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Suh E, Stopard IJ, Lambert B, Waite JL, Dennington NL, Churcher TS, Thomas MB. Estimating the effects of temperature on transmission of the human malaria parasite, Plasmodium falciparum. Nat Commun 2024; 15:3230. [PMID: 38649361 PMCID: PMC11035611 DOI: 10.1038/s41467-024-47265-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
Despite concern that climate change could increase the human risk to malaria in certain areas, the temperature dependency of malaria transmission is poorly characterized. Here, we use a mechanistic model fitted to experimental data to describe how Plasmodium falciparum infection of the African malaria vector, Anopheles gambiae, is modulated by temperature, including its influences on parasite establishment, conversion efficiency through parasite developmental stages, parasite development rate, and overall vector competence. We use these data, together with estimates of the survival of infected blood-fed mosquitoes, to explore the theoretical influence of temperature on transmission in four locations in Kenya, considering recent conditions and future climate change. Results provide insights into factors limiting transmission in cooler environments and indicate that increases in malaria transmission due to climate warming in areas like the Kenyan Highlands, might be less than previously predicted.
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Affiliation(s)
- Eunho Suh
- Center for Infectious Disease Dynamics, Department of Entomology, The Pennsylvania State University, University Park, PA, USA.
| | - Isaac J Stopard
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Ben Lambert
- Department of Statistics, University of Oxford, Oxford, UK
| | - Jessica L Waite
- Center for Infectious Disease Dynamics, Department of Entomology, The Pennsylvania State University, University Park, PA, USA
- Research Development, University of Vermont, Burlington, VT, USA
| | - Nina L Dennington
- Center for Infectious Disease Dynamics, Department of Entomology, The Pennsylvania State University, University Park, PA, USA
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Matthew B Thomas
- Center for Infectious Disease Dynamics, Department of Entomology, The Pennsylvania State University, University Park, PA, USA
- Department of Biology, University of York, York, UK
- Invasion Science Research Institute and Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
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Boruah AP, Thakur KT. Arthropod-borne encephalitis: an overview for the clinician and emerging considerations. Postgrad Med J 2023; 99:826-833. [PMID: 37130817 PMCID: PMC10464853 DOI: 10.1136/pmj-2022-142002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/18/2022] [Indexed: 11/04/2022]
Abstract
The rapid spread of arboviral infections in recent years has continually established arthropod-borne encephalitis to be a pressing global health concern. Causing a wide range of clinical presentations ranging from asymptomatic infection to fulminant neurological disease, the hallmark features of arboviral infection are important to clinically recognise. Arboviral infections may cause severe neurological presentations such as meningoencephalitis, epilepsy, acute flaccid paralysis and stroke. While the pathogenesis of arboviral infections is still being investigated, shared neuroanatomical pathways among these viruses may give insight into future therapeutic targets. The shifting infection transmission patterns and evolving distribution of arboviral vectors are heavily influenced by global climate change and human environmental disruption, therefore it is of utmost importance to consider this potential aetiology when assessing patients with encephalitic presentations.
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Affiliation(s)
- Abhilasha Pankaj Boruah
- Department of Neurology, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, USA
- Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Kiran T Thakur
- Department of Neurology, NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, USA
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Brown JJ, Pascual M, Wimberly MC, Johnson LR, Murdock CC. Humidity - The overlooked variable in the thermal biology of mosquito-borne disease. Ecol Lett 2023; 26:1029-1049. [PMID: 37349261 DOI: 10.1111/ele.14228] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/05/2023] [Indexed: 06/24/2023]
Abstract
Vector-borne diseases cause significant financial and human loss, with billions of dollars spent on control. Arthropod vectors experience a complex suite of environmental factors that affect fitness, population growth and species interactions across multiple spatial and temporal scales. Temperature and water availability are two of the most important abiotic variables influencing their distributions and abundances. While extensive research on temperature exists, the influence of humidity on vector and pathogen parameters affecting disease dynamics are less understood. Humidity is often underemphasized, and when considered, is often treated as independent of temperature even though desiccation likely contributes to declines in trait performance at warmer temperatures. This Perspectives explores how humidity shapes the thermal performance of mosquito-borne pathogen transmission. We summarize what is known about its effects and propose a conceptual model for how temperature and humidity interact to shape the range of temperatures across which mosquitoes persist and achieve high transmission potential. We discuss how failing to account for these interactions hinders efforts to forecast transmission dynamics and respond to epidemics of mosquito-borne infections. We outline future research areas that will ground the effects of humidity on the thermal biology of pathogen transmission in a theoretical and empirical framework to improve spatial and temporal prediction of vector-borne pathogen transmission.
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Affiliation(s)
- Joel J Brown
- Department of Entomology, Cornell University, Ithaca, New York, USA
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, USA
| | - Michael C Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, USA
| | - Leah R Johnson
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
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Tian H, Li N, Li Y, Kraemer MUG, Tan H, Liu Y, Li Y, Wang B, Wu P, Cazelles B, Lourenço J, Gao D, Sun D, Song W, Li Y, Pybus OG, Wang G, Dye C. Malaria elimination on Hainan Island despite climate change. COMMUNICATIONS MEDICINE 2022; 2:12. [PMID: 35603266 PMCID: PMC9053252 DOI: 10.1038/s43856-022-00073-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 01/11/2022] [Indexed: 11/09/2022] Open
Abstract
Background Rigorous assessment of the effect of malaria control strategies on local malaria dynamics is a complex but vital step in informing future strategies to eliminate malaria. However, the interactions between climate forcing, mass drug administration, mosquito control and their effects on the incidence of malaria remain unclear. Methods Here, we analyze the effects of interventions on the transmission dynamics of malaria (Plasmodium vivax and Plasmodium falciparum) on Hainan Island, China, controlling for environmental factors. Mathematical models were fitted to epidemiological data, including confirmed cases and population-wide blood examinations, collected between 1995 and 2010, a period when malaria control interventions were rolled out with positive outcomes. Results Prior to the massive scale-up of interventions, malaria incidence shows both interannual variability and seasonality, as well as a strong correlation with climatic patterns linked to the El Nino Southern Oscillation. Based on our mechanistic model, we find that the reduction in malaria is likely due to the large scale rollout of insecticide-treated bed nets, which reduce the infections of P. vivax and P. falciparum malaria by 93.4% and 35.5%, respectively. Mass drug administration has a greater contribution in the control of P. falciparum (54.9%) than P. vivax (5.3%). In a comparison of interventions, indoor residual spraying makes a relatively minor contribution to malaria control (1.3%–9.6%). Conclusions Although malaria transmission on Hainan Island has been exacerbated by El Nino Southern Oscillation, control methods have eliminated both P. falciparum and P. vivax malaria from this part of China. Several malaria control strategies have been implemented on Hainan Island, China, and it is important to determine which of these have been effective to guide future efforts to control malaria. Here, we use mathematical and statistical methods to assess the effectiveness of control methods using data on malaria cases on Hainan, considering the impact of climate change simultaneously, since malaria transmission is affected by the climate. We observe time-related trends in malaria incidence and a strong relationship with climate before the large-scale rollout of malaria control interventions. We find that insecticide-treated bed nets are the most effective strategy in decreasing malaria incidence, while mass drug administration and indoor residual spraying also contribute to malaria control. Our findings provide evidence that a combination of strategies reduces the burden of malaria in affected regions. Tian et al. use mathematical modelling to estimate the impact of various interventions on malaria incidence on Hainan Island, also taking into account climate change. They find that although malaria transmission has been exacerbated by climate change, insecticide-treated bed nets and other interventions were effective in controlling the disease.
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Atanu FO, Rotimi D, Ilesanmi OB, Al Malki JS, Batiha GE, Idakwoji PA. Hydroethanolic Extracts of Senna alata Leaves Possess Antimalarial Effects and Reverses Haematological and Biochemical Pertubation in Plasmodium berghei-infected Mice. J Evid Based Integr Med 2022; 27:2515690X221116407. [PMID: 35929106 PMCID: PMC9358563 DOI: 10.1177/2515690x221116407] [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] [Indexed: 11/23/2022] Open
Abstract
The current work investigated the chemical profile, antimalarial potential and capacity of hydroethanolic Senna alata extract (SAE) to reverse hematological and biochemical pertubation in Plasmodium berghei infected mice. Results of the phytochemical analysis revealed the presence of alkaloids, flavonoids, phenolics, tannins, terpenoids, saponins, steroids and cardiac glycosides. Total phenolic and flavonoid content was estimated to be 45.29 ± 2.34 mg GAE/g and 25.22 ± 2.26 mg QE/g respectively. In vitro analysis of the extract also confirmed its antioxidant property. Results of the test for prophylaxis of P. berghei indicated that SAE suppressed parasitemia significantly in treated groups in a dose dependent manner when compared with negative control group. Similarly, SAE improved the mean survival time (MST) and packed cell volume (PCV) of infected mice. The test for curative effect showed that SAE significantly suppressed parasitemia to 4.50 ± 1.05% compared to untreated group 29.83 ± 3.49%. Results of liver and kidney functions indices of treated animals indicated that whereas infection with P. berghei caused increase in the levels of AST, ALT, ALP, urea and creatinine, treatment with SAE significantly reversed the perturbation. Similarly, infected mice were dyslipidemic with concomitant increased activity of HMG CoA reductase and decreased activity of antioxidant enzymes with increase in lipid peroxides levels. However, these alterations were significantly reversed by administration of SAE. Results of this study shows that Senna alata possess antimalarial activity and therefore justify the traditional use of plant for the treatment of malaria.
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Affiliation(s)
- Francis O Atanu
- Department of Biochemistry, 223207Faculty of Natural Sciences, Kogi State University, Anyigba, Nigeria
| | - Damilare Rotimi
- Department of Biochemistry, Faculty of Pure and Applied Sciences, 233773Landmark University, Omu-Aran, Kwara State, Nigeria
| | - Omotayo B Ilesanmi
- Department of Biochemistry, Faculty of Science, Federal University Otuoke, Yenagoa, Bayelsa State, Nigeria
| | - Jamila S Al Malki
- Department of Biology, College of Sciences, 125895Taif University, Taif, Saudi Arabia
| | - Gaber E Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, 110146Damanhour University, Damanhour, Albeheira, Egypt
| | - Precious A Idakwoji
- Department of Biochemistry, 223207Faculty of Natural Sciences, Kogi State University, Anyigba, Nigeria
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SHAHANDEH K, BASSERI HR. Challenges and the Path Forward on Malaria Elimination Intervention: A Systematic Review. IRANIAN JOURNAL OF PUBLIC HEALTH 2019; 48:1004-1013. [PMID: 31341841 PMCID: PMC6635336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND This systematic review was conducted to highlights key challenges, and outlines important next steps to maximize the potential to contribute to the broader malaria elimination interventions. METHODS This systematic review on malaria elimination intervention and challenges was undertaken searching six databases, between 1995 and 2018. Inclusion and exclusion criteria were set. The references were collated and categorized according to type of study, intervention, population, and health outcome. Articles selection based on title and abstract, retrieval of full text and additions of articles from reference lists and recommendations from experts. Disagreement in data extraction was solved by consultation of third reviewer. RESULTS Overall, 4039 records were examined related to malaria elimination that initially identified by our designated electronic databases search. Overall, 35 studies contained 14 experimental studies (40%) and 21 analytic observational studies (60%) met the inclusion criteria for this review. Studies used a wide variety of malaria elimination interventions. Types of interventions either elimination-focused interventions or general interventions on educational, prevention and treatment of malaria are included. This review pointed out the variety of challenges for eliminate malaria among low and high endemic countries. CONCLUSION Malaria elimination is facilitated by strong health systems, determined leadership, appropriate incentivization, an effective surveillance system, and regional collaborations. We have identified areas for elimination-specific interventions deserve more attention in the conduct and reporting.
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Affiliation(s)
- Khandan SHAHANDEH
- Deputy of Research and Technology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Reza BASSERI
- Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Corresponding Author:
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7
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Campos M, Conn JE, Alonso DP, Vinetz JM, Emerson KJ, Ribolla PEM. Microgeographical structure in the major Neotropical malaria vector Anopheles darlingi using microsatellites and SNP markers. Parasit Vectors 2017; 10:76. [PMID: 28193289 PMCID: PMC5307779 DOI: 10.1186/s13071-017-2014-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 01/31/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In recent decades, throughout the Amazon Basin, landscape modification contributing to profound ecological change has proceeded at an unprecedented rate. Deforestation that accompanies human activities can significantly change aspects of anopheline biology, though this may be site-specific. Such local changes in anopheline biology could have a great impact on malaria transmission. The aim of this study was to investigate population genetics of the main malaria vector in Brazil, Anopheles darlingi, from a microgeographical perspective. METHODS Microsatellites and ddRADseq-derived single nucleotide polymorphisms (SNPs) were used to assess levels of population genetic structuring among mosquito populations from two ecologically distinctive agricultural settlements (~60 km apart) and a population from a distant (~700 km) urban setting in the western Amazon region of Brazil. RESULTS Significant microgeographical population differentiation was observed among Anopheles darlingi populations via both model- and non-model-based analysis only with the SNP dataset. Microsatellites detected moderate differentiation at the greatest distances, but were unable to differentiate populations from the two agricultural settlements. Both markers showed low polymorphism levels in the most human impacted sites. CONCLUSIONS At a microgeographical scale, signatures of genetic heterogeneity and population divergence were evident in Anopheles darlingi, possibly related to local environmental anthropic modification. This divergence was observed only when using high coverage SNP markers.
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Affiliation(s)
- Melina Campos
- Biotechnology Institute (IBTEC) & Biosciences Institute at Botucatu (IBB), Sao Paulo State University (UNESP), Sao Paulo, Brazil
| | - Jan E Conn
- Department of Biomedical Sciences, School of Public Health, University at Albany (State University of New York), Albany, NY, USA.,New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Diego Peres Alonso
- Biotechnology Institute (IBTEC) & Biosciences Institute at Botucatu (IBB), Sao Paulo State University (UNESP), Sao Paulo, Brazil
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California, La Jolla, San Diego, CA, USA.,Instituto de Medicina Tropical "Alexander von Humboldt," and Departamento de Ciencias Celulares y Moleculares, Laboratorio de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Kevin J Emerson
- Biology Department, St. Mary's College of Maryland, St. Mary's City, MD, USA
| | - Paulo Eduardo Martins Ribolla
- Biotechnology Institute (IBTEC) & Biosciences Institute at Botucatu (IBB), Sao Paulo State University (UNESP), Sao Paulo, Brazil.
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Kibret S, Lautze J, McCartney M, Nhamo L, Wilson GG. Malaria and large dams in sub-Saharan Africa: future impacts in a changing climate. Malar J 2016; 15:448. [PMID: 27592590 PMCID: PMC5011356 DOI: 10.1186/s12936-016-1498-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/18/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sub-Saharan Africa (SSA) has embarked on a new era of dam building to improve food security and promote economic development. Nonetheless, the future impacts of dams on malaria transmission are poorly understood and seldom investigated in the context of climate and demographic change. METHODS The distribution of malaria in the vicinity of 1268 existing dams in SSA was mapped under the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathways (RCP) 2.6 and 8.5. Population projections and malaria incidence estimates were used to compute population at risk of malaria in both RCPs. Assuming no change in socio-economic interventions that may mitigate impacts, the change in malaria stability and malaria burden in the vicinity of the dams was calculated for the two RCPs through to the 2080s. Results were compared against the 2010 baseline. The annual number of malaria cases associated with dams and climate change was determined for each of the RCPs. RESULTS The number of dams located in malarious areas is projected to increase in both RCPs. Population growth will add to the risk of transmission. The population at risk of malaria around existing dams and associated reservoirs, is estimated to increase from 15 million in 2010 to 21-23 million in the 2020s, 25-26 million in the 2050s and 28-29 million in the 2080s, depending on RCP. The number of malaria cases associated with dams in malarious areas is expected to increase from 1.1 million in 2010 to 1.2-1.6 million in the 2020s, 2.1-3.0 million in the 2050s and 2.4-3.0 million in the 2080s depending on RCP. The number of cases will always be higher in RCP 8.5 than RCP 2.6. CONCLUSION In the absence of changes in other factors that affect transmission (e.g., socio-economic), the impact of dams on malaria in SSA will be significantly exacerbated by climate change and increases in population. Areas without malaria transmission at present, which will transition to regions of unstable transmission, may be worst affected. Modifying conventional water management frameworks to improve malaria control, holds the potential to mitigate some of this increase and should be more actively implemented.
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Affiliation(s)
- Solomon Kibret
- Program in Public Health, University of California Irvine, Irvine, CA, 92697, USA.
| | - Jonathan Lautze
- International Water Management Institute, Pretoria, South Africa
| | - Matthew McCartney
- International Water Management Institute, Vientiane, Lao People's Democratic Republic
| | - Luxon Nhamo
- International Water Management Institute, Pretoria, South Africa
| | - G Glenn Wilson
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
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Bokhorst S, Pedersen SH, Brucker L, Anisimov O, Bjerke JW, Brown RD, Ehrich D, Essery RLH, Heilig A, Ingvander S, Johansson C, Johansson M, Jónsdóttir IS, Inga N, Luojus K, Macelloni G, Mariash H, McLennan D, Rosqvist GN, Sato A, Savela H, Schneebeli M, Sokolov A, Sokratov SA, Terzago S, Vikhamar-Schuler D, Williamson S, Qiu Y, Callaghan TV. Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts. AMBIO 2016; 45:516-37. [PMID: 26984258 PMCID: PMC4980315 DOI: 10.1007/s13280-016-0770-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/03/2015] [Accepted: 02/05/2016] [Indexed: 05/07/2023]
Abstract
Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although much progress has been made in understanding and predicting snow-cover changes and their multiple consequences, many uncertainties remain. In this paper, we review advances in snow monitoring and modelling, and the impact of snow changes on ecosystems and society in Arctic regions. Interdisciplinary activities are required to resolve the current limitations on measuring and modelling snow characteristics through the cold season and at different spatial scales to assure human well-being, economic stability, and improve the ability to predict manage and adapt to natural hazards in the Arctic region.
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Affiliation(s)
- Stef Bokhorst
- FRAM – High North Research Centre on Climate and the Environment, Norwegian Institute for Nature Research (NINA), PO Box 6606, Langnes, 9296 Tromsø Norway
- Department of Ecological Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Stine Højlund Pedersen
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Ludovic Brucker
- NASA GSFC Cryospheric Sciences Laboratory, Code 615, Greenbelt, MD 20771 USA
- Goddard Earth Sciences Technology and Research Studies and Investigations, Universities Space Research Association, Columbia, MD 21044 USA
| | - Oleg Anisimov
- State Hydrological Institute of Roshydromet, 23 Second Line V.O., St.Petersburg, Russia 199053
- International Centre for Science and Education “Best”, North-East Federal University, Yakutsk, Russia
| | - Jarle W. Bjerke
- FRAM – High North Research Centre on Climate and the Environment, Norwegian Institute for Nature Research (NINA), PO Box 6606, Langnes, 9296 Tromsø Norway
| | - Ross D. Brown
- Climate Research Division, Environment Canada Ouranos, 550 Sherbrooke St. West, 19th Floor, Montreal, QC H3A 1B9 Canada
| | - Dorothee Ehrich
- Department of Arctic and Marine Biology, University of Tromsø, 9037 Tromsø, Norway
| | | | - Achim Heilig
- Institute of Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
| | - Susanne Ingvander
- Department of Physical Geography, Stockholm University, 106 91 Stockholm, Sweden
| | - Cecilia Johansson
- Department of Earth Sciences, Uppsala University, Villavägen 16, 75236 Uppsala, Sweden
| | - Margareta Johansson
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
- Royal Swedish Academy of Sciences, PO Box 50005, 104 05 Stockholm, Sweden
| | - Ingibjörg Svala Jónsdóttir
- University Centre in Svalbard, PO Box 156, 9171 Longyearbyen, Norway
- Faculty of Life- and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavík, Iceland
| | - Niila Inga
- Leavas Sámi Community, Box 53, 981 21 Kiruna, Sweden
| | - Kari Luojus
- Arctic Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
| | - Giovanni Macelloni
- IFAC-CNR - Institute of Applied Physics “Nello Carrara”, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI Italy
| | - Heather Mariash
- National Wildlife Research Centre, Environment Canada, 1125 Colonel By Drive, Ottawa, K1A 0H3 Canada
| | - Donald McLennan
- Canadian High Arctic Research Station (CHARS), 360 Albert Street, Suite 1710, Ottawa, ON K1R 7X7 Canada
| | - Gunhild Ninis Rosqvist
- Department of Physical Geography, Stockholm University, 106 91 Stockholm, Sweden
- Department of Earth Sciences, University of Bergen, 5020 Bergen, Norway
| | - Atsushi Sato
- Snow and Ice Research Center, National Research Institute for Earth Science and Disaster Prevention, 187-16 Suyoshi, Nagaoka, Niigata 940-0821 Japan
| | - Hannele Savela
- Thule Insitute, University of Oulu, PO Box 7300, 90014 Oulu, Finland
| | - Martin Schneebeli
- WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260 Davos Dorf, Switzerland
| | - Aleksandr Sokolov
- Arctic Research Station of Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Sciences, Labytnangi, Russia 629400
- Science Center for Arctic Studies, State Organization of Yamal-Nenets Autonomous District, Salekhard, Russia
| | - Sergey A. Sokratov
- Arctic Environment Laboratory, Faculty of Geography, M.V. Lomonosov Moscow State University, Leninskie gory 1, Moscow, Russia 119991
| | - Silvia Terzago
- Institute of Atmospheric Sciences and Climate, National Research Council (ISAC-CNR), Corso Fiume 4, 10133 Turin, Italy
| | - Dagrun Vikhamar-Schuler
- Division for Model and Climate Analysis, R&D Department, The Norwegian Meteorological Institute, Postboks 43, Blindern, 0313 Oslo, Norway
| | - Scott Williamson
- Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Bldg., Edmonton, AB T6G 2E9 Canada
| | - Yubao Qiu
- Institute of Remote Sensing and Digital Earth, Chinese Academic of Science, Beijing, 100094 China
- Group on Earth Observations, Cold Regions Initiative, Geneva, Switzerland
| | - Terry V. Callaghan
- Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 223 62 Lund, Sweden
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN UK
- National Research Tomsk Stated University, 36, Lenin Ave., Tomsk, Russia 634050
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Ocampo D, Booth M. The application of evolutionary medicine principles for sustainable malaria control: a scoping study. Malar J 2016; 15:383. [PMID: 27449143 PMCID: PMC4957922 DOI: 10.1186/s12936-016-1446-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/18/2016] [Indexed: 11/10/2022] Open
Abstract
Background Current interventions against malaria have significantly reduced the number of people infected and the number of deaths. Concerns about emerging resistance of both mosquitoes and parasites to intervention have been raised, and questions remain about how best to generate wider knowledge of the underlying evolutionary processes. The pedagogical and research principles of evolutionary medicine may provide an answer to this problem. Methods Eight programme managers and five academic researchers were interviewed by telephone or videoconference to elicit their first-hand views and experiences of malaria control given that evolution is a constant threat to sustainable control. Interviewees were asked about their views on the relationship between practit groups and academics and for their thoughts on whether or not evolutionary medicine may provide a solution to reported tensions. Results There was broad agreement that evolution of both parasites and vectors presents an obstacle to sustainable control. It was also widely agreed that through more efficient monitoring, evolution could be widely monitored. Interviewees also expressed the view that even well planned interventions may fail if the evolutionary biology of the disease is not considered, potentially making current tools redundant. Conclusions This scoping study suggests that it is important to make research, including evolutionary principles, available and easily applicable for programme managers and key decision-makers, including donors and politicians. The main conclusion is that sharing knowledge through the educational and research processes embedded within evolutionary medicine has potential to relieve tensions and facilitate sustainable control of malaria and other parasitic infections. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1446-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Denise Ocampo
- Department of Anthropology, Durham University, Stockton Rd, Durham, UK
| | - Mark Booth
- School of Medicine, Pharmacy and Health, Durham University, University Boulevard, Thornaby, UK.
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11
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Walker PGT, Griffin JT, Ferguson NM, Ghani AC. Estimating the most efficient allocation of interventions to achieve reductions in Plasmodium falciparum malaria burden and transmission in Africa: a modelling study. LANCET GLOBAL HEALTH 2016; 4:e474-84. [PMID: 27269393 DOI: 10.1016/s2214-109x(16)30073-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 04/04/2016] [Accepted: 04/21/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Reducing the burden of malaria is a global priority, but financial constraints mean that available resources must be allocated rationally to maximise their effect. We aimed to develop a model to estimate the most efficient (ie, minimum cost) ordering of interventions to reduce malaria burden and transmission. We also aimed to estimate the efficiency of different spatial scales of implementation. METHODS We combined a dynamic model capturing heterogeneity in malaria transmission across Africa with financial unit cost data for key malaria interventions. We combined estimates of patterns of malaria endemicity, seasonality in rainfall, and mosquito composition to map optimum packages of these interventions across Africa. Using non-linear optimisation methods, we examined how these optimum packages vary when control measures are deployed and assessed at national, subnational first administrative (provincial), or fine-scale (5 km(2) pixel) spatial scales. FINDINGS The most efficient package in a given setting varies depending on whether disease reduction or elimination is the target. Long-lasting insecticide-treated nets are generally the most cost-effective first intervention to achieve either goal, with seasonal malaria chemoprevention or indoor residual spraying added second depending on seasonality and vector species. These interventions are estimated to reduce malaria transmission to less than one case per 1000 people per year in 43·4% (95% CI 40·0-49·0) of the population at risk in Africa. Adding three rounds of mass drug administration per year is estimated to increase this proportion to 90·9% (95% CI 86·9-94·6). Further optimisation can be achieved by targeting policies at the provincial level, achieving an estimated 32·1% (95% CI 29·6-34·5) cost saving relative to adopting country-wide policies. Nevertheless, we predict that only 26 (95% CI 22-29) of 41 countries could reduce transmission to these levels with these approaches. INTERPRETATION These results highlight the cost-benefits of carefully tailoring malaria interventions to the ecological landscape of different areas. However, novel interventions are necessary if malaria eradication is to be achieved. FUNDING Bill & Melinda Gates Foundation, UK Medical Research Council.
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Affiliation(s)
- Patrick G T Walker
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Jamie T Griffin
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Neil M Ferguson
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Azra C Ghani
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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Parham PE, Waldock J, Christophides GK, Hemming D, Agusto F, Evans KJ, Fefferman N, Gaff H, Gumel A, LaDeau S, Lenhart S, Mickens RE, Naumova EN, Ostfeld RS, Ready PD, Thomas MB, Velasco-Hernandez J, Michael E. Climate, environmental and socio-economic change: weighing up the balance in vector-borne disease transmission. Philos Trans R Soc Lond B Biol Sci 2015; 370:rstb.2013.0551. [PMID: 25688012 DOI: 10.1098/rstb.2013.0551] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Arguably one of the most important effects of climate change is the potential impact on human health. While this is likely to take many forms, the implications for future transmission of vector-borne diseases (VBDs), given their ongoing contribution to global disease burden, are both extremely important and highly uncertain. In part, this is owing not only to data limitations and methodological challenges when integrating climate-driven VBD models and climate change projections, but also, perhaps most crucially, to the multitude of epidemiological, ecological and socio-economic factors that drive VBD transmission, and this complexity has generated considerable debate over the past 10-15 years. In this review, we seek to elucidate current knowledge around this topic, identify key themes and uncertainties, evaluate ongoing challenges and open research questions and, crucially, offer some solutions for the field. Although many of these challenges are ubiquitous across multiple VBDs, more specific issues also arise in different vector-pathogen systems.
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Affiliation(s)
- Paul E Parham
- Department of Public Health and Policy, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3GL, UK Grantham Institute for Climate Change, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, St Mary's Campus, London W2 1PG, UK
| | - Joanna Waldock
- The Cyprus Institute, Nicosia, Cyprus Imperial College London, London SW7 2AZ, UK
| | | | - Deborah Hemming
- Meteorological Office Hadley Centre, UK Meteorological Office, Fitzroy Road, Exeter, EX1 3PB, UK
| | - Folashade Agusto
- Department of Mathematics, Austin Peay State University, Clarksville, TN 37044, USA
| | - Katherine J Evans
- Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831, USA
| | - Nina Fefferman
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ 08901, USA
| | - Holly Gaff
- Department of Biological Sciences, Old Dominium University, Norfolk, VA 23529, USA
| | - Abba Gumel
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ 85287-1904, USA School of Mathematical and Natural Sciences, Arizona State University, Phoenix, AZ 85069-7100, USA
| | - Shannon LaDeau
- Cary Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545-0129, USA
| | - Suzanne Lenhart
- Department of Mathematics, University of Tennessee, Knoxville, TN 37996-1300, USA
| | - Ronald E Mickens
- Department of Physics, Clark Atlanta University, PO Box 172, Atlanta, GA 30314, USA
| | - Elena N Naumova
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, MA 02155, USA
| | - Richard S Ostfeld
- Cary Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545-0129, USA
| | - Paul D Ready
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Matthew B Thomas
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA
| | - Jorge Velasco-Hernandez
- Universidad Nacional Autnoma de Mexico Institute of Mathematics Mexico City, Distrito Federal, Mexico
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-0369, USA
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