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Mousa A, Cuomo-Dannenburg G, Thompson HA, Chico RM, Beshir KB, Sutherland CJ, Schellenberg D, Gosling R, Alifrangis M, Hocke EF, Hansson H, Chopo-Pizarro A, Mbacham WF, Ali IM, Chaponda M, Roper C, Okell LC. Measuring protective efficacy and quantifying the impact of drug resistance: A novel malaria chemoprevention trial design and methodology. PLoS Med 2024; 21:e1004376. [PMID: 38723040 PMCID: PMC11081503 DOI: 10.1371/journal.pmed.1004376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/14/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND Recently revised WHO guidelines on malaria chemoprevention have opened the door to more tailored implementation. Countries face choices on whether to replace old drugs, target additional age groups, and adapt delivery schedules according to local drug resistance levels and malaria transmission patterns. Regular routine assessment of protective efficacy of chemoprevention is key. Here, we apply a novel modelling approach to aid the design and analysis of chemoprevention trials and generate measures of protection that can be applied across a range of transmission settings. METHODS AND FINDINGS We developed a model of genotype-specific drug protection, which accounts for underlying risk of infection and circulating genotypes. Using a Bayesian framework, we fitted the model to multiple simulated scenarios to explore variations in study design, setting, and participant characteristics. We find that a placebo or control group with no drug protection is valuable but not always feasible. An alternative approach is a single-arm trial with an extended follow-up (>42 days), which allows measurement of the underlying infection risk after drug protection wanes, as long as transmission is relatively constant. We show that the currently recommended 28-day follow-up in a single-arm trial results in low precision of estimated 30-day chemoprevention efficacy and low power in determining genotype differences of 12 days in the duration of protection (power = 1.4%). Extending follow-up to 42 days increased precision and power (71.5%) in settings with constant transmission over this time period. However, in settings of unstable transmission, protective efficacy in a single-arm trial was overestimated by 24.3% if recruitment occurred during increasing transmission and underestimated by 15.8% when recruitment occurred during declining transmission. Protective efficacy was estimated with greater precision in high transmission settings, and power to detect differences by resistance genotype was lower in scenarios where the resistant genotype was either rare or too common. CONCLUSIONS These findings have important implications for the current guidelines on chemoprevention efficacy studies and will be valuable for informing where these studies should be optimally placed. The results underscore the need for a comparator group in seasonal settings and provide evidence that the extension of follow-up in single-arm trials improves the accuracy of measures of protective efficacy in settings with more stable transmission. Extension of follow-up may pose logistical challenges to trial feasibility and associated costs. However, these studies may not need to be repeated multiple times, as the estimates of drug protection against different genotypes can be applied to different settings by adjusting for transmission intensity and frequency of resistance.
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Affiliation(s)
- Andria Mousa
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gina Cuomo-Dannenburg
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Hayley A. Thompson
- Malaria and Neglected Tropical Diseases, PATH, Seattle, Washington, United States of America
| | - R. Matthew Chico
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Khalid B. Beshir
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Colin J. Sutherland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David Schellenberg
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Roly Gosling
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malaria Elimination Initiative, Institute of Global Health, University of California, San Francisco, California, United States of America
| | - Michael Alifrangis
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Emma Filtenborg Hocke
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Helle Hansson
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Ana Chopo-Pizarro
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Wilfred F. Mbacham
- The Biotechnology Centre, University of Yaoundé, Yaoundé, Cameroon
- The Fobang Institutes for Innovation in Science and Technology, Yaoundé, Cameroon
- The Faculty of Northwest University, Faculty of Natural and Agricultural Sciences, Potchefstroom, South Africa
| | - Innocent M. Ali
- The Biotechnology Centre, University of Yaoundé, Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Mike Chaponda
- Department of Clinical Sciences, Tropical Diseases Research Centre, Ndola, Zambia
| | - Cally Roper
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, 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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Courlet P, Wilkins JJ, Oeuvray C, Gao W, Khandelwal A. Semi-mechanistic population pharmacokinetic/pharmacodynamic modeling of a Plasmodium elongation factor 2 inhibitor cabamiquine for prevention and cure of malaria. Antimicrob Agents Chemother 2023; 67:e0089123. [PMID: 37966273 PMCID: PMC10720512 DOI: 10.1128/aac.00891-23] [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: 07/06/2023] [Accepted: 09/23/2023] [Indexed: 11/16/2023] Open
Abstract
Cabamiquine is a novel antimalarial agent that demonstrates the potential for chemoprevention and treatment of malaria. In this article, the dose-exposure-response relationship of cabamiquine was characterized using a population pharmacokinetic (PK)/pharmacodynamic (PD) model, incorporating the effects of cabamiquine on parasite dynamics at the liver and blood stages of malaria infection. Modeling was performed sequentially. First, a three-compartmental population PK model was developed, comprising linear elimination, a transit absorption model in combination with first-order absorption, and a recirculation model. Second, this model was expanded into a PK/PD model using parasitemia data from an induced blood stage malaria (IBSM) human challenge model. To describe the parasite growth and killing in the blood, a turnover model was used. Finally, the liver stage parasite dynamics were characterized using data from a sporozoite challenge model (SpzCh), and system parameters were fixed based on biological plausibility. Cabamiquine concentration in the central compartment was used to drive parasite killing at the blood and liver stages. Blood stage minimum inhibitory concentrations (MICb) were estimated at 7.12 ng/mL [95% confidence interval (CI95%): 6.26-7.88 ng/mL] and 1.28 ng/mL (CI95%: 1.12-1.43 ng/mL) for IBSM and SpzCh populations, respectively, while liver stage MICl was lower (0.61 ng/mL; CI95%: 0.24-0.96 ng/mL). In conclusion, a population PK/PD model was developed by incorporating parasite dynamics and drug activity at the blood and liver stages based on clinical data and biological knowledge. This model can potentially facilitate antimalarial agent development by supporting the efficient selection of the optimal dosing regimen.
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Affiliation(s)
- Perrine Courlet
- Merck Institute for Pharmacometrics, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), Lausanne, Switzerland
| | | | - Claude Oeuvray
- The Global Health Institute of Merck (an affiliate of Merck KGaA, Darmstadt, Germany), Eysins, Switzerland
| | - Wei Gao
- EMD Serono Research and Development Institute, Inc., Billerica, Massachusetts, USA
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3
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Fulgheri F, Manca ML, Fernàndez-Busquets X, Manconi M. Analysis of complementarities between nanomedicine and phytodrugs for the treatment of malarial infection. Nanomedicine (Lond) 2023; 18:1681-1696. [PMID: 37955573 DOI: 10.2217/nnm-2023-0116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023] Open
Abstract
The use of nanocarriers in medicine, so-called nanomedicine, is one of the most innovative strategies for targeting drugs at the action site and increasing their activity index and effectiveness. Phytomedicine is the oldest traditional method used to treat human diseases and solve health problems. The recent literature on the treatment of malaria infections using nanodelivery systems and phytodrugs or supplements has been analyzed. For the first time, in the present review, a careful look at the considerable potential of nanomedicine in promoting phytotherapeutic efficacy was done, and its key role in addressing a translation through a significant reduction of the current burden of malaria in many parts of the world has been underlined.
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Affiliation(s)
- Federica Fulgheri
- Department of Life & Environmental Sciences, University of Cagliari, University Campus, S.P. Monserrato-Sestu Km 0.700, Monserrato, 09042 CA, Italy
| | - Maria Letizia Manca
- Department of Life & Environmental Sciences, University of Cagliari, University Campus, S.P. Monserrato-Sestu Km 0.700, Monserrato, 09042 CA, Italy
| | - Xavier Fernàndez-Busquets
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic-Universitat de Barcelona, Rosselló 1 49-153, 08036 Barcelona, Spain
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, 08028 Barcelona, Spain
- Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Maria Manconi
- Department of Life & Environmental Sciences, University of Cagliari, University Campus, S.P. Monserrato-Sestu Km 0.700, Monserrato, 09042 CA, Italy
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4
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Chaccour C, Casellas A, Hammann F, Ruiz-Castillo P, Nicolas P, Montaña J, Mael M, Selvaraj P, Duthaler U, Mrema S, Kakolwa M, Lyimo I, Okumu F, Marathe A, Schürch R, Elobolobo E, Sacoor C, Saute F, Xia K, Jones C, Rist C, Maia M, Rabinovich NR. BOHEMIA: Broad One Health Endectocide-based Malaria Intervention in Africa-a phase III cluster-randomized, open-label, clinical trial to study the safety and efficacy of ivermectin mass drug administration to reduce malaria transmission in two African settings. Trials 2023; 24:128. [PMID: 36810194 PMCID: PMC9942013 DOI: 10.1186/s13063-023-07098-2] [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: 11/19/2022] [Accepted: 01/17/2023] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND Residual malaria transmission is the result of adaptive mosquito behavior that allows malaria vectors to thrive and sustain transmission in the presence of good access to bed nets or insecticide residual spraying. These behaviors include crepuscular and outdoor feeding as well as intermittent feeding upon livestock. Ivermectin is a broadly used antiparasitic drug that kills mosquitoes feeding on a treated subject for a dose-dependent period. Mass drug administration with ivermectin has been proposed as a complementary strategy to reduce malaria transmission. METHODS A cluster randomized, parallel arm, superiority trial conducted in two settings with distinct eco-epidemiological conditions in East and Southern Africa. There will be three groups: human intervention, consisting of a dose of ivermectin (400 mcg/kg) administered monthly for 3 months to all the eligible population in the cluster (>15 kg, non-pregnant and no medical contraindication); human and livestock intervention, consisting human treatment as above plus treatment of livestock in the area with a single dose of injectable ivermectin (200 mcg/kg) monthly for 3 months; and controls, consisting of a dose of albendazole (400 mg) monthly for 3 months. The main outcome measure will be malaria incidence in a cohort of children under five living in the core of each cluster followed prospectively with monthly RDTs DISCUSSION: The second site for the implementation of this protocol has changed from Tanzania to Kenya. This summary presents the Mozambique-specific protocol while the updated master protocol and the adapted Kenya-specific protocol undergo national approval in Kenya. BOHEMIA will be the first large-scale trial evaluating the impact of ivermectin-only mass drug administration to humans or humans and cattle on local malaria transmission TRIAL REGISTRATION: ClinicalTrials.gov NCT04966702 . Registered on July 19, 2021. Pan African Clinical Trials Registry PACTR202106695877303.
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Affiliation(s)
- Carlos Chaccour
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
- Universidda de Navarra, Pamplona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Madrid, Spain
| | - Aina Casellas
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
| | - Felix Hammann
- University Hospital of Bern, Inselspital, Bern, Switzerland
| | | | - Patricia Nicolas
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
| | - Julia Montaña
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
| | - Mary Mael
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
| | | | | | | | | | - Issa Lyimo
- Ifakara Health Institute, Ifakara, Tanzania
| | | | | | - Roger Schürch
- Virginia Polytechnic Institute and State University, Blacksburg, USA
| | - Eldo Elobolobo
- Centro de Investigação em Saúde de Manhiça, Manhica, Mozambique
| | | | - Francisco Saute
- Centro de Investigação em Saúde de Manhiça, Manhica, Mozambique
| | - Kang Xia
- Virginia Polytechnic Institute and State University, Blacksburg, USA
| | | | - Cassidy Rist
- Virginia Polytechnic Institute and State University, Blacksburg, USA
| | - Marta Maia
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - N. Regina Rabinovich
- ISGlobal, Barcelona Institute for Global Health, Barcelona, Spain
- TH Chan Harvard School of Public Health, Boston, USA
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5
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Blanken SL, Soumare HDM, Andolina C, Lanke K, Bousema T. How to Interpret Parasite Persistence and Transmission to Mosquitoes After Antimalarial Treatment in Kenya? Clin Infect Dis 2023; 76:555-557. [PMID: 36069392 DOI: 10.1093/cid/ciac740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/02/2022] [Indexed: 11/14/2022] Open
Affiliation(s)
- Sara Lynn Blanken
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Harouna Dit Massire Soumare
- Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Chiara Andolina
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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6
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Okell LC, Kwambai TK, Dhabangi A, Khairallah C, Nkosi-Gondwe T, Winskill P, Opoka R, Mousa A, Kühl MJ, Lucas TCD, Challenger JD, Idro R, Weiss DJ, Cairns M, Ter Kuile FO, Phiri K, Robberstad B, Mori AT. Projected health impact of post-discharge malaria chemoprevention among children with severe malarial anaemia in Africa. Nat Commun 2023; 14:402. [PMID: 36697413 PMCID: PMC9876927 DOI: 10.1038/s41467-023-35939-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Children recovering from severe malarial anaemia (SMA) remain at high risk of readmission and death after discharge from hospital. However, a recent trial found that post-discharge malaria chemoprevention (PDMC) with dihydroartemisinin-piperaquine reduces this risk. We developed a mathematical model describing the daily incidence of uncomplicated and severe malaria requiring readmission among 0-5-year old children after hospitalised SMA. We fitted the model to a multicentre clinical PDMC trial using Bayesian methods and modelled the potential impact of PDMC across malaria-endemic African countries. In the 20 highest-burden countries, we estimate that only 2-5 children need to be given PDMC to prevent one hospitalised malaria episode, and less than 100 to prevent one death. If all hospitalised SMA cases access PDMC in moderate-to-high transmission areas, 38,600 (range 16,900-88,400) malaria-associated readmissions could be prevented annually, depending on access to hospital care. We estimate that recurrent SMA post-discharge constitutes 19% of all SMA episodes in moderate-to-high transmission settings.
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Affiliation(s)
- Lucy C Okell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College, London, W2 1PG, UK.
| | - Titus K Kwambai
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
- Department of Clinical Sciences, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Aggrey Dhabangi
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Carole Khairallah
- Department of Clinical Sciences, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Thandile Nkosi-Gondwe
- Kamuzu University of Health Sciences, Blantyre, Malawi
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Peter Winskill
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College, London, W2 1PG, UK
| | - Robert Opoka
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Andria Mousa
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College, London, W2 1PG, UK
| | - Melf-Jakob Kühl
- Section for Ethics and Health Economics, Department of Global Public Health and Primary Care, University of Bergen, P.O. Box 7804, 5020, Bergen, Norway
| | - Tim C D Lucas
- Big Data Institute, University of Oxford, Oxford, UK
| | - Joseph D Challenger
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College, London, W2 1PG, UK
| | - Richard Idro
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Daniel J Weiss
- Malaria Atlas Project, Telethon Kids Institute, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, Australia
- Curtin University, Bentley, Australia
| | - Matthew Cairns
- International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Feiko O Ter Kuile
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
- Department of Clinical Sciences, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Kamija Phiri
- Kamuzu University of Health Sciences, Blantyre, Malawi
- Training and Research Unit of Excellence, Blantyre, Malawi
| | - Bjarne Robberstad
- Section for Ethics and Health Economics, Department of Global Public Health and Primary Care, University of Bergen, P.O. Box 7804, 5020, Bergen, Norway
| | - Amani Thomas Mori
- Section for Ethics and Health Economics, Department of Global Public Health and Primary Care, University of Bergen, P.O. Box 7804, 5020, Bergen, Norway.
- Chr. Michelsen Institute, P.O. Box 6033, N-5892, Bergen, Norway.
- Muhimbili University of Health and Allied Sciences, P.O.Box 65001, Dar es Salaam, Tanzania.
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7
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Assefa A, Mohammed H, Anand A, Abera A, Sime H, Minta AA, Tadesse M, Tadesse Y, Girma S, Bekele W, Etana K, Alemayehu BH, Teka H, Dilu D, Haile M, Solomon H, Moriarty LF, Zhou Z, Svigel SS, Ezema B, Tasew G, Woyessa A, Hwang J, Murphy M. Therapeutic efficacies of artemether-lumefantrine and dihydroartemisinin-piperaquine for the treatment of uncomplicated Plasmodium falciparum and chloroquine and dihydroartemisinin-piperaquine for uncomplicated Plasmodium vivax infection in Ethiopia. Malar J 2022; 21:359. [PMID: 36451216 PMCID: PMC9714156 DOI: 10.1186/s12936-022-04350-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/27/2022] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Routine monitoring of anti-malarial drugs is recommended for early detection of drug resistance and to inform national malaria treatment guidelines. In Ethiopia, the national treatment guidelines employ a species-specific approach. Artemether-lumefantrine (AL) and chloroquine (CQ) are the first-line schizonticidal treatments for Plasmodium falciparum and Plasmodium vivax, respectively. The National Malaria Control and Elimination Programme in Ethiopia is considering dihydroartemisinin-piperaquine (DHA/PPQ) as an alternative regimen for P. falciparum and P. vivax. METHODS The study assessed the clinical and parasitological efficacy of AL, CQ, and DHA/PPQ in four arms. Patients over 6 months and less than 18 years of age with uncomplicated malaria mono-infection were recruited and allocated to AL against P. falciparum and CQ against P. vivax. Patients 18 years or older with uncomplicated malaria mono-infection were recruited and randomized to AL or dihydroartemisinin-piperaquine (DHA/PPQ) against P. falciparum and CQ or DHA/PPQ for P. vivax. Patients were followed up for 28 (for CQ and AL) or 42 days (for DHA/PPQ) according to the WHO recommendations. Polymerase chain reaction (PCR)-corrected and uncorrected estimates were analysed by Kaplan Meier survival analysis and per protocol methods. RESULTS A total of 379 patients were enroled in four arms (n = 106, AL-P. falciparum; n = 75, DHA/PPQ- P. falciparum; n = 142, CQ-P. vivax; n = 56, DHA/PPQ-P. vivax). High PCR-corrected adequate clinical and parasitological response (ACPR) rates were observed at the primary end points of 28 days for AL and CQ and 42 days for DHA/PPQ. ACPR rates were 100% in AL-Pf (95% CI: 96-100), 98% in CQ-P. vivax (95% CI: 95-100) at 28 days, and 100% in the DHA/PPQ arms for both P. falciparum and P. vivax at 42 days. For secondary endpoints, by day three 99% of AL-P. falciparum patients (n = 101) cleared parasites and 100% were afebrile. For all other arms, 100% of patients cleared parasites and were afebrile by day three. No serious adverse events were reported. CONCLUSION This study demonstrated high therapeutic efficacy for the anti-malarial drugs currently used by the malaria control programme in Ethiopia and provides information on the efficacy of DHA/PPQ for the treatment of P. falciparum and P. vivax as an alternative option.
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Affiliation(s)
- Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia. .,Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Hussein Mohammed
- grid.452387.f0000 0001 0508 7211Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Anjoli Anand
- grid.416738.f0000 0001 2163 0069Epidemic Intelligence Service, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA ,grid.416738.f0000 0001 2163 0069Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Adugna Abera
- grid.452387.f0000 0001 0508 7211Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Heven Sime
- grid.452387.f0000 0001 0508 7211Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Anna A. Minta
- grid.416738.f0000 0001 2163 0069Epidemic Intelligence Service, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA ,grid.416738.f0000 0001 2163 0069Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | | | | | - Samuel Girma
- ICAP at Columbia University, Addis Ababa, Ethiopia ,U.S. President’s Malaria Initiative, USA Agency for International Development, Addis Ababa, Ethiopia
| | - Worku Bekele
- World Health Organization, Addis Ababa, Ethiopia
| | - Kebede Etana
- grid.414835.f0000 0004 0439 6364Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | | | - Hiwot Teka
- U.S. President’s Malaria Initiative, USA Agency for International Development, Addis Ababa, Ethiopia
| | - Dereje Dilu
- grid.414835.f0000 0004 0439 6364Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Mebrahtom Haile
- grid.414835.f0000 0004 0439 6364Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- grid.414835.f0000 0004 0439 6364Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Leah F. Moriarty
- grid.416738.f0000 0001 2163 0069U.S. President’s Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Zhiyong Zhou
- grid.416738.f0000 0001 2163 0069Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Samaly Souza Svigel
- grid.416738.f0000 0001 2163 0069Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Bryan Ezema
- grid.416738.f0000 0001 2163 0069Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Geremew Tasew
- grid.452387.f0000 0001 0508 7211Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Adugna Woyessa
- grid.452387.f0000 0001 0508 7211Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Jimee Hwang
- grid.416738.f0000 0001 2163 0069U.S. President’s Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Matthew Murphy
- grid.416738.f0000 0001 2163 0069U.S. President’s Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA USA
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8
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Cohee LM, Peterson I, Buchwald AG, Coalson JE, Valim C, Chilombe M, Ngwira A, Bauleni A, Schaffer-DeRoo S, Seydel KB, Wilson ML, Taylor TE, Mathanga DP, Laufer MK. School-Based Malaria Screening and Treatment Reduces Plasmodium falciparum Infection and Anemia Prevalence in Two Transmission Settings in Malawi. J Infect Dis 2022; 226:138-146. [PMID: 35290461 PMCID: PMC9373151 DOI: 10.1093/infdis/jiac097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/12/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In areas highly endemic for malaria, Plasmodium falciparum infection prevalence peaks in school-age children, adversely affecting health and education. School-based intermittent preventive treatment reduces this burden but concerns about cost and widespread use of antimalarial drugs limit enthusiasm for this approach. School-based screening and treatment is an attractive alternative. In a prospective cohort study, we evaluated the impact of school-based screening and treatment on the prevalence of P. falciparum infection and anemia in 2 transmission settings. METHODS We screened 704 students in 4 Malawian primary schools for P. falciparum infection using rapid diagnostic tests (RDTs), and treated students who tested positive with artemether-lumefantrine. We determined P. falciparum infection by microscopy and quantitative polymerase chain reaction (qPCR), and hemoglobin concentrations over 6 weeks in all students. RESULTS Prevalence of infection by RDT screening was 37% (9%-64% among schools). An additional 9% of students had infections detected by qPCR. Following the intervention, significant reductions in infections were detected by microscopy (adjusted relative reduction [aRR], 48.8%; P < .0001) and qPCR (aRR, 24.5%; P < .0001), and in anemia prevalence (aRR, 30.8%; P = .003). Intervention impact was reduced by infections not detected by RDT and new infections following treatment. CONCLUSIONS School-based screening and treatment reduced P. falciparum infection and anemia. This approach could be enhanced by repeating screening, using more-sensitive screening tests, and providing longer-acting drugs. CLINICAL TRIALS REGISTRATION NCT04858087.
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Affiliation(s)
- Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ingrid Peterson
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jenna E Coalson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Moses Chilombe
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andrew Ngwira
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andy Bauleni
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Karl B Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | - Terrie E Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Don P Mathanga
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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9
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Liu Y, Liang X, Li J, Chen J, Huang H, Zheng Y, He J, Ehapo CS, Eyi UM, Yang P, Lin L, Chen W, Sun G, Liu X, Zha G, Wang J, Wang C, Wei H, Lin M. Molecular Surveillance of Artemisinin-Based Combination Therapies Resistance in Plasmodium falciparum Parasites from Bioko Island, Equatorial Guinea. Microbiol Spectr 2022; 10:e0041322. [PMID: 35670601 PMCID: PMC9241599 DOI: 10.1128/spectrum.00413-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Artemisinin-based combination therapies (ACTs) resistance has emerged and could be diffusing in Africa. As an offshore island on the African continent, the island of Bioko in Equatorial Guinea is considered severely affected and resistant to drug-resistant Plasmodium falciparum malaria. However, the spatial and temporal distribution remain unclear. Molecular monitoring targeting the Pfcrt, Pfk13, Pfpm2, and Pfmdr1 genes was conducted to provide insight into the impact of current antimalarial drug resistance on the island. Furthermore, polymorphic characteristics, haplotype network, and the effect of natural selection of the Pfk13 gene were evaluated. A total of 152 Plasmodium falciparum samples (collected from 2017 to 2019) were analyzed for copy number variation of the Pfpm2 gene and Pfk13, Pfcrt, and Pfmdr1 mutations. Statistical analysis of Pfk13 sequences was performed following different evolutionary models using 96 Bioko sequences and 1322 global sequences. The results showed that the prevalence of Pfk13, Pfcrt, and Pfmdr1 mutations was 73.68%, 78.29%, and 75.66%, respectively. Large proportions of isolates with multiple copies of Pfpm2 were observed (67.86%). In Bioko parasites, the genetic diversity of Pfk13 was low, and purifying selection was suggested by Tajima's D test (-1.644, P > 0.05) and the dN/dS test (-0.0004438, P > 0.05). The extended haplotype homozygosity analysis revealed that Pfk13_K189T, although most frequent in Africa, has not yet conferred a selective advantage for parasitic survival. The results suggested that the implementation of continuous drug monitoring on Bioko Island is an essential measure. IMPORTANCE Malaria, one of the tropical parasitic diseases with a high transmission rate in Bioko Island, Equatorial Guinea, especially caused by P. falciparum is highly prevalent in this region and is commonly treated locally with ACTs. The declining antimalarial susceptibility of artemisinin-based drugs suggested that resistance to artemisinin and its derivatives is developing in P. falciparum. Copy number variants in Pfpm2 and genetic polymorphisms in Pfk13, Pfcrt, and Pfmdr1 can be used as risk assessment indicators to track the development and spread of drug resistance. This study reported for the first time the molecular surveillance of Pfpm2, Pfcrt, Pfk13, and Pfmdr1 genes in Bioko Island from 2017 to 2019 to assess the possible risk of local drug-resistant P. falciparum.
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Affiliation(s)
- YaQun Liu
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - XueYan Liang
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - Jian Li
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei, People’s Republic of China
| | - JiangTao Chen
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong, People's Republic of China
- Department of Medical Laboratory, Huizhou Central Hospital, Huizhou, Guangdong, People's Republic of China
| | - HuiYing Huang
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, Hubei, People’s Republic of China
| | - YuZhong Zheng
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - JinQuan He
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong, People's Republic of China
| | - Carlos Salas Ehapo
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - Urbano Monsuy Eyi
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - PeiKui Yang
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - LiYun Lin
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - WeiZhong Chen
- Department of Medical Laboratory, Chaozhou People’s Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong, People's Republic of China
| | - GuangYu Sun
- Department of Medical Laboratory, Chaozhou People’s Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong, People's Republic of China
| | - XiangZhi Liu
- Department of Medical Laboratory, Chaozhou People’s Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong, People's Republic of China
| | - GuangCai Zha
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
| | - JunLi Wang
- School of Laboratory Medicine, Youjiang Medical University for Nationalities, Baise, Guangxi, People’s Republic of China
| | - ChunFang Wang
- School of Laboratory Medicine, Youjiang Medical University for Nationalities, Baise, Guangxi, People’s Republic of China
| | - HuaGui Wei
- School of Laboratory Medicine, Youjiang Medical University for Nationalities, Baise, Guangxi, People’s Republic of China
| | - Min Lin
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, Guangdong, People’s Republic of China
- School of Laboratory Medicine, Youjiang Medical University for Nationalities, Baise, Guangxi, People’s Republic of China
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10
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Cohen JM, Okumu F, Moonen B. The fight against malaria: Diminishing gains and growing challenges. Sci Transl Med 2022; 14:eabn3256. [PMID: 35767649 DOI: 10.1126/scitranslmed.abn3256] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Since the year 2000, historic reductions in malaria incidence and mortality have been driven by the widespread distribution of bed nets, drugs, and insecticides for the prevention and treatment of malaria. Scale-up of these tools has been enabled by an increase in malaria financing compounded by price reductions, yet these trends are unlikely to continue at the same rate. Rapid population growth in high-endemic areas requires procurement of more of these tools just to maintain current coverage, even as prices are likely to increase as resistance to drugs and insecticides forces shifts to newer products. Further progress toward the long-term goal of malaria eradication requires a combination of greater funding, more cost-effective resource allocation, and fundamental changes to the global malaria control strategy.
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Affiliation(s)
| | - Fredros Okumu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, Ifakara, Tanzania.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Bruno Moonen
- Bill & Melinda Gates Foundation, Seattle, WA, USA
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11
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Patra S, Singh M, Wasnik K, Pareek D, Gupta PS, Mukherjee S, Paik P. Polymeric Nanoparticle Based Diagnosis and Nanomedicine for Treatment and Development of Vaccines for Cerebral Malaria: A Review on Recent Advancement. ACS APPLIED BIO MATERIALS 2021; 4:7342-7365. [PMID: 35006689 DOI: 10.1021/acsabm.1c00635] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebral malaria occurs due to Plasmodium falciparum infection, which causes 228 million infections and 450,000 deaths worldwide every year. African people are mostly affected with nearly 91% cases, of which 86% are pregnant women and infants. India and Brazil are the other two countries severely suffering from malaria endemicity. Commonly used drugs have severe side effects, and unfortunately no suitable vaccine is available in the market today. In this line, this review is focused on polymeric nanomaterials and nanocapsules that can be used for the development of effective diagnostic strategies, nanomedicines, and vaccines in the management of cerebral malaria. Further, this review will help scientists and medical professionals by updating the status on the development stages of polymeric nanoparticle based diagnostics, nanomedicines, and vaccines and strategies to eradicate cerebral malaria. In addition to this, the predominant focus of this review is antimalarial agents based on polymer nanomedicines that are currently in the preclinical and clinical trial stages, and potential developments are suggested as well. This review further will have an important social and commercial impact worldwide for the development of polymeric nanomedicines and strategies for the treatment of cerebral malaria.
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Affiliation(s)
- Sukanya Patra
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Monika Singh
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Kirti Wasnik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Divya Pareek
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Prem Shankar Gupta
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Sudip Mukherjee
- Department of Bioengineering, Rice University, Houston, Texas 77030, United States
| | - Pradip Paik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
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12
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Artemether confers neuroprotection on cerebral ischemic injury through stimulation of the Erk1/2-P90rsk-CREB signaling pathway. Redox Biol 2021; 46:102069. [PMID: 34303216 PMCID: PMC8327154 DOI: 10.1016/j.redox.2021.102069] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 04/01/2021] [Accepted: 07/12/2021] [Indexed: 12/17/2022] Open
Abstract
Ischemic stroke is one of the leading causes of death and disability among adults. Despite the economic burden of the disease, available treatment options are still very limited. With the exception of anti-thrombolytics and hypothermia, current therapies fail to reduce neuronal injury, neurological deficits and mortality rates, suggesting that the development of novel and more effective therapies against ischemic stroke is urgent. In the present study, we found that artemether, which has been used in the clinic as an anti-malarial drug, was able to improve the neurological deficits, attenuate the infarction volume and the brain water content in a middle cerebral artery occlusion (MCAO) animal model. Furthermore, artemether treatment significantly suppressed cell apoptosis, stimulated cell proliferation and promoted the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), P90rsk and cAMP responsive element-binding protein (CREB). Artemether protective effect was attenuated by PD98059, an ERK1/2 inhibitor, administration. Similarly, in oxygen-glucose deprivation/reperfusion (OGD/RP) cell models, artemether pre-treatment induced the suppression of the intracellular ROS, the down-regulation of LDH activity, the reduction of caspase 3 activity and of the apoptosis cell rate and reversed the decrease of mitochondrial membrane potential. As with MCAO animal model, artemether promoted the activation of Erk1/2-P90rsk-CREB signaling pathway. This effect was blocked by the inhibition or knock-down of ERK1/2. The present study provides evidences of the neuroprotective effect of artemether unravelling its potential as a new therapeutic candidate for the prevention and treatment of stroke. Artemether conferred neuroprotection in a middle cerebral artery occlusion (MCAO) animal model. Artemether conferred neuroprotection on oxygen-glucose deprivation/reperfusion-induced cell injury model. Artemether promoted the activation of Erk1/2-P90rsk-CREB signaling pathway in vitro and in vivo.
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13
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Ali SW, Mangrio FA, Li F, Dwivedi P, Rajput MU, Ali R, Khan MI, Ding W, Xu RX. Co-delivery of artemether and piperine via core-shell microparticles for enhanced sustained release. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102505] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Abamecha A, Yilma D, Adissu W, Yewhalaw D, Abdissa A. Efficacy and safety of artemether-lumefantrine for treatment of uncomplicated Plasmodium falciparum malaria in Ethiopia: a systematic review and meta-analysis. Malar J 2021; 20:213. [PMID: 33957925 PMCID: PMC8101141 DOI: 10.1186/s12936-021-03745-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/21/2021] [Indexed: 11/20/2022] Open
Abstract
Background Regular monitoring of anti-malarial drug efficacy is vital for establishing rational malaria treatment guidelines and ensuring adequate treatment outcomes. This study aimed to synthesize the available evidence on the efficacy of artemether–lumefantrine for the management of uncomplicated falciparum malaria in Ethiopia. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Relevant published studies were searched from the databases (PubMed, Google Scholar and Clinical trial registry) on published artemether–lumefantrine therapeutic efficacy studies conducted in Ethiopia from 2004 to 2020. The retrieved studies were assessed for quality using the modified Newcastle Ottawa Scale for observational studies and modified Jadad scale for interventional studies. Risk of bias was also assessed by using ROBINS-I tool. OpenMeta-Analyst software was used for the statistical analysis. The review protocol is registered in PROSPERO, number CRD42020201859. Results Fifteen studies (1523 participants) were included in the final analysis. The overall PCR-uncorrected pooled proportion of treatment success of artemether–lumefantrine therapy for uncomplicated falciparum malaria was 98.4% (95%CI 97.6–99.1). A random-effects model was used because of considerable heterogeneity [χ2 = 20.48, df (14), P = 0.011 and I2 = 31.65]. PCR-corrected pooled proportion of treatment success of artemether–lumefantrine therapy was 98.7% (95% CI 97.7–99.6). A random-effects model was used [χ2 = 7.37, df(6), P = 0.287 and I2 = 18.69]. Most studies included in the present review achieved a rapid reduction of fevers and parasitaemia between D0 and D3 of assessment. Adverse events were mostly mild and only two cases were reported as serious, but were not directly attributed to the drug. Conclusion The present meta-analysis suggests that artemether–lumefantrine therapy is efficacious and safe in treating uncomplicated falciparum malaria in Ethiopia. However, owing to the high risk of bias in the included studies, strong conclusions cannot be drawn. Further high-quality RCTs assessing anti-malarial efficacy and safety should be performed to demonstrates strong evidence of changes in parasite sensitivity to artemether–lumefantrine in Ethiopia. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03745-8.
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Affiliation(s)
- Abdulhakim Abamecha
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia. .,Clinical Trial Unit, Jimma University, Jimma, Ethiopia. .,Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia. .,Department of Biomedical, College of Public Health and Medical Science, Mettu University, Mettu, Ethiopia.
| | - Daniel Yilma
- Department of Internal Medicine, Institute of Health, Jimma University, Jimma, Ethiopia.,Clinical Trial Unit, Jimma University, Jimma, Ethiopia
| | - Wondimagegn Adissu
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.,Clinical Trial Unit, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.,Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia
| | - Alemseged Abdissa
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.,Clinical Trial Unit, Jimma University, Jimma, Ethiopia.,Armauer Hansen Research Institute, Addis Ababa, Ethiopia
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15
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Barry A, Bradley J, Stone W, Guelbeogo MW, Lanke K, Ouedraogo A, Soulama I, Nébié I, Serme SS, Grignard L, Patterson C, Wu L, Briggs JJ, Janson O, Awandu SS, Ouedraogo M, Tarama CW, Kargougou D, Zongo S, Sirima SB, Marti M, Drakeley C, Tiono AB, Bousema T. Higher gametocyte production and mosquito infectivity in chronic compared to incident Plasmodium falciparum infections. Nat Commun 2021; 12:2443. [PMID: 33903595 PMCID: PMC8076179 DOI: 10.1038/s41467-021-22573-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 03/09/2021] [Indexed: 11/09/2022] Open
Abstract
Plasmodium falciparum gametocyte kinetics and infectivity may differ between chronic and incident infections. In the current study, we assess parasite kinetics and infectivity to mosquitoes among children (aged 5-10 years) from Burkina Faso with (a) incident infections following parasite clearance (n = 48) and (b) chronic asymptomatic infections (n = 60). In the incident infection cohort, 92% (44/48) of children develop symptoms within 35 days, compared to 23% (14/60) in the chronic cohort. All individuals with chronic infection carried gametocytes or developed them during follow-up, whereas only 35% (17/48) in the incident cohort produce gametocytes before becoming symptomatic and receiving treatment. Parasite multiplication rate (PMR) and the relative abundance of ap2-g and gexp-5 transcripts are positively associated with gametocyte production. Antibody responses are higher and PMR lower in chronic infections. The presence of symptoms and sexual stage immune responses are associated with reductions in gametocyte infectivity to mosquitoes. We observe that most incident infections require treatment before the density of mature gametocytes is sufficient to infect mosquitoes. In contrast, chronic, asymptomatic infections represent a significant source of mosquito infections. Our observations support the notion that malaria transmission reduction may be expedited by enhanced case management, involving both symptom-screening and infection detection.
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Affiliation(s)
- Aissata Barry
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
- Radboud Institute for Health Sciences and Radboud Center for Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Will Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Moussa W Guelbeogo
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences and Radboud Center for Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Alphonse Ouedraogo
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Issiaka Soulama
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Issa Nébié
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Samuel S Serme
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Lynn Grignard
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Catriona Patterson
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Lindsey Wu
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Jessica J Briggs
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Owen Janson
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Shehu S Awandu
- Radboud Institute for Health Sciences and Radboud Center for Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Mireille Ouedraogo
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Casimire W Tarama
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Désiré Kargougou
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Soumanaba Zongo
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Sodiomon B Sirima
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Matthias Marti
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Chris Drakeley
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou 01, Burkina Faso
| | - Teun Bousema
- Radboud Institute for Health Sciences and Radboud Center for Infectious Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands.
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16
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A trio of quinoline-isoniazid-phthalimide with promising antiplasmodial potential: Synthesis, in-vitro evaluation and heme-polymerization inhibition studies. Bioorg Med Chem 2021; 39:116159. [PMID: 33895706 DOI: 10.1016/j.bmc.2021.116159] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 11/21/2022]
Abstract
Quinoline-isoniazid-phthalimide triads have been synthesised to assess their antiplasmodial efficacy and cytotoxicity against chloroquine-resistant W2 strain of P. falciparum and Vero cells, respectively. Most of the synthesized compounds displayed IC50 in lower nM range and appeared to be approximately five to twelve fold more active than chloroquine. Heme-binding studies were also carried out to delineate the mode of action. The promising compounds with IC50s in range of 11-30 nM and selectivity index >2800, may act as promising template for the design of new antiplasmodials.
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17
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Guan Q, Reich BJ, Laber EB. A spatiotemporal recommendation engine for malaria control. Biostatistics 2021; 23:1023-1038. [PMID: 33838029 DOI: 10.1093/biostatistics/kxab010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 03/09/2021] [Accepted: 03/14/2021] [Indexed: 11/13/2022] Open
Abstract
Malaria is an infectious disease affecting a large population across the world, and interventions need to be efficiently applied to reduce the burden of malaria. We develop a framework to help policy-makers decide how to allocate limited resources in realtime for malaria control. We formalize a policy for the resource allocation as a sequence of decisions, one per intervention decision, that map up-to-date disease related information to a resource allocation. An optimal policy must control the spread of the disease while being interpretable and viewed as equitable to stakeholders. We construct an interpretable class of resource allocation policies that can accommodate allocation of resources residing in a continuous domain and combine a hierarchical Bayesian spatiotemporal model for disease transmission with a policy-search algorithm to estimate an optimal policy for resource allocation within the pre-specified class. The estimated optimal policy under the proposed framework improves the cumulative long-term outcome compared with naive approaches in both simulation experiments and application to malaria interventions in the Democratic Republic of the Congo.
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Affiliation(s)
- Qian Guan
- Department of Statistics, North Carolina State University, 2311 Stinson Dr. Raleigh, NC 27695-8203, USA
| | - Brian J Reich
- Department of Statistics, North Carolina State University, 2311 Stinson Dr. Raleigh, NC 27695-8203, USA
| | - Eric B Laber
- Department of Statistics, North Carolina State University, 2311 Stinson Dr. Raleigh, NC 27695-8203, USA
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18
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Shibeshi W, Alemkere G, Mulu A, Engidawork E. Efficacy and safety of artemisinin-based combination therapies for the treatment of uncomplicated malaria in pediatrics: a systematic review and meta-analysis. BMC Infect Dis 2021; 21:326. [PMID: 33827422 PMCID: PMC8028735 DOI: 10.1186/s12879-021-06018-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/26/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Malaria is a major cause of morbidity and mortality in pediatrics in malaria endemic areas. Artemisinin-based combination therapies (ACTs) are the drugs of choice for malaria management particularly across malaria-endemic countries. This systematic review and meta-analysis was performed to assess efficacy and safety of ACTs for uncomplicated malaria in pediatric populations. METHODS A body of evidence was searched for published ACT trials until March 06, 2020. The search was focused on efficacy and safety studies of ACTs for uncomplicated malaria in pediatrics. PubMed library was searched using best adapted search terms after multiple trials. References were exported to the endnote library and then to Covidence for screening. Data was extracted using the Covidence platform. The per-protocol analysis report for the efficacy and the intention-to-treat analysis for the safety were synthesized. Met-analysis was carried using Open Meta-Analyst software. Random effects model was applied and the heterogeneity of studies was evaluated using I2 statistic. RESULTS Nineteen studies were included in the final analysis. Overall, crude, PCR-corrected P. falciparum malaria treatment success rate was 96.3 and 93.9% for day 28 and 42, respectively. In the subgroup analysis, PCR-corrected adequate clinical and parasitological response (ACPR) of dihydroartemisinin-piperaquine (DP) was 99.6% (95% CI: 99.1 to 100%, I2 = 0%; 4 studies) at day 28 and 99.6% (95% CI of 99 to 100%, I2 = 0%; 3 studies) at day 42. Nine studies reported ACT related adverse drug reactions (ADR) (8.3%, 356/4304). The reported drug related adverse reactions ranged from 1.8% in DP (two studies) to 23.3% in artesunate-pyronaridine (AP). Gastrointestinal symptoms were the most common ACT related adverse effects, and all ADRs were reported to resolve spontaneously. CONCLUSION ACTs demonstrated a high crude efficacy and tolerability against P. falciparum. The high treatment success and tolerability with low heterogeneity conferred by DP has implication for policy makers who plan the use of ACTs for uncomplicated falciparum malaria treatment in pediatrics.
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Affiliation(s)
- Workineh Shibeshi
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Getachew Alemkere
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Assefa Mulu
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Chaccour C, Zulliger R, Wagman J, Casellas A, Nacima A, Elobolobo E, Savaio B, Saifodine A, Fornadel C, Richardson J, Candrinho B, Robertson M, Saute F. Incremental impact on malaria incidence following indoor residual spraying in a highly endemic area with high standard ITN access in Mozambique: results from a cluster-randomized study. Malar J 2021; 20:84. [PMID: 33568137 PMCID: PMC7877039 DOI: 10.1186/s12936-021-03611-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 01/28/2021] [Indexed: 11/17/2022] Open
Abstract
Background Attaining the goal of reducing the global malaria burden is threatened by recent setbacks in maintaining the effectiveness of vector control interventions partly due to the emergence of pyrethroid resistant vectors. One potential strategy to address these setbacks could be combining indoor residual spraying (IRS) with non-pyrethroids and standard insecticide-treated nets (ITNs). This study aimed to provide evidence on the incremental epidemiological benefit of using third-generation IRS product in a highly endemic area with high ITN ownership. Methods A cluster-randomized, open-label, parallel-arms, superiority trial was conducted in the Mopeia district in Zambezia, Mozambique from 2016 to 2018. The district had received mass distribution of alphacypermethrin ITNs two years before the trial and again mid-way. 86 clusters were defined, stratified and randomized to receive or not receive IRS with pirimiphos-methyl (Actellic®300 CS). Efficacy of adding IRS was assessed through malaria incidence in a cohort of children under five followed prospectively for two years, enhanced passive surveillance at health facilities and by community health workers, and yearly cross-sectional surveys at the peak of the transmission season. Findings A total of 1536 children were enrolled in the cohort. Children in the IRS arm experienced 4,801 cases (incidence rate of 3,532 per 10,000 children-month at risk) versus 5,758 cases in the no-IRS arm (incidence rate of 4,297 per 10,000 children-month at risk), resulting in a crude risk reduction of 18% and an incidence risk ratio of 0.82 (95% CI 0.79–0.86, p-value < 0.001). Facility and community passive surveillance showed a malaria incidence of 278 per 10,000 person-month in the IRS group (43,974 cases over 22 months) versus 358 (95% CI 355–360) per 10,000 person-month at risk in the no-IRS group (58,030 cases over 22 months), resulting in an incidence rate ratio of 0.65 (95% CI 0.60–0.71, p < 0.001). In the 2018 survey, prevalence in children under five in the IRS arm was significantly lower than in the no-IRS arm (OR 0.54, 95% CI, 0.31–0.92, p = 0.0241). Conclusion In a highly endemic area with high ITN access and emerging pyrethroid resistance, adding IRS with pirimiphos-methyl resulted in significant additional protection for children under five years of age. Trial registration: ClinicalTrials.gov identifier NCT02910934, registered 22 September 2016, https://clinicaltrials.gov/ct2/show/NCT02910934?term=NCT02910934&draw=2&rank=1.
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Affiliation(s)
- Carlos Chaccour
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
| | - Rose Zulliger
- President's Malaria Initiative, US Centers for Disease Control and Prevention, Maputo, Mozambique
| | | | - Aina Casellas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Amilcar Nacima
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Eldo Elobolobo
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | | | - Abuchahama Saifodine
- President's Malaria Initiative, United States Agency for International Development, Maputo, Mozambique
| | | | | | | | | | - Francisco Saute
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
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20
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Mahamar A, Lanke K, Graumans W, Diawara H, Sanogo K, Diarra K, Niambele SM, Gosling R, Drakeley C, Chen I, Dicko A, Bousema T, Roh ME. Persistence of mRNA indicative of Plasmodium falciparum ring-stage parasites 42 days after artemisinin and non-artemisinin combination therapy in naturally infected Malians. Malar J 2021; 20:34. [PMID: 33422068 PMCID: PMC7797096 DOI: 10.1186/s12936-020-03576-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 12/31/2020] [Indexed: 11/10/2022] Open
Abstract
Background Malaria control in sub-Saharan Africa relies upon prompt case management with artemisinin-based combination therapy (ACT). Ring-stage parasite mRNA, measured by sbp1 quantitative reverse-transcriptase PCR (qRT-PCR), was previously reported to persist after ACT treatment and hypothesized to reflect temporary arrest of the growth of ring-stage parasites (dormancy) following exposure to artemisinins. Here, the persistence of ring-stage parasitaemia following ACT and non-ACT treatment was examined. Methods Samples were used from naturally infected Malian gametocyte carriers who received dihydroartemisinin–piperaquine (DP) or sulfadoxine–pyrimethamine (SP–AQ) with or without gametocytocidal drugs. Gametocytes and ring-stage parasites were quantified by qRT-PCR during 42 days of follow-up. Results At baseline, 89% (64/73) of participants had measurable ring-stage parasite mRNA. Following treatment, the proportion of ring-stage parasite-positive individuals and estimated densities declined for all four treatment groups. Ring-stage parasite prevalence and density was generally lower in arms that received DP compared to SP–AQ. This finding was most apparent days 1, 2, and 42 of follow-up (p < 0.01). Gametocytocidal drugs did not influence ring-stage parasite persistence. Ring-stage parasite density estimates on days 14 and 28 after initiation of treatment were higher among individuals who subsequently experienced recurrent parasitaemia compared to those who remained free of parasites until day 42 after initiation of treatment (pday 14 = 0.011 and pday 28 = 0.068). No association of ring-stage persistence with gametocyte carriage was observed. Conclusions The current findings of lower ring-stage persistence after ACT without an effect of gametocytocidal partner drugs affirms the use of sbp1 as ring-stage marker. Lower persistence of ring-stage mRNA after ACT treatment suggests the marker may not reflect dormant parasites whilst it was predictive of re-appearance of parasitaemia.
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Affiliation(s)
- Almahamoudou Mahamar
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Kjerstin Lanke
- Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 26-28, PO Box 9101, 6525GA, Nijmegen, The Netherlands
| | - Wouter Graumans
- Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 26-28, PO Box 9101, 6525GA, Nijmegen, The Netherlands
| | - Halimatou Diawara
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Koualy Sanogo
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Kalifa Diarra
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Sidi Mohamed Niambele
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Roly Gosling
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Chris Drakeley
- Department of Infection & Immunity, London School of Hygiene & Tropical Medicine, London, UK
| | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy, Medicine, and Dentistry, University of Science, Techniques, and Technologies of Bamako, Bamako, Mali
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 26-28, PO Box 9101, 6525GA, Nijmegen, The Netherlands. .,Department of Infection & Immunity, London School of Hygiene & Tropical Medicine, London, UK.
| | - Michelle E Roh
- Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, CA, USA
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21
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Mumtaz R, Okell LC, Challenger JD. Asymptomatic recrudescence after artemether-lumefantrine treatment for uncomplicated falciparum malaria: a systematic review and meta-analysis. Malar J 2020; 19:453. [PMID: 33298080 PMCID: PMC7724891 DOI: 10.1186/s12936-020-03520-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/25/2020] [Indexed: 01/05/2023] Open
Abstract
Background In clinical trials of therapy for uncomplicated Plasmodium falciparum, there are usually some patients who fail treatment even in the absence of drug resistance. Treatment failures, which can be due to recrudescence or re-infection, are categorized as ‘clinical’ or ‘parasitological’ failures, the former indicating that symptoms have returned. Asymptomatic recrudescence has public health implications for continued malaria transmission and may be important for the spread of drug-resistant malaria. As the number of recrudescences in an individual trial is often low, it is difficult to assess how commonplace asymptomatic recrudescence is, and with what factors it is associated. Methods A systematic literature review was carried out on clinical trials of artemether-lumefantrine (AL) in patients seeking treatment for symptomatic uncomplicated falciparum malaria, and information on symptoms during treatment failure was recorded. Only treatment failures examined by polymerase chain reaction (PCR) were included, so as to exclude re-infections. A multivariable Bayesian regression model was used to explore factors potentially explaining the proportion of recrudescent infections which are symptomatic across the trials included in the study. Results Across 60 published trials, including 9137 malaria patients, 37.8% [95% CIs (26.6–49.4%)] of recrudescences were symptomatic. A positive association was found between transmission intensity and the observed proportion of recrudescences that were asymptomatic. Symptoms were more likely to return in trials that only enrolled children aged < 72 months [odds ratio = 1.62, 95% CIs (1.01, 2.59)]. However, 84 studies had to be excluded from this analysis, as recrudescences were not specified as symptomatic or asymptomatic. Conclusions AL, the most widely used treatment for uncomplicated P. falciparum in Africa, remains a highly efficacious drug in most endemic countries. However in the small proportion of patients where AL does not clear parasitaemia, the majority of patients do not develop symptoms again and thus would be unlikely to seek another course of treatment. This continued asymptomatic parasite carriage in patients who have been treated may have implications for drug-resistant parasites being introduced into high-transmissions settings.
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Affiliation(s)
- Rida Mumtaz
- Faculty of Medicine, Imperial College London, London, UK
| | - Lucy C Okell
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Joseph D Challenger
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
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22
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Eisele TP, Bennett A, Silumbe K, Finn TP, Porter TR, Chalwe V, Hamainza B, Moonga H, Kooma E, Chizema Kawesha E, Kamuliwo M, Yukich JO, Keating J, Schneider K, Conner RO, Earle D, Slutsker L, Steketee RW, Miller JM. Impact of Four Rounds of Mass Drug Administration with Dihydroartemisinin-Piperaquine Implemented in Southern Province, Zambia. Am J Trop Med Hyg 2020; 103:7-18. [PMID: 32618247 PMCID: PMC7416977 DOI: 10.4269/ajtmh.19-0659] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Over the past decade, Zambia has made substantial progress against malaria and has recently set the ambitious goal of eliminating by 2021. In the context of very high vector control and improved access to malaria diagnosis and treatment in Southern Province, we implemented a community-randomized controlled trial to assess the impact of four rounds of community-wide mass drug administration (MDA) and household-level MDA (focal MDA) with dihydroartemisinin-piperaquine (DHAP) implemented between December 2014 and February 2016. The mass treatment campaigns achieved relatively good household coverage (63-79%), were widely accepted by the community (ranging from 87% to 94%), and achieved very high adherence to the DHAP regimen (81-96%). Significant declines in all malaria study end points were observed, irrespective of the exposure group, with the overall parasite prevalence during the peak transmission season declining by 87.2% from 31.3% at baseline to 4.0% in 2016 at the end of the trial. Children in areas of lower transmission (< 10% prevalence at baseline) that received four MDA rounds had a 72% (95% CI = 12-91%) reduction in malaria parasite prevalence as compared with those with the standard of care without any mass treatment. Mass drug administration consistently had the largest short-term effect size across study end points in areas of lower transmission following the first two MDA rounds. In the context of achieving very high vector control coverage and improved access to diagnosis and treatment for malaria, our results suggest that MDA should be considered for implementation in African settings for rapidly reducing malaria outcomes in lower transmission settings.
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Affiliation(s)
- Thomas P Eisele
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California
| | - Kafula Silumbe
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | - Timothy P Finn
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Travis R Porter
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Victor Chalwe
- Institute for Medical Research and Training, University Teaching Hospital, Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | - Hawela Moonga
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | - Emmanuel Kooma
- National Malaria Elimination Centre, Zambia Ministry of Health, Lusaka, Zambia
| | | | - Mulakwa Kamuliwo
- Zambia Ministry of Health, Southern Provincial Health Office, Choma, Zambia
| | - Joshua O Yukich
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Joseph Keating
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | | | | | - Duncan Earle
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
| | | | | | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), Lusaka, Zambia
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23
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Ghosh A, Banerjee T. Nanotized curcumin-benzothiophene conjugate: A potential combination for treatment of cerebral malaria. IUBMB Life 2020; 72:2637-2650. [PMID: 33037778 DOI: 10.1002/iub.2394] [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: 08/20/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 11/07/2022]
Abstract
The declining effectiveness of the available antimalarial drugs due to drug resistance requires a continued effort to develop new therapeutic approaches. In this context, combination therapies hold a great promise for developing effective first-line antimalarial treatments for reducing malaria mortality. The present study explores the antimalarial efficacy of nanotized formulation of curcumin in combination with benzothiophene compound 6 (3-bromo-N-(4-fluorobenzyl)-benzo[b]thiophene-2-carboxamide) with a view to achieve better efficacy at a very low dose in comparison to that accomplished with monotherapy alone. Herein, we formulated nanotized conjugate of curcumin and compound 6 (cur-compound 6) in the size range of 30-90 nm as observed via TEM, AFM and DLS analysis in the study. The nanotized preparation was found to be readily dispersible in water, physically and chemically stable and exhibited sustained release profile of both curcumin and compound 6 till 48 hr. Treatment of P. falciparum parasites with the nanotized conjugate for 24 hr resulted in rapid clearance of the parasites. Furthermore, P. berghei infected mice treated with nanotized conjugate formulation survived till 90 days with complete eradication of the parasites from RBC. This improved efficacy of the nanotized formulation was possible because of the increased absorption of the compounds via oral administration owing to enhanced dispersibility of the formulation in aqueous medium. Moreover, an improved oral bioavailability of the nanotized formulation lowered the dosage at which the pharmacological effect was achieved while avoiding any observable adverse harmful side effects.
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Affiliation(s)
- Aparajita Ghosh
- Molecular Sciences Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Tanushree Banerjee
- Dr. D. Y. Patil Biotechnology & Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
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Ashley EA, Poespoprodjo JR. Treatment and prevention of malaria in children. THE LANCET CHILD & ADOLESCENT HEALTH 2020; 4:775-789. [PMID: 32946831 DOI: 10.1016/s2352-4642(20)30127-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/11/2020] [Accepted: 03/25/2020] [Indexed: 10/23/2022]
Abstract
Malaria disproportionately affects children younger than 5 years. Falciparum malaria is responsible for more than 200 000 child deaths per year in Africa and vivax malaria is well documented as a cause of severe anaemia and excess mortality in children in Asia and Oceania. For the treatment of malaria in children, paediatric dosing recommendations for several agents, including parenteral artesunate and dihydroartemisinin-piperaquine, have belatedly been shown to be suboptimal. Worsening antimalarial resistance in Plasmodium falciparum in the Greater Mekong Subregion threatens to undermine global efforts to control malaria. Triple antimalarial combination therapies are being evaluated to try to impede this threat. The RTS,S/AS01 vaccine gives partial protection against falciparum malaria and is being evaluated in large, pilot studies in Ghana, Malawi, and Kenya as a complementary tool to other preventive measures. Seasonal malaria chemoprevention in west Africa has resulted in declines in malaria incidence and deaths and there is interest in scaling up efforts by expanding the age range of eligible recipients. Preventing relapse in Plasmodium vivax infection with primaquine is challenging because treating children who have G6PD deficiency with primaquine can cause acute haemolytic anaemia. The safety of escalating dose regimens for primaquine is being studied to mitigate this risk.
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Affiliation(s)
- Elizabeth A Ashley
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Jeanne Rini Poespoprodjo
- Timika Research Facility, Papuan Health and Community Development Foundation, Timika, Indonesia; Department of Child Health, Faculty of Medicine, Public Health and Nursing, Gadjah Mada University, Yogyakarta, Indonesia
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25
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Walker PGT, Cairns M, Slater H, Gutman J, Kayentao K, Williams JE, Coulibaly SO, Khairallah C, Taylor S, Meshnick SR, Hill J, Mwapasa V, Kalilani-Phiri L, Bojang K, Kariuki S, Tagbor H, Griffin JT, Madanitsa M, Ghani ACH, Desai M, Ter Kuile FO. Modelling the incremental benefit of introducing malaria screening strategies to antenatal care in Africa. Nat Commun 2020; 11:3799. [PMID: 32732892 PMCID: PMC7393377 DOI: 10.1038/s41467-020-17528-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/29/2020] [Indexed: 12/01/2022] Open
Abstract
Plasmodium falciparum in pregnancy is a major cause of adverse pregnancy outcomes. We combine performance estimates of standard rapid diagnostic tests (RDT) from trials of intermittent screening and treatment in pregnancy (ISTp) with modelling to assess whether screening at antenatal visits improves upon current intermittent preventative therapy with sulphadoxine-pyrimethamine (IPTp-SP). We estimate that RDTs in primigravidae at first antenatal visit are substantially more sensitive than in non-pregnant adults (OR = 17.2, 95% Cr.I. 13.8-21.6), and that sensitivity declines in subsequent visits and with gravidity, likely driven by declining susceptibility to placental infection. Monthly ISTp with standard RDTs, even with highly effective drugs, is not superior to monthly IPTp-SP. However, a hybrid strategy, recently adopted in Tanzania, combining testing and treatment at first visit with IPTp-SP may offer benefit, especially in areas with high-grade SP resistance. Screening and treatment in the first trimester, when IPTp-SP is contraindicated, could substantially improve pregnancy outcomes.
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Affiliation(s)
- Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Matt Cairns
- London School of Hygiene and Tropical Medicine, London, UK
| | - Hannah Slater
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
- PATH, Seattle, WA, USA
| | - Julie Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kassoum Kayentao
- Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, Pharmacy, and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali
| | | | - Sheick O Coulibaly
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Carole Khairallah
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Steve Taylor
- Global Health Institute, Duke University, Durham, NC, USA
| | | | - Jenny Hill
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Victor Mwapasa
- College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Kalifa Bojang
- Medical Research Council, London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Simon Kariuki
- Kenya Medical Research Institute/Centre for Global Health Research, Kisumu, Kenya
| | - Harry Tagbor
- University of Health and Allied Sciences, Ho, Ghana
| | - Jamie T Griffin
- School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, UK
| | | | - Azra C H Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Feiko O Ter Kuile
- Faculty of Health Sciences, University of Ouagadougou, Ouagadougou, Burkina Faso
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26
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Jackson KD, Higgins CR, Laing SK, Mwila C, Kobayashi T, Ippolito MM, Sylvia S, Ozawa S. Impact of substandard and falsified antimalarials in Zambia: application of the SAFARI model. BMC Public Health 2020; 20:1083. [PMID: 32646393 PMCID: PMC7350731 DOI: 10.1186/s12889-020-08852-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 05/05/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many countries are striving to become malaria-free, but global reduction in case estimates has stagnated in recent years. Substandard and falsified medicines may contribute to this lack of progress. Zambia aims to eliminate their annual burden of 1.2 million pediatric malaria cases and 2500 child deaths due to malaria. We examined the health and economic impact of poor-quality antimalarials in Zambia. METHODS An agent-based model, Substandard and Falsified Antimalarial Research Impact (SAFARI), was modified and applied to Zambia. The model was developed to simulate population characteristics, malaria incidence, patient care-seeking, disease progression, treatment outcomes, and associated costs of malaria for children under age five. Zambia-specific demographic, epidemiological, and cost inputs were extracted from the literature. Simulations were run to estimate the health and economic impact of poor-quality antimalarials, the effect of potential artemisinin resistance, and six additional malaria focused policy interventions. RESULTS We simulated annual malaria cases among Zambian children under five. At baseline, we found 2610 deaths resulting in $141.5 million in annual economic burden of malaria. We estimated that elimination of substandard and falsified antimalarials would result in an 8.1% (n = 213) reduction in under-five deaths, prevent 937 hospitalizations, and realize $8.5 million in economic savings, annually. Potential artemisinin resistance could further increase deaths by 6.3% (n = 166) and cost an additional $9.7 million every year. CONCLUSIONS Eliminating substandard and falsified antimalarials is an important step towards a malaria-free Zambia. Beyond the dissemination of insecticide-treated bed nets, indoor residual spraying, and other malaria control measures, attention must also be paid to assure the quality of antimalarial treatments.
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Affiliation(s)
- Kathryn D Jackson
- Department of Health Policy and Management, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Colleen R Higgins
- Division of Practice Advancement and Clinical Education, UNC Eshelman School of Pharmacy, University of North Carolina, CB#7574, Beard Hall, 115H, Chapel Hill, NC, 27599, USA
| | - Sarah K Laing
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Chiluba Mwila
- Department of Pharmacy, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | - Tamaki Kobayashi
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Matthew M Ippolito
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Division of Clinical Pharmacology and Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sean Sylvia
- Department of Health Policy and Management, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.,Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| | - Sachiko Ozawa
- Division of Practice Advancement and Clinical Education, UNC Eshelman School of Pharmacy, University of North Carolina, CB#7574, Beard Hall, 115H, Chapel Hill, NC, 27599, USA. .,Department of Maternal and Child Health, UNC Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
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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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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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Shalini, Legac J, Adeniyi AA, Kisten P, Rosenthal PJ, Singh P, Kumar V. Functionalized Naphthalimide-4-aminoquinoline Conjugates as Promising Antiplasmodials, with Mechanistic Insights. ACS Med Chem Lett 2020; 11:154-161. [PMID: 32071682 DOI: 10.1021/acsmedchemlett.9b00521] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/08/2020] [Indexed: 01/05/2023] Open
Abstract
A series of 25 conjugates has been synthesized to evaluate their antiplasmodial potency and cytotoxicity against the chloroquine resistant (CQR) W2 strain of P. falciparum and Vero kidney cell lines, respectively. Most of the compounds showed IC50 values in the lower nM range and proved to be many fold more active than chloroquine (CQ). The studies were extended to decipher modes of action using techniques including UV-vis absorption, NMR titrations, and mass spectrometry, and conclusions were strengthened by docking and density functional theory (DFT) simulations. The most active compound, with IC50 15 nM and selectivity index >4000, proved to be an interesting template for antimalarial drug discovery. To the best of our knowledge this is the first report of a potent naphthalimide based antiplasmodial conjugate.
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Affiliation(s)
- Shalini
- Department of Chemistry, Guru Nanak Dev University, Amritsar-143005, Punjab, India
| | - Jenny Legac
- Department of Medicine, University of California, San Francisco, California 94115, United States
| | - Adebayo A. Adeniyi
- Department of Industrial Chemistry, Federal University of Oye-Ekiti, Oye 371104, Nigeria
| | - Prishani Kisten
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville, Durban-4000, South Africa
| | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, California 94115, United States
| | - Parvesh Singh
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville, Durban-4000, South Africa
| | - Vipan Kumar
- Department of Chemistry, Guru Nanak Dev University, Amritsar-143005, Punjab, India
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30
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Mohammadi S, Jafari B, Asgharian P, Martorell M, Sharifi-Rad J. Medicinal plants used in the treatment of Malaria: A key emphasis to Artemisia, Cinchona, Cryptolepis, and Tabebuia genera. Phytother Res 2020; 34:1556-1569. [PMID: 32022345 DOI: 10.1002/ptr.6628] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/14/2019] [Accepted: 01/14/2020] [Indexed: 01/30/2023]
Abstract
Malaria is one of the life-threatening parasitic diseases that is endemic in tropical areas. The increased prevalence of malaria due to drug resistance leads to a high incidence of mortality. Drug discovery based on natural products and secondary metabolites is considered as alternative approaches for antimalarial therapy. Herbal medicines have advantages over modern medicines, including fewer side effects, cost-effectiveness, and affordability encouraging the herbal-based drug discovery. Several naturally occurring, semisynthetic, and synthetic antimalarial medications are on the market. For example, chloroquine is a synthetic medication for antimalarial therapy derived from quinine. Moreover, artemisinin, and its derivative, artesunate with sesquiterpene lactone backbone, is an antimalarial agent originated from Artemisia annua L. A. annua traditionally has been used to detoxify blood and eliminate fever in China. Although the artemisinin-based combination therapy against malaria has shown exceptional responses, the limited medicinal options demand novel therapeutics. Furthermore, drug resistance is the cause in most cases, and new medications are proposed to overcome the resistance. In addition to conventional therapeutics, this review covers some important genera in this area, including Artemisia, Cinchona, Cryptolepis, and Tabebuia, whose antimalarial activities are finely verified.
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Affiliation(s)
- Samin Mohammadi
- Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behzad Jafari
- Department of Medicinal Chemistry, Faculty of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran
| | - Parina Asgharian
- Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.,Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Miquel Martorell
- Department of Nutrition and Dietetics, Faculty of Pharmacy, University of Concepcion, Chile.,Unidad de Desarrollo Tecnológico (UDT), Universidad de Concepción, Chile
| | - Javad Sharifi-Rad
- Phytochemistry Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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31
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Mukhtar AYA, Munyakazi JB, Ouifki R. Assessing the role of human mobility on malaria transmission. Math Biosci 2019; 320:108304. [PMID: 31883985 DOI: 10.1016/j.mbs.2019.108304] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 12/12/2019] [Accepted: 12/12/2019] [Indexed: 11/26/2022]
Abstract
South Sudan accounts for a large proportion of all annual malaria cases in Africa. In recent years, the country has witnessed an unprecedented number of people on the move, refugees, internally displaced people, people who have returned to their counties or areas of origin, stateless people and other populations of concern, posing challenges to malaria control. Thus, one can claim that human mobility is one of the contributing factors to the resurgence of malaria. The aim of this paper is to assess the impact of human mobility on the burden of malaria disease in South Sudan. For this, we formulate an SIR-type model that describes the transmission dynamics of malaria disease between multiple patches. The proposed model is a system of stochastic differential equations consisting of ordinary differential equations perturbed by a stochastic Wiener process. For the deterministic part of the model, we calculate the basic reproduction number. Concerning the whole stochastic model, we use the maximum likelihood approach to fit the model to weekly malaria data of 2011 from Central Equatoria State, Western Bahr El Ghazal State and Warrap State. Using the parameters estimated on the fitted model, we simulate the future observation of the disease pattern. The disease was found to persist in the low transmission patches when there is human inflow in these patches and although the intervention coverage reaches 75%.
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Affiliation(s)
- Abdulaziz Y A Mukhtar
- Department of Mathematics and Applied Mathematics, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; DST-NRF Centre of Excellence in Mathematical and Statistical Sciences (CoE-Mass), South Africa.
| | - Justin B Munyakazi
- Department of Mathematics and Applied Mathematics, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Rachid Ouifki
- Department of Mathematics and Applied Mathematics, Faculty of Natural & Agricultural Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Shen Q, Huang H, Zhao Y, Xie L, He Q, Zhong Y, Wang Y, Wang Y, Tang K. The Transcription Factor Aabzip9 Positively Regulates the Biosynthesis of Artemisinin in Artemisia annua. FRONTIERS IN PLANT SCIENCE 2019; 10:1294. [PMID: 31787989 PMCID: PMC6855008 DOI: 10.3389/fpls.2019.01294] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/18/2019] [Indexed: 05/26/2023]
Abstract
Artemisinin-based therapies are the only effective treatment for malaria, which reached to 219 million cases and killed 435,000 people in 2017. To meet the growing demand for artemisinin and make it accessible to the poorest, genetic engineering of Artemisia annua becomes one of the most promising approaches to improve artemisinin yield. In this work, AabZIP9 transcription factor has been identified and characterized. The expression profile of AabZIP9 revealed that it was clustered with the artemisinin specific biosynthetic pathway genes ADS, CYP71AV1, DBR2, and ALDH1. Furthermore, the transiently dual-LUC analysis showed that the activation of ADS promoter was enhanced by AabZIP9. Meanwhile, yeast one-hybrid assay showed that AabZIP9 was able to bind to the "ACGT" cis-element present in both ADS and CYP71AV1 promoters. AabZIP9 gene was driven by the constitutive CaMV35S promoter and the glandular trichome specific CYP71AV1 promoter and stably transformed into A. annua plants. The transcript level of AabZIP9 was increased in both of the 35S and CYP71AV1 driven transgenic plants compared with the wild type or GUS control plants. All the transgenic A. annua plants overexpressing AabZIP9 showed elevated transcript level of ADS, but the transcription levels of CYP71AV1, DBR2, and ALDH1 have no significant change in both types of transgenic plants. The significantly upregulated ADS promoted the accumulation of artemisinin, dihydroartemisinic acid, and artemisinic acid biosynthesis in the transgenic A. annua plants. These results suggest that AabZIP9 can positively regulate the biosynthesis of artemisinin.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kexuan Tang
- *Correspondence: Yuliang, Wang ; Kexuan Tang,
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33
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Jensen PE, Scharff LB. Engineering of plastids to optimize the production of high-value metabolites and proteins. Curr Opin Biotechnol 2019; 59:8-15. [DOI: 10.1016/j.copbio.2019.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/08/2018] [Accepted: 01/18/2019] [Indexed: 10/27/2022]
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Arroz JAH, Candrinho B, Mendis C, Lopez M, Martins MDRO. Cost-effectiveness of two long-lasting insecticidal nets delivery models in mass campaign in rural Mozambique. BMC Res Notes 2019; 12:578. [PMID: 31521189 PMCID: PMC6744705 DOI: 10.1186/s13104-019-4620-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 09/07/2019] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The aim is to compare the cost-effectiveness of two long-lasting insecticidal nets (LLINs) delivery models (standard vs. new) in universal coverage (UC) campaigns in rural Mozambique. RESULTS The total financial cost of delivering LLINs was US$ 231,237.30 and US$ 174,790.14 in the intervention (302,648 LLINs were delivered) and control districts (219,613 LLINs were delivered), respectively. The average cost-effectiveness ratio (ACER) per LLIN delivered and ACER per household (HH) achieving UC was lower in the intervention districts. The incremental cost-effectiveness ratio (ICER) per LLIN and ICER per HH reaching UC were US$ 0.68 and US$ 2.24, respectively. Both incremental net benefit (for delivered LLIN and for HHs reaching UC) were positive (intervention deemed cost-effective). Overall, the newer delivery model was the more cost-effective intervention. However, the long-term sustainability of either delivery models is far from guaranteed in Mozambique's current economic context.
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Affiliation(s)
| | | | | | | | - Maria do Rosário O. Martins
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Rua da Junqueira 100, 1349-008 Lisbon, Portugal
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Mayor A, Menéndez C, Walker PGT. Targeting Pregnant Women for Malaria Surveillance. Trends Parasitol 2019; 35:677-686. [PMID: 31395496 PMCID: PMC6708786 DOI: 10.1016/j.pt.2019.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022]
Abstract
Women attending antenatal care (ANC) are a generally healthy, easy-access population, contributing valuable data for infectious disease surveillance at the community level. ANC-based malaria surveillance would provide a routine measure of the malaria burden in pregnancy, which countries lack, whilst potentially improving pregnancy outcomes. It could also offer contemporary information on temporal trends and the geographic distribution of malaria burden as well as intervention coverage in the population to guide resource allocation and to assess progress towards elimination. Here, we review the factors underlying the relationship between Plasmodium falciparum in pregnancy and in the community, and outline strengths and limitations of an ANC-based surveillance in sub-Saharan Africa, its potential role within wider malaria surveillance systems, and subsequent programmatic applications.
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Affiliation(s)
- Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique.
| | - Clara Menéndez
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
| | - Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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Li S, Chaudhary SC, Zhao X, Gaur U, Fang J, Yan F, Zheng W. Artemisinin Protects Human Retinal Pigmented Epithelial Cells Against Hydrogen Peroxide-induced Oxidative Damage by Enhancing the Activation of AMP-active Protein Kinase. Int J Biol Sci 2019; 15:2016-2028. [PMID: 31523201 PMCID: PMC6743300 DOI: 10.7150/ijbs.30536] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/27/2019] [Indexed: 12/12/2022] Open
Abstract
Dry age-related macular degeneration (AMD), a leading cause of blindness in aged population, is directly associated with oxidative stress induced damage of the retinal pigmented epithelial (RPE) cells. In the current study, we investigated the role of AMPK in the protective effect of artemisinin, an FDA approved anti-malarial Chinese herbal drug, on RPE cell line D407, against H2O2 induced oxidative stress. Our results showed that artemisinin promoted the survival of D407 cells from H2O2. Artemisinin reduced intracellular ROS generation and oxidative stress, decreased LDH release and the loss of mitochondrial membrane potential in D407 cells treated with H2O2. Western blotting showed that artemisinin concentration- and time-dependently stimulated the phosphorylation of AMP-activated protein kinase (AMPK) in D407 cells while AMPK inhibitor Compound C or knock-down of AMPK by si-RNA, inhibited the survival protective effect of artemisinin. More importantly, artemisinin produced a similar protective effect in primary cultured retinal pigment cells which was also blocked by inhibitors of AMPK. Taken together, these results suggested that artemisinin promotes survival of human retinal pigment cells against H2O2-induced cell death at least in part through enhancing the activation of AMPK. Therefore, artemisinin may be a beneficial therapeutic candidate for the treatment of age-related diseases, including retinal disorders like AMD.
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Affiliation(s)
- Shuai Li
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Shubhash Chandra Chaudhary
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Xia Zhao
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Uma Gaur
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Jiankang Fang
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Fengxia Yan
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Wenhua Zheng
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.,Institute of Translation Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
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Predicting the Outcomes of New Short-Course Regimens for Multidrug-Resistant Tuberculosis Using Intrahost and Pharmacokinetic-Pharmacodynamic Modeling. Antimicrob Agents Chemother 2018; 62:AAC.01487-18. [PMID: 30249697 DOI: 10.1128/aac.01487-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022] Open
Abstract
Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential to shorten MDR-TB treatment to less than 6 months when used in conjunction with standard anti-TB drugs. However, the feasibility of BDQ in shortening MDR-TB treatment duration remains to be established. Mathematical modeling provides a platform to investigate different treatment regimens and predict their efficacy. We developed a mathematical model to capture the immune response to TB inside a human host environment. This model was then combined with a pharmacokinetic-pharmacodynamic model to simulate various short-course BDQ-containing regimens. Our modeling suggests that BDQ could reduce MDR-TB treatment duration to just 18 weeks (4 months) while still maintaining a very high treatment success rate (100% for daily BDQ for 2 weeks, or 95% for daily BDQ for 1 week during the intensive phase). The estimated time to bacterial clearance of these regimens ranges from 27 to 33 days. Our findings provide the justification for empirical evaluation of short-course BDQ-containing regimens. If short-course BDQ-containing regimens are found to improve outcomes, then we anticipate clear cost savings and a subsequent improvement in the efficiency of national TB programs.
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Pasupureddy R, Atul, Seshadri S, Pande V, Dixit R, Pandey KC. Current scenario and future strategies to fight artemisinin resistance. Parasitol Res 2018; 118:29-42. [PMID: 30478733 DOI: 10.1007/s00436-018-6126-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/19/2018] [Indexed: 02/05/2023]
Abstract
Despite several setbacks in the fight against malaria such as insecticide and drug resistance as well as low efficacy of available vaccines, considerable success in reducing malaria burden has been achieved in the past decade. Artemisinins (ARTs and their combination therapies, ACTs), the current frontline drugs against uncomplicated malaria, rapidly kill plasmodial parasites and are non-toxic at short exposures. Though the exact mode of action remains unclear, the endoperoxide bridge, indispensable for ART activity, is thought to react with heme released from hemoglobin hydrolysis and generate free radicals that alkylate multiple protein targets, thereby disrupting proteostasis pathways. However, rapid development of ART resistance in recent years with no potential alternatives on the horizon threaten the elimination efforts. The Greater Mekong Subregion in South-East Asia continues to churn out mutants resistant to multiple ACTs and detected in increasingly expanding geographies. Extensive research on ART-resistant strains have identified a potential candidate Kelch13, crucial for mediating ART resistance. Parasites with mutations in the propeller domains of Plasmodium falciparum Kelch13 protein were shown to have enhanced phosphatidylinositol 3-kinase levels that were concomitant with delayed parasite clearance. Current research focused on understanding the mechanism of Kelch13-mediated ART resistance could provide better insights into Plasmodium resistome. This review covers the current proposed mechanisms of ART activity, resistance strategies adopted by the parasite in response to ACTs and possible future approaches to mitigate the spread of resistance from South-East Asia.
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Affiliation(s)
- Rahul Pasupureddy
- National Institute of Malaria Research, Dwarka Sector 8, New Delhi, 110077, India.,Institute of Science, Nirma University, SG Highway, Ahmedabad, Gujarat, 382481, India
| | - Atul
- National Institute of Malaria Research, Dwarka Sector 8, New Delhi, 110077, India.,Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, 263001, India
| | - Sriram Seshadri
- Institute of Science, Nirma University, SG Highway, Ahmedabad, Gujarat, 382481, India
| | - Veena Pande
- Department of Biotechnology, Kumaun University, Nainital, Uttarakhand, 263001, India
| | - Rajnikant Dixit
- National Institute of Malaria Research, Dwarka Sector 8, New Delhi, 110077, India
| | - Kailash C Pandey
- National Institute of Malaria Research, Dwarka Sector 8, New Delhi, 110077, India. .,Department of Biochemistry, Indian Council of Medical Research, National Institute for Research in Environmental Health, Bhopal, Madhya Pradesh, 462001, India.
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Smith NR, Trauer JM, Gambhir M, Richards JS, Maude RJ, Keith JM, Flegg JA. Agent-based models of malaria transmission: a systematic review. Malar J 2018; 17:299. [PMID: 30119664 PMCID: PMC6098619 DOI: 10.1186/s12936-018-2442-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/04/2018] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Much of the extensive research regarding transmission of malaria is underpinned by mathematical modelling. Compartmental models, which focus on interactions and transitions between population strata, have been a mainstay of such modelling for more than a century. However, modellers are increasingly adopting agent-based approaches, which model hosts, vectors and/or their interactions on an individual level. One reason for the increasing popularity of such models is their potential to provide enhanced realism by allowing system-level behaviours to emerge as a consequence of accumulated individual-level interactions, as occurs in real populations. METHODS A systematic review of 90 articles published between 1998 and May 2018 was performed, characterizing agent-based models (ABMs) relevant to malaria transmission. The review provides an overview of approaches used to date, determines the advantages of these approaches, and proposes ideas for progressing the field. RESULTS The rationale for ABM use over other modelling approaches centres around three points: the need to accurately represent increased stochasticity in low-transmission settings; the benefits of high-resolution spatial simulations; and heterogeneities in drug and vaccine efficacies due to individual patient characteristics. The success of these approaches provides avenues for further exploration of agent-based techniques for modelling malaria transmission. Potential extensions include varying elimination strategies across spatial landscapes, extending the size of spatial models, incorporating human movement dynamics, and developing increasingly comprehensive parameter estimation and optimization techniques. CONCLUSION Collectively, the literature covers an extensive array of topics, including the full spectrum of transmission and intervention regimes. Bringing these elements together under a common framework may enhance knowledge of, and guide policies towards, malaria elimination. However, because of the diversity of available models, endorsing a standardized approach to ABM implementation may not be possible. Instead it is recommended that model frameworks be contextually appropriate and sufficiently described. One key recommendation is to develop enhanced parameter estimation and optimization techniques. Extensions of current techniques will provide the robust results required to enhance current elimination efforts.
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Affiliation(s)
- Neal R Smith
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
| | - James M Trauer
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Manoj Gambhir
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
- IBM Research Australia, Melbourne, Australia
| | - Jack S Richards
- Life Sciences, Burnet Institute, Melbourne, Australia
- Department of Medicine, University of Melbourne, Parkville, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Australia
| | - Richard J Maude
- 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
- Harvard TH Chan School of Public Health, Harvard University, Boston, USA
| | - Jonathan M Keith
- School of Mathematical Sciences, Monash University, Clayton, Australia
| | - Jennifer A Flegg
- School of Mathematics and Statistics, University of Melbourne, Parkville, Australia
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Goldlust SM, Thuan PD, Giang DDH, Thang ND, Thwaites GE, Farrar J, Thanh NV, Nguyen TD, Grenfell BT, Boni MF, Hien TT. The decline of malaria in Vietnam, 1991-2014. Malar J 2018; 17:226. [PMID: 29880051 PMCID: PMC5992833 DOI: 10.1186/s12936-018-2372-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/28/2018] [Indexed: 02/04/2023] Open
Abstract
Background Despite the well-documented clinical efficacy of artemisinin-based combination therapy (ACT) against malaria, the population-level effects of ACT have not been studied thoroughly until recently. An ideal case study for these population-level effects can be found in Vietnam’s gradual adoption of artemisinin in the 1990s. Methods and results Analysis of Vietnam’s national annual malaria reports (1991–2014) revealed that a 10% increase in artemisinin procurement corresponded to a 32.8% (95% CI 27.7–37.5%) decline in estimated malaria cases. There was no consistent national or regional effect of vector control on malaria. The association between urbanization and malaria was generally negative and sometimes statistically significant. Conclusions The decline of malaria in Vietnam can largely be attributed to the adoption of artemisinin-based case management. Recent analyses from Africa showed that insecticide-treated nets had the greatest effect on lowering malaria prevalence, suggesting that the success of interventions is region-specific. Continuing malaria elimination efforts should focus on both vector control and increased access to ACT. Electronic supplementary material The online version of this article (10.1186/s12936-018-2372-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sandra M Goldlust
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Department of Biology, Georgetown University, Washington, DC, USA.,Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Phung Duc Thuan
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Dang Duy Hoang Giang
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Ngo Duc Thang
- National Institutes for Malariology, Parasitology, and Entomology, Hanoi, Vietnam
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jeremy Farrar
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,The Wellcome Trust, London, UK
| | - Ngo Viet Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Tran Dang Nguyen
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
| | - Bryan T Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Maciej F Boni
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA, USA.
| | - Tran Tinh Hien
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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41
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Roth JM, Sawa P, Omweri G, Osoti V, Makio N, Bradley J, Bousema T, Schallig HDFH, Mens PF. Plasmodium falciparum gametocyte dynamics after pyronaridine-artesunate or artemether-lumefantrine treatment. Malar J 2018; 17:223. [PMID: 29866116 PMCID: PMC5987563 DOI: 10.1186/s12936-018-2373-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/29/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Artemisinin-based combinations differ in their impact on gametocyte prevalence and density. This study assessed female and male gametocyte dynamics after treating children with uncomplicated Plasmodium falciparum malaria with either pyronaridine-artesunate (PA) or artemether-lumefantrine (AL). METHODS Kenyan children with uncomplicated Plasmodium falciparum malaria were included and randomly assigned to PA or AL treatment. Filter paper blood samples were collected as a source of RNA for quantitative reverse-transcription PCR (qRT-PCR) and nucleic acid sequence based amplification (QT-NASBA) to detect female gametocytes (targeting Pfs25 mRNA). Male gametocytes were detected by qRT-PCR (targeting PfMGET mRNA). Duration of gametocyte carriage, the female and male gametocyte response and the agreement between qRT-PCR and QT-NASBA were determined. RESULTS The mean duration of female gametocyte carriage was significantly longer for PA (4.9 days) than for AL (3.8 days) as estimated by QT-NASBA (P = 0.036), but this difference was less clear when determined by Pfs25 qRT-PCR (4.5 days for PA and 3.7 for AL, P = 0.166). qRT-PCR based female gametocyte prevalence decreased from 100% (75/75) at baseline to 6.06% (4/66) at day 14 in the AL group and from 97.7% (83/85) to 13.9% (11/79) in the PA group. Male gametocyte prevalence decreased from 41.3% (31/75) at baseline to 19.7% (13/66) at day 14 in the AL group and from 35.3% (30/85) to 22.8% (18/79) in the PA group. There was good agreement between Pfs25 qRT-PCR and QT-NASBA female gametocyte prevalence (0.85, 95% CI 0.82-0.87). CONCLUSIONS This study indicates that female gametocyte clearance may be slightly faster after AL compared to PA. Male gametocytes showed similar post-treatment clearance between study arms. Future studies should further address potential differences between the post-treatment transmission potential after PA compared to AL. Trial registration This study is registered at clinicaltrials.gov under NCT02411994. Registration date: 8 April 2015. https://clinicaltrials.gov/ct2/show/NCT02411994?term=pyronaridine-artesunate&cond=Malaria&cntry=KE&rank=1.
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Affiliation(s)
- Johanna M Roth
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Patrick Sawa
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - George Omweri
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - Victor Osoti
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - Nicodemus Makio
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Henk D F H Schallig
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Pètra F Mens
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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Davlantes E, Dimbu PR, Ferreira CM, Florinda Joao M, Pode D, Félix J, Sanhangala E, Andrade BN, Dos Santos Souza S, Talundzic E, Udhayakumar V, Owens C, Mbounga E, Wiesner L, Halsey ES, Martins JF, Fortes F, Plucinski MM. Efficacy and safety of artemether-lumefantrine, artesunate-amodiaquine, and dihydroartemisinin-piperaquine for the treatment of uncomplicated Plasmodium falciparum malaria in three provinces in Angola, 2017. Malar J 2018; 17:144. [PMID: 29615039 PMCID: PMC5883595 DOI: 10.1186/s12936-018-2290-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/23/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The Angolan government recommends three artemisinin-based combinations for the treatment of uncomplicated Plasmodium falciparum malaria: artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ), and dihydroartemisinin-piperaquine (DP). Due to the threat of emerging anti-malarial drug resistance, it is important to periodically monitor the efficacy of artemisinin-based combination therapy (ACT). This study evaluated these medications' therapeutic efficacy in Benguela, Lunda Sul, and Zaire Provinces. METHODS Enrollment occurred between March and July 2017. Study participants were children with P. falciparum monoinfection from each provincial capital. Participants received a 3-day course of a quality-assured artemisinin-based combination and were monitored for 28 (AL and ASAQ arms) or 42 days (DP arm). Each ACT was assessed in two provinces. The primary study endpoints were: (1) follow-up without complications and (2) failure to respond to treatment or development of recurrent P. falciparum infection. Parasites from each patient experiencing recurrent infection were genotyped to differentiate new infection from recrudescence of persistent parasitaemia. These parasites were also analysed for molecular markers associated with ACT resistance. RESULTS Of 608 children enrolled in the study, 540 (89%) reached a primary study endpoint. Parasitaemia was cleared within 3 days of medication administration in all participants, and no early treatment failures were observed. After exclusion of reinfections, the corrected efficacy of AL was 96% (91-100%, 95% confidence interval) in Zaire and 97% (93-100%) in Lunda Sul. The corrected efficacy of ASAQ was 100% (97-100%) in Benguela and 93% (88-99%) in Zaire. The corrected efficacy of DP was 100% (96-100%) in Benguela and 100% in Lunda Sul. No mutations associated with artemisinin resistance were identified in the pfk13 gene in the 38 cases of recurrent P. falciparum infection. All 33 treatment failures in the AL and ASAQ arms carried pfmdr1 or pfcrt mutations associated with lumefantrine and amodiaquine resistance, respectively, on day of failure. CONCLUSIONS AL, ASAQ, and DP continue to be efficacious against P. falciparum malaria in these provinces of Angola. Rapid parasite clearance and the absence of genetic evidence of artemisinin resistance are consistent with full susceptibility to artemisinin derivatives. Periodic monitoring of in vivo drug efficacy remains a priority routine activity for Angola.
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Affiliation(s)
- Elizabeth Davlantes
- Epidemic Intelligence Service, United States Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA, 30333, USA.
| | | | | | | | - Dilunvuidi Pode
- Field Epidemiology Training Programme, Ministry of Health, Luanda, Angola
| | - Jacinto Félix
- Field Epidemiology Training Programme, Ministry of Health, Luanda, Angola
| | - Edgar Sanhangala
- Field Epidemiology Training Programme, Ministry of Health, Luanda, Angola
| | | | | | - Eldin Talundzic
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Chantelle Owens
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
- United States President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Eliane Mbounga
- United States President's Malaria Initiative, United States Agency for International Development, Luanda, Angola
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Eric S Halsey
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
- United States President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Filomeno Fortes
- National Malaria Control Programme, Ministry of Health, Luanda, Angola
| | - Mateusz M Plucinski
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
- United States President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Abstract
An efficient strategy for the formal total synthesis of selaginpulvilins A and C has been reported. This approach involves 6 and 7 linear synthetic operations and is associated with 10% and 7% overall yields respectively for selaginpulvilins A and C.
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Affiliation(s)
| | - Beeraiah Baire
- Department of Chemistry
- Institute of Technology Madras
- Chennai-600036
- India
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44
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Efficacy and Tolerability Outcomes of a Phase II, Randomized, Open-Label, Multicenter Study of a New Water-Dispersible Pediatric Formulation of Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Plasmodium falciparum Malaria in African Infants. Antimicrob Agents Chemother 2017; 62:AAC.00596-17. [PMID: 29061746 PMCID: PMC5740378 DOI: 10.1128/aac.00596-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/12/2017] [Indexed: 01/29/2023] Open
Abstract
Artemisinin combination therapies are considered the mainstay of malaria treatment, but pediatric-friendly formulations for the treatment of infants are scarce. We sought to evaluate the efficacy and safety of a new dispersible-tablet formulation of dihydroartemisinin/piperaquine phosphate (DHA/PQP) in comparison to the marketed tablet (Eurartesim) in the treatment of infants with uncomplicated Plasmodium falciparum malaria. Reported here are the results of a large phase II, randomized, open-label, multicenter trial conducted in African infants (6 to 12 months of age) from Mozambique, Burkina Faso, The Gambia, the Democratic Republic of the Congo, and Tanzania. Primary efficacy endpoint was the PCR-corrected adequate clinical and parasitological response (ACPR) at day 28. Analysis was performed for the intention-to-treat (ITT) and per-protocol (PP) populations. A total of 201 patients received the dispersible-tablet formulation, and 99 received the conventional one administered as crushed tablets. At day 28, the PCR-corrected ACPRs were 86.9% (ITT) and 98.3% (PP) in the dispersible-tablet group and 84.9% (ITT) and 100% (PP) in the crushed-tablet group. At day 42, these values were 85.9% (ITT) and 96.5% (PP) in the dispersible-tablet group and 82.8% (ITT) and 96.4% (PP) in the crushed-tablet group. The comparison between survival curves for time to new infections showed no statistically significant differences (P = 0.409). The safety and tolerability profile for the two groups was similar in terms of type and frequency of adverse events and was consistent with that expected in African infants with malaria. A standard 3-day treatment with the new dispersible DHA/PQP formulation is as efficacious as the currently used tablet in African infants and has a comparable safety profile. (This trial was registered at ClinicalTrials.gov under registration no. NCT01992900.).
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Assessing the impact of imperfect adherence to artemether-lumefantrine on malaria treatment outcomes using within-host modelling. Nat Commun 2017; 8:1373. [PMID: 29123086 PMCID: PMC5680187 DOI: 10.1038/s41467-017-01352-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 09/12/2017] [Indexed: 12/31/2022] Open
Abstract
Artemether-lumefantrine (AL) is the most widely-recommended treatment for uncomplicated Plasmodium falciparum malaria worldwide. Its safety and efficacy have been extensively demonstrated in clinical trials; however, its performance in routine health care settings, where adherence to drug treatment is unsupervised and therefore may be suboptimal, is less well characterised. Here we develop a within-host modelling framework for estimating the effects of sub-optimal adherence to AL treatment on clinical outcomes in malaria patients. Our model incorporates the data on the human immune response to the parasite, and AL's pharmacokinetic and pharmacodynamic properties. Utilising individual-level data of adherence to AL in 482 Tanzanian patients as input for our model predicted higher rates of treatment failure than were obtained when adherence was optimal (9% compared to 4%). Our model estimates that the impact of imperfect adherence was worst in children, highlighting the importance of advice to caregivers.
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Abstract
This paper summarises key advances and priorities since the 2011 presentation of the Malaria Eradication Research Agenda (malERA), with a focus on the combinations of intervention tools and strategies for elimination and their evaluation using modelling approaches. With an increasing number of countries embarking on malaria elimination programmes, national and local decisions to select combinations of tools and deployment strategies directed at malaria elimination must address rapidly changing transmission patterns across diverse geographic areas. However, not all of these approaches can be systematically evaluated in the field. Thus, there is potential for modelling to investigate appropriate 'packages' of combined interventions that include various forms of vector control, case management, surveillance, and population-based approaches for different settings, particularly at lower transmission levels. Modelling can help prioritise which intervention packages should be tested in field studies, suggest which intervention package should be used at a particular level or stratum of transmission intensity, estimate the risk of resurgence when scaling down specific interventions after local transmission is interrupted, and evaluate the risk and impact of parasite drug resistance and vector insecticide resistance. However, modelling intervention package deployment against a heterogeneous transmission background is a challenge. Further validation of malaria models should be pursued through an iterative process, whereby field data collected with the deployment of intervention packages is used to refine models and make them progressively more relevant for assessing and predicting elimination outcomes.
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Howard N, Guinness L, Rowland M, Durrani N, Hansen KS. Cost-effectiveness of adding indoor residual spraying to case management in Afghan refugee settlements in Northwest Pakistan during a prolonged malaria epidemic. PLoS Negl Trop Dis 2017; 11:e0005935. [PMID: 29059179 PMCID: PMC5695615 DOI: 10.1371/journal.pntd.0005935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/02/2017] [Accepted: 09/05/2017] [Indexed: 11/24/2022] Open
Abstract
Introduction Financing of malaria control for displaced populations is limited in scope and duration, making cost-effectiveness analyses relevant but difficult. This study analyses cost-effectiveness of adding prevention through targeted indoor residual spraying (IRS) to case management in Afghan refugee settlements in Pakistan during a prolonged malaria epidemic. Methods/Findings An intervention study design was selected, taking a societal perspective. Provider and household costs of vector control and case management were collected from provider records and community survey. Health outcomes (e.g. cases and DALYs averted) were derived and incremental cost-effectiveness ratios (ICERs) for cases prevented and DALYs averted calculated. Population, treatment cost, women’s time, days of productivity lost, case fatality rate, cases prevented, and DALY assumptions were tested in sensitivity analysis. Malaria incidence peaked at 44/1,000 population in year 2, declining to 14/1,000 in year 5. In total, 370,000 malaria cases, 80% vivax, were diagnosed and treated and an estimated 67,988 vivax cases and 18,578 falciparum and mixed cases prevented. Mean annual programme cost per capita was US$0.56. The additional cost of including IRS over five years per case prevented was US$39; US$50 for vivax (US$43 in years 1–3, US$80 in years 4–5) and US$182 for falciparum (US$139 in years 1–3 and US$680 in years 4–5). Per DALY averted this was US$266 (US$220 in years 1–3 and US$486 in years 4–5) and thus ‘highly cost-effective’ or cost-effective using WHO and comparison thresholds. Conclusions Adding IRS was cost-effective in this moderate endemicity, low mortality setting. It was more cost-effective when transmission was highest, becoming less so as transmission reduced. Because vivax was three times more common than falciparum and the case fatality rate was low, cost-effectiveness estimations for cases prevented appear reliable and more definitive for vivax malaria. We conducted a cost-effectiveness analysis of adding malaria prevention to routine malaria diagnosis and treatment in Afghan refugee settlements in Pakistan during a five-year malaria epidemic. We found that malaria incidence peaked at 44 per 1,000 in year 2 and declined to 14 per 1,000 in year 5, with an average annual programme cost per capita of US$0.56 in 2015 currency. Cost per case prevented averaged US$88 (US$111 for vivax, US$442 for falciparum), per death prevented averaged US$316,734, and per DALY averted averaged US$601. The additional cost of including IRS over five years per case prevented was US$39 (US$50 for vivax and US$182 for falciparum malaria case prevented) and per DALY averted was US$266. While our cost-effectiveness results were relatively high, when compared with internationally recognised cost-effectiveness thresholds both prevention and case management were highly cost-effective, indicating the relevance of an integrated approach for epidemic malaria control and global malaria elimination.
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Affiliation(s)
- Natasha Howard
- London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Lorna Guinness
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Mark Rowland
- London School of Hygiene and Tropical Medicine, London, United Kingdom
- HealthNet-TPO, Peshawar, Pakistan
| | | | - Kristian S. Hansen
- London School of Hygiene and Tropical Medicine, London, United Kingdom
- Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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Bretscher MT, Griffin JT, Ghani AC, Okell LC. Modelling the benefits of long-acting or transmission-blocking drugs for reducing Plasmodium falciparum transmission by case management or by mass treatment. Malar J 2017; 16:341. [PMID: 28814310 PMCID: PMC5559805 DOI: 10.1186/s12936-017-1988-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 08/09/2017] [Indexed: 11/16/2022] Open
Abstract
Background Anti-malarial drugs are an important tool for malaria control and elimination. Alongside their direct benefit in the treatment of disease, drug use has a community-level effect, clearing the reservoir of infection and reducing onward transmission of the parasite. Different compounds potentially have different impacts on transmission—with some providing periods of prolonged chemoprophylaxis whilst others have greater transmission-blocking potential. The aim was to quantify the relative benefit of such properties for transmission reduction to inform target product profiles in the drug development process and choice of first-line anti-malarial treatment in different endemic settings. Methods A mathematical model of Plasmodium falciparum epidemiology was used to estimate the transmission reduction that can be achieved by using drugs of varying chemoprophylactic (protection for 3, 30 or 60 days) or transmission-blocking activity (blocking 79, 92 or 100% of total onward transmission). Simulations were conducted at low, medium or high transmission intensity (slide-prevalence in 2–10 year olds being 1, 10 or 40%, respectively), with drugs administered either via case management or mass drug administration (MDA). Results Transmission reductions depend strongly on deployment strategy, treatment coverage and endemicity level. Transmission-blocking was most effective at low endemicity, whereas chemoprophylaxis was most useful at high endemicity levels. Increasing the duration of protection as much as possible was beneficial. Increasing transmission-blocking activity from the level of ACT to a 100% transmission-blocking drug (close to the effect estimated for ACT combined with primaquine) produced moderate impact but was not as effective as increasing the duration of protection in medium-to-high transmission settings (slide prevalence 10–40%). Combining both good transmission-blocking activity (e.g. as achieved by ACT or ACT + primaquine) and a long duration of protection (30 days or more, such as provided by piperaquine or mefloquine) within a drug regimen can substantially increase impact compared with drug regimens with only one of these properties in medium to high transmission areas (slide-prevalence in 2–10 year olds ~10 to 40%). These results applied whether the anti-malarials were used for case management or for MDA. Discussion These results emphasise the importance of increasing access to treatment for routine case management, and the potential value of choosing first-line anti-malarial treatment policies according to local malaria epidemiology to maximise impact on transmission. There is no indication that the optimal drug choice should differ between delivery via case management or MDA. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1988-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael T Bretscher
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis & Modelling, Imperial College, London, UK.,F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Jamie T Griffin
- School of Mathematical Sciences, Queen Mary University of London, London, UK
| | - Azra C Ghani
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis & Modelling, Imperial College, London, UK
| | - Lucy C Okell
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis & Modelling, Imperial College, London, UK.
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Tadesse FG, Lanke K, Nebie I, Schildkraut JA, Gonçalves BP, Tiono AB, Sauerwein R, Drakeley C, Bousema T, Rijpma SR. Molecular Markers for Sensitive Detection of Plasmodium falciparum Asexual Stage Parasites and their Application in a Malaria Clinical Trial. Am J Trop Med Hyg 2017; 97:188-198. [PMID: 28719294 PMCID: PMC5508903 DOI: 10.4269/ajtmh.16-0893] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum parasite life stages respond differently to antimalarial drugs. Sensitive stage-specific molecular assays may help to examine parasite dynamics at microscopically detectable and submicroscopic parasite densities in epidemiological and clinical studies. In this study, we compared the performance of skeleton-binding protein 1 (SBP1), ring-infected erythrocyte surface antigen, Hyp8, ring-exported protein 1 (REX1), and PHISTb mRNA for detecting ring-stage trophozoite-specific transcripts using quantitative reverse transcriptase polymerase chain reaction. Markers were tested on tightly synchronized in vitro parasites and clinical trial samples alongside established markers of parasite density (18S DNA and rRNA) and gametocyte density (Pfs25 mRNA). SBP1 was the most sensitive marker but showed low-level expression in mature gametocytes. Novel markers REX1 and PHISTb showed lower sensitivity but higher specificity for ring-stage trophozoites. Using in vivo clinical trial samples from gametocyte-negative patients, we observed evidence of persisting trophozoite transcripts for at least 14 days postinitiation of treatment. It is currently not clear if these transcripts represent viable parasites that may have implications for clinical treatment outcome or transmission potential.
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Affiliation(s)
- Fitsum G Tadesse
- Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.,Medical Biotechnology Unit, Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Issa Nebie
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou,Burkina Faso
| | - Jodie A Schildkraut
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou,Burkina Faso
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, 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
| | - Sanna R Rijpma
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
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50
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Drake TL, Lubell Y. Malaria and Economic Evaluation Methods: Challenges and Opportunities. APPLIED HEALTH ECONOMICS AND HEALTH POLICY 2017; 15:291-297. [PMID: 28105555 PMCID: PMC5427088 DOI: 10.1007/s40258-016-0304-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There is a growing evidence base on the cost effectiveness of malaria interventions. However, certain characteristics of malaria decision problems present a challenge to the application of healthcare economic evaluation methods. This paper identifies five such challenges. The complexities of (i) declining incidence and cost effectiveness in the context of an elimination campaign; (ii) international aid and its effect on resource constraints; and (iii) supranational priority setting, all affect how health economists might use a cost-effectiveness threshold. Consensus and guidance on how to determine and interpret cost-effectiveness thresholds in the context of internationally financed elimination campaigns is greatly needed. (iv) Malaria interventions are often complimentary and evaluations may need to construct intervention bundles to represent relevant policy positions as sets of mutually exclusive alternatives. (v) Geographic targeting is a key aspect of malaria policy making that is only beginning to be addressed in economic evaluations. An approach to budget-based geographic resource allocation is described in an accompanying paper in this issue and addresses some of these methodological challenges.
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Affiliation(s)
- Tom L Drake
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar.
- Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Yoel Lubell
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
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