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Kamal MA, Ganguly S, Kadambi A, Smith PF. Extended Model-Informed Drug Development: Beyond Clinical Trials and Regulatory Approval. Clin Pharmacol Ther 2024; 116:518-521. [PMID: 39010652 DOI: 10.1002/cpt.3357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 06/04/2024] [Indexed: 07/17/2024]
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2
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Kokori E, Olatunji G, Akinboade A, Akinoso A, Egbunu E, Aremu SA, Okafor CE, Oluwole O, Aderinto N. Triple artemisinin-based combination therapy (TACT): advancing malaria control and eradication efforts. Malar J 2024; 23:25. [PMID: 38238781 PMCID: PMC10797909 DOI: 10.1186/s12936-024-04844-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 01/05/2024] [Indexed: 01/22/2024] Open
Abstract
This paper examines the far-reaching implications of Triple Artemisinin-Based Combination Therapy (TACT) in the global battle against malaria. Artemisinin-Based Combination Therapy (ACT) is recognized for its cost-effectiveness, lower likelihood of adverse events, and widespread acceptance by patients and healthcare providers. However, TACT introduces novel dimensions to the fight against malaria that make them a superior choice in several aspects. TACT has been demonstrated to address resistance, offer a broader spectrum of action, reduce the risk of treatment failure, and can be tailored to meet regional needs, strengthening the global effort to combat malaria. However, maximizing these benefits of TACT depends on accessibility, particularly in resource-limited regions where malaria is most prevalent. Collaborative efforts among stakeholders, sustainable pricing strategies, efficient supply chains, and public-private partnerships are essential to ensure that TACT reaches needy populations. Moreover, dispelling prevalent malaria myths through health education campaigns is critical in this endeavour. The paper underscores the significance of collaborative initiatives and partnerships among governments, international organizations, research institutions, acadaemia, pharmaceutical companies, and local communities. Together, these efforts can pave the way for the acceptance, adoption, and success of TACT, ultimately advancing the global goal of a malaria-free world.
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Affiliation(s)
- Emmanuel Kokori
- Department of Medicine and Surgery, University of Ilorin, Ilorin, Kwara, Nigeria
| | - Gbolahan Olatunji
- Department of Medicine and Surgery, University of Ilorin, Ilorin, Kwara, Nigeria
| | - Adeola Akinboade
- Department of Medicine and Surgery, University of Ilorin, Ilorin, Kwara, Nigeria
| | - Aminat Akinoso
- Department of Medicine and Surgery, University of Ilorin, Ilorin, Kwara, Nigeria
| | | | | | | | | | - Nicholas Aderinto
- Department of Medicine, Ladoke Akintola University of Technology, Ogbomosho, Nigeria.
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3
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Masserey T, Lee T, Golumbeanu M, Shattock AJ, Kelly SL, Hastings IM, Penny MA. The influence of biological, epidemiological, and treatment factors on the establishment and spread of drug-resistant Plasmodium falciparum. eLife 2022; 11:e77634. [PMID: 35796430 PMCID: PMC9262398 DOI: 10.7554/elife.77634] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Abstract
The effectiveness of artemisinin-based combination therapies (ACTs) to treat Plasmodium falciparum malaria is threatened by resistance. The complex interplay between sources of selective pressure-treatment properties, biological factors, transmission intensity, and access to treatment-obscures understanding how, when, and why resistance establishes and spreads across different locations. We developed a disease modelling approach with emulator-based global sensitivity analysis to systematically quantify which of these factors drive establishment and spread of drug resistance. Drug resistance was more likely to evolve in low transmission settings due to the lower levels of (i) immunity and (ii) within-host competition between genotypes. Spread of parasites resistant to artemisinin partner drugs depended on the period of low drug concentration (known as the selection window). Spread of partial artemisinin resistance was slowed with prolonged parasite exposure to artemisinin derivatives and accelerated when the parasite was also resistant to the partner drug. Thus, to slow the spread of partial artemisinin resistance, molecular surveillance should be supported to detect resistance to partner drugs and to change ACTs accordingly. Furthermore, implementing more sustainable artemisinin-based therapies will require extending parasite exposure to artemisinin derivatives, and mitigating the selection windows of partner drugs, which could be achieved by including an additional long-acting drug.
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Affiliation(s)
- Thiery Masserey
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Tamsin Lee
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Monica Golumbeanu
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Andrew J Shattock
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Sherrie L Kelly
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
| | - Ian M Hastings
- Liverpool School of Tropical MedicineLiverpoolUnited Kingdom
| | - Melissa A Penny
- Swiss Tropical and Public Health InstituteAllschwilSwitzerland
- University of BaselBaselSwitzerland
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4
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de Haan F, Boon WPC, Amaratunga C, Dondorp AM. Expert perspectives on the introduction of Triple Artemisinin-based Combination Therapies (TACTs) in Southeast Asia: a Delphi study. BMC Public Health 2022; 22:864. [PMID: 35490212 PMCID: PMC9055751 DOI: 10.1186/s12889-022-13212-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Triple Artemisinin-based Combination Therapies (TACTs) are being developed as a response to artemisinin and partner drug resistance in Southeast Asia. However, the desirability, timing and practical feasibility of introducing TACTs in Southeast Asia is subject to debate. This study systematically assesses perspectives of malaria experts towards the introduction of TACTs as first-line treatment for uncomplicated falciparum malaria in Southeast Asia. METHODS A two-round Delphi study was conducted. In the first round, 53 malaria experts answered open-ended questions on what they consider the most important advantages, disadvantages, and implementation barriers for introducing TACTs in Southeast Asia. In the second round, the expert panel rated the relevance of each statement on a 5-point Likert scale. RESULTS Malaria experts identified 15 advantages, 15 disadvantages and 13 implementation barriers for introducing TACTs in Southeast Asia in the first round of data collection. In the second round, consensus was reached on 13 advantages (8 perceived as relevant, 5 as not-relevant), 12 disadvantages (10 relevant, 2 not-relevant), and 13 implementation barriers (all relevant). Advantages attributed highest relevance related to the clinical and epidemiological rationale of introducing TACTs. Disadvantages attributed highest relevance related to increased side-effects, unavailability of fixed-dose TACTs, and potential cost increases. Implementation barriers attributed highest relevance related to obtaining timely regulatory approval, timely availability of fixed-dose TACTs, and generating global policy support for introducing TACTs. CONCLUSIONS The study provides a structured oversight of malaria experts' perceptions on the major advantages, disadvantages and implementation challenges for introducing TACTs in Southeast Asia, over current practices of rotating ACTs when treatment failure is observed. The findings can benefit strategic decision making in the battle against drug-resistant malaria.
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Affiliation(s)
- Freek de Haan
- Copernicus Institute of Sustainable Development, Utrecht University, Princetonlaan 8a, 3484 CB, Utrecht, the Netherlands.
| | - Wouter P C Boon
- Copernicus Institute of Sustainable Development, Utrecht University, Princetonlaan 8a, 3484 CB, Utrecht, the Netherlands
| | - Chanaki Amaratunga
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi DistrictBangkok, 10400, Thailand
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Ratchathewi DistrictBangkok, 10400, Thailand
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5
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Kretzschmar ME, Ashby B, Fearon E, Overton CE, Panovska-Griffiths J, Pellis L, Quaife M, Rozhnova G, Scarabel F, Stage HB, Swallow B, Thompson RN, Tildesley MJ, Villela D. Challenges for modelling interventions for future pandemics. Epidemics 2022; 38:100546. [PMID: 35183834 PMCID: PMC8830929 DOI: 10.1016/j.epidem.2022.100546] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 12/16/2022] Open
Abstract
Mathematical modelling and statistical inference provide a framework to evaluate different non-pharmaceutical and pharmaceutical interventions for the control of epidemics that has been widely used during the COVID-19 pandemic. In this paper, lessons learned from this and previous epidemics are used to highlight the challenges for future pandemic control. We consider the availability and use of data, as well as the need for correct parameterisation and calibration for different model frameworks. We discuss challenges that arise in describing and distinguishing between different interventions, within different modelling structures, and allowing both within and between host dynamics. We also highlight challenges in modelling the health economic and political aspects of interventions. Given the diversity of these challenges, a broad variety of interdisciplinary expertise is needed to address them, combining mathematical knowledge with biological and social insights, and including health economics and communication skills. Addressing these challenges for the future requires strong cross-disciplinary collaboration together with close communication between scientists and policy makers.
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Affiliation(s)
- Mirjam E Kretzschmar
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
| | - Ben Ashby
- Department of Mathematical Sciences, University of Bath, Bath BA2 7AY, UK
| | - Elizabeth Fearon
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK; Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, UK
| | - Christopher E Overton
- Department of Mathematics, University of Manchester, UK; Joint UNIversities Pandemic and Epidemiological Research, UK; Clinical Data Science Unit, Manchester University NHS Foundation Trust, UK
| | - Jasmina Panovska-Griffiths
- The Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK; The Queen's College, University of Oxford, Oxford, UK
| | - Lorenzo Pellis
- Department of Mathematics, University of Manchester, UK; Joint UNIversities Pandemic and Epidemiological Research, UK; The Alan Turing Institute, London, UK
| | - Matthew Quaife
- TB Modelling Group, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, UK
| | - Ganna Rozhnova
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; BioISI-Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Francesca Scarabel
- Department of Mathematics, University of Manchester, UK; Joint UNIversities Pandemic and Epidemiological Research, UK; CDLab - Computational Dynamics Laboratory, Department of Mathematics, Computer Science and Physics, University of Udine, Italy
| | - Helena B Stage
- Department of Mathematics, University of Manchester, UK; Joint UNIversities Pandemic and Epidemiological Research, UK; University of Potsdam, Germany; Humboldt University of Berlin, Germany
| | - Ben Swallow
- School of Mathematics and Statistics, University of Glasgow, Glasgow, UK; Scottish Covid-19 Response Consortium, UK
| | - Robin N Thompson
- Joint UNIversities Pandemic and Epidemiological Research, UK; Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK; Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, University of Warwick, Coventry CV4 7AL, UK
| | - Michael J Tildesley
- Joint UNIversities Pandemic and Epidemiological Research, UK; Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK; Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, University of Warwick, Coventry CV4 7AL, UK
| | - Daniel Villela
- Program of Scientific Computing, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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6
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Silal SP. Operational research: A multidisciplinary approach for the management of infectious disease in a global context. EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2021; 291:929-934. [PMID: 32836716 PMCID: PMC7377991 DOI: 10.1016/j.ejor.2020.07.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/04/2020] [Accepted: 07/19/2020] [Indexed: 05/04/2023]
Abstract
Infectious diseases, both established and emerging, impose a significant burden globally. Successful management of infectious diseases requires considerable effort and a multidisciplinary approach to tackle the complex web of interconnected biological, public health and economic systems. Through a wide range of problem-solving techniques and computational methods, operational research can strengthen health systems and support decision-making at all levels of disease control. From improved understanding of disease biology, intervention planning and implementation, assessing economic feasibility of new strategies, identifying opportunities for cost reductions in routine processes, and informing health policy, this paper highlights areas of opportunity for operational research to contribute to effective and efficient infectious disease management and improved health outcomes.
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Affiliation(s)
- Sheetal Prakash Silal
- Modelling and Simulation Hub, Africa, University of Cape Town, Cape Town, South Africa
- Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
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7
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Vlachakis D, Vlamos P. Mathematical Multidimensional Modelling and Structural Artificial Intelligence Pipelines Provide Insights for the Designing of Highly Specific AntiSARS-CoV2 Agents. MATHEMATICS IN COMPUTER SCIENCE 2021; 15. [PMCID: PMC8205651 DOI: 10.1007/s11786-021-00517-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
COVID19 is the most impactful pandemic of recent times worldwide. It is a highly infectious disease that is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), To date there is specific drug nor vaccination against COVID19. Therefor the need for novel and pioneering anti-COVID19 is of paramount importance. In this direction, computer-aided drug design constitutes a very promising antiviral approach for the discovery and analysis of drugs and molecules with biological activity against SARS-CoV2. In silico modelling takes advantage of the massive amounts of biological and chemical data available on the nature of the interactions between the targeted systems and molecules, as well as the rapid progress of computational tools and software. Herein, we describe the potential of the merging of mathematical modelling, artificial intelligence and learning techniques into seamless computational pipelines for the rapid and efficient discovery and design of potent anti- SARS-CoV-2 modulators.
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Affiliation(s)
- Dimitrios Vlachakis
- Laboratory of Genetics, Department of Biotechnology, Genetics and Computational Biology Group, School of Applied Biology and Biotechnology, Agricultural University of Athens, Iera Odos 75 Str. GR11855, Athens, Greece
- Laboratory of Molecular Endocrinology, Division of Endocrinology and Metabolism, Center of Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Soranou Ephessiou Str. GR11527, Athens, Greece
- University Research Institute of Maternal and Child Health and Precision Medicine, Medical School, National and Kapodistrian University of Athens, Thivon 1 & Papadiamantopoulou Str. GR11527, Athens, Greece
| | - Panayiotis Vlamos
- Department of Informatics, Ionian University, Plateia Tsirigoti 7, 49100 Corfu, Greece
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8
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van der Pluijm RW, Amaratunga C, Dhorda M, Dondorp AM. Triple Artemisinin-Based Combination Therapies for Malaria - A New Paradigm? Trends Parasitol 2020; 37:15-24. [PMID: 33060063 DOI: 10.1016/j.pt.2020.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 01/31/2023]
Abstract
Recent gains in the fight against malaria are threatened by the emergence and spread of artemisinin and partner drug resistance in Plasmodium falciparum in the Greater Mekong Subregion (GMS). When artemisinins are combined with a single partner drug, all recommended artemisinin-based combination therapies have shown reduced efficacy in some countries in the GMS at some point. Novel drugs are not available for the near future. Triple artemisinin-based combination therapies, combining artemisinins with two currently available partner drugs, will provide one of the last remaining safe and effective treatments for falciparum malaria that can be deployed rapidly in the GMS, whereas their deployment beyond the GMS could delay or prevent the global emergence and spread of resistance to currently available drugs.
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Affiliation(s)
- Rob W van der Pluijm
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chanaki Amaratunga
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; WorldWide Antimalarial Resistance Network - Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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9
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Brew J, Pradhan M, Broerse J, Bassat Q. Researchers' perceptions of malaria eradication: findings from a mixed-methods analysis of a large online survey. Malar J 2020; 19:359. [PMID: 33032614 PMCID: PMC7545840 DOI: 10.1186/s12936-020-03430-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/01/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The value of malaria eradication, the permanent reduction to zero of the worldwide incidence of malaria infection caused by human malaria parasites, would be enormous. However, the expected value of an investment in an intended, but uncertain, outcome hinges on the probability of, and time until, its fulfilment. Though the long-term benefits of global malaria eradication promise to be large, the upfront costs and uncertainty regarding feasibility and timeframe make it difficult for policymakers and researchers to forecast the return on investment. METHODS A large online survey of 844 peer-reviewed malaria researchers of different scientific backgrounds administered in order to estimate the probability and time frame of eradication. Adjustments were made for potential selection bias, and thematic analysis of free text comments was carried out. RESULTS The average perceived likelihood of global eradication among malaria researchers approximates the number of years into the future: approximately 10% of researchers believe that eradication will occur in the next 10 years, 30% believe it will occur in the next 30 years, and half believe eradication will require 50 years or more. Researchers who gave free form comments highlighted systemic challenges and the need for innovation as chief among obstacles to achieving global malaria eradication. CONCLUSIONS The findings highlight the difficulty and complexity of malaria eradication, and can be used in prospective cost-benefit analyses to inform stakeholders regarding the likely return on eradication-specific investments.
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Affiliation(s)
- Joe Brew
- Barcelona Institute for Global Health, Hospital Clinic, c/Rosselló, 132, 5è 2a, 08036, Barcelona, Spain. .,Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam, Netherlands.
| | - Menno Pradhan
- Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam, Netherlands.,University of Amsterdam, REC E, Roetersstraat 11, Amsterdam, Netherlands
| | - Jacqueline Broerse
- Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam, Netherlands
| | - Quique Bassat
- Barcelona Institute for Global Health, Hospital Clinic, c/Rosselló, 132, 5è 2a, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Institució Catalana de Recerca i Estudis Avançats, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública, Madrid, Spain
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10
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Stepniewska K, Humphreys GS, Gonçalves BP, Craig E, Gosling R, Guerin PJ, Price RN, Barnes KI, Raman J, Smit MR, D’Alessandro U, Stone WJR, Bjorkman A, Samuels AM, Arroyo-Arroyo MI, Bastiaens GJH, Brown JM, Dicko A, El-Sayed BB, Elzaki SEG, Eziefula AC, Kariuki S, Kwambai TK, Maestre AE, Martensson A, Mosha D, Mwaiswelo RO, Ngasala BE, Okebe J, Roh ME, Sawa P, Tiono AB, Chen I, Drakeley CJ, Bousema T. Efficacy of Single-Dose Primaquine With Artemisinin Combination Therapy on Plasmodium falciparum Gametocytes and Transmission: An Individual Patient Meta-Analysis. J Infect Dis 2020; 225:1215-1226. [PMID: 32778875 PMCID: PMC8974839 DOI: 10.1093/infdis/jiaa498] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/06/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Since the World Health Organization recommended single low-dose (0.25 mg/kg) primaquine (PQ) in combination with artemisinin-based combination therapies (ACTs) in areas of low transmission or artemisinin-resistant Plasmodium falciparum, several single-site studies have been conducted to assess efficacy. METHODS An individual patient meta-analysis to assess gametocytocidal and transmission-blocking efficacy of PQ in combination with different ACTs was conducted. Random effects logistic regression was used to quantify PQ effect on (1) gametocyte carriage in the first 2 weeks post treatment; and (2) the probability of infecting at least 1 mosquito or of a mosquito becoming infected. RESULTS In 2574 participants from 14 studies, PQ reduced PCR-determined gametocyte carriage on days 7 and 14, most apparently in patients presenting with gametocytemia on day 0 (odds ratio [OR], 0.22; 95% confidence interval [CI], .17-.28 and OR, 0.12; 95% CI, .08-.16, respectively). Rate of decline in gametocyte carriage was faster when PQ was combined with artemether-lumefantrine (AL) compared to dihydroartemisinin-piperaquine (DP) (P = .010 for day 7). Addition of 0.25 mg/kg PQ was associated with near complete prevention of transmission to mosquitoes. CONCLUSIONS Transmission blocking is achieved with 0.25 mg/kg PQ. Gametocyte persistence and infectivity are lower when PQ is combined with AL compared to DP.
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Affiliation(s)
- Kasia Stepniewska
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Infectious Diseases Data Observatory, Oxford, United Kingdom,Kasia Stepniewska, PhD, WorldWide Antimalarial Resistance Network (WWARN), Centre for Tropical Medicine and Global Health, Churchill Hospital, CCVTM, University of Oxford, Old Road, Oxford OX3 7LE, UK
| | - Georgina S Humphreys
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Infectious Diseases Data Observatory, Oxford, United Kingdom,Green Templeton College, University of Oxford, Oxford, United Kingdom
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Elaine Craig
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Infectious Diseases Data Observatory, Oxford, United Kingdom
| | - Roly Gosling
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA,Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, California, USA
| | - Philippe J Guerin
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Infectious Diseases Data Observatory, Oxford, United Kingdom
| | - Ric N Price
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom,Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Norther Territory, Australia,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Karen I Barnes
- WorldWide Antimalarial Resistance Network, Oxford, United Kingdom,University of Cape Town/Medical Research Council Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa,Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Jaishree Raman
- University of Cape Town/Medical Research Council Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Services, Johannesburg, South Africa,Wits Research Institute for Malaria, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Menno R Smit
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Will J R Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Anders Bjorkman
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Aaron M Samuels
- Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA,Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Maria I Arroyo-Arroyo
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
| | - Guido J H Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands,Department of Microbiology and Immunology, Rijnstate Hospital, Arnhem, the Netherlands
| | - Joelle M Brown
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Badria B El-Sayed
- Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Salah-Eldin G Elzaki
- Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Alice C Eziefula
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom,Department of Global Health and Infection, Brighton and Sussex Medical School, Brighton, United Kingdom
| | | | - Titus K Kwambai
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom,Kenya Medical Research Institute, Kisian, Kenya
| | - Amanda E Maestre
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
| | - Andreas Martensson
- Department of Women’s and Children’s Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - Dominic Mosha
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania,Africa Academy for Public Health, Dar es Salaam, Tanzania
| | - Richard O Mwaiswelo
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Billy E Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Joseph Okebe
- Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michelle E Roh
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA,Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, California, USA
| | - Patrick Sawa
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, California, USA
| | - Chris J Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands,Correspondence: Teun Bousema, PhD, Department of Medical Microbiology, Radboud Institute for Health Science, Radboudumc, PO Box 9101, 6500 HB Nijmegen, The Netherlands ()
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11
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Ayala MJC, Villela DAM. Early transmission of sensitive strain slows down emergence of drug resistance in Plasmodium vivax. PLoS Comput Biol 2020; 16:e1007945. [PMID: 32555701 PMCID: PMC7363008 DOI: 10.1371/journal.pcbi.1007945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 06/29/2020] [Accepted: 05/13/2020] [Indexed: 11/19/2022] Open
Abstract
The spread of drug resistance of Plasmodium falciparum and Plasmodium vivax parasites is a challenge towards malaria elimination. P. falciparum has shown an early and severe drug resistance in comparison to P. vivax in various countries. In fact, P. vivax differs in its life cycle and treatment in various factors: development and duration of sexual parasite forms differ, symptoms severity are unequal, relapses present only in P. vivax cases and the Artemisinin-based combination therapy (ACT) is only mandatory in P. falciparum cases. We compared the spread of drug resistance for both species through two compartmental models using ordinary differential equations. The model structure describes how sensitive and resistant parasite strains infect a human population treated with antimalarials. We found that an early transmission,i.e., before treatment and low effectiveness of drug coverage, supports the prevalence of sensitive parasites delaying the emergence of resistant P. vivax. These results imply that earlier attention of both symptomatic cases and reservoirs of P. vivax are essential in controlling transmission but also accelerate the spread of drug resistance.
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Affiliation(s)
- Mario J. C. Ayala
- Programa de Computação Científica, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Daniel A. M. Villela
- Programa de Computação Científica, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
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12
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South A, Lees R, Garrod G, Carson J, Malone D, Hastings I. The role of windows of selection and windows of dominance in the evolution of insecticide resistance in human disease vectors. Evol Appl 2020; 13:738-751. [PMID: 32211064 PMCID: PMC7086049 DOI: 10.1111/eva.12897] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 01/23/2023] Open
Abstract
Persistent insecticides sprayed onto house walls, and incorporated into insecticide-treated bednets, provide long-acting, cost-effective control of vector-borne diseases such as malaria and leishmaniasis. The high concentrations that occur immediately postdeployment may kill both resistant and susceptible insects. However, insecticide concentration, and therefore killing ability, declines in the months after deployment. As concentrations decline, resistant insects start to survive, while susceptible insects are still killed. The period of time after deployment, within which the mortality of resistant individuals is lower than that of susceptible ones, has been termed the "window of selection" in other contexts. It is recognized as driving resistance in bacteria and malaria parasites, both of which are predominantly haploid. We argue that paying more attention to these mortality differences can help understand the evolution of insecticide resistance. Because insects are diploid, resistance encoded by single genes generates heterozygotes. This gives the potential for a narrower "window of dominance," within the window of selection, where heterozygote mortality is lower than that of susceptible homozygotes. We explore the general properties of windows of selection and dominance in driving resistance. We quantify their likely effect using data from new laboratory experiments and published data from the laboratory and field. These windows can persist months or years after insecticide deployments. Differential mortalities of resistant, susceptible and heterozygous genotypes, after public health deployments, constitute a major challenge to controlling resistance. Greater attention to mortality differences by genotype would inform strategies to reduce the evolution of resistance to existing and new insecticides.
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Affiliation(s)
- Andy South
- Liverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | - Rosemary Lees
- Liverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | - Gala Garrod
- Liverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | | | - David Malone
- Innovative Vector Control Consortium (IVCC)LiverpoolUK
- Present address:
Bill & Melinda Gates FoundationLondonUK
| | - Ian Hastings
- Liverpool School of Tropical Medicine (LSTM)LiverpoolUK
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13
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Khoury DS, Zaloumis SG, Grigg MJ, Haque A, Davenport MP. Malaria Parasite Clearance: What Are We Really Measuring? Trends Parasitol 2020; 36:413-426. [PMID: 32298629 DOI: 10.1016/j.pt.2020.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 02/11/2020] [Accepted: 02/24/2020] [Indexed: 01/22/2023]
Abstract
Antimalarial drugs are vital for treating malaria and controlling transmission. Measuring drug efficacy in the field requires large clinical trials and thus we have identified proxy measures of drug efficacy such as the parasite clearance curve. This is often assumed to measure the rate of drug activity against parasites and is used to predict optimal treatment regimens required to completely clear a blood-stage infection. We discuss evidence that the clearance curve is not measuring the rate of drug killing. This has major implications for how we assess optimal treatment regimens, as well as how we prioritise new drugs in the drug development pipeline.
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Affiliation(s)
- David S Khoury
- Kirby Institute, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Sophie G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
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14
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Burgert L, Rottmann M, Wittlin S, Gobeau N, Krause A, Dingemanse J, Möhrle JJ, Penny MA. Ensemble modeling highlights importance of understanding parasite-host behavior in preclinical antimalarial drug development. Sci Rep 2020; 10:4410. [PMID: 32157151 PMCID: PMC7064600 DOI: 10.1038/s41598-020-61304-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 02/20/2020] [Indexed: 11/23/2022] Open
Abstract
Emerging drug resistance and high-attrition rates in early and late stage drug development necessitate accelerated development of antimalarial compounds. However, systematic and meaningful translation of drug efficacy and host-parasite dynamics between preclinical testing stages is missing. We developed an ensemble of mathematical within-host parasite growth and antimalarial action models, fitted to extensive data from four antimalarials with different modes of action, to assess host-parasite interactions in two preclinical drug testing systems of murine parasite P. berghei in mice, and human parasite P. falciparum in immune-deficient mice. We find properties of the host-parasite system, namely resource availability, parasite maturation and virulence, drive P. berghei dynamics and drug efficacy, whereas experimental constraints primarily influence P. falciparum infection and drug efficacy. Furthermore, uninvestigated parasite behavior such as dormancy influences parasite recrudescence following non-curative treatment and requires further investigation. Taken together, host-parasite interactions should be considered for meaningful translation of pharmacodynamic properties between murine systems and for predicting human efficacious treatment.
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Affiliation(s)
- Lydia Burgert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Andreas Krause
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jasper Dingemanse
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jörg J Möhrle
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Medicines for Malaria Venture, Geneva, Switzerland
| | - Melissa A Penny
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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15
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Karbwang J, Na‐Bangchang K. The Role of Clinical Pharmacology in Chemotherapy of Multidrug‐Resistant
Plasmodium falciparum. J Clin Pharmacol 2020; 60:830-847. [DOI: 10.1002/jcph.1589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 01/21/2020] [Indexed: 01/02/2023]
Affiliation(s)
- Juntra Karbwang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
- Department of Clinical Product developmentNagasaki Institute of Tropical MedicineNagasaki University Nagasaki Japan
| | - Kesara Na‐Bangchang
- Graduate Program in Bioclinical SciencesChulabhorn International College of MedicineThammasat University (Rangsit Campus) Pathumthani Thailand
- Center of Excellence in Pharmacology and Molecular Biology of Malaria and CholangiocarcinomaThammasat University (Rangsit Campus) Pathumthani Thailand
- Drug Discovery and Development Center, Office of Advanced Science and TechnologyThammasat University (Rangsit Campus) Pathumthani Thailand
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16
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Bretscher MT, Dahal P, Griffin J, Stepniewska K, Bassat Q, Baudin E, D'Alessandro U, Djimde AA, Dorsey G, Espié E, Fofana B, González R, Juma E, Karema C, Lasry E, Lell B, Lima N, Menéndez C, Mombo-Ngoma G, Moreira C, Nikiema F, Ouédraogo JB, Staedke SG, Tinto H, Valea I, Yeka A, Ghani AC, Guerin PJ, Okell LC. The duration of chemoprophylaxis against malaria after treatment with artesunate-amodiaquine and artemether-lumefantrine and the effects of pfmdr1 86Y and pfcrt 76T: a meta-analysis of individual patient data. BMC Med 2020; 18:47. [PMID: 32098634 PMCID: PMC7043031 DOI: 10.1186/s12916-020-1494-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 01/09/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The majority of Plasmodium falciparum malaria cases in Africa are treated with the artemisinin combination therapies artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ), with amodiaquine being also widely used as part of seasonal malaria chemoprevention programs combined with sulfadoxine-pyrimethamine. While artemisinin derivatives have a short half-life, lumefantrine and amodiaquine may give rise to differing durations of post-treatment prophylaxis, an important additional benefit to patients in higher transmission areas. METHODS We analyzed individual patient data from 8 clinical trials of AL versus AS-AQ in 12 sites in Africa (n = 4214 individuals). The time to PCR-confirmed reinfection after treatment was used to estimate the duration of post-treatment protection, accounting for variation in transmission intensity between settings using hidden semi-Markov models. Accelerated failure-time models were used to identify potential effects of covariates on the time to reinfection. The estimated duration of chemoprophylaxis was then used in a mathematical model of malaria transmission to determine the potential public health impact of each drug when used for first-line treatment. RESULTS We estimated a mean duration of post-treatment protection of 13.0 days (95% CI 10.7-15.7) for AL and 15.2 days (95% CI 12.8-18.4) for AS-AQ overall. However, the duration varied significantly between trial sites, from 8.7-18.6 days for AL and 10.2-18.7 days for AS-AQ. Significant predictors of time to reinfection in multivariable models were transmission intensity, age, drug, and parasite genotype. Where wild type pfmdr1 and pfcrt parasite genotypes predominated (<=20% 86Y and 76T mutants, respectively), AS-AQ provided ~ 2-fold longer protection than AL. Conversely, at a higher prevalence of 86Y and 76T mutant parasites (> 80%), AL provided up to 1.5-fold longer protection than AS-AQ. Our simulations found that these differences in the duration of protection could alter population-level clinical incidence of malaria by up to 14% in under-5-year-old children when the drugs were used as first-line treatments in areas with high, seasonal transmission. CONCLUSION Choosing a first-line treatment which provides optimal post-treatment prophylaxis given the local prevalence of resistance-associated markers could make a significant contribution to reducing malaria morbidity.
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Affiliation(s)
- Michael T Bretscher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Prabin Dahal
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jamie Griffin
- School of Mathematical Sciences, Queen Mary University of London, London, UK
| | - Kasia Stepniewska
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Quique Bassat
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Umberto D'Alessandro
- MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Abdoulaye A Djimde
- Malaria Research and Training Center, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, USA
| | - Emmanuelle Espié
- Epicentre, Paris, France.,Clinical and Epidemiology Department, GSK Vaccines, R&D Center, Wavre, Belgium
| | - Bakary Fofana
- Malaria Research and Training Center, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Raquel González
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Elizabeth Juma
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Corine Karema
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Bertrand Lell
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria.,Centre de Recherches Medicales de Lambarene, Lambarene, Gabon
| | - Nines Lima
- Department of Paediatrics, University of Calabar, Calabar, Nigeria
| | - Clara Menéndez
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Medicales de Lambarene, Lambarene, Gabon.,Institute for Tropical Medicine, University of Tubingen, Tubingen, Germany.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine and I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clarissa Moreira
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Frederic Nikiema
- Institut de Recherche en Science de la Sante, Bobo-Dioulasso, Burkina Faso
| | - Jean B Ouédraogo
- Institut de Recherche en Science de la Sante, Bobo-Dioulasso, Burkina Faso
| | - Sarah G Staedke
- Department of Clinical Research, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Halidou Tinto
- Institut de Recherche en Science de la Sante, Nanoro, Burkina Faso
| | - Innocent Valea
- Institut de Recherche en Science de la Sante, Nanoro, Burkina Faso
| | - Adoke Yeka
- Uganda Malaria Surveillance Project, Kampala, Uganda
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Philippe J Guerin
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Lucy C Okell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
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17
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Challenger JD, Gonçalves BP, Bradley J, Bruxvoort K, Tiono AB, Drakeley C, Bousema T, Ghani AC, Okell LC. How delayed and non-adherent treatment contribute to onward transmission of malaria: a modelling study. BMJ Glob Health 2019; 4:e001856. [PMID: 31908862 PMCID: PMC6936434 DOI: 10.1136/bmjgh-2019-001856] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 12/31/2022] Open
Abstract
Introduction Artemether-lumefantrine (AL) is the most widely-recommended treatment for uncomplicated Plasmodium falciparum malaria. Its efficacy has been extensively assessed in clinical trials. In routine healthcare settings, however, its effectiveness can be diminished by delayed access to treatment and poor adherence. As well as affecting clinical outcomes, these factors can lead to increased transmission, which is the focus of this study. Methods We extend a within-host model of P. falciparum to include gametocytes, the parasite forms responsible for onward transmission. The model includes a pharmacokinetic–pharmacodynamic model of AL, calibrated against both immature and mature gametocytes using individual-level patient data, to estimate the impact that delayed access and imperfect adherence to treatment can have on onward transmission of the parasite to mosquitoes. Results Using survey data from seven African countries to determine the time taken to acquire antimalarials following fever increased our estimates of mean total infectivity of a malaria episode by up to 1.5-fold, compared with patients treated after 24 hours. Realistic adherence behaviour, based on data from a monitored cohort in Tanzania, increased the contribution to transmission by 2.2 to 2.4-fold, compared with a perfectly-adherent cohort. This was driven largely by increased rates of treatment failure leading to chronic infection, rather than prolonged gametocytaemia in patients who have slower, but still successful, clearance of parasites after imperfect adherence to treatment. Our model estimated that the mean infectivity of untreated infections was 29–51 times higher than that of treated infections (assuming perfect drug adherence), underlining the importance of improving treatment coverage. Conclusion Using mathematical modelling, we quantify how delayed treatment and non-adherent treatment can increase transmission compared with prompt effective treatment. We also highlight that transmission from the large proportion of infections which never receive treatment is substantially higher than those treated.
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Affiliation(s)
- Joseph D Challenger
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Katia Bruxvoort
- Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alfred B Tiono
- Public Health Department, Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Radboud Institute of Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Lucy C Okell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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18
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Hochberg ME. An ecosystem framework for understanding and treating disease. EVOLUTION MEDICINE AND PUBLIC HEALTH 2018; 2018:270-286. [PMID: 30487969 PMCID: PMC6252061 DOI: 10.1093/emph/eoy032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 12/28/2022]
Abstract
Pathogens and cancers are pervasive health risks in the human population. I argue that if we are to better understand disease and its treatment, then we need to take an ecological perspective of disease itself. I generalize and extend an emerging framework that views disease as an ecosystem and many of its components as interacting in a community. I develop the framework for biological etiological agents (BEAs) that multiply within humans—focusing on bacterial pathogens and cancers—but the framework could be extended to include other host and parasite species. I begin by describing why we need an ecosystem framework to understand disease, and the main components and interactions in bacterial and cancer disease ecosystems. Focus is then given to the BEA and how it may proceed through characteristic states, including emergence, growth, spread and regression. The framework is then applied to therapeutic interventions. Central to success is preventing BEA evasion, the best known being antibiotic resistance and chemotherapeutic resistance in cancers. With risks of evasion in mind, I propose six measures that either introduce new components into the disease ecosystem or manipulate existing ones. An ecosystem framework promises to enhance our understanding of disease, BEA and host (co)evolution, and how we can improve therapeutic outcomes.
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Affiliation(s)
- Michael E Hochberg
- Institut des Sciences de l'Evolution, Université de Montpellier, 34095 Montpellier, France.,Santa Fe Institute, Santa Fe, NM 87501, USA.,Institute for Advanced Study in Toulouse, 31015 Toulouse, France
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19
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Graves P, Gelband H, Garner P, Choi L. Gametocytocidal drugs: taking the population perspective. THE LANCET. INFECTIOUS DISEASES 2018; 18:719. [PMID: 29976523 DOI: 10.1016/s1473-3099(18)30337-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Patricia Graves
- Cochrane Infectious Diseases Group, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
| | - Hellen Gelband
- Cochrane Infectious Diseases Group, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Paul Garner
- Cochrane Infectious Diseases Group, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Leslie Choi
- Cochrane Infectious Diseases Group, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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20
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Cortopassi WA, Celmar Costa Franca T, Krettli AU. A systems biology approach to antimalarial drug discovery. Expert Opin Drug Discov 2018; 13:617-626. [DOI: 10.1080/17460441.2018.1471056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Wilian Augusto Cortopassi
- Department of Pharmaceutical Chemistry, University of California, San Francisco (UCSF), San Francisco, CA, USA
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21
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Bastiaens GJH, Tiono AB, Okebe J, Pett HE, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Bradley J, Lanke KHW, Niemi M, Sirima SB, d’Alessandro U, Bousema T, Drakeley C. Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials. PLoS One 2018; 13:e0190272. [PMID: 29324864 PMCID: PMC5764271 DOI: 10.1371/journal.pone.0190272] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022] Open
Abstract
Background Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. Methods and findings In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. Conclusions Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the study participants developed moderate or severe anemia; there were no severe adverse events. This indicates that single low-dose PQ is safe in G6PDd African males when used with artemisinin-based combination therapy. Trial registration Clinicaltrials.gov NCT02174900 Clinicaltrials.gov NCT02654730
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Affiliation(s)
- Guido J. H. Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
| | - Alfred B. Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Helmi E. Pett
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sam A. Coulibaly
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner P. Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Muna Affara
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Edith C. Bougouma
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Guillaume S. Sanou
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Kjerstin H. W. Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sodiomon B. Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Umberto d’Alessandro
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
- Department of Disease Control, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Hsiang MS, Ranadive N, Chitundu S, Ntshalintshali N, Greenhouse B. Reply to Rossi et al. Clin Infect Dis 2017; 65:1770-1771. [PMID: 29020318 PMCID: PMC5850315 DOI: 10.1093/cid/cix627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas
- Malaria Elimination Initiative, Global Health Group
- Department of Pediatrics, University of California, San Francisco Benioff Children’s Hospital
| | - Nikhil Ranadive
- Global Health Sciences
- Emory University School of Medicine, Atlanta, Georgia
| | | | | | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California
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