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1. A non-stationary model for reconstruction of historical annual runoff on tropical catchments under increasing urbanization (Yaoundé, Cameroon)

Author

Benjamin Ngounou Ngatcha, Roger Moussa, Cécile Llovel, Jean-Pierre Bedimo Bedimo, Camille Jourdan, Armand Crabit, Jean-Jacques Braun, Jules Remy Ndam Ngoupayou, Valérie Borrell-Estupina, David Sebag, Eric Servat, Alain Fezeu, Sandra Van-Exter, François Colin, Observatoire de REcherche Méditerranéen de l'Environnement (OSU OREME), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Hydrosciences Montpellier (HSM), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Indo-French Cell for Water Sciences (IFCWS), Indian Institute of Science [Bangalore] (IISc Bangalore), Centre de Recherche Hydrologique, Institut de Recherche Géologique et Minière, Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), Institut de Recherche pour le Développement (IRD), Ginger Environnement, consultant, Laboratory MAT-IRD, University of Yaoundé [Cameroun], Département des Sciences de la Terre [Univ Ngaoundéré] (UN-FS), Faculté de Sciences [Univ Ngaoundéré] (UN-FS), Université de Ngaoundéré/University of Ngaoundéré [Cameroun] (UN)-Université de Ngaoundéré/University of Ngaoundéré [Cameroun] (UN), Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD [ Madagascar])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro), University of Yaounde I, Department of Geology, Department of Geology, University of Ngaoundere, Cameroon, Laboratoire d'étude des interactions entre sols, agrosystèmes et hydrosystèmes (LISAH), and Institut National de la Recherche Agronomique (INRA)

Subjects
Hydrology, geography, geography.geographical_feature_category, 0208 environmental biotechnology, Drainage basin, Hydrograph, Context (language use), 02 engineering and technology, 15. Life on land, Structural basin, Urban area, 020801 environmental engineering, Water balance, 13. Climate action, Urbanization, [SDE]Environmental Sciences, 11. Sustainability, Environmental science, Surface runoff
Abstract

Inter-tropical regions are nowadays faced to major land-use changes in data-sparse context leading to difficulties to assess hydrological signatures and their evolution. This work is part of the theme Panta Rhei of the IAHS, and aims to develop a combined approach of data acquisition and a new semi-distributed model taking into account land-use changes to reconstruct and predict annual runoff on an urban catchment. Applications were conducted on the Mefou catchment at Nsimalen (421 km2; Yaoundé, Cameroon) under rapid increase in urbanization since 1960. The data acquisition step combines an historical data processing and a short-term spatially-dense dedicated instrumentation (2017–2018), leading to 12 donor catchments, 6 from historical studies and 6 from the instrumentation presenting various topographic, soil and land-use characteristics. We developed an annual rainfall-runoff model based on mathematical relationships similar to the SCS model. The model needs the definition of a hydrological index I which is time variable and enables to take into account land-use changes and non-stationary relationships between rainfall and runoff. The index I is an empirical indicator defined as a combination of several components such as topography, soil, and land-use. The rules for the construction of I are obtained from data analysis on donor catchments. Then, the model was calibrated on donor catchments. Finally, two applications were conducted on eight target catchments composing the Mefou in order: (i) to study the spatial hydrological functioning and calculate the water balance during the short instrumentation period; (ii) to reconstruct the hydrograph at the Mefou and to simulate the impact of future scenarios of land-use and urbanization. Results show that that the Mfoundi catchment, integrating the three more urbanized sub-catchments, contributes near to 40 % of the Mefou despite covering only 23 % of the basin. The most urbanized sub-catchments present annual runoff coefficient about 0.86 against 0.24 for the most natural sub-catchments. The second result is the reconstruction of historical annual runoff from 1930–2017 with r2 = 0.68, RMSE = 99 mm and a mean absolute normalized error Ē = 14.5 % over the 29 observed years. The reconstruction of the annual runoff at Nsimalen confirms the moderate impact of urbanization on annual runoff before 1980. However, a decrease of about 50 % of the forest cover and an increase from 10 % to 35 % of the urban area between 1980 and 2017 are associated with an increase of 53 % of annual runoff coefficient for the Mefou at Nsimalen (0.44 against 0.29). Application for a fictive plausible scenario of urbanization in 2030 leads to an increase of more than 85 % of the annual runoff in comparison of the values observed in 1980. The coupled experimental-modelling approach proposed herein opens promising perspectives regarding the evaluation of the annual runoff in catchments under changes.

Published
2019
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2. A Worldwide Map of Plasmodium falciparum K13-Propeller Polymorphisms

Author

Benoit Witkowski, Hans-Peter Fuehrer, Garib Das Thakur, Céline Barnadas, Djibrine Djalle, Michael Ramharter, Mindy Leelawong, Wasif Ali-Khan, Harald Noedl, Bouasy Hongvanthong, Mohammad Shafiul-Alam, Hypolite Muhindo-Mavoko, Abdillahi Mohamed Hassan, Judith Straimer, Nimol Khim, Kigbafori D. Silué, Kaknika Loch, Barbara H. Stokes, Maria Dorina Bustos, Laura Berne, Dylan R. Pillai, Ayola A. Adegnika, Lin Hua Tang, Rotha Eam, Saorin Kim, Alioune Dieye, Mei Li, Carole E. Eboumbou-Moukoko, Lydie Canier, Marian Warsame, Didier Menard, David A. Fidock, Yap Boum, Lyndes Wini, Abdiqani Sheikh-Omar, Patrick Tshibangu-Wa-Tshibangu, Maman Laminou Ibrahim, Mohammad Jahirul-Karim, Malen Ken, Monique A. Dorkenoo, Sócrates Herrera, Odile Mercereau-Puijalon, Lise Musset, Valentine Duru, Eric Legrand, Maniphone Khanthavong, Pascal Ringwald, Bruno Pradines, Sandrine Houzé, Rachida Tahar, Olukemi K. Amodu, Johann Beghain, Sandie Menard, Liwang Cui, Colin J. Sutherland, Jun Hu Chen, Kesara Na-Bangchang, Khin Lin, Michael Nambozi, Rithea Leang, Jean Christophe Barale, Milijaona Randrianarivelojosia, Marcus V. G. Lacerda, Sophy Chy, Frédéric Ariey, Jean-Bosco Ouédraogo, Isabelle Morlais, Maria de Fátima Ferreira-da-Cruz, Lubin Jiang, Christophe Rogier, Jun Cao, Peter G. Kremsner, Bui Quang-Phuc, Inès Vigan-Womas, Din Syafruddin, Jetsumon Sattabongkot, Shigeyuki Kano, Abebe A. Fola, Louis Collet, Karamoko Niaré, Thierry Fandeur, Sedigheh Zakeri, Sodiomon B. Sirima, Antoine Berry, Jean Baptiste Mazarati, Fe Espino, Ghulam Rahim-Awab, Chanra Khean, Offianan Andre Toure, Institut Pasteur du Cambodge, Réseau International des Instituts Pasteur (RIIP), Génétique et Génomique des Insectes vecteurs, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Centre de Recherche Médicale de Lambaréné, Albert Schweitzer, Leiden University Medical Center (LUMC), Universiteit Leiden, International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), University of Ibadan, Nangarhar University, Mahidol University [Bangkok], The Walter and Eliza Hall Institute of Medical Research (WEHI), University of Melbourne, Papua New Guinea Institute for Medical Research (PNGIMR), Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Mbarara University of Science and Technology [Mbarara] (MUST), Epicentre Ouganda [Mbarara] [Médecins Sans Frontières], Epicentre [Paris] [Médecins Sans Frontières], World Health Organization (WHO), country office for Thailand, Organisation Mondiale de la Santé / World Health Organization Office (OMS / WHO), JiangSu University, National Institute of Parasitic Diseases, Center for Disease Control, China, Centre Hospitalier de Mayotte, Pennsylvania State University (Penn State), Penn State System, Epidemiology and Disease Control division (EDCD), Ministry of Public Health [Nepal], Institut Pasteur de Dakar, Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Institut Pasteur de Bangui, Université de Lomé [Togo], Université de Douala, Centre Pasteur du Cameroun, Research Institute for Tropical Medicine, Centre International de Recherches Médicales de Franceville (CIRMF), Fundação Oswaldo Cruz / Oswaldo Cruz Foundation (FIOCRUZ), University of Gondar, Institute of Parasitology [Vienna], University of Veterinary Medicine, Vienna, World Health Organisation (WHO), country office for Somalia, Caucaseco scientific research center = Centro de Investigación Científica Caucaseco, National Center for Malariology, Parasitology and Entomology, Ministry of Health [Mozambique], Hôpital Bichat - Claude Bernard, Mère et enfant en milieu tropical : pathogènes, système de santé et transition épidémiologique (MERIT - UMR_D 216), Institut de Recherche pour le Développement (IRD)-Université Paris Descartes - Paris 5 (UPD5), Centre de Recherche Médicale et Sanitaire (Niamey, Niger) (CERMES), Directorate General of Health Services (DGHS), Institut Pasteur de Shanghai, Académie des Sciences de Chine - Chinese Academy of Sciences (IPS-CAS), National Center for Global Health and Medicine [Japan] (NCGM), Institut Pasteur du Laos, Instituto Leônidas e Maria Deane - Fiocruz Amazônia [Manaus, Brésil] (ILMD), Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD), National Center for Malaria Control, Parasitology and Entomology, Ministry of Health of Cambodgia, Henry M. Jackson Foundation for the Advancement of Military Medicine (HJM), U.S. Naval Medical Research, The Department of Medical Research (Upper Myanmar), Rwanda Biomedical Center (RBC), Centre de Physiopathologie Toulouse Purpan (CPTP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), Institut de Recherche pour le Développement (IRD), University of Kinshasa (UNIKIN), University of Antwerp (UA), Institut Pasteur de la Guyane, Thammasat University (TU), Tropical Diseases Research Center (TDRC), Université de Bamako, Medizinische Universität Wien = Medical University of Vienna, Institut de Recherche en Sciences de la Santé (IRSS) / Centre Muraz, Medicines for Malaria Venture (MMV), Université de Genève = University of Geneva (UNIGE), Global Malaria Programme, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR48, Institut des sciences biologiques (INSB-CNRS)-Institut des sciences biologiques (INSB-CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de Référence du Paludisme, Institut Pasteur de Madagascar, Ministry of Health and Human Services [Somalia], Centre Suisse de Recherches Scientifiques en Cote d'Ivoire [Abidjan] (CSRS-CI), Université Félix Houphouët-Boigny (UFHB), Groupe de recherche action en santé (GRAS), London School of Hygiene and Tropical Medicine (LSHTM), University of Hasanuddin, Eijkman Institute for Molecular Biology [Jakarta], Institut Pasteur de Côte d'Ivoire, Ministry of Health and Medical Services, Institut Pasteur d'Iran, Centre National de Référence du Paludisme [Cayenne, Guyane française] (CNR - laboratoire associé), Microbiologie structurale - Structural Microbiology (Microb. Struc. (UMR_3528 / U-Pasteur_5)), Institut Pasteur [Paris] (IP)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Columbia University Irving Medical Center (CUIMC), Institut de Recherche Biomédicale des Armées [Antenne Marseille] (IRBA), AP-HP - Hôpital Cochin Broca Hôtel Dieu [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Paris Descartes - Paris 5 (UPD5), Supported by the Institut Pasteur Paris, Institut Pasteur International Division, Institut Pasteur Cambodia, and the World Health Organization, by a grant (ANR-10-LABX-62-IBEID) from the French Government Investissement d’Avenir program, Laboratoire d’Excellence 'Integrative Biology of Emerging Infectious Diseases', a grant from Natixis Banques, a grant (R01I109023, to Dr. Fidock) from the National Institutes of Health, grants from the Fiocruz Fundação Oswaldo Cruz, Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Fundação de Amparo à Pesquisa do Estado do Amazonas, the Brazilian National Council for Scientific and Technological Development, the Agence Nationale de la Recherche (13-BSV3-0018-01 and11-BSV7-009-01), the Austrian Federal Ministry of Science, Research, and Econo-my, the Calgary Laboratory Services, the Centre International de Recherches Médicales de Franceville, the European and Developing Countries Clinical Trials Partnership (CT-2004-31070-001), the Drugs for Neglected Diseases Initiative, the Else Kroener Fresenius Stiftung, the Holger Poehlmann Stiftung, the European Community African–European Research Initiative 'IDEA' (HEALTH-F3-2009-241642), the Fonds Wetenschappelijk Onderzoek, the Vlaamse Interuniversitaire Raad–Universitaire Ontwikkelingssamenwerking, the Belgian Technical Cooperation in Democratic Republic of Congo, the European Community Seventh Framework Program (FP7/2007-2013, 242095, and 223601), the European Commission (REGPOT-CT-2011-285837-STRONGER), the Ministère de la Santé Publique du Niger (Laboratoire National de Référence Résistance aux Antipaludiques), the Foundation of National Science and Technology Major Program (2012ZX10004-220), the French Ministry of Health (Institut National de Veille Sanitaire), the Global Fund to Fight AIDS, Tuberculosis and Malaria, the 5% Initiative program (French Ministry of Foreign Affairs, France Expertise Internationale, 12INI109), the Institut Pasteur de Madagascar, the Government of the Philippines, the Institut de Recherche pour le Développement, the Foundation des Treilles, the Délégation Générale pour l’Armement (PDH-2-NRBC-4-B1-402), the Institut Pasteur de Bangui, the International Society for Health Research and Training, the Malaria Research Initiative Bandarban, Vienna, International Centre for Diarrhoeal Disease Research, Bangladesh, the Médecins sans Frontières (Centre Opérationnel Paris, France), Medicines for Malaria Venture, the National Research Council of Thailand, the Thammasat University, the National Natural Science Foundation of China (81271870, 81361120405, and 81271863), the Natural Science Foundation of Jiangsu Province (BK20130114 and BK20150001), the Jiangsu Science and Technology Department (BM2015024), the National Institutes of Health (R01 AI11646601, AI109023, and ICEMR U19AI089702, U19AI089672), the Pasteur Institute of Iran, the Malaria Division of the Iranian Center for Diseases Management and Control, Public Health England (Malaria Reference Service Contract), the Government of Rwanda, the U.S. Department of Defense Armed Forces Health Surveillance Center, Global Emerging Infections Surveillance and Response System (P0463-14-N6), the Fogarty International Center of the National Institutes of Health training (D43 TW007393), the Mahidol-Oxford Research Unit, the Government of Japan (Science and Technology Agency, Agency for Medical Research and Development, Japan International Cooperation Agency, and Science and Technology Research Partnership for Sustainable Development), and the President’s Malaria Initiative of the U.S. Agency for International Development., The KARMA Consortium, ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-13-BSV3-0018,MALARTRES,Résistance de Plasmodium aux antipaludiques de la famille des artémisinines(2013), ANR-13-BSV7-0009,NEBEDIV,Le rôle des ennemis naturels dans la diversité béta des arbres tropicaux(2013), European Project: CT-2004-31070-001,EDCCTP, European Project: HEALTH-F3-2009-24164,IDEA, European Project: FP7/2007-2013, 24209,FP7, European Project: FP7/2007-2013, 22360,FP7, European Project: 285837,EC:FP7:REGPOT,FP7-REGPOT-2011-1,STRONGER(2011), European Project: 242095,EC:FP7:HEALTH,FP7-HEALTH-2009-single-stage,EVIMALAR(2009), European Project: 223601,EC:FP7:HEALTH,FP7-HEALTH-2007-B,MALVECBLOK(2009), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), CHU Toulouse [Toulouse], Fundação Oswaldo Cruz (FIOCRUZ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), INSB-INSB-Centre National de la Recherche Scientifique (CNRS), Centre National de Référence du Paludisme [Cayenne, Guyane française] (CNR), Université Paris Diderot - Paris 7 (UPD7)-Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Eberhard Karls Universität Tübingen, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia., Centre International de Recherches Médicales de Franceville, Caucaseco scientific research center, Mère et enfant face aux infections tropicales (MERIT - UMR_D 216), National Center for Global Health and Medicine (NCGM), Instituto Leônidas e Maria Deane (ILMD), Centre de Physiopathologie Toulouse Purpan ex IFR 30 et IFR 150 (CPTP), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement [Yaoundé], Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Eijkman Institute for Molecular Biology, Laboratoire de Parasitologie, Centre National de Référence du Paludisme - Région Antilles-Guyane, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-WHO Collaborating Center for Surveillance of Antimalarial Drug Resistance, Institut Pasteur [Paris]-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-62-IBEID,IBEID,Laboratoire d'Excellence 'Integrative Biology of Emerging Infectious Diseases'(2010), Van geertruyden, Jean-Pierre, and KARMA Consortium

Subjects
0301 basic medicine, Nonsynonymous substitution, MESH: Sequence Analysis, DNA, Endemic Diseases, MESH: Asia, Southeastern, Drug Resistance, Protozoan Proteins, Drug resistance, MESH: Genotype, Lactones, 0302 clinical medicine, Genotype, Artemisinin, Malaria, Falciparum, MESH: Protozoan Proteins, Asia, Southeastern, MESH: Plasmodium falciparum, Genetics, biology, MESH: Malaria, Falciparum, General Medicine, Artemisinins, MESH: China, 3. Good health, MESH: Endemic Diseases, MESH: Drug Resistance, Algorithms, MESH: Lactones, medicine.drug, China, MESH: Mutation, 030231 tropical medicine, 030106 microbiology, Plasmodium falciparum, MESH: Algorithms, 03 medical and health sciences, parasitic diseases, MESH: Artemisinins, MESH: Polymorphism, Genetic, medicine, Humans, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, Allele, Polymorphism, Genetic, MESH: Humans, Haplotype, Sequence Analysis, DNA, medicine.disease, biology.organism_classification, Virology, Mutation, Human medicine, Malaria
Abstract

Comment inK13-Propeller Mutations and Malaria Resistance, http://www.nejm.org/doi/full/10.1056/NEJMe1604520; International audience; BACKGROUND:Recent gains in reducing the global burden of malaria are threatened by the emergence of Plasmodium falciparum resistance to artemisinins. The discovery that mutations in portions of a P. falciparum gene encoding kelch (K13)-propeller domains are the major determinant of resistance has provided opportunities for monitoring such resistance on a global scale.METHODS:We analyzed the K13-propeller sequence polymorphism in 14,037 samples collected in 59 countries in which malaria is endemic. Most of the samples (84.5%) were obtained from patients who were treated at sentinel sites used for nationwide surveillance of antimalarial resistance. We evaluated the emergence and dissemination of mutations by haplotyping neighboring loci.RESULTS:We identified 108 nonsynonymous K13 mutations, which showed marked geographic disparity in their frequency and distribution. In Asia, 36.5% of the K13 mutations were distributed within two areas--one in Cambodia, Vietnam, and Laos and the other in western Thailand, Myanmar, and China--with no overlap. In Africa, we observed a broad array of rare nonsynonymous mutations that were not associated with delayed parasite clearance. The gene-edited Dd2 transgenic line with the A578S mutation, which expresses the most frequently observed African allele, was found to be susceptible to artemisinin in vitro on a ring-stage survival assay.CONCLUSIONS:No evidence of artemisinin resistance was found outside Southeast Asia and China, where resistance-associated K13 mutations were confined. The common African A578S allele was not associated with clinical or in vitro resistance to artemisinin, and many African mutations appear to be neutral. (Funded by Institut Pasteur Paris and others.).

Published
2016
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3. Chikungunya Virus, Cameroon, 2006

Author

Olivier L. Merle, Patrice Tchendjou, Boris Pastorino, Helene Mansaray, Marc Grandadam, Régis Pouillot, Aurélia Vessière, Hugues Tolou, Patrice Imbert, Christophe N. Peyrefitte, Fabienne Tock, Maël Bessaud, Jean-Paul Durand, Dominique Rousset, Christophe Paupy, Aurélie Pascual, Institut de Médecine Tropicale du Service de Santé des Armées (IMTSSA), Service de Santé des Armées, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur (RIIP), Hôpital Central de Yaoundé [Yaoundé], Hôpital d'Instruction des Armées Begin, Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), and Institut de Recherche pour le Développement (IRD)

Subjects
Male, Epidemiology, viruses, lcsh:Medicine, medicine.disease_cause, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, Serology, Disease Outbreaks, 0302 clinical medicine, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, alphavirus, Chikungunya, Cameroon, Child, Phylogeny, 0303 health sciences, education.field_of_study, [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, Dispatch, virus diseases, Middle Aged, 3. Good health, Infectious Diseases, Child, Preschool, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, Female, Chikungunya virus, Microbiology (medical), Adult, 030231 tropical medicine, Population, Biology, Disease cluster, Virus, lcsh:Infectious and parasitic diseases, 03 medical and health sciences, parasitic diseases, medicine, Humans, lcsh:RC109-216, Serologic Tests, Alphavirus infection, education, 030304 developmental biology, Alphavirus Infections, lcsh:R, Outbreak, Central africa, Infant, medicine.disease, Virology, arbovirus, Dengue viruses
Abstract

International audience; We report the isolation of chikungunya virus from a patient during an outbreak of a denguelike syndrome in Cameroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa.

Published
2007
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4. Molecular Species Delimitation and Morphology of Aquatic and Sub-Aquatic Bugs (Heteroptera) in Cameroon

Author

Pingping Chen, Dominique Pluot-Sigwalt, E. Petit, Nico Nieser, Eric Guilbert, Sara Eyangoh, Solange Meyin A Ebong, Philippe Le Gall, Myriam Harry, Laurent Marsollier, Jean-François Guégan, Flobert Njiokou, Université de Yaoundé I, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur (RIIP), Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), Institut de Recherche pour le Développement (IRD), Évolution, génomes, comportement et écologie (EGCE), Université Paris-Sud - Paris 11 (UP11)-IRD-Centre National de la Recherche Scientifique (CNRS), National Museum of Natural History - Leiden, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Cancérologie Nantes-Angers (CRCNA), Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Nantes Angers Le Mans (UNAM)-Hôtel-Dieu de Nantes-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Laennec-Centre National de la Recherche Scientifique (CNRS)-Faculté de Médecine d'Angers-Centre hospitalier universitaire de Nantes (CHU Nantes), Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Bernardo, Elizabeth, Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Génétique et évolution des maladies infectieuses (GEMI), and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE)

Subjects
Bacterial Diseases, Male, 0106 biological sciences, 0301 basic medicine, Aquatic Organisms, Species Delimitation, Molecular biology, Speciation, Biodiversity, lcsh:Medicine, 01 natural sciences, DNA barcoding, Geographical Locations, Medicine and Health Sciences, Nepomorpha, Cameroon, lcsh:Science, Buruli Ulcer, Phylogeny, Data Management, Molecular systematics, Multidisciplinary, Ecology, biology, Heteroptera, Infectious Diseases, Female, Taxonomy (biology), Research Article, Neglected Tropical Diseases, Computer and Information Sciences, Multiple Alignment Calculation, Evolutionary Processes, Evolutionary systematics, Zoology, [SDV.CAN]Life Sciences [q-bio]/Cancer, Research and Analysis Methods, 010603 evolutionary biology, 03 medical and health sciences, [SDV.CAN] Life Sciences [q-bio]/Cancer, Phylogenetics, Computational Techniques, Animals, DNA Barcoding, Taxonomic, Nymph, Taxonomy, Evolutionary Biology, Metamorphosis, Ecology and Environmental Sciences, lcsh:R, Biology and Life Sciences, DNA, Tropical Diseases, biology.organism_classification, Split-Decomposition Method, Nymphs, Molecular biology techniques, 030104 developmental biology, People and Places, Africa, lcsh:Q, Gerromorpha, Sequence Alignment, Developmental Biology
Abstract

International audience; Aquatic and semi-aquatic bugs (Heteroptera) represent a remarkable diversity and a resurging interest has been given to documenting at the species level these insects inhabiting Cameroon in Central Africa due to their potential implication in the transmission of the bacterium Mycobacterium ulcerans, the causal agent of Buruli ulcer, an emerging human disease. A survey was carried out over two years in Cameroon. Morphological analyses were done in two steps. A first step consisted in separating the specimens based on broadly shared characters into morphotypes. The specimens were then separated into two independent batches containing each the same representation of each morphotype. One batch (309 specimens) was used by taxonomy experts on aquatic bugs for species level identification and/or to reconcile nymph with their corresponding adult species. The second batch (188 specimens) was used to define species based on the COI DNA sequences (standard sequence used for "DNA barcoding") and using the Automatic Barcode Gap Discovery (ABGD) method. The first morphological analysis step separated the specimens into 63 different morphotypes (49 adults and 14 nymphs), which were then found to belong to 54 morphological species in the infra-orders Gerromorpha and Nepomorpha based on the species-level morphological identification, and 41-45 putative molecular species according to the gap value retained in the ABGD. Integrating morphology and "DNA barcoding" reconciled all the specimens into 62 aquatic bug species in Cameroon. Generally, we obtained a good congruence between species a priori identified based on morphology from adult morphotypes and molecular putative species. Moreover, molecular identification has allowed the association of 86% of nymphs with adults. This work illustrates the importance of integrative taxonomy.

Published
2015
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5. Geographic expansion of Buruli ulcer disease, Cameroon

Author

Pascal Boisier, Philippe Le Gall, Arnaud Fontanet, Jordi Landier, Alphonse Umboock, Sara Eyangoh, Laurent Marsollier, Noumen Djeunga, Jacques Aubry, Estelle Marion, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur (RIIP), Institut Pasteur [Paris] (IP), Université d'Angers (UA), Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), Institut de Recherche pour le Développement (IRD), Université de Nantes (UN), Hôpital de District de Bankim [Bankim, Cameroon] (HDB), Aide aux Lépreux Emmaüs Suisse [Yaoundé, Cameroon] (ALES), International des Instituts Pasteurs (PTR212, Inter-Pasteurien Concerted Actions)the foundation Pierre LedouxJeunesse International, the Fondation Raoul Follereau, Institut National de la Recherche Médicalethe Conférence des Présidents d’Université–Institut de Recherche pour le Développement (IRD) project (Jeune Equipe Associé à l’IRDAtomyc), marion, estelle, and Institut Pasteur [Paris]

Subjects
Male, Buruli ulcer, Veterinary medicine, Epidemiology, Bankim, lcsh:Medicine, 0302 clinical medicine, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Cameroon, Child, bacteria, ComputingMilieux_MISCELLANEOUS, Nepidae, 0303 health sciences, education.field_of_study, Naucoridae, biology, Ecology, Incidence (epidemiology), Heteroptera, 3. Good health, Belostomatidae, Infectious Diseases, Mycobacterium ulcerans, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Female, Adult, Microbiology (medical), Adolescent, 030231 tropical medicine, Population, letter, lcsh:Infectious and parasitic diseases, Young Adult, 03 medical and health sciences, medicine, Animals, Humans, lcsh:RC109-216, Letters to the Editor, education, heteroptera, 030304 developmental biology, 030306 microbiology, lcsh:R, Mycobacterium infections/epidemiology, biology.organism_classification, medicine.disease, Insect Vectors, tuberculosis and other mycobacteria, [SDE.BE] Environmental Sciences/Biodiversity and Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract

To the Editor: Buruli ulcer disease (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans that affects mostly children in humid, tropical areas (1). The exact mode of M. ulcerans transmission remains unclear, although the role of water bugs has been supported by various observations and experimental studies (2,3). We report the identification of a new BU-endemic area in Cameroon, the Bankim district, and specify ecologic and clinical characteristics of M. ulcerans infection in this area. These characteristics hint at the possible role of environmental changes (building of a dam several years ago) in the expansion of BU in this area. Since 1969, only 1 BU-endemic area in Cameroon has been described: the Nyong River basin, where equatorial forest predominates (4). In 2004, clinically suspected cases of BU in the district of Bankim have been reported (5). This region differs from the first BU-endemic area by geography and climate. Representing a transition between forested south and savanna north, this area has benefited from the building of a dam on the Mape River in 1989, which created an artificial lake of 3.2 billion m3 capacity. From January 2007 through June 2009, all cases of skin lesions evocative of active BU were recorded as BU probable cases according to World Health Organization guidelines (6). During this period, 195 clinically suspected cases were reported from the Bankim health district (Figure). The overall median age for these 195 patients was 19.5 years (interquartile range 10–37 years). No significant difference in age was found according to gender, but a significant trend of decreasing overall median age was found (20 years in 2007 to 12 years in 2009. The most frequent type of lesion was ulcer. Since March 2009, the Centre Pasteur of Cameroon has performed laboratory confirmation for suspected BU cases: microscopic examination for acid-fast bacilli, culture, and M. ulcerans DNA detection by PCR (6). From April through June 2009, of 34 consecutive samples tested in the reference laboratory, 10 were positive for M. ulcerans by at least microscopy and PCR. Figure Distribution of Buruli ulcer (BU) patients reported January 2007–June 2009, and of water bodies with aquatic bugs harboring Mycobacterium ulcerans, Cameroon. Inset, Bankim area. A color version of this figure is available online (www.cdc.gov/EID/content/17/3/551-F.htm ... Whether BU is emerging in Bankim or is just a newly recognized preexisting disease is difficult to establish. However, that the incidence of BU in the region is increasing is unquestionable. The decreasing median age of patients since 2007 might be consistent with emergence of BU as a new disease in Bankim. This observation could suggest either an increasing level of acquired immunity in the population, leading to protection correlated with age, or the expansion of risky sites for human infection with M. ulcerans. During 1 week in January 2008, water bugs were collected from the artificial lake and water bodies located within or close to each community. A previously described sampling method was used (2). To detect M. ulcerans DNA, we pooled the insects per family in groups of up to 10. Moreover, 99 members of the families Belostomatidae and Naucoridae were kept alive for saliva collection (2). The DNA of insect pool homogenized tissues and individual saliva samples were purified. We then searched for M. ulcerans molecular signatures (2). Among 1,349 insect specimens, 8 from the aquatic Heteroptera families were identified, and 12 (5%) of 244 insect pools were M. ulcerans positive. M. ulcerans–positive saliva was found in 11 (18%) of 61 insects in the family Belostomatidae and in 3 (8%) of 38 in the family Naucoridae. Water bodies where M. ulcerans–positive insects were collected are shown in the Figure. The emergence of BU may be a consequence of the marked changes in the environment caused by the building of the dam. Elsewhere, human environmental modifications such as construction of dams have been linked with increased incidence of BU (1). The main visible environmental effect is the large amount of flooded farmland. According to the seasons, the reservoir margins change the milieu of swamps and meadows. All these modifications affect plant and animal resources in the reservoir area by favoring rapid growth of aquatic macrophyte populations during reservoir filling, thus providing breeding sites for insects and leading to the extinction of area-endemic species and creation of new niches (7). These changes might favor development of M. ulcerans in biofilms on aquatic plants, which are then ingested by herbivorous animals, which are further prey for water bug predators, hosts, and possible vectors of M. ulcerans (8,9). The water bugs that were most frequently trapped and colonized by M. ulcerans (families Belostomatidae, Naucoridae, Nepidae, Notonectidae) are carnivorous and able to bite humans (10). Our study confirms expansion of BU in Cameroon. To facilitate detection of new BU foci, and to improve patient treatment (medical, surgical, rehabilitative), health care workers involved in tuberculosis/leprosy control programs should be educated about BU.

Published
2011
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6. Age-structured gametocyte allocation links immunity to epidemiology in malaria parasites

Author

Christian Boudin, Timoléon Tchuinkam, Sarah Bonnet, Richard Paul, Vincent Robert, Unité d'Entomologie Médicale [Dakar] (UEM), Institut Pasteur de Dakar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Génétique de la Réponse aux Infections chez l'Homme, Institut Pasteur [Paris], Institut de Recherche pour le Développement [Yaoundé, Cameroun] (IRD [Cameroun]), Institut de Recherche pour le Développement (IRD), Interactions Hôte-Parasite-Milieu (IHPM), Ecole Nationale Vétérinaire de Nantes-Institut National de la Recherche Agronomique (INRA), Institut de recherche pour le développement (IRD [Sénégal]), Muséum national d'Histoire naturelle (MNHN), This work was supported by the Strategic Anopheles Horizontal Research Programme, Institut Pasteur., Institut Pasteur [Paris] (IP), and Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire de Nantes

Subjects
Rural Population, Time Factors, Urban Population, [SDV]Life Sciences [q-bio], Parasitemia, law.invention, 0302 clinical medicine, law, Parasite hosting, Cameroon, Malaria, Falciparum, Child, WESTERN KENYA, 0303 health sciences, Natural selection, Age Factors, 3. Good health, MOSQUITO, Transmission (mechanics), Infectious Diseases, Phenotype, Child, Preschool, POPULATIONS, SEX-RATIOS, Adult, Opinion, lcsh:Arctic medicine. Tropical medicine, Adolescent, TRANSMISSION, lcsh:RC955-962, 030231 tropical medicine, Plasmodium falciparum, Zoology, Biology, Models, Biological, lcsh:Infectious and parasitic diseases, Host-Parasite Interactions, 03 medical and health sciences, parasitic diseases, medicine, Gametocyte, Animals, Humans, INFECTIVITY, lcsh:RC109-216, Selection, Genetic, 030304 developmental biology, SRI-LANKA, PLASMODIUM-FALCIPARUM MALARIA, PAPUA-NEW-GUINEA, ANOPHELES-GAMBIAE, Reproductive success, Infant, medicine.disease, biology.organism_classification, Insect Vectors, Malaria, Culicidae, Germ Cells, Immunology, Parasitology
Abstract

Background Despite a long history of attempts to model malaria epidemiology, the over-riding conclusion is that a detailed understanding of host-parasite interactions leading to immunity is required. It is still not known what governs the duration of an infection and how within-human parasite dynamics relate to malaria epidemiology. Presentation of the hypothesis Immunity to Plasmodium falciparum develops slowly and requires repeated exposure to the parasite, which thus generates age-structure in the host-parasite interaction. An age-structured degree of immunity would present the parasite with humans of highly variable quality. Evolutionary theory suggests that natural selection will mould adaptive phenotypes that are more precise (less variant) in "high quality" habitats, where lifetime reproductive success is best. Variability in malaria parasite gametocyte density is predicted to be less variable in those age groups who best infect mosquitoes. Thus, the extent to which variation in gametocyte density is a simple parasite phenotype reflecting the complex within-host parasite dynamics is addressed. Testing the hypothesis Gametocyte densities and corresponding infectiousness to mosquitoes from published data sets and studies in both rural and urban Cameroon are analysed. The mean and variation in gametocyte density according to age group are considered and compared with transmission success (proportion of mosquitoes infected). Across a wide range of settings endemic for malaria, the age group that infected most mosquitoes had the least variation in gametocyte density, i.e. there was a significant relationship between the variance rather than the mean gametocyte density and age-specific parasite transmission success. In these settings, the acquisition of immunity over time was evident as a decrease in asexual parasite densities with age. By contrast, in an urban setting, there were no such age-structured relationships either with variation in gametocyte density or asexual parasite density. Implications of the hypothesis Gametocyte production is seemingly predicted by evolutionary theory, insofar as a reproductive phenotype (gametocyte density) is most precisely expressed (i.e. is most invariant) in the most infectious human age group. This human age group would thus be expected to be the habitat most suitable for the parasite. Comprehension of the immuno-epidemiology of malaria, a requisite for any vaccine strategies, remains poor. Immunological characterization of the human population stratified by parasite gametocyte allocation would be a step forward in identifying the salient immunological pathways of what makes a human a good habitat.

Published
2007
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