401
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Bentivoglio M, Bertini G. Alive and Ticking: Trypanosoma brucei Assaults the Circadian Clocks. Trends Parasitol 2018; 34:265-267. [PMID: 29555198 DOI: 10.1016/j.pt.2018.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/05/2018] [Indexed: 10/17/2022]
Abstract
Rijo-Ferreira et al. report alterations of circadian rhythmicity at the behavioral, tissue, cellular, and molecular levels in mice after Trypanosoma brucei infection, showing that targeting cell clocks is a specific feature of these parasites. Thus, African trypanosomes cause a severe disease by disrupting time-keeping mechanisms and their synchrony.
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Affiliation(s)
- Marina Bentivoglio
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Giuseppe Bertini
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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402
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Büscher P, Bart JM, Boelaert M, Bucheton B, Cecchi G, Chitnis N, Courtin D, Figueiredo LM, Franco JR, Grébaut P, Hasker E, Ilboudo H, Jamonneau V, Koffi M, Lejon V, MacLeod A, Masumu J, Matovu E, Mattioli R, Noyes H, Picado A, Rock KS, Rotureau B, Simo G, Thévenon S, Trindade S, Truc P, Van Reet N. Do Cryptic Reservoirs Threaten Gambiense-Sleeping Sickness Elimination? Trends Parasitol 2018; 34:197-207. [PMID: 29396200 PMCID: PMC5840517 DOI: 10.1016/j.pt.2017.11.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/18/2017] [Accepted: 11/27/2017] [Indexed: 12/22/2022]
Abstract
Trypanosoma brucei gambiense causes human African trypanosomiasis (HAT). Between 1990 and 2015, almost 440000 cases were reported. Large-scale screening of populations at risk, drug donations, and efforts by national and international stakeholders have brought the epidemic under control with <2200 cases in 2016. The World Health Organization (WHO) has set the goals of gambiense-HAT elimination as a public health problem for 2020, and of interruption of transmission to humans for 2030. Latent human infections and possible animal reservoirs may challenge these goals. It remains largely unknown whether, and to what extend, they have an impact on gambiense-HAT transmission. We argue that a better understanding of the contribution of human and putative animal reservoirs to gambiense-HAT epidemiology is mandatory to inform elimination strategies.
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Affiliation(s)
- Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium.
| | - Jean-Mathieu Bart
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France; Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Calle Sinesio Delgado 4, 28029 Madrid, Spain
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
| | - Bruno Bucheton
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Giuliano Cecchi
- Sub-regional Office for Eastern Africa, Food and Agriculture Organization of the United Nations, CMC Road, Bole Sub City, Kebele 12/13, P O Box 5536, Addis Ababa, Ethiopia
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, Postfach, 4002 Basel, Switzerland; University of Basel, Switzerland
| | - David Courtin
- Université Paris Descartes, Institut de Recherche pour le Développement, Unité MERIT, Mère et enfant face aux infections tropicales, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Prof Egas Moniz, 1649-028 Lisboa, Portugal
| | - José-Ramon Franco
- Control of Neglected Tropical Diseases, Innovative and Intensified Disease Management, World Health Organization, Via Appia 20, 1202 Geneva, Switzerland
| | - Pascal Grébaut
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Epco Hasker
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
| | - Hamidou Ilboudo
- Institut de Recherche sur les Bases Biologiques de la Lutte Intégrée, Centre International de Recherche-Développement sur l'Élevage en zone Subhumide, 01 BP 454 Bobo-Dioulasso 01, Burkina Faso
| | | | - Mathurin Koffi
- Université Jean Lorougnon Guédé, BP 150 Daloa, Côte d'Ivoire
| | - Veerle Lejon
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Annette MacLeod
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Henry Wellcome Building, 464 Bearsden Road, Glasgow, UK
| | - Justin Masumu
- Département de Parasitologie, Institut National de Recherche Biomédicale, Avenue de la Démocratie, BP 1197 Kinshasa 1, République Démocratique du Congo
| | - Enock Matovu
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P O Box 7062 Kampala, Uganda
| | - Raffaele Mattioli
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00153 Rome, Italy
| | - Harry Noyes
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Albert Picado
- Foundation for Innovative New Diagnostics, 9 Chemin des Mines, 1202 Geneva, Switzerland
| | - Kat S Rock
- Zeeman Institute for Systems Biology & Infectious Disease Research, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, 25, rue du Docteur Roux, 75015 Paris, France
| | - Gustave Simo
- Department of Biochemistry, Faculty of Science, University of Dschang, P O Box 67 Dschang, Cameroon
| | - Sophie Thévenon
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France; CIRAD, INTERTRYP, Montpellier, France
| | - Sandra Trindade
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Prof Egas Moniz, 1649-028 Lisboa, Portugal
| | - Philippe Truc
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Nick Van Reet
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
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403
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Laperchia C, Xu YZ, Mumba Ngoyi D, Cotrufo T, Bentivoglio M. Neural Damage in Experimental Trypanosoma brucei gambiense Infection: Hypothalamic Peptidergic Sleep and Wake-Regulatory Neurons. Front Neuroanat 2018. [PMID: 29535612 PMCID: PMC5835115 DOI: 10.3389/fnana.2018.00013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Neuron populations of the lateral hypothalamus which synthesize the orexin (OX)/hypocretin or melanin-concentrating hormone (MCH) peptides play crucial, reciprocal roles in regulating wake stability and sleep. The disease human African trypanosomiasis (HAT), also called sleeping sickness, caused by extracellular Trypanosoma brucei (T. b.) parasites, leads to characteristic sleep-wake cycle disruption and narcoleptic-like alterations of the sleep structure. Previous studies have revealed damage of OX and MCH neurons during systemic infection of laboratory rodents with the non-human pathogenic T. b. brucei subspecies. No information is available, however, on these peptidergic neurons after systemic infection with T. b. gambiense, the etiological agent of 97% of HAT cases. The present study was aimed at the investigation of immunohistochemically characterized OX and MCH neurons after T. b. gambiense or T. b. brucei infection of a susceptible rodent, the multimammate mouse, Mastomysnatalensis. Cell counts and evaluation of OX fiber density were performed at 4 and 8 weeks post-infection, when parasites had entered the brain parenchyma from the periphery. A significant decrease of OX neurons (about 44% reduction) and MCH neurons (about 54% reduction) was found in the lateral hypothalamus and perifornical area at 8 weeks in T. b. gambiense-infected M. natalensis. A moderate decrease (21% and 24% reduction, respectively), which did not reach statistical significance, was found after T. b. brucei infection. In two key targets of diencephalic orexinergic innervation, the peri-suprachiasmatic nucleus (SCN) region and the thalamic paraventricular nucleus (PVT), densitometric analyses showed a significant progressive decrease in the density of orexinergic fibers in both infection paradigms, and especially during T. b. gambiense infection. Altogether the findings provide novel information showing that OX and MCH neurons are highly vulnerable to chronic neuroinflammatory signaling caused by the infection of human-pathogenic African trypanosomes.
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Affiliation(s)
- Claudia Laperchia
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Yuan-Zhong Xu
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Dieudonné Mumba Ngoyi
- Institut National de Recherche Biomédicale (INRB), Kinshasa, Democratic Republic of Congo
| | - Tiziana Cotrufo
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Marina Bentivoglio
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,National Institute of Neuroscience (INN), Verona Unit, Verona, Italy
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404
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Stijlemans B, De Baetselier P, Magez S, Van Ginderachter JA, De Trez C. African Trypanosomiasis-Associated Anemia: The Contribution of the Interplay between Parasites and the Mononuclear Phagocyte System. Front Immunol 2018; 9:218. [PMID: 29497418 PMCID: PMC5818406 DOI: 10.3389/fimmu.2018.00218] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/25/2018] [Indexed: 12/16/2022] Open
Abstract
African trypanosomosis (AT) is a chronically debilitating parasitic disease of medical and economic importance for the development of sub-Saharan Africa. The trypanosomes that cause this disease are extracellular protozoan parasites that have developed efficient immune escape mechanisms to manipulate the entire host immune response to allow parasite survival and transmission. During the early stage of infection, a profound pro-inflammatory type 1 activation of the mononuclear phagocyte system (MPS), involving classically activated macrophages (i.e., M1), is required for initial parasite control. Yet, the persistence of this M1-type MPS activation in trypanosusceptible animals causes immunopathology with anemia as the most prominent pathological feature. By contrast, in trypanotolerant animals, there is an induction of IL-10 that promotes the induction of alternatively activated macrophages (M2) and collectively dampens tissue damage. A comparative gene expression analysis between M1 and M2 cells identified galectin-3 (Gal-3) and macrophage migration inhibitory factor (MIF) as novel M1-promoting factors, possibly acting synergistically and in concert with TNF-α during anemia development. While Gal-3 enhances erythrophagocytosis, MIF promotes both myeloid cell recruitment and iron retention within the MPS, thereby depriving iron for erythropoiesis. Hence, the enhanced erythrophagocytosis and suppressed erythropoiesis lead to anemia. Moreover, a thorough investigation using MIF-deficient mice revealed that the underlying mechanisms in AT-associated anemia development in trypanosusceptible and tolerant animals are quite distinct. In trypanosusceptible animals, anemia resembles anemia of inflammation, while in trypanotolerant animals’ hemodilution, mainly caused by hepatosplenomegaly, is an additional factor contributing to anemia. In this review, we give an overview of how trypanosome- and host-derived factors can contribute to trypanosomosis-associated anemia development with a focus on the MPS system. Finally, we will discuss potential intervention strategies to alleviate AT-associated anemia that might also have therapeutic potential.
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Affiliation(s)
- Benoit Stijlemans
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Patrick De Baetselier
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Stefan Magez
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea
| | - Jo A Van Ginderachter
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Carl De Trez
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
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405
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Tesoriero C, Xu YZ, Mumba Ngoyi D, Bentivoglio M. Neural Damage in Experimental Trypanosoma brucei gambiense Infection: The Suprachiasmatic Nucleus. Front Neuroanat 2018; 12:6. [PMID: 29491832 PMCID: PMC5817918 DOI: 10.3389/fnana.2018.00006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/12/2018] [Indexed: 01/01/2023] Open
Abstract
Trypanosoma brucei (T. b.) gambiense is the parasite subspecies responsible for most reported cases of human African trypanosomiasis (HAT) or sleeping sickness. This severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. Most animal models of the disease have been hitherto based on infection of laboratory rodents with the T. b. brucei subspecies, which is not infectious to humans. In these animal models, functional, rather than structural, alterations of the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN), have been reported. Information on the SCN after infection with the human pathogenic T. b. gambiense is instead lacking. The present study was aimed at the examination of the SCN after T. b. gambiense infection of a susceptible rodent, the multimammate mouse, Mastomys natalensis, compared with T. b. brucei infection of the same host species. The animals were examined at 4 and 8 weeks post-infection, when parasites (T. b. gambiense or T. b. brucei) were detected in the brain parenchyma, indicating that the disease was in the encephalitic stage. Neuron and astrocyte changes were examined with Nissl staining, immunophenotyping and quantitative analyses. Interestingly, significant neuronal loss (about 30% reduction) was documented in the SCN during the progression of T. b. gambiense infection. No significant neuronal density changes were found in the SCN of T. b. brucei-infected animals. Neuronal cell counts in the hippocampal dentate gyrus of T. b. gambiense-infected M. natalensis did not point out significant changes, indicating that no widespread neuron loss had occurred in the brain. Marked activation of astrocytes was detected in the SCN after both T. b. gambiense and T. b. brucei infections. Altogether the findings reveal that neurons of the biological clock are highly susceptible to the infection caused by human pathogenic African trypanosomes, which have the capacity to cause permanent partial damage of this structure.
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Affiliation(s)
- Chiara Tesoriero
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Yuan-Zhong Xu
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Dieudonné Mumba Ngoyi
- Institut National de Recherche Biomedicale (INRB), Kinshasa, Democratic Republic of Congo
| | - Marina Bentivoglio
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,National Institute of Neuroscience (INN), Verona Unit, Verona, Italy
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406
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Bauerenol Acetate, the Pentacyclic Triterpenoid from Tabernaemontana longipes, is an Antitrypanosomal Agent. Molecules 2018; 23:molecules23020355. [PMID: 29419735 PMCID: PMC5911922 DOI: 10.3390/molecules23020355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/02/2018] [Accepted: 02/06/2018] [Indexed: 01/11/2023] Open
Abstract
The Latin American plant Tabernaemontana longipes was studied in this work as a potential source of antiparasitic agents. The chloroform extract of T. longipes leaves was separated into several fractions, and tested for antitrypanosomal activity. One of the fractions displayed significant growth inhibitory activity against Trypanosoma brucei. The active principle in the fraction was isolated, purified, and characterized by NMR and mass spectrometry. The antitrypanosomal agent in the CHCl3 extract of T. longipes leaves is the pentacyclic triterpenoid bauerenol acetate. A metabolite profiling assay suggest that the triterpenoid influences cholesterol metabolism. The molecular target(s) of bauerenol and its acetate, like many other antiparasitic pentacyclic triterpenoids is/are unknown, but they present privileged structural scaffolds that can be explored for structure-based activity optimization studies using phenotypic assays.
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407
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Perry JA, Sinclair-Davis AN, McAllaster MR, de Graffenried CL. TbSmee1 regulates hook complex morphology and the rate of flagellar pocket uptake in Trypanosoma brucei. Mol Microbiol 2018; 107:344-362. [PMID: 29178204 PMCID: PMC5777864 DOI: 10.1111/mmi.13885] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/20/2017] [Accepted: 11/22/2017] [Indexed: 01/26/2023]
Abstract
Trypanosoma brucei uses multiple mechanisms to evade detection by its insect and mammalian hosts. The flagellar pocket (FP) is the exclusive site of uptake from the environment in trypanosomes and shields receptors from exposure to the host. The FP neck is tightly associated with the flagellum via a series of cytoskeletal structures that include the hook complex (HC) and the centrin arm. These structures are implicated in facilitating macromolecule entry into the FP and nucleating the flagellum attachment zone (FAZ), which adheres the flagellum to the cell surface. TbSmee1 (Tb927.10.8820) is a component of the HC and a putative substrate of polo-like kinase (TbPLK), which is essential for centrin arm and FAZ duplication. We show that depletion of TbSmee1 in the insect-resident (procyclic) form of the parasite causes a 40% growth decrease and the appearance of multinucleated cells that result from defective cytokinesis. Cells lacking TbSmee1 contain HCs with aberrant morphology and show delayed uptake of both fluid-phase and membrane markers. TbPLK localization to the tip of the new FAZ is also blocked. These results argue that TbSmee1 is necessary for maintaining HC morphology, which is important for the parasite's ability to take up molecules from its environment.
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Affiliation(s)
- Jenna A. Perry
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Amy N. Sinclair-Davis
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Michael R. McAllaster
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
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408
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Sesquiterpene Lactones from Vernonia cinerascens Sch. Bip. and Their in Vitro Antitrypanosomal Activity. Molecules 2018; 23:molecules23020248. [PMID: 29382040 PMCID: PMC6017816 DOI: 10.3390/molecules23020248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/24/2018] [Accepted: 01/26/2018] [Indexed: 11/24/2022] Open
Abstract
In the endeavor to obtain new antitrypanosomal agents, particularly sesquiterpene lactones, from Kenyan plants of the family Asteraceae, Vernonia cinerascens Sch. Bip. was investigated. Bioactivity-guided fractionation and isolation in conjunction with LC/MS-based dereplication has led to the identification of vernodalol (1) and isolation of vernodalin (2), 11β,13-dihydrovernodalin (3), 11β,13-dihydrovernolide (4), vernolide (5), 11β,13-dihydrohydroxyvernolide (6), hydroxyvernolide (7), and a new germacrolide type sesquiterpene lactone vernocinerascolide (8) from the dichloromethane extract of V. cinerascens leaves. Compounds 3–8 were characterized by extensive analysis of their 1D and 2D NMR spectroscopic and HR/MS spectrometric data. All the compounds were evaluated for their in vitro biological activity against bloodstream forms of Trypanosoma brucei rhodesiense and for cytotoxicity against the mammalian cell line L6. Vernodalin (2) was the most active compound with an IC50 value of 0.16 µM and a selectivity index of 35. Its closely related congener 11β,13-dihydrovernodalin (3) registered an IC50 value of 1.1 µM and a selectivity index of 4.2.
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409
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Affiliation(s)
- Doug Fink
- The Hospital for Tropical Diseases, Mortimer Market Centre, London, UK
- Division of Infection and Immunity, University College London, London, UK
| | - Robert Serafino Wani
- Department of Infection, Barts Health NHS Trust, Royal London Hospital, London, UK
| | - Victoria Johnston
- The Hospital for Tropical Diseases, Mortimer Market Centre, London, UK
- London School of Hygiene and Tropical Medicine, London, UK
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410
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In Vitro and In Vivo Studies of the Trypanocidal Effect of Novel Quinolines. Antimicrob Agents Chemother 2018; 62:AAC.01936-17. [PMID: 29203485 DOI: 10.1128/aac.01936-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/20/2017] [Indexed: 12/12/2022] Open
Abstract
Therapies for human African trypanosomiasis and Chagas disease, caused by Trypanosoma brucei and Trypanosoma cruzi, respectively, are limited, providing minimal therapeutic options for the millions of individuals living in very poor communities. Here the effects of 10 novel quinolines are evaluated in silico and by phenotypic studies using in vitro and in vivo models. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties revealed that most molecules did not infringe on Lipinski's rules, which is a prediction of good oral absorption. These quinolines showed high probabilities of Caco2 permeability and human intestinal absorption and low probabilities of mutagenicity and of hERG1 inhibition. In vitro screens against bloodstream forms of T. cruzi demonstrated that all quinolines were more active than the reference drug (benznidazole [Bz]), except for DB2171 and DB2192, with five (DB2187, DB2131, DB2186, DB2191, and DB2217) displaying 50% effective concentrations (EC50s) of <3 μM (4-fold lower than that of Bz). Nine quinolines were more effective than Bz (2.7 μM) against amastigotes, showing EC50s ranging from 0.6 to 0.1 μM. All quinolines were also highly active in vitro against African trypanosomes, showing EC50s of ≤0.25 μM. The most potent and highly selective candidates for each parasite species were tested in in vivo models. Results for DB2186 were promising in mice with T. cruzi and T. brucei infections, reaching a 70% reduction of the parasitemia load for T. cruzi, and it cured 2 out of 4 mice infected with T. brucei DB2217 was also active in vivo and cured all 4 mice (100% cure rate) with T. brucei infection.
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411
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Guillon J, Cohen A, Das RN, Boudot C, Gueddouda NM, Moreau S, Ronga L, Savrimoutou S, Basmaciyan L, Tisnerat C, Mestanier S, Rubio S, Amaziane S, Dassonville-Klimpt A, Azas N, Courtioux B, Mergny JL, Mullié C, Sonnet P. Design, synthesis, and antiprotozoal evaluation of new 2,9-bis[(substituted-aminomethyl)phenyl]-1,10-phenanthroline derivatives. Chem Biol Drug Des 2018; 91:974-995. [PMID: 29266861 DOI: 10.1111/cbdd.13164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/04/2017] [Accepted: 12/07/2017] [Indexed: 01/06/2023]
Abstract
A series of new 2,9-bis[(substituted-aminomethyl)phenyl]-1,10-phenanthroline derivatives was synthesized, and the compounds were screened in vitro against three protozoan parasites (Plasmodium falciparum, Leishmania donovani, and Trypanosoma brucei brucei). Biological results showed antiparasitic activity with IC50 values in the μm range. The in vitro cytotoxicity of these molecules was assessed by incubation with human HepG2 cells; for some derivatives, cytotoxicity was observed at significantly higher concentrations than antiparasitic activity. The 2,9-bis[(substituted-aminomethyl)phenyl]-1,10-phenanthroline 1h was identified as the most potent antimalarial candidate with ratios of cytotoxic-to-antiparasitic activities of 107 and 39 against a chloroquine-sensitive and a chloroquine-resistant strain of P. falciparum, respectively. As the telomeres of the parasite P. falciparum are the likely target of this compound, we investigated stabilization of the Plasmodium telomeric G-quadruplexes by our phenanthroline derivatives through a FRET melting assay. The ligands 1f and 1m were noticed to be more specific for FPf8T with higher stabilization for FPf8T than for the human F21T sequence.
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Affiliation(s)
- Jean Guillon
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Anita Cohen
- Laboratory of Parasitology, UMR-MD3, Faculty of Pharmacy, Aix-Marseille University, Marseille, France
| | - Rabindra Nath Das
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Clotilde Boudot
- INSERM U1094, Tropical Neuroepidemiology, Limoges, France.,Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, Limoges, France
| | - Nassima Meriem Gueddouda
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Stéphane Moreau
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Luisa Ronga
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Solène Savrimoutou
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Louise Basmaciyan
- Laboratory of Parasitology, UMR-MD3, Faculty of Pharmacy, Aix-Marseille University, Marseille, France
| | - Camille Tisnerat
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Sacha Mestanier
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Sandra Rubio
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Sophia Amaziane
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France
| | - Alexandra Dassonville-Klimpt
- Laboratoire de Glycochimie, des Antimicrobiens et des Agroressouces, UMR CNRS 7378, UFR de Pharmacie, Université de Picardie Jules Verne, Amiens, France
| | - Nadine Azas
- Laboratory of Parasitology, UMR-MD3, Faculty of Pharmacy, Aix-Marseille University, Marseille, France
| | - Bertrand Courtioux
- INSERM U1094, Tropical Neuroepidemiology, Limoges, France.,Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, Limoges, France
| | - Jean-Louis Mergny
- INSERM U1212, UMR CNRS 5320, ARNA Laboratory, UFR des Sciences Pharmaceutiques, Université de Bordeaux, Bordeaux, France.,Institute of Biophysics of the CAS, v.v.i., Brno, Czech Republic
| | - Catherine Mullié
- Laboratoire de Glycochimie, des Antimicrobiens et des Agroressouces, UMR CNRS 7378, UFR de Pharmacie, Université de Picardie Jules Verne, Amiens, France
| | - Pascal Sonnet
- Laboratoire de Glycochimie, des Antimicrobiens et des Agroressouces, UMR CNRS 7378, UFR de Pharmacie, Université de Picardie Jules Verne, Amiens, France
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412
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Affiliation(s)
- François Chappuis
- Division of Tropical and Humanitarian Medicine, Geneva University Hospitals and University of Geneva, 1211 Geneva 14, Switzerland.
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413
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Huits R, De Ganck G, Clerinx J, Büscher P, Bottieau E. A veterinarian with fever, rash and chancre after holidays in Uganda. J Travel Med 2018; 25:5134099. [PMID: 30329077 DOI: 10.1093/jtm/tay104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/15/2018] [Indexed: 11/13/2022]
Affiliation(s)
- Ralph Huits
- Department of Clinical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium
| | - Gonda De Ganck
- Gonda's Veterinary Practice, Rotherham, 17 Blyth Rd, Maltby, Rotherham, UK
| | - Joannes Clerinx
- Department of Clinical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium
| | - Emmanuel Bottieau
- Department of Clinical Sciences, Institute of Tropical Medicine, Nationalestraat 155, Antwerp, Belgium
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414
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Abstract
Many pathogens evade host immunity by periodically changing the proteins they express on their surface - a phenomenon termed antigenic variation. An extreme form of antigenic variation, based around switching the composition of a Variant Surface Glycoprotein (VSG) coat, is exhibited by the African trypanosome Trypanosoma brucei, which causes human disease. The molecular details of VSG switching in T. brucei have been extensively studied over the last three decades, revealing in increasing detail the machinery and mechanisms by which VSG expression is controlled and altered. However, several key components of the models of T. brucei antigenic variation that have emerged have been challenged through recent discoveries. These discoveries include new appreciation of the importance of gene mosaics in generating huge levels of new VSG variants, the contributions of parasite development and body compartmentation in the host to the infection dynamics and, finally, potential differences in the strategies of antigenic variation and host infection used by the crucial livestock trypanosomes T. congolense and T. vivax. This review will discuss all these observations, which raise questions regarding how secure the existing models of trypanosome antigenic variation are. In addition, we will discuss the importance of continued mathematical modelling to understand the purpose of this widespread immune survival process.
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415
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Resistance to trypanocidal drugs in cattle populations of Zambezia Province, Mozambique. Parasitol Res 2017; 117:429-436. [PMID: 29264718 DOI: 10.1007/s00436-017-5718-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
African animal trypanosomosis is a debilitating tsetse-transmitted parasitic disease of sub-Saharan Africa. Therapeutic and prophylactic drugs were introduced more than 50 years ago, and drug resistance is increasingly reported. In a cross-sectional study, 467 cattle were microscopically screened for trypanosomes. Samples were collected in May-July 2014 from five villages (Botao, Mungama, Zalala-Electrosul, Zalala-Madal, and Namitangurine) in Nicoadala district, Zambezia province. To evaluate treatment efficacy, trypanosome-positive animals in each village were randomly assigned to two groups, one treated with 0.5 mg/kg b.w. isometamidium (Inomidium®), the second with 3.5 mg/kg b.w. diminazene (Inomazene®). Cattle were microscopically monitored at days 0, 14, and 28 post-treatment. At day 28, trypanocides were swapped to investigate single or multiple resistance. Microscopically negative samples from the monitoring days were tested using 18S-PCR-RFLP. 22.9% (107/467) was found positive on day 0. On day 14, nine animals in Botao and seven in Mungama were positive. On day 28, in Botao, four animals from the diminazene group and four from the isometamidium group were positive. In Mungama, four animals from the diminazene group were positive on day 28. On day 42, six animals (9%) in Botao and two (9.5%) in Mungama remained positive after drug swap. No relapses occurred in Namitangurine. The 18S-PCR-RFLP consistently detected more positive than microscopy: indeed, positives reached 12, 13, and 8 in Botao and 9, 7, and 4 in Mungama, at days 14, 28, and 42, respectively. Single- and multi-drug resistance in Nicoadala district, Zambezia province, is thus here confirmed. This should be considered when choosing control options.
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416
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Dieme C, Rotureau B, Mitri C. Microbial Pre-exposure and Vectorial Competence of Anopheles Mosquitoes. Front Cell Infect Microbiol 2017; 7:508. [PMID: 29376030 PMCID: PMC5770632 DOI: 10.3389/fcimb.2017.00508] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/23/2017] [Indexed: 11/16/2022] Open
Abstract
Anopheles female mosquitoes can transmit Plasmodium, the malaria parasite. During their aquatic life, wild Anopheles mosquito larvae are exposed to a huge diversity of microbes present in their breeding sites. Later, adult females often take successive blood meals that might also carry different micro-organisms, including parasites, bacteria, and viruses. Therefore, prior to Plasmodium ingestion, the mosquito biology could be modulated at different life stages by a suite of microbes present in larval breeding sites, as well as in the adult environment. In this article, we highlight several naturally relevant scenarios of Anopheles microbial pre-exposure that we assume might impact mosquito vectorial competence for the malaria parasite: (i) larval microbial exposures; (ii) protist co-infections; (iii) virus co-infections; and (iv) pathogenic bacteria co-infections. In addition, significant behavioral changes in African Anopheles vectors have been associated with increasing insecticide resistance. We discuss how these ethological modifications may also increase the repertoire of microbes to which mosquitoes could be exposed, and that might also influence their vectorial competence. Studying Plasmodium–Anopheles interactions in natural microbial environments would efficiently contribute to refining the transmission risks.
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Affiliation(s)
- Constentin Dieme
- Genetics and Genomics of Insect Vectors Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.,Centre National de la Recherche Scientifique Unit of Hosts, Vectors and Pathogens (URA3012), Paris, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Christian Mitri
- Genetics and Genomics of Insect Vectors Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.,Centre National de la Recherche Scientifique Unit of Hosts, Vectors and Pathogens (URA3012), Paris, France
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417
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Boelaert M, Mukendi D, Bottieau E, Kalo Lilo JR, Verdonck K, Minikulu L, Barbé B, Gillet P, Yansouni CP, Chappuis F, Lutumba P. A Phase III Diagnostic Accuracy Study of a Rapid Diagnostic Test for Diagnosis of Second-Stage Human African Trypanosomiasis in the Democratic Republic of the Congo. EBioMedicine 2017; 27:11-17. [PMID: 29246478 PMCID: PMC5828295 DOI: 10.1016/j.ebiom.2017.10.032] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 10/22/2017] [Accepted: 10/31/2017] [Indexed: 11/27/2022] Open
Abstract
Objectives To estimate the diagnostic accuracy of HAT Sero K-SeT for the field diagnosis of second-stage human African trypanosomiasis (HAT). Design A phase III diagnostic accuracy design. Consecutive patients with symptoms clinically suggestive of HAT were prospectively enrolled. We compared results of the index test HAT Sero K-SeT with those of a composite reference standard: demonstration of trypanosomes in cerebrospinal fluid (CSF), or trypanosomes detected in any other body fluid AND white blood cell count in CSF > 5/μl. Setting Rural hospital in the Democratic Republic of the Congo. Participants All patients above five years old presenting at Mosango hospital with a neurological problem of recent onset at the exclusion of trauma. Interventions n.a. Main Outcome Measures Sensitivity and specificity of HAT Sero K-SeT test. Results The sensitivity of the HAT Sero K-SeT was 8/8 or 100.0% (95% confidence interval: 67.6 to 100.0%) and the specificity was 258/266 or 97.0% (94.2% to 98.5%). Conclusion The high sensitivity of the HAT Sero K-SeT is in line with previously published estimates, though the sample of HAT cases in this study was small. The specificity estimate was very high and precise. This test, when negative, allows the clinician to rule out HAT in a clinical suspect in a hospital setting in this endemic region. The HAT Sero K-SeT was evaluated in a rural hospital on patients with a neurological syndrome. This new rapid diagnostic test for sleeping sickness was highly sensitive and specific. A negative HAT Sero K-SeT test allows to rule out sleeping sickness in this setting.
Rapid Diagnostic Tests (RDT) are promising tools for clinical management of sleeping sickness or Human African Trypanosomiasis (HAT), as most patients live in remote rural areas in Central or West Africa. We evaluated the HAT Sero-K-SeT, a novel RDT in a series of consecutively enrolled patients with clinical symptoms suggestive of second-stage sleeping sickness. This design is known as phase III in diagnostic accuracy studies, as the patient set is representative of future use of the RDT. The test showed high sensitivity and specificity. We conclude that in such patients, an RDT for HAT should be done. If negative, HAT can be ruled out. If positive, the likelihood of HAT is very high.
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Affiliation(s)
- Marleen Boelaert
- Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
| | - Deby Mukendi
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
| | - Emmanuel Bottieau
- Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
| | - Jean Roger Kalo Lilo
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
| | - Kristien Verdonck
- Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
| | - Luigi Minikulu
- Hôpital Général de Mosango, Ministry of Health, Democratic Republic of the Congo.
| | - Barbara Barbé
- Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
| | - Philippe Gillet
- Institute of Tropical Medicine, Nationalestraat 155, Antwerp B-2000, Belgium.
| | | | | | - Pascal Lutumba
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
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418
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Palmer JJ, Robert O, Kansiime F. Including refugees in disease elimination: challenges observed from a sleeping sickness programme in Uganda. Confl Health 2017; 11:22. [PMID: 29213301 PMCID: PMC5710113 DOI: 10.1186/s13031-017-0125-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 10/04/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Ensuring equity between forcibly-displaced and host area populations is a key challenge for global elimination programmes. We studied Uganda's response to the recent refugee influx from South Sudan to identify key governance and operational lessons for national sleeping sickness programmes working with displaced populations today. A refugee policy which favours integration of primary healthcare services for refugee and host populations and the availability of rapid diagnostic tests (RDTs) to detect sleeping sickness at this health system level makes Uganda well-placed to include refugees in sleeping sickness surveillance. METHODS Using ethnographic observations of coordination meetings, review of programme data, interviews with sleeping sickness and refugee authorities and group discussions with health staff and refugees (2013-2016), we nevertheless identified some key challenges to equitably integrating refugees into government sleeping sickness surveillance. RESULTS Despite fears that refugees were at risk of disease and posed a threat to elimination, six months into the response, programme coordinators progressed to a sentinel surveillance strategy in districts hosting the highest concentrations of refugees. This meant that RDTs, the programme's primary surveillance tool, were removed from most refugee-serving facilities, exacerbating existing inequitable access to surveillance and leading refugees to claim that their access to sleeping sickness tests had been better in South Sudan. This was not intentionally done to exclude refugees from care, rather, four key governance challenges made it difficult for the programme to recognise and correct inequities affecting refugees: (a) perceived donor pressure to reduce the sleeping sickness programme's scope without clear international elimination guidance on surveillance quality; (b) a problematic history of programme relations with refugee-hosting districts which strained supervision of surveillance quality; (c) difficulties that government health workers faced to produce good quality surveillance in a crisis; and (d) reluctant engagement between the sleeping sickness programme and humanitarian structures. CONCLUSIONS Despite progressive policy intentions, several entrenched governance norms and practices worked against integration of refugees into the national sleeping sickness surveillance system. Elimination programmes which marginalise forced migrants risk unwittingly contributing to disease spread and reinforce social inequities, so new norms urgently need to be established at local, national and international levels.
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Affiliation(s)
- Jennifer J. Palmer
- Centre of African Studies, School of Social and Political Sciences, University of Edinburgh, 15a George Square, Edinburgh, EH8 9LD UK
- Health in Humanitarian Crises Centre, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT UK
| | - Okello Robert
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT UK
| | - Freddie Kansiime
- Department of Public and Community Health, Busitema University, PO Box 236, Tororo, Uganda
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419
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