G, Mboera LEG, Hakizimana JN, Ogola K. Trypanosoma Congolense Resistant to Trypanocidal Drugs Homidium and Diminazene and their Molecular Characterization in Lambwe, Kenya. Acta Parasitol 2023; 68:130-144. [PMID: 36441294 DOI: 10.1007/s11686-022-00640-3] [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: 05/13/2022] [Accepted: 11/03/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE African animal trypanosomiasis (AAT) is a disease affecting livestock in sub-Saharan Africa. The use of trypanocidal agents is common practice to control AAT. This study aimed to identify drug-resistant Trypanosoma congolense in Lambwe, Kenya, and assess if molecular test backed with mice tests is reliable in detecting drug sensitivity. METHODS Blood samples were collected from cattle, in Lambwe, subjected to buffy coat extraction and Trypanosoma spp. detected under a microscope. Field and archived isolates were subjected to molecular characterization. Species-specific T. congolense and TcoAde2 genes were amplified using PCR to detect polymorphisms. Phylogenetic analysis were performed. Four T. congolense isolates were evaluated individually in 24 test mice per isolate. Test mice were then grouped (n=6) per treatement with diminazene, homidium, isometamidium, and controls. Mice were subsequently assessed for packed cell volume (PCV) and relapses using microscopy. RESULTS Of 454 samples, microscopy detected 11 T. congolense spp, eight had TcoAde2 gene, six showed polymorphisms in molecular assay. Phylogenetic analysis grouped isolates into five. Two archived isolates were homidium resistant, one was also diminazene resistant in mice. Two additional isolates were sensitive to all the drugs. Interestingly, one sensitive isolate lacked polymorphisms, while the second lacked TcoAde2, indicating the gene is not involved in drug sensitivity. Decline in PCV was pronounced in relapsed isolates. CONCLUSION T. congolense associated with homidium and diminazene resistance exist in Lambwe. The impact can be their spread and AAT increase. Polymorphisms are present in Lambwe strains. TcoAde2 is unlikely involved in drug sensitivity. Molecular combined with mice tests is reliable drug sensitivity test and can be applied to other genes. Decline in PCV in infected-treated host could suggest drug resistance.
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Affiliation(s)
- Ivy Okello
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals in East and Southern Africa, SACIDS Foundation for One Health, P.O. Box 3297, Morogoro, Tanzania. .,Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. BOX 3019, Morogoro, Tanzania.
| | - Eliakunda Mafie
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. BOX 3019, Morogoro, Tanzania
| | - Jahashi Nzalawahe
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. BOX 3019, Morogoro, Tanzania
| | - Gillian Eastwood
- Department of Entomology, College of Agriculture & Life Sciences, Virginia Polytechnic Institute & State University, Blacksburg, VA, USA
| | - Leonard E G Mboera
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals in East and Southern Africa, SACIDS Foundation for One Health, P.O. Box 3297, Morogoro, Tanzania
| | - Jean Nepomuscene Hakizimana
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals in East and Southern Africa, SACIDS Foundation for One Health, P.O. Box 3297, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. BOX 3019, Morogoro, Tanzania
| | - Kennedy Ogola
- Pharmacology & Molecular Laboratory, Agricultural & Livestock Research Organization, Biotechnology Research Institute, P. O. Box 362, Kikuyu, Kenya
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Prevalence and Associated Risk Factors of African Animal Trypanosomiasis in Cattle in Lambwe, Kenya. J Parasitol Res 2022; 2022:5984376. [PMID: 35872666 PMCID: PMC9303511 DOI: 10.1155/2022/5984376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 12/03/2022] Open
Abstract
Background African animal trypanosomiasis (AAT) affects livestock productivity in sub-Saharan Africa. This study aimed to determine cattle AAT's prevalence and associated risk factors in Lambwe Valley, Kenya. Methods In a cross-sectional survey, livestock owners were recruited from four villages of Lambwe in Homa Bay, Kenya. Blood samples were collected from the jugular veins of cattle, and buffy coat smears were examined under a microscope. Parasites were further detected using polymerase chain reaction (PCR). Using a semistructured questionnaire, livestock owners were interviewed on their knowledge of AAT and control practices. Chi-square and multilevel models were used for the analysis. Results The overall prevalence was 15.63% (71/454). Trypanosoma vivax 10.31% and T. congolense Savannah 6.01% were the common species and subspecies. A total of 61 livestock keepers were involved in the study. Of these, 91.80% (56/61) knew AAT, and 90.16% (55/61) could describe the symptoms well and knew tsetse fly bite as transmission mode. Self-treatment (54.09%; 33/61) was common, with up to 50.00% of the farmers using drugs frequently. Isometamidium (72.13%; 44/61) and diminazene (54.09%; 33/61) were drugs frequently used. Although 16.39% (10/61) of the farmers claimed to use chemoprophylactic treatment, 6/10 did not use the right drugs. Animals (92.1%; 58/63) with clinical signs had positive infections. Villages closer to the national park recorded a higher prevalence. Infections were higher in cattle owned by those self-treating (27.23%; 58/213), those using drug treatment without vector control (27.62%; 50/181), those using single-drug therapy, and those practicing communal grazing (20.00%; 59/295). Clinical signs strongly associate with positive infections under multilevel modeling. Conclusion Cattle trypanosomiasis is prevalent in the Lambwe region of Kenya. This is influenced by inappropriate control practices, communal grazing, and the proximity of farms to the national park. In addition, clinical signs of the disease have a strong association with infections.
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Diall O, Desquesnes M, Faye B, Dia ML, Jacquiet P, Sazmand A, Otranto D, Touratier L. Development of a progressive control pathway for Trypanosoma evansi infection (surra) in camels in Africa. Acta Trop 2022; 234:106583. [DOI: 10.1016/j.actatropica.2022.106583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 06/23/2022] [Accepted: 06/30/2022] [Indexed: 11/16/2022]
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Drug-resistant trypanosome isolates populations in dogs in Enugu North Senatorial Zone, Southeastern Nigeria. Parasitol Res 2021; 121:423-431. [PMID: 34746978 DOI: 10.1007/s00436-021-07362-x] [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: 06/10/2021] [Accepted: 10/27/2021] [Indexed: 10/19/2022]
Abstract
African animal trypanosomosis is an important wasting and endemic protozoan disease causing morbidities and mortalities in animals in the sub-Saharan Africa. Currently, chemotherapy is the widely used method of African animal trypanosomosis control, especially in dogs in the sub-Saharan Africa. However, their efficacy is threatened by the emergence of drug-resistant trypanosomes owing to their extensive use and misuse over several decades amongst other factors. Thus, this study focused on the trypanocidal sensitivity and characterization of Trypanosoma species isolated from dogs in Enugu North Senatorial Zone (ENSZ), Southeastern Nigeria. Trypanosoma brucei (n = 44) and T. congolense (n = 4) isolated from naturally infected dogs in ENSZ, Southeastern Nigeria, between January and August 2016 were subjected to single dose test to assess their sensitivity to diminazene aceturate (DA) and isometamidium chloride (ISM). Subsequently, DA and multidrug-resistant isolates were further subjected to DA multi-dose test and CD50 was determined and was used to characterize the drug-resistant trypanosomes. Clones were derived from a randomly selected multidrug-resistant isolate and their sensitivity also assessed. 100% and 83.3% of T. congolense and T. brucei respectively were resistant to the trypanocides. Amongst the drug-resistant isolates, 50%, 16.7%, and 33.3% were resistant to DA, ISM, and both trypanocides respectively with CD50 ranging between 11 and 32.34 mg/kg. Drug-resistant trypanosomes were characterized into highly resistant (CD50 = 11-24.99 mg/kg) and very highly resistant (CD50 = > 25 mg/kg) trypanosome isolates. Clones also expressed high levels of resistance to both DA and ISM with CD50 values between 35.58 and 38.85 mg/kg. Trypanocidal resistance was, thus, confirmed and appears to be widespread in dogs in ENSZ, Southeastern Nigeria. The adoption of an integrated trypanosomosis control strategy in ENSZ is most desirous.
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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: 17] [Impact Index Per Article: 5.7] [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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Efficacy of diminazene diaceturate and isometamidium chloride hydrochloride for the treatment of Trypanosoma evansi in mice model. J Parasit Dis 2020; 45:131-136. [PMID: 33746398 DOI: 10.1007/s12639-020-01289-3] [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: 06/16/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022] Open
Abstract
Diminazene diaceturate (DIM) and isometamidium chloride hydrochloride (ISMM) have been widely used for the treatment of animal trypanosomosis. We evaluated the efficacy of standard doses of DIM and ISMM followed by their double doses for the treatment of Trypanosoma evansi in experimentally infected mice. A T. evansi strain obtained from a naturally infected camel in Afar was used. 25 swiss white mice randomly divided in to five groups were inoculated with 0.2 mL of blood containing 103 trypanosomes. At the peak of parasitemia (≈ 2 weeks post infection), groups A and B were treated with the standard dose (3.5 mg/kg body weight [BWT]) of DIM; groups C and D were treated with the standard dose (0.5 mg/kg BWT) of ISMM; and group E served as infected control. In the DIM standard dose groups, relapses and peak parasitemia were observed 20- and 25-days post treatment respectively. Similarly, relapses and peak parasitemia were observed 21- and 27-days post treatment in the ISMM standard dose groups. All mice in the control group died within two weeks post infection. Following relapses, mice were treated with the double doses of DIM (7 mg/kg BWT) or ISMM (1 mg/kg BWT). Parasitemia was not detected for 3 months following the double dose treatments. Following dexamethasone administration for 7 days, all but one mouse in the DIM group remained negative for another month. In general, although the T. evansi strain was resistant to the standard doses of DIM and ISMM their double doses completely cleared the infection.
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Sheferaw D, Abebe R, Fekadu A, Kassaye S, Amenu K, Data D, Geresu E, Olbamo G, Anjulo A, Yigebahal Z, Estiphanos E, Mekuria S. Prevalence of bovine trypanosomosis and vector density in a dry season in Gamo-Gofa and Dawuro Zones, Southern Ethiopia. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2019; 18:100343. [PMID: 31796171 DOI: 10.1016/j.vprsr.2019.100343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 08/13/2019] [Accepted: 10/02/2019] [Indexed: 11/17/2022]
Abstract
Trypanosomosis remains one of the biggest constraints of livestock productivity in sub-Saharan Africa. It is of particular concern in Ethiopia where crop production is largely dependent on animal traction power. This study was conducted between November 2015 and March 2016 to estimate the prevalence of bovine trypanosomosis and vector density in Gamo-Gofa and Dawuro Zones located in Southern Ethiopia. For the entomological survey, a total of 305 NGU traps were deployed for three consecutive days at different positions in the two study areas. For parasitological study, blood samples were collected from 2402 cattle and examined for the presence of trypanosomes by the buffy coat technique (BCT). Blood samples that were positive in the BCT were further tested with Giemsa-stained thin smears for identification of Trypanosoma species. In the entomological survey, a total of 4113 flies were captured of which 1605 (39%) were tsetse flies while 2508 (61%) were other biting flies of the genus Stomoxys and Tabanus. Glossina pallidipes was the only tsetse fly identified in the study areas. The overall mean apparent density of G. pallidipes was 1.8 flies per trap per day (FTD). The overall prevalence of trypanosomosis in the study areas was 5.1% (95% CI: 4.2-6.0); however, it was significantly (p < 0.001) higher in Dawuro Zone (10%) than Gamo-Gofa (1.9%). Prevalence was also noted to be significantly (p < 0.001) higher in cattle with black coat colour and those with poor body condition. Trypanosomosis was caused mainly by Trypanosoma congolense (61.8%) and to a lesser extent by T. vivax (28.5%). Mixed infection by the two spp. was seen in 9.8% of the total positive animals. Evaluation of the mean packed cell volume (PCV) of the study animals with infection status revealed a significantly (p < 0.001) lower mean PCV in parasitaemic animals (21.5 ± 0.46SE) than aparasitaemic ones (24.3 ± 0.11SE). Generally, the prevalence noted in the current study is moderate. However the observation of such level of infection in a dry season suggests that the disease is still an important constraint of cattle production in the study areas. Thus, we recommend that theexisting parasite and vector control interventions need to be strengthened with special emphasis to Dawuro Zone where the prevalence was significantly higher. As the current sampling was done only once and in a dry season only, further longitudinal studies including all the seasons of the year need to be considered in the future.
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Affiliation(s)
- Desie Sheferaw
- Faculty of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia.
| | - Rahmeto Abebe
- Faculty of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia
| | - Amene Fekadu
- Faculty of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia
| | - Surafel Kassaye
- Department of Animal and Range Sciences, Selalle University, Selalle, Ethiopia
| | - Kebede Amenu
- College of Veterinary Medicine and Agriculture, Addis Ababa University, Debre-Zeit, Ethiopia
| | | | | | | | | | - Zelalem Yigebahal
- Faculty of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia
| | | | - Solomon Mekuria
- Faculty of Veterinary Medicine, Hawassa University, Hawassa, Ethiopia
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Drug quality analysis of isometamidium chloride hydrochloride and diminazene diaceturate used for the treatment of African animal trypanosomosis in West Africa. BMC Vet Res 2018; 14:361. [PMID: 30458767 PMCID: PMC6247674 DOI: 10.1186/s12917-018-1633-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/26/2018] [Indexed: 11/16/2022] Open
Abstract
Background Diminazene diaceturate (DA) and isometamidium chloride hydrochloride (ISM) are with homidium bromide, the main molecules used to treat African Animal Trypanosomosis (AAT). These drugs can be purchased from official suppliers but also from unofficial sources like local food markets or street vendors. The sub-standard quality of some of these trypanocides is jeopardizing the efficacy of treatment of sick livestock, leading thus to economic losses for the low-resource farmers and is contributing to the emergence and spread of drug resistance. The objective of this study was to assess the quality of trypanocidal drugs sold in French speaking countries of West Africa. In total, 308 drug samples including 282 of DA and 26 of ISM were purchased from official and unofficial sources in Benin, Burkina Faso, Côte d’Ivoire, Mali, Niger and Togo. All samples were analysed at LACOMEV (Dakar, Senegal), a reference laboratory of the World Organisation for Animal Health, by galenic inspection and high performance liquid chromatography. Results The results showed that 51.90% of the samples were non-compliant compared to the standards and were containing lower quantity of the active ingredient compared to the indications on the packaging. The non-compliances ranged from 63.27% in Togo to 32.65% in Burkina Faso (61.82% in Benin, 53.84% in Mali, 50% in Côte d’Ivoire, 47.36% in Niger). The rates of non-compliance were not statistically different (P = 0.572) from official or unofficial suppliers and ranged from 30 to 75% and from 0 to 65% respectively. However, the non-compliance was significantly higher for ISM compared to DA (P = 0.028). Conclusions The high non-compliance revealed in this study compromises the efficacy of therapeutic strategies against AAT, and is likely to exacerbate chemoresistance in West Africa. Corrective actions against sub-standard trypanocides urgently need to be taken by policy makers and control authorities.
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Isometamidium chloride and homidium chloride fail to cure mice infected with Ethiopian Trypanosoma evansi type A and B. PLoS Negl Trop Dis 2018; 12:e0006790. [PMID: 30208034 PMCID: PMC6152993 DOI: 10.1371/journal.pntd.0006790] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 09/24/2018] [Accepted: 08/27/2018] [Indexed: 01/09/2023] Open
Abstract
Background Trypanosoma evansi is mechanically transmitted by biting flies and affects camels, equines, and other domestic and wild animals in which it causes a disease called surra. At least two types of Trypanosoma evansi circulate in Ethiopia: type A, which is present in Africa, Latin America and Asia, and type B, which is prevalent in Eastern Africa. Currently, no information is available about the drug sensitivity of any Ethiopian T. evansi type. Methodology/principal findings This study was conducted with the objective of determining the in vivo drug sensitivity of two T. evansi type A and two type B stocks that were isolated from camels from the Tigray and Afar regions of Northern Ethiopia. We investigated the efficacy of four trypanocidal drugs to cure T. evansi infected mice: melarsamine hydrochloride (Cymelarsan), diminazene diaceturate (Veriben and Sequzene), isometamidium chloride (Veridium) and homidium chloride (Bovidium). Per experimental group, 6 mice were inoculated intraperitoneally with trypanosomes, treated at first peak parasitemia by daily drug injections for 4 consecutive days and followed-up for 60 days. Cymelarsan at 2 mg/kg and Veriben at 20 mg/kg cured all mice infected with any T. evansi stock, while Sequzene at 20 mg/kg caused relapses in all T. evansi stocks. In contrast, Veridium and Bovidium at 1 mg/kg failed to cure any T. evansi infection in mice. Conclusions/significance We conclude that mice infected with Ethiopian T. evansi can be cured with Cymelarsan and Veriben regardless of T. evansi type. In contrast, Veridium and Bovidium are not efficacious to cure any T. evansi type. Although innate resistance to phenanthridines was previously described for T. evansi type A, this report is the first study to show that this phenomenom also occurs in T. evansi type B infections. Surra is a vector borne disease in camels, horses, water buffaloes, cattle and other domestic animals caused by Trypanosoma (T.) evansi. This protozoan parasite is transmitted by biting flies such as tabanids and stable flies and is endemic in many countries in Northern and Eastern Africa, Latin America and Asia. Surra is responsible for high economic losses due to mortality and morbidity of draught animals and leads to animal trade restrictions in endemic regions. Control of surra is mainly based on the treatment of sick animals presenting clinical symptoms. In Ethiopia two different types of T. evansi (A and B) have been described, yet no data existed about the drug sensitivity of any T. evansi type. In this study, we show for the first time that T. evansi type B is naturally in vivo resistant to the phenanthridine class of trypanocidal drugs, a phenonomen that was previously described for T. evansi type A. All Ethiopian T. evansi types are sensitive to melarsamine hydrochloride and diminazene diaceturate. Unfortunately, the most efficacious drugs are either not registered in Ethiopia or escape quality control of the active substance in commercial drug formulations. Furthermore, the inefficacious drugs remain accessible on the market despite their toxicity for animals.
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Tekle T, Terefe G, Cherenet T, Ashenafi H, Akoda KG, Teko-Agbo A, Van Den Abbeele J, Gari G, Clausen PH, Hoppenheit A, Mattioli RC, Peter R, Marcotty T, Cecchi G, Delespaux V. Aberrant use and poor quality of trypanocides: a risk for drug resistance in south western Ethiopia. BMC Vet Res 2018; 14:4. [PMID: 29304792 PMCID: PMC5755418 DOI: 10.1186/s12917-017-1327-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 12/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Trypanocidal drugs have been used to control African animal trypanosomosis for several decades. In Ethiopia, these drugs are available from both authorized (legal) and unauthorized (illegal) sources but documentation on utilization practices and quality of circulating products is scanty. This study looked at the practices of trypanocidal drug utilization by farmers and the integrity of active ingredient in trypanocides sold in Gurage zone, south western Ethiopia. The surveys were based on a structured questionnaire and drug quality determination of commonly used brands originating from European and Asian companies and sold at both authorized and unauthorized markets. One hundred farmers were interviewed and 50 drug samples were collected in 2013 (Diminazene aceturate = 33 and Isometamidium chloride = 17; 25 from authorized and 25 from unauthorized sources). Samples were tested at the OIE-certified Veterinary Drug Control Laboratory (LACOMEV) in Dakar, Senegal, by using galenic standards and high performance liquid chromatography. RESULTS Trypanosomosis was found to be a major threat according to all interviewed livestock keepers in the study area. Diminazene aceturate and isometamidium chloride were preferred by 79% and 21% of the respondents respectively, and 85% of them indicated that an animal receives more than six treatments per year. About 60% of these treatments were reported to be administered by untrained farmers. Trypanocidal drug sources included both unauthorized outlets (56%) and authorized government and private sources (44%). A wide availability and usage of substandard quality drugs was revealed. Twenty eight percent of trypanocidal drugs tested failed to comply with quality requirements. There was no significant difference in the frequency of non-compliance between diminazene-based and isometamidium chloride products (P = 0.87) irrespective of the marketing channel (official and unofficial). However, higher rates of non-compliant trypanocides were detected for drugs originating from Asia than from Europe (P = 0.029). CONCLUSION The findings revealed the presence of risk factors for the development of drug resistance, i.e. wide distribution of poor quality drugs as well as substandard administration practices. Therefore, it is strongly recommended to enforce regulatory measures for quality control of veterinary drugs, to expand and strengthen veterinary services and to undertake trypanocidal drug efficacy studies of wider coverage.
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Affiliation(s)
- T Tekle
- National Animal Health Diagnostic and Investigation Center-Protozoology unit, P.O. Box 8615, Addis Ababa, Ethiopia
| | - G Terefe
- Department of Pathology & Parasitology, Addis Ababa University College of Veterinary Medicine and Agriculture, P.O.Box 34, Bishoftu, Ethiopia.
| | - T Cherenet
- Minstry of Livestock and Fisheries, Addis Ababa, Ethiopia
| | - H Ashenafi
- Department of Pathology & Parasitology, Addis Ababa University College of Veterinary Medicine and Agriculture, P.O.Box 34, Bishoftu, Ethiopia
| | - K G Akoda
- Ecole Inter- Etats des Sciences et Médecine vétérinaires de Dakar, P.O.Box 5077, Dakar, Fann, Senegal
| | - A Teko-Agbo
- Ecole Inter- Etats des Sciences et Médecine vétérinaires de Dakar, P.O.Box 5077, Dakar, Fann, Senegal
| | - J Van Den Abbeele
- Department of Biomedical Sciences Veterinary Protozoology, Institute of Tropical Medicine, Unit 155 Nationalestraat, B-2000, Antwerp, Belgium
| | - G Gari
- National Animal Health Diagnostic and Investigation Center-Protozoology unit, P.O. Box 8615, Addis Ababa, Ethiopia
| | - P-H Clausen
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Robert-von-Ostertag Str. 7-13, 14163, Berlin, Germany
| | - A Hoppenheit
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universitaet Berlin, Robert-von-Ostertag Str. 7-13, 14163, Berlin, Germany
| | - R C Mattioli
- Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00153, Rome, Italy
| | - R Peter
- Global Alliance for Livestock Veterinary Medicines (GALVmed), Doherty Building, Pentlands Park, Bush Loan, Edinburgh, EH26 0PZ, UK
| | - T Marcotty
- Veterinary Epidemiology and Risk Analysis - Research and Development (VERDI-R&D), Rue du Gravier 7, 4141, Sprimont, Belgium
| | - G Cecchi
- Food and Agriculture Organization of the United Nations, Sub-Regional Office for Eastern Africa, Addis Ababa, Ethiopia
| | - V Delespaux
- Faculty of Sciences and Bio-engineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
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15
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More S, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Baldinelli F, Broglia A, Candiani D, Beltrán Beck B, Kohnle L, Morgado J, Bicout D. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): Trypanosoma evansi infections (including Surra). EFSA J 2017; 15:e04892. [PMID: 32625557 PMCID: PMC7010157 DOI: 10.2903/j.efsa.2017.4892] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Trypanosoma evansi infections (including Surra) have been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of T. evansi infections (including Surra) to be listed, Article 9 for the categorisation of T. evansi infections (including Surra) according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to T. evansi infections (including Surra). The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, it is inconclusive whether T. evansi infections (including Surra) can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL because there was no full consensus on the criterion 5 A(v). Consequently, the assessment on compliance of T. evansi infections (including Surra) with the criteria as in sections 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (d) and (e) of Article 9(1) is also inconclusive, as well as which animal species can be considered to be listed for T. evansi infections (including Surra) according to Article 8(3) of the AHL.
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Diall O, Cecchi G, Wanda G, Argilés-Herrero R, Vreysen MJB, Cattoli G, Viljoen GJ, Mattioli R, Bouyer J. Developing a Progressive Control Pathway for African Animal Trypanosomosis. Trends Parasitol 2017; 33:499-509. [PMID: 28456474 DOI: 10.1016/j.pt.2017.02.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/21/2017] [Accepted: 02/22/2017] [Indexed: 11/25/2022]
Abstract
Progressive control pathways (PCPs) are stepwise approaches for the reduction, elimination, and eradication of human and animal diseases. They provide systematic frameworks for planning and evaluating interventions. Here we outline a PCP for tsetse-transmitted animal trypanosomosis, the scourge of poor livestock keepers in tropical Africa. Initial PCP stages focus on the establishment of national coordination structures, engagement of stakeholders, development of technical capacities, data collection and management, and pilot field interventions. The intermediate stage aims at a sustainable and economically profitable reduction of disease burden, while higher stages target elimination. The mixed-record of success and failure in past efforts against African animal trypanosomosis (AAT) makes the development of this PCP a high priority.
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Affiliation(s)
- Oumar Diall
- Food and Agriculture Organization of the United Nations (FAO), Sub-Regional Office for Eastern Africa, Addis Ababa, Ethiopia
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations (FAO), Sub-Regional Office for Eastern Africa, Addis Ababa, Ethiopia.
| | - Gift Wanda
- African Union - Pan African Tsetse and Trypanosomosis Eradication Campaign (AU-PATTEC), Addis Ababa, Ethiopia
| | - Rafael Argilés-Herrero
- Joint FAO/International Atomic Energy Agency (IAEA) Programme of Nuclear Techniques in Food and Agriculture, Insect Pest Control Sub-Programme, Vienna, Austria
| | - Marc J B Vreysen
- Joint FAO/International Atomic Energy Agency (IAEA) Programme of Nuclear Techniques in Food and Agriculture, Insect Pest Control Sub-Programme, Vienna, Austria
| | - Giovanni Cattoli
- Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Animal Production and Health Sub-Programme, Vienna, Austria
| | - Gerrit J Viljoen
- Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Animal Production and Health Sub-Programme, Vienna, Austria
| | | | - Jérémy Bouyer
- Unité Mixte de Recherche INTERTRYP, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier, France; Unité Mixte de Recherche "Animal, Santé, Territoires, Risques et Ecosystèmes" (ASTRE), CIRAD, Montpellier, France
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17
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Boulangé A, Pillay D, Chevtzoff C, Biteau N, Comé de Graça V, Rempeters L, Theodoridis D, Baltz T. Development of a rapid antibody test for point-of-care diagnosis of animal African trypanosomosis. Vet Parasitol 2017; 233:32-38. [DOI: 10.1016/j.vetpar.2016.11.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 11/15/2016] [Accepted: 11/19/2016] [Indexed: 01/13/2023]
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Abstract
Pathogenic animal trypanosomes affecting livestock have represented a major constraint to agricultural development in Africa for centuries, and their negative economic impact is increasing in South America and Asia. Chemotherapy and chemoprophylaxis represent the main means of control. However, research into new trypanocides has remained inadequate for decades, leading to a situation where the few compounds available are losing efficacy due to the emergence of drug-resistant parasites. In this review, we provide a comprehensive overview of the current options available for the treatment and prophylaxis of the animal trypanosomiases, with a special focus on the problem of resistance. The key issues surrounding the main economically important animal trypanosome species and the diseases they cause are also presented. As new investment becomes available to develop improved tools to control the animal trypanosomiases, we stress that efforts should be directed towards a better understanding of the biology of the relevant parasite species and strains, to identify new drug targets and interrogate resistance mechanisms.
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Eze AA, Gould MK, Munday JC, Tagoe DNA, Stelmanis V, Schnaufer A, De Koning HP. Reduced Mitochondrial Membrane Potential Is a Late Adaptation of Trypanosoma brucei brucei to Isometamidium Preceded by Mutations in the γ Subunit of the F1Fo-ATPase. PLoS Negl Trop Dis 2016; 10:e0004791. [PMID: 27518185 PMCID: PMC4982688 DOI: 10.1371/journal.pntd.0004791] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/30/2016] [Indexed: 11/19/2022] Open
Abstract
Background Isometamidium is the main prophylactic drug used to prevent the infection of livestock with trypanosomes that cause Animal African Trypanosomiasis. As well as the animal infective trypanosome species, livestock can also harbor the closely related human infective subspecies T. b. gambiense and T. b. rhodesiense. Resistance to isometamidium is a growing concern, as is cross-resistance to the diamidine drugs diminazene and pentamidine. Methodology/Principal Findings Two isometamidium resistant Trypanosoma brucei clones were generated (ISMR1 and ISMR15), being 7270- and 16,000-fold resistant to isometamidium, respectively, which retained their ability to grow in vitro and establish an infection in mice. Considerable cross-resistance was shown to ethidium bromide and diminazene, with minor cross-resistance to pentamidine. The mitochondrial membrane potentials of both resistant cell lines were significantly reduced compared to the wild type. The net uptake rate of isometamidium was reduced 2-3-fold but isometamidium efflux was similar in wild-type and resistant lines. Fluorescence microscopy and PCR analysis revealed that ISMR1 and ISMR15 had completely lost their kinetoplast DNA (kDNA) and both lines carried a mutation in the nuclearly encoded γ subunit gene of F1 ATPase, truncating the protein by 22 amino acids. The mutation compensated for the loss of the kinetoplast in bloodstream forms, allowing near-normal growth, and conferred considerable resistance to isometamidium and ethidium as well as significant resistance to diminazene and pentamidine, when expressed in wild type trypanosomes. Subsequent exposure to either isometamidium or ethidium led to rapid loss of kDNA and a further increase in isometamidium resistance. Conclusions/Significance Sub-lethal exposure to isometamidium gives rise to viable but highly resistant trypanosomes that, depending on sub-species, are infective to humans and cross-resistant to at least some diamidine drugs. The crucial mutation is in the F1 ATPase γ subunit, which allows loss of kDNA and results in a reduction of the mitochondrial membrane potential. Isometamidium is the only prophylactic treatment of Animal African Trypanosomiasis, a wasting disease of livestock and domestic animals in sub-Saharan Africa. Unfortunately resistance threatens the continued utility of this drug after decades of use. Not only does this disease have severe impacts on agriculture, but some subspecies of Trypanosoma brucei are human-infective as well (causing sleeping sickness) and there is concern that cross-resistance with trypanocides of the diamidine class could further undermine treatment of both veterinary and human infections. It is therefore essential to understand the mechanism of isometamidium resistance and the likelihood for cross-resistance with other first-line trypanocides. Here, we report that isometamidium resistance can be caused by a mutation in an important mitochondrial protein, the γ subunit of the F1 ATPase, and that this mutation alone is sufficient for high levels of resistance, cross-resistance to various drugs, and a strongly reduced mitochondrial membrane potential. This report will for the first time enable a structural assessment of isometamidium resistance genes in T. brucei spp.
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Affiliation(s)
- Anthonius A. Eze
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Matthew K. Gould
- Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jane C. Munday
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel N. A. Tagoe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Valters Stelmanis
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Achim Schnaufer
- Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Harry P. De Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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Desquesnes M, Yangtara S, Kunphukhieo P, Chalermwong P, Jittapalapong S, Herder S. Zoonotic trypanosomes in South East Asia: Attempts to control Trypanosoma lewisi using veterinary drugs. Exp Parasitol 2016; 165:35-42. [PMID: 26988923 DOI: 10.1016/j.exppara.2016.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 02/18/2016] [Accepted: 03/05/2016] [Indexed: 11/20/2022]
Abstract
A growing number of atypical human infections due to the livestock parasite Trypanosoma evansi, or to the rat parasite Trypanosoma lewisi, are reported in humans in Asia. In some cases, clinical evolutions request treatments, however, so far, there were very few attempts to control T. lewisi using trypanocidal drugs. In a study published elsewhere, the efficacy of human trypanocides is evaluated in laboratory rats, and it concludes that none of them is able to cure rats experimentally infected with T. lewisi. Control of T. lewisi in rat would be a step for identification of drugs against this parasite. In the present study, 4 veterinary drugs: diminazene aceturate, isometamidium chloride, melarsomine hydrochloride and quinapyramine sulfate and chloride, were evaluated at low and high doses, in intra-muscular injections to normal rats experimentally infected with a stock of T. lewisi from Thailand. None of these treatments being efficient, a trial was also made using melarsomine hydrochloride in T. evansi infected rats and in mixed T. lewisi and T. evansi infected rats, in order to demonstrate the efficacy of the drugs under the present protocol. T. evansi was cleared from the rat's blood the day after the treatment, while, T. lewisi remained unaffected until the end of the experiment. These observations clearly demonstrated the efficacy of melarsomine hydrochloride against T. evansi and its inefficacy against T. lewisi. In conclusion none of the veterinary drugs was efficient against this stock of T. lewisi. Other protocols using higher doses or other drugs and T. lewisi stocks should be investigated in further studies. The control of T. lewisi infection in Wistar rats, using veterinary trypanocidal drugs, remains so far unsuccessful.
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Affiliation(s)
- Marc Desquesnes
- CIRAD, UMR InterTryp, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier, F-34000, France; Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Sarawut Yangtara
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Pawinee Kunphukhieo
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Piangjai Chalermwong
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Sathaporn Jittapalapong
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.
| | - Stéphane Herder
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand; Institut de Recherches pour le Développement (IRD), UMR Intertryp, Campus International de Baillarguet, F-34398, Montpellier, France
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