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Manh ND, Thanh NV, Quang HH, Van NTT, San NN, Phong NC, Birrell GW, Edgel KA, Martin NJ, Edstein MD, Chavchich M. Therapeutic efficacy of pyronaridine-artesunate (Pyramax) in treating Plasmodium vivax malaria in the central highlands of Vietnam. Antimicrob Agents Chemother 2024:e0004424. [PMID: 39046237 DOI: 10.1128/aac.00044-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 05/19/2024] [Indexed: 07/25/2024] Open
Abstract
The emergence and spread of chloroquine-resistant Plasmodium vivax have necessitated the assessment of alternative blood schizonticidal drugs. In Vietnam, chloroquine-resistant P. vivax malaria has been reported. In an open-label, single-arm trial, the safety, tolerability, and efficacy of pyronaridine-artesunate (Pyramax, PA) was evaluated in Dak Nong province, Vietnam. A 3-day course of PA was administered to adults and children (≥20 kg) infected with P. vivax. Patients also received primaquine (0.25 mg/kg daily for 14 days). PA was well tolerated with transient asymptomatic increases in liver transaminases. The per-protocol proportion of patients with day 42 PCR-unadjusted adequate clinical and parasitological response was 96.0% (95% CI, 84.9%-99.0%, n = 48/50). The median parasite clearance time was 12 h (range, 12-36 h), with a median fever clearance time of 24 h (range, 12-60 h). Single nucleotide polymorphisms (SNPs) as potential genetic markers of reduced drug susceptibility were analyzed in three putative drug resistance markers, Pvcrt-o, Pvmdr1, and PvK12. Insertion at position K10 of the Pvcrt-o gene was found in 74.6% (44/59) of isolates. Pvmdr1 SNPs at Y976F and F1076L were present in 61% (36/59) and 78% (46/59), respectively. Amplification of Pvmdr1 gene (two copies) was found in 5.1% (3/59) of parasite samples. Only 5.1% (3/59) of isolates had mutation 552I of the PvK12 gene. Overall, PA rapidly cleared P. vivax blood asexual stages and was highly efficacious in treating vivax malaria, with no evidence of artemisinin resistance found. PA provides an alternative to chloroquine treatment for vivax malaria in Vietnam. CLINICAL TRIALS This study is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12618001429246.
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Affiliation(s)
- Nguyen Duc Manh
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Nguyen Van Thanh
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Huynh Hong Quang
- Vietnam Ministry of Health Institute of Malariology, Parasitology and Entomology, Qui Nhon, Vietnam
| | | | - Nguyen Ngoc San
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Nguen Chinh Phong
- Vietnam People's Army Military Institute of Preventive Medicine, Hanoi, Vietnam
| | - Geoffrey W Birrell
- Australian Defense Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | | | | | - Michael D Edstein
- Australian Defense Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Marina Chavchich
- Australian Defense Force Malaria and Infectious Disease Institute, Brisbane, Australia
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Nandal R, Kumar D, Aggarwal N, Kumar V, Narasimhan B, Marwaha RK, Sharma PC, Kumar S, Bansal N, Chopra H, Deep A. Recent advances, challenges and updates on the development of therapeutics for malaria. EXCLI JOURNAL 2024; 23:672-713. [PMID: 38887396 PMCID: PMC11180964 DOI: 10.17179/excli2023-6856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 04/03/2024] [Indexed: 06/20/2024]
Abstract
Malaria has developed as a serious worldwide health issue as a result of the introduction of resistant Plasmodium species strains. Because of the common chemo resistance to most of the existing drugs on the market, it poses a severe health problem and significant obstacles in drug research. Malaria treatment has evolved during the last two decades in response to Plasmodium falciparum drug sensitivity and a return of the disease in tropical areas. Plasmodium falciparum is now highly resistant to the majority of antimalarial drugs. The parasite resistance drew focus to developing novel antimalarials to combat parasite resistance. The requirement for many novel antimalarial drugs in the future year necessitates adopting various drug development methodologies. Different innovative strategies for discovering antimalarial drugs are now being examined here. This review is primarily concerned with the description of newly synthesized antimalarial compounds, i.e. Tafenoquine, Cipargamin, Ferroquine, Artefenomel, DSM265, MMV390048 designed to improve the activity of pure antimalarial enantiomers. In this review, we selected the representative malarial drugs in clinical trials, classified them with detailed targets according to their action, discussed the relationship within the human trials, and generated a summative discussion with prospective expectations.
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Affiliation(s)
- Rimmy Nandal
- Shri Baba MastNath Institute of Pharmaceutical Sciences and Research, Baba Mast Nath University, Asthal Bohar, Rohtak-124001, Haryana, India
| | - Davinder Kumar
- College of Pharmacy, PGIMS University of Health Sciences, Rohtak-124001, Haryana, India
| | - Navidha Aggarwal
- MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala 133207, India
| | - Virender Kumar
- College of Pharmacy, PGIMS University of Health Sciences, Rohtak-124001, Haryana, India
| | | | - Rakesh Kumar Marwaha
- Department of Pharmaceutical Sciences, Maharishi Dayanand University, Rohtak 124001 Haryana, India
| | - Prabodh Chander Sharma
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Surender Kumar
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani-127021, India
| | - Nitin Bansal
- Department of Pharmaceutical Sciences, Chaudhary Bansi Lal University, Bhiwani-127021, Haryana, India
| | - Hitesh Chopra
- Department of Biosciences, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai - 602105, Tamil Nadu, India
| | - Aakash Deep
- Department of Pharmaceutical Sciences, Chaudhary Bansi Lal University, Bhiwani-127021, Haryana, India
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Flegg JA, Kandanaarachchi S, Guerin PJ, Dondorp AM, Nosten FH, Otienoburu SD, Golding N. Spatio-temporal spread of artemisinin resistance in Southeast Asia. PLoS Comput Biol 2024; 20:e1012017. [PMID: 38626207 PMCID: PMC11051648 DOI: 10.1371/journal.pcbi.1012017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 04/26/2024] [Accepted: 03/22/2024] [Indexed: 04/18/2024] Open
Abstract
Current malaria elimination targets must withstand a colossal challenge-resistance to the current gold standard antimalarial drug, namely artemisinin derivatives. If artemisinin resistance significantly expands to Africa or India, cases and malaria-related deaths are set to increase substantially. Spatial information on the changing levels of artemisinin resistance in Southeast Asia is therefore critical for health organisations to prioritise malaria control measures, but available data on artemisinin resistance are sparse. We use a comprehensive database from the WorldWide Antimalarial Resistance Network on the prevalence of non-synonymous mutations in the Kelch 13 (K13) gene, which are known to be associated with artemisinin resistance, and a Bayesian geostatistical model to produce spatio-temporal predictions of artemisinin resistance. Our maps of estimated prevalence show an expansion of the K13 mutation across the Greater Mekong Subregion from 2000 to 2022. Moreover, the period between 2010 and 2015 demonstrated the most spatial change across the region. Our model and maps provide important insights into the spatial and temporal trends of artemisinin resistance in a way that is not possible using data alone, thereby enabling improved spatial decision support systems on an unprecedented fine-scale spatial resolution. By predicting for the first time spatio-temporal patterns and extents of artemisinin resistance at the subcontinent level, this study provides critical information for supporting malaria elimination goals in Southeast Asia.
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Affiliation(s)
- Jennifer A. Flegg
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, United Kingdom
| | | | - Philippe J. Guerin
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, United Kingdom
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Arjen M. Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Francois H. Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Sabina Dahlström Otienoburu
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, United Kingdom
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- College of Science, Technology, Engineering and Mathematics, Johnson C. Smith University, Charlotte, North Carolina, United States of America
| | - Nick Golding
- Telethon Kids Institute and Curtin University, Perth, Australia
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Wamae K, Ndwiga L, Kharabora O, Kimenyi K, Osoti V, de Laurent Z, Wambua J, Musyoki J, Ngetsa C, Kalume P, Mwambingu G, Hamaluba M, van der Pluijm R, Dondorp AM, Bailey J, Juliano J, Bejon P, Ochola-Oyier L. Targeted amplicon deep sequencing of ama1 and mdr1 to track within-host P. falciparum diversity throughout treatment in a clinical drug trial. Wellcome Open Res 2024; 7:95. [PMID: 37456906 PMCID: PMC10349275 DOI: 10.12688/wellcomeopenres.17736.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2024] [Indexed: 07/20/2023] Open
Abstract
Introduction Antimalarial therapeutic efficacy studies are routinely conducted in malaria-endemic countries to assess the effectiveness of antimalarial treatment strategies. Targeted amplicon sequencing (AmpSeq) uniquely identifies and quantifies genetically distinct parasites within an infection. In this study, AmpSeq of Plasmodium falciparum apical membrane antigen 1 ( ama1), and multidrug resistance gene 1 ( mdr1), were used to characterise the complexity of infection (COI) and drug-resistance genotypes, respectively. Methods P. falciparum-positive samples were obtained from a triple artemisinin combination therapy clinical trial conducted in 30 children under 13 years of age between 2018 and 2019 in Kilifi, Kenya. Nine of the 30 participants presented with recurrent parasitemia from day 26 (624h) onwards. The ama1 and mdr1 genes were amplified and sequenced, while msp1, msp2 and glurp data were obtained from the original clinical study. Results The COI was comparable between ama1 and msp1, msp2 and glurp; overall, ama1 detected more microhaplotypes. Based on ama1, a stable number of microhaplotypes were detected throughout treatment until day 3. Additionally, a recrudescent infection was identified with an ama1 microhaplotype initially observed at 30h and later in an unscheduled follow-up visit. Using the relative frequencies of ama1 microhaplotypes and parasitemia, we identified a fast (<1h) and slow (>5h) clearing microhaplotype. As expected, only two mdr1 microhaplotypes (NF and NY) were identified based on the combination of amino acid polymorphisms at codons 86 and 184. Conclusions This study highlights AmpSeq as a tool for highly-resolution tracking of parasite microhaplotypes throughout treatment and can detect variation in microhaplotype clearance estimates. AmpSeq can also identify slow-clearing microhaplotypes, a potential early sign of selection during treatment. Consequently, AmpSeq has the capability of improving the discriminatory power to distinguish recrudescences from reinfections accurately.
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Affiliation(s)
- Kevin Wamae
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Leonard Ndwiga
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Oksana Kharabora
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Kelvin Kimenyi
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Victor Osoti
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Juliana Wambua
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jennifer Musyoki
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Caroline Ngetsa
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Peter Kalume
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Mainga Hamaluba
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rob van der Pluijm
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Arjen M. Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jeffrey Bailey
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI, 02903, USA
| | - Jonathan Juliano
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27516, USA
- Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Philip Bejon
- Bioscience, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Mawuli MA, Amoah LE, Cui L, Quashie NB, Afrane YA. Effectiveness of artemether-lumefantrine for treating uncomplicated malaria in low- and high-transmission areas of Ghana. Malar J 2024; 23:40. [PMID: 38317164 PMCID: PMC10845584 DOI: 10.1186/s12936-024-04850-0] [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] [Received: 09/04/2023] [Accepted: 01/11/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Artemisinin-based combination therapy (ACT) has been effective in the supervised treatment of uncomplicated malaria in Ghana. Since ACT usage is primarily unsupervised, this study aimed to determine the effectiveness of artemether-lumefantrine (AL) for treating malaria patients in two transmission settings in Ghana. METHODS Eighty-four individuals with uncomplicated Plasmodium falciparum malaria were recruited from Lekma Hospital (LH) in Accra (low-transmission area; N = 28), southern Ghana, and King's Medical Centre (KMC) in Kumbungu (high-transmission area; N = 56), northern Ghana. Participants were followed up for 28 days after unsupervised treatment with AL. The presence of asexual parasites was determined by microscopic examination of Giemsa-stained blood smears. Plasmodium species identification was confirmed using species-specific primers targeting the 18S rRNA gene. Parasite recrudescence or reinfection was determined by genotyping the Pfmsp 1 and Pfmsp 2 genes. RESULTS After AL treatment, 3.6% (2/56) of the patients from KMC were parasitaemic on day 3 compared to none from the LH patients. One patient from KMC with delayed parasite clearance on day 3 remained parasite-positive by microscopy on day 7 but was parasite-free by day 14. While none of the patients from LH experienced parasite recurrence during the 28-day follow-up, three and two patients from KMC had recurrent parasitaemia on days 21 and 28, respectively. Percentage reduction in parasite densities from day 1, 2, and 3 for participants from the KMC was 63.2%, 89.5%, and 84.5%. Parasite densities for participants from the LH reduced from 98.2%, 99.8% on day 1, and 2 to 100% on day 3. The 28-day cumulative incidence rate of treatment failure for KMC was 12.8% (95% confidence interval: 1.9-23.7%), while the per-protocol effectiveness of AL in KMC was 89.47%. All recurrent cases were assigned to recrudescence after parasite genotyping by Pfmsp 1 and Pfmsp 2. CONCLUSION While AL is efficacious in treating uncomplicated malaria in Ghana, when taken under unsupervised conditions, it showed an 89.4% PCR-corrected cure rate in northern Ghana, which is slightly below the WHO-defined threshold.
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Affiliation(s)
- Mawusi Adepa Mawuli
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana.
- Department of Pathology, University of Ghana Medical School, College of Health Sciences, University of Ghana, Korle-Bu, Accra, Ghana.
| | - Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research College of Health Sciences, University of Ghana, Legon, Accra, Ghana
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, 3720 Spectrum Blvd, Tampa, FL, 33612, USA
| | - Neils Ben Quashie
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
- Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, University of Ghana, Korle-Bu, Accra, Ghana
| | - Yaw Asare Afrane
- Department of Medical Microbiology, University of Ghana Medical School College of Health Sciences, University of Ghana, Korle-Bu, Accra, Ghana
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Ishengoma DS, Mandara CI, Bakari C, Fola AA, Madebe RA, Seth MD, Francis F, Buguzi C, Moshi R, Garimo I, Lazaro S, Lusasi A, Aaron S, Chacky F, Mohamed A, Njau RJA, Kitau J, Rasmussen C, Bailey JA, Juliano JJ, Warsame M. Evidence of artemisinin partial resistance in North-western Tanzania: clinical and drug resistance markers study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.31.24301954. [PMID: 38352311 PMCID: PMC10863006 DOI: 10.1101/2024.01.31.24301954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
Background Artemisinin-based combination therapies (ACTs) are the recommended antimalarial drugs for the treatment of uncomplicated malaria. The recent emergence of artemisinin partial resistance (ART-R) in Rwanda, Uganda and Eritrea is of great concern. In Tanzania, a nationwide molecular malaria surveillance in 2021 showed a high prevalence of the Kelch13 (K13) 561H mutation in Plasmodium falciparum from the north-western region, close to the border with Rwanda and Uganda. This study was conducted in 2022 to evaluate the efficacy of artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) for the treatment of uncomplicated falciparum malaria and to confirm the presence of ART-R in Tanzania. Methods This single-arm study evaluated the efficacy of AL and ASAQ in eligible children aged six months to 10 years at Bukangara Dispensary in Karagwe District, Kagera Region. Clinical and parasitological responses were monitored for 28 days according to standard WHO protocol. Mutations in K13 gene and extended haplotypes with these mutations were analysed using Sanger and whole genome sequencing data, respectively. Findings 176 children (88 in each AL and ASAQ group) were enrolled and all achieved the defined outcomes. PCR-corrected adequate clinical and parasitological response (ACPR) was 98.3% (95% CI: 90.8-100) and 100.0% (95% CI: 95.8-100) for AL and ASAQ, respectively. Parasitaemia on day 3 was observed in 11/88 (12.5%) and 17/88 (19.3%) in the AL and ASAQ groups, respectively. The half-life of parasitaemia was significantly higher (>6.5 hrs) in patients with parasitaemia on day 3 and/or mutations in K13 gene at enrolment. Most patients with parasitaemia on day 3 (8/11 = 72.7% in the AL group and 10/17 = 58.8% in the ASAQ group) had 561H mutation at enrolment. The parasites with K13 mutations were not similar to those from south-east Asia and Rwanda, but had the same core haplotype of a new 561H haplotype reported in Kagera in 2021. Interpretation These findings confirm the presence of ART-R in Tanzania. A context-specific strategy to respond to artemisinin partial resistance is urgently needed. Although both AL and ASAQ showed high efficacy, increased vigilance for reduced efficacy of these ACTs and detection of ART-R in other parts of the country is critical.
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Affiliation(s)
- Deus S. Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, VIC, Australia
- Department of Biochemistry, Kampala International University in Tanzania, Dar es Salaam, Tanzania
| | | | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Abebe A. Fola
- Department of Pathology and Laboratory Medicine and Center for Computational Molecular Biology, Brown University, Providence, RI, USA
| | - Rashid A. Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Misago D. Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Filbert Francis
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Creyton Buguzi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Issa Garimo
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Samwel Lazaro
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | | | - Sijenunu Aaron
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Frank Chacky
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Ally Mohamed
- National Malaria Control Program (NMCP), Dodoma, Tanzania
| | - Ritha J. A. Njau
- Malariologist and Public Health Specialist, Muhimbili University of Health and Allied Sciences, School of Public Health and Social Sciences Dar es Salaam, Tanzania
| | - Jovin Kitau
- World Health Organization Country Office, Dar es Salaam, Tanzania
| | | | - Jeffrey A. Bailey
- Department of Pathology and Laboratory Medicine and Center for Computational Molecular Biology, Brown University, Providence, RI, USA
| | | | - Marian Warsame
- Gothenburg University, Gothenburg, Sweden
- Benadir University, Mogadishu, Somalia
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Jajosky RP. Clarifying the terms parasitemia, parasite density, and parasite count. Transfus Apher Sci 2023; 62:103788. [PMID: 37657948 DOI: 10.1016/j.transci.2023.103788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/03/2023]
Affiliation(s)
- Ryan Philip Jajosky
- Joint Program in Transfusion Medicine, Brigham and Women's Hospital, Harvard Medical School, New Research Building, Room 630E, Dr. Sean Stowell's Lab, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA; Biconcavity Inc., Lilburn, GA, USA.
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Yin X, Li Y, Bagchus W, Yalkinoglu Ö, Bezuidenhout D, Tappert A, McCarthy J, Marquart L, Oeuvray C. Evaluation of a multiphasic parasite clearance profile after treatment of experimental human infection with the investigational anti-malarial M5717 using segmented mixed effect models. Malar J 2023; 22:199. [PMID: 37381013 DOI: 10.1186/s12936-023-04627-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 06/16/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Evaluation of parasite clearance patterns in experimental human infection trials helps increase understanding of drug action. In a previously reported phase Ib trial of a new investigational anti-malarial drug M5717, parasite clearance showed a biphasic linear pattern: slow removal phase with a near flat clearance rate followed by a fast clearance phase with a steep slope. In this study three statistical approaches were implemented and compared to estimate the parasite clearance rate for each phase and the time point corresponding to the change of clearance rates (changepoint between the two phases). METHODS Data using three M5717 doses 150 mg (n = 6), 400 mg (n = 8), 800 mg (n = 8) were used to estimate biphasic clearance rates. Three models were investigated: firstly, segmented mixed models with estimated changepoint-models with/without random effects in various parameters were compared. Secondly, a segmented mixed model using grid search-this method is similar to the first except that changepoints were not estimated, instead they were selected based on model fit from given candidate values. Thirdly, a two-stage approach whereby a segmented regression model fit to each participant followed by a meta-analysis method. Hourly rate of parasite clearance (HRPC) interpreted as the percentage of parasites removed each hour was calculated. RESULTS The three models generated similar results. Using segmented mixed models, the estimated changepoints after treatment in hours (95% CI) were: 150 mg: 33.9 (28.7, 39.1); 400 mg: 57.4 (52.5, 62.4); and 800 mg: 52.8 (47.4, 58.1). For all three treatment groups, there was nearly no clearance before the changepoints, but rapid clearance in the second phase (HRPC [95% CI]): 150 mg: 16.8% (14.3, 19.1%); 400 mg: 18.6% (16.0, 21.1%); and 800 mg: 11.7% (9.3, 14.1%). CONCLUSIONS All three statistical approaches are effective tools to characterize the bi-phasic clearance of M5717 in the phase 1b experimental Plasmodium falciparum malaria human infection study. The statistical approaches produced similar results to estimate the two-phase clearance rates and the changepoint for each treatment dose of M5717. However, the segmented mixed model with random changepoints has several advantages: it is computationally efficient, provides precision for changepoint estimates and is robust concerning outlying datapoints or individuals.
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Affiliation(s)
- Xiaoyan Yin
- EMD Serono Research & Development Institute, Inc. (an Affiliate of Merck KGaA), 45 Middlesex Turnpike, Billerica, MA, 01821, USA.
| | - Ying Li
- EMD Serono Research & Development Institute, Inc. (an Affiliate of Merck KGaA), 45 Middlesex Turnpike, Billerica, MA, 01821, USA
| | - Wilhelmina Bagchus
- WMB: Merck Serono S.A (an Affiliate of Merck KGaA), Lausanne, Switzerland
| | | | - Deon Bezuidenhout
- WMB: Merck Serono S.A (an Affiliate of Merck KGaA), Lausanne, Switzerland
| | | | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Claude Oeuvray
- The Global Health Institute of Merck (an Affiliate of Merck KGaA), Eysins, Switzerland
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Wynberg E, Commons RJ, Humphreys G, Ashurst H, Burrow R, Adjei GO, Adjuik M, Anstey NM, Anvikar A, Baird KJ, Barber BE, Barennes H, Baudin E, Bell DJ, Bethell D, Binh TQ, Borghini-Fuhrer I, Chu CS, Daher A, D’Alessandro U, Das D, Davis TME, de Vries PJ, Djimde AA, Dondorp AM, Dorsey G, Faucher JFF, Fogg C, Gaye O, Grigg M, Hatz C, Kager PA, Lacerda M, Laman M, Mårtensson A, Menan HIE, Monteiro WM, Moore BR, Nosten F, Ogutu B, Osorio L, Penali LK, Pereira DB, Rahim AG, Ramharter M, Sagara I, Schramm B, Seidlein L, Siqueira AM, Sirima SB, Starzengruber P, Sutanto I, Taylor WR, Toure OA, Utzinger J, Valea I, Valentini G, White NJ, William T, Woodrow CJ, Richmond CL, Guerin PJ, Price RN, Stepniewska K. Variability in white blood cell count during uncomplicated malaria and implications for parasite density estimation: a WorldWide Antimalarial Resistance Network individual patient data meta-analysis. Malar J 2023; 22:174. [PMID: 37280686 DOI: 10.1186/s12936-023-04583-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/07/2023] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND The World Health Organization (WHO) recommends that when peripheral malarial parasitaemia is quantified by thick film microscopy, an actual white blood cell (WBC) count from a concurrently collected blood sample is used in calculations. However, in resource-limited settings an assumed WBC count is often used instead. The aim of this study was to describe the variability in WBC count during acute uncomplicated malaria, and estimate the impact of using an assumed value of WBC on estimates of parasite density and clearance. METHODS Uncomplicated malaria drug efficacy studies that measured WBC count were selected from the WorldWide Antimalarial Resistance Network data repository for an individual patient data meta-analysis of WBC counts. Regression models with random intercepts for study-site were used to assess WBC count variability at presentation and during follow-up. Inflation factors for parasitaemia density, and clearance estimates were calculated for methods using assumed WBC counts (8000 cells/µL and age-stratified values) using estimates derived from the measured WBC value as reference. RESULTS Eighty-four studies enrolling 27,656 patients with clinically uncomplicated malaria were included. Geometric mean WBC counts (× 1000 cells/µL) in age groups < 1, 1-4, 5-14 and ≥ 15 years were 10.5, 8.3, 7.1, 5.7 and 7.5, 7.0, 6.5, 6.0 for individuals with falciparum (n = 24,978) and vivax (n = 2678) malaria, respectively. At presentation, higher WBC counts were seen among patients with higher parasitaemia, severe anaemia and, for individuals with vivax malaria, in regions with shorter regional relapse periodicity. Among falciparum malaria patients, using an assumed WBC count of 8000 cells/µL resulted in parasite density underestimation by a median (IQR) of 26% (4-41%) in infants < 1 year old but an overestimation by 50% (16-91%) in adults aged ≥ 15 years. Use of age-stratified assumed WBC values removed systematic bias but did not improve precision of parasitaemia estimation. Imprecision of parasite clearance estimates was only affected by the within-patient WBC variability over time, and remained < 10% for 79% of patients. CONCLUSIONS Using an assumed WBC value for parasite density estimation from a thick smear may lead to underdiagnosis of hyperparasitaemia and could adversely affect clinical management; but does not result in clinically consequential inaccuracies in the estimation of the prevalence of prolonged parasite clearance and artemisinin resistance.
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10
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T. Thurai Rathnam J, Grigg MJ, Dini S, William T, Sakam SS, Cooper DJ, Rajahram GS, Barber BE, Anstey NM, Haghiri A, Rajasekhar M, Simpson JA. Quantification of parasite clearance in Plasmodium knowlesi infections. Malar J 2023; 22:54. [PMID: 36782162 PMCID: PMC9926767 DOI: 10.1186/s12936-023-04483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/04/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND The incidence of zoonotic Plasmodium knowlesi infections in humans is rising in Southeast Asia, leading to clinical studies to monitor the efficacy of anti-malarial treatments for knowlesi malaria. One of the key outcomes of anti-malarial drug efficacy is parasite clearance. For Plasmodium falciparum, parasite clearance is typically estimated using a two-stage method, that involves estimating parasite clearance for individual patients followed by pooling of individual estimates to derive population estimates. An alternative approach is Bayesian hierarchical modelling which simultaneously analyses all parasite-time patient profiles to determine parasite clearance. This study compared these methods for estimating parasite clearance in P. knowlesi treatment efficacy studies, with typically fewer parasite measurements per patient due to high susceptibility to anti-malarials. METHODS Using parasite clearance data from 714 patients with knowlesi malaria and enrolled in three trials, the Worldwide Antimalarial Resistance Network (WWARN) Parasite Clearance Estimator (PCE) standard two-stage approach and Bayesian hierarchical modelling were compared. Both methods estimate the parasite clearance rate from a model that incorporates a lag phase, slope, and tail phase for the parasitaemia profiles. RESULTS The standard two-stage approach successfully estimated the parasite clearance rate for 678 patients, with 36 (5%) patients excluded due to an insufficient number of available parasitaemia measurements. The Bayesian hierarchical estimation method was applied to the parasitaemia data of all 714 patients. Overall, the Bayesian method estimated a faster population mean parasite clearance (0.36/h, 95% credible interval [0.18, 0.65]) compared to the standard two-stage method (0.26/h, 95% confidence interval [0.11, 0.46]), with better model fits (compared visually). Artemisinin-based combination therapy (ACT) is more effective in treating P. knowlesi than chloroquine, as confirmed by both methods, with a mean estimated parasite clearance half-life of 2.5 and 3.6 h, respectively using the standard two-stage method, and 1.8 and 2.9 h using the Bayesian method. CONCLUSION For clinical studies of P. knowlesi with frequent parasite measurements, the standard two-stage approach (WWARN's PCE) is recommended as this method is straightforward to implement. For studies with fewer parasite measurements per patient, the Bayesian approach should be considered. Regardless of method used, ACT is more efficacious than chloroquine, confirming the findings of the original trials.
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Affiliation(s)
- Jeyamalar T. Thurai Rathnam
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Matthew J. Grigg
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Saber Dini
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Sitti Saimah Sakam
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Daniel J. Cooper
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.5335.00000000121885934Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Giri S. Rajahram
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.415759.b0000 0001 0690 5255Clinical Research Centre, Queen Elizabeth II Hospital, Ministry of Health, Kota Kinabalu, Sabah, Malaysia
| | - Bridget E. Barber
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia ,grid.1049.c0000 0001 2294 1395QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nicholas M. Anstey
- grid.1043.60000 0001 2157 559XMenzies School of Health Research and Charles Darwin University, Darwin, NT Australia ,Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Ali Haghiri
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Megha Rajasekhar
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Julie A. Simpson
- grid.1008.90000 0001 2179 088XCentre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
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11
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Lek D, Rachmat A, Harrison D, Chin G, Chaoratanakawee S, Saunders D, Menard D, Rogers WO. Efficacy of three anti-malarial regimens for uncomplicated Plasmodium falciparum malaria in Cambodia, 2009-2011: a randomized controlled trial and brief review. Malar J 2022; 21:259. [PMID: 36071520 PMCID: PMC9450427 DOI: 10.1186/s12936-022-04279-3] [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] [Received: 12/16/2021] [Accepted: 08/28/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Anti-malarial resistance remains an important public health challenge in Cambodia. The effectiveness of three therapies for uncomplicated falciparum malaria was evaluated in Oddar Meanchey province in Northern Cambodia from 2009 to 2011. METHODS In this randomized, open-label, parallel group-controlled trial, 211 subjects at least 5 years old with uncomplicated falciparum malaria were treated with 3 days of directly observed therapy: 63 received artesunate-mefloquine (AS/MQ), 77 received dihydroartemisinin-piperaquine (DHA/PPQ), and 71 received atovaquone-proguanil (ATQ/PG). The subjects were followed for 42 days or until recurrent parasitaemia. Genotyping of msp1, msp2, and glurp among individual parasite isolates distinguished recrudescence from reinfection. Pfmdr1 copy number was measured by real-time PCR and half-maximal parasite inhibitory concentrations (IC50) were measured in vitro by 48-h isotopic hypoxanthine incorporation assay. RESULTS The per-protocol PCR-adjusted efficacy (95% confidence interval) at 42 days was 80.6% (70.8-90.5%) for AS/MQ, 97.2% (93.3-100%) for DHA/PPQ, and 92.9% (86.1-99.6%) for ATQ/PG. On day 3, 57.9% remained parasitaemic in the AS/MQ and DHA/PPQ arms. At baseline, 46.9% had microscopic Plasmodium falciparum gametocytaemia. Both recurrences in the DHA/PPQ arm lost Pfmdr1 copy number amplification at recrudescence. All four recurrences in the ATQ/PG arm were wild-type for cytochrome bc1. One subject withdrew from the ATQ/PG arm due to drug allergy. CONCLUSIONS This study was conducted at the epicentre of substantial multi-drug resistance that emerged soon thereafter. Occurring early in the national transition from AS/MQ to DHA/PPQ, both DHA/PPQ and ATQ/PG had acceptable efficacy against uncomplicated falciparum malaria. However, efficacy of AS/MQ was only 80% with apparent mefloquine resistance based on elevated Pfmdr1 copy number and IC50. By 2009, there was already significant evidence of artemisinin resistance not previously reported at the Northern Cambodia-Thai border. This study suggests the basis for early development of significant DHA/PPQ failures within 3 years of introduction. Artemisinin resistance likely occurred on the Northern border concurrently with that reported along the Western border in Pailin. Trial registration This legacy trial was conducted prior to International Committee of Medical Journal Editors' requirements for preregistration on ClinicalTrials.gov. The full protocol has been provided.
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Affiliation(s)
- Dysoley Lek
- National Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia.
| | - Agus Rachmat
- U.S. Naval Medical Research Unit 2, Phnom Penh, Cambodia
| | | | - Geoffrey Chin
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | | | - David Saunders
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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12
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Yeda R, Okudo C, Owiti E, Biwot G, Momanyi C, Korir W, Mitsanze T, Tegerei C, Juma D, Opot B, Mwakio E, Chemwor G, Okoth R, Ochora DO, Cheruiyot AC, Roth A, Akala HM, Andagalu B. Burden of malaria infection among individuals of varied blood groups in Kenya. Malar J 2022; 21:251. [PMID: 36050680 PMCID: PMC9438094 DOI: 10.1186/s12936-022-04251-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 07/28/2022] [Indexed: 11/23/2022] Open
Abstract
Background The ABO blood groups consist of A, B, and H carbohydrate antigens, which regulate protein activities during malaria infection in humans. Understanding the interplay between the malaria parasite and blood group antigens is essential in understanding new interventions to reduce the global burden of malaria. This study assessed the burden of malaria infection among individuals with varying blood groups seeking treatment at selected hospitals in Kenya. Methods A total of 366 samples from an ongoing malaria surveillance study were diagnosed for malaria by microscopy and further typed for blood group using ABO blood grouping. Age and sex were recorded in a data sheet, and analysed using R software version 4. Groups’ proportions (blood group, malaria infection, age and sex) were compared using Pearson’s Chi-square and Fischer exact tests. Wilcoxon and Kruskal-Wallis tests were performed and P-value < 0.05 was considered significant after Bonferroni correction for multiple comparisons. To understand the effect of each blood group on parasitaemia, multivariate logistic regression was used to model ABO blood group in relation to parasitaemia. Results Of the 366 samples analysed, 312 were malaria positive, mean age was 9.83 years (< 5 years n = 152 (48.41%), 6 to 17 years n = 101 (32.16%) and > 18 years n = 61 (19.43%)). Malaria prevalence was higher among females than males, 54.46% and 45.54%, respectively. Kisumu enrolled the highest number 109 (35%)) of malaria cases, Kombewa 108 (35%), Malindi 32 (10%), Kisii 28 (9%), Marigat 23 (7%), and Kericho 12 (4%). Blood group O+ was the most prevalent among the enrolled individuals (46.50%), A+ (27.71%), B+ (21.02%) and AB+ (4.78%) respectively. Compared to blood group O+, blood group B+ individuals were (14%) were more likely to habour Plasmodium falciparum infection as opposed to A+ and AB+ individuals, that were 7% and 20%, respectively,. Those living in malaria-endemic zones presented with higher parasite densities compared to those living in malaria-epidemic (p = 0.0061). Individuals bearing B + blood group are more likely to habour high parasitaemia compared to O + blood group bearers (OR = 4.47, CI = 1.53–13.05, p = 0.006). Conclusion Individuals of blood group B harbour high parasitaemia compared with the blood group O, Additionally, blood group A and B present with symptoms at lower parasitaemia than blood group O. Regardles of malaria transmission zones, individuals from endemic zones showed up with high parasitaemia and among them were more individuals of blood groups A and B than individuals of blood group O. Implying that these individuals were more at risk and require additional attention and effective case management. Garphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04251-1.
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Affiliation(s)
- Redemptah Yeda
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya.
| | - Charles Okudo
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Eunice Owiti
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Gladys Biwot
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Cliff Momanyi
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Winnie Korir
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Thoya Mitsanze
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Caroline Tegerei
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Dennis Juma
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Benjamin Opot
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Edwin Mwakio
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Gladys Chemwor
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Raphael Okoth
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Douglas O Ochora
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya.,Department of Plant Sciences, Microbiology & Biotechnology, College of Natural Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda
| | - Agnes C Cheruiyot
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Amanda Roth
- Walter Reed Army Institute of Research, Silver Spring, USA
| | - Hoseah M Akala
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Ben Andagalu
- Malaria Drug Resistance Laboratory, United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
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13
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White NJ. The assessment of antimalarial drug efficacy in vivo. Trends Parasitol 2022; 38:660-672. [PMID: 35680541 PMCID: PMC7613059 DOI: 10.1016/j.pt.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/19/2022]
Abstract
Currently recommended methods of assessing uncomplicated falciparum malaria treatment work less well in high transmission than in low transmission settings. There is also uncertainty how to assess intermittent preventive therapies and seasonal malaria chemoprevention, and P. vivax radical cure. A “pharmacometric antimalarial resistance monitoring (PARM)” approach is proposed for slowly eliminated antimalarial drugs in areas of high transmission. In PARM antimalarial drug concentrations at recurrent parasitaemia are measured to identify outliers (i.e. recurrent parasitaemias in the presence of normally suppressive drug concentrations), and to characterise changes over time. PARM requires characterization of pharmacometric profiles but should be simpler and more sensitive than current methodologies. PARM does not require parasite genotyping, and can be applied to the assessment of both prevention and treatment.
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Affiliation(s)
- Nicholas J White
- 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, Oxford University, Oxford, UK.
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14
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Cutts JC, O'Flaherty K, Zaloumis SG, Ashley EA, Chan JA, Onyamboko MA, Fanello C, Dondorp AM, Day NP, Phyo AP, Dhorda M, Imwong M, Fairhurst RM, Lim P, Amaratunga C, Pukrittayakamee S, Hien TT, Htut Y, Mayxay M, Abdul Faiz M, Takashima E, Tsuboi T, Beeson JG, Nosten F, Simpson JA, White NJ, Fowkes FJI. Comparison of antibody responses and parasite clearance in artemisinin therapeutic efficacy studies in Democratic Republic of Congo and Asia. J Infect Dis 2022; 226:324-331. [PMID: 35703955 PMCID: PMC9400417 DOI: 10.1093/infdis/jiac232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/12/2022] [Indexed: 12/05/2022] Open
Abstract
Background Understanding the effect of immunity on Plasmodium falciparum clearance is essential for interpreting therapeutic efficacy studies designed to monitor emergence of artemisinin drug resistance. In low-transmission areas of Southeast Asia, where resistance has emerged, P. falciparum antibodies confound parasite clearance measures. However, variation in naturally acquired antibodies across Asian and sub-Saharan African epidemiological contexts and their impact on parasite clearance re yet to be quantified. Methods In an artemisinin therapeutic efficacy study, antibodies to 12 pre-erythrocytic and erythrocytic P. falciparum antigens were measured in 118 children with uncomplicated P. falciparum malaria in the Democratic Republic of Congo (DRC) and compared with responses in patients from Asian sites, described elsewhere. Results Parasite clearance half-life was shorter in DRC patients (median, 2 hours) compared with most Asian sites (median, 2–7 hours), but P. falciparum antibody levels and seroprevalences were similar. There was no evidence for an association between antibody seropositivity and parasite clearance half-life (mean difference between seronegative and seropositive, −0.14 to +0.40 hour) in DRC patients. Conclusions In DRC, where artemisinin remains highly effective, the substantially shorter parasite clearance time compared with Asia was not explained by differences in the P. falciparum antibody responses studied.
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Affiliation(s)
- Julia C Cutts
- Burnet Institute, Melbourne, Victoria 3004, Australia.,Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
| | | | - Sophie G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne, School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Lao-Oxford-Mahosot Hospital-Wellcome Trust-Research Unit, Mahosot Hospital, Vientiane, Lao PDR
| | - Jo Anne Chan
- Burnet Institute, Melbourne, Victoria 3004, Australia.,Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia.,Department of Immunology, Monash University, Melbourne Australia
| | - Marie A Onyamboko
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | - Caterina Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Nicholas P Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | | | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Worldwide Antimalarial Resistance Network, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Mallika Imwong
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Pharath Lim
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Chanaki Amaratunga
- Worldwide Antimalarial Resistance Network, Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | | | - Tran Tinh Hien
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ye Htut
- Department of Medical Research, Yangon, Myanmar
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Institute of Research and Education Development, University of Health Sciences, Vientiane, Lao PDR.,Lao-Oxford-Mahosot Hospital-Wellcome Trust-Research Unit, Mahosot Hospital, Vientiane, Lao PDR
| | - M Abdul Faiz
- Malaria Research Group & Dev Care Foundation, Chittagong, Bangladesh
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - James G Beeson
- Burnet Institute, Melbourne, Victoria 3004, Australia.,Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia.,Department of Immunology, Monash University, Melbourne Australia
| | - Francois Nosten
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne, School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, Victoria 3004, Australia.,Centre for Epidemiology and Biostatistics, Melbourne, School of Population and Global Health, The University of Melbourne, Melbourne, Australia.,Department of Infectious Diseases and Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia
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15
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Peto TJ, Tripura R, Callery JJ, Lek D, Nghia HDT, Nguon C, Thuong NTH, van der Pluijm RW, Dung NTP, Sokha M, Van Luong V, Long LT, Sovann Y, Duanguppama J, Waithira N, Hoglund RM, Chotsiri P, Chau NH, Ruecker A, Amaratunga C, Dhorda M, Miotto O, Maude RJ, Rekol H, Chotivanich K, Tarning J, von Seidlein L, Imwong M, Mukaka M, Day NPJ, Hien TT, White NJ, Dondorp AM. Triple therapy with artemether-lumefantrine plus amodiaquine versus artemether-lumefantrine alone for artemisinin-resistant, uncomplicated falciparum malaria: an open-label, randomised, multicentre trial. THE LANCET. INFECTIOUS DISEASES 2022; 22:867-878. [PMID: 35276064 PMCID: PMC9132777 DOI: 10.1016/s1473-3099(21)00692-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/14/2021] [Accepted: 10/27/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Late treatment failures after artemisinin-based combination therapies (ACTs) for falciparum malaria have increased in the Greater Mekong subregion in southeast Asia. Addition of amodiaquine to artemether-lumefantrine could provide an efficacious treatment for multidrug-resistant infections. METHODS We conducted an open-label, randomised trial at five hospitals or health centres in three locations (western Cambodia, eastern Cambodia, and Vietnam). Eligible participants were male and female patients aged 2-65 years with uncomplicated Plasmodium falciparum malaria. Patients were randomly allocated (1:1 in blocks of eight to 12) to either artemether-lumefantrine alone (dosed according to WHO guidelines) or artemether-lumefantrine plus amodiaquine (10 mg base per kg/day), both given orally as six doses over 3 days. All received a single dose of primaquine (0·25 mg/kg) 24 h after the start of study treatment to limit transmission of the parasite. Parasites were genotyped, identifying artemisinin resistance. The primary outcome was Kaplan-Meier 42-day PCR-corrected efficacy against recrudescence of the original parasite, assessed by intent-to-treat. Safety was a secondary outcome. This completed trial is registered at ClinicalTrials.gov (NCT03355664). FINDINGS Between March 18, 2018, and Jan 30, 2020, 310 patients received randomly allocated treatment; 154 received artemether-lumefantrine alone and 156 received artemether-lumefantrine plus amodiaquine. Parasites from 305 of these patients were genotyped. 42-day PCR-corrected treatment efficacy was noted in 151 (97%, 95% CI 92-99) of 156 patients with artemether-lumefantrine plus amodiaquine versus 146 (95%, 89-97) of 154 patients with artemether-lumefantrine alone; hazard ratio (HR) for recrudescence 0·6 (95% CI 0·2-1·9, p=0·38). Of the 13 recrudescences, 12 were in 174 (57%) of 305 infections with pfkelch13 mutations indicating artemisinin resistance, for which 42-day efficacy was noted in 89 (96%) of 93 infections with artemether-lumefantrine plus amodiaquine versus 73 (90%) of 81 infections with artemether-lumefantrine alone; HR for recrudescence 0·44 (95% CI 0·14-1·40, p=0·17). Artemether-lumefantrine plus amodiaquine was generally well tolerated, but the number of mild (grade 1-2) adverse events, mainly gastrointestinal, was greater in this group compared with artemether-lumefantrine alone (vomiting, 12 [8%] with artemether-lumefantrine plus amodiaquine vs three [2%] with artemether-lumefantrine alone, p=0·03; and nausea, 11 [7%] with artemether-lumefantrine plus amodiaquine vs three [2%] with artemether-lumefantrine alone, p=0·05). Early vomiting within 1 h of treatment, requiring retreatment, occurred in no patients of 154 with artemether-lumefantrine alone versus five (3%) of 156 with artemether-lumefantrine plus amodiaquine, p=0·06. Bradycardia (≤54 beats/min) of any grade was noted in 59 (38%) of 154 patients with artemether-lumefantrine alone and 95 (61%) of 156 with artemether-lumefantrine plus amodiaquine, p=0·0001. INTERPRETATION Artemether-lumefantrine plus amodiaquine provides an alternative to artemether-lumefantrine alone as first-line treatment for multidrug-resistant P falciparum malaria in the Greater Mekong subregion, and could prolong the therapeutic lifetime of artemether-lumefantrine in malaria-endemic populations. FUNDING Bill & Melinda Gates Foundation, Wellcome Trust.
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Affiliation(s)
- Thomas J Peto
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Rupam Tripura
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia; School of Public Health, National Institute of Public Health, Phnom Penh, Cambodia
| | - Ho Dang Trung Nghia
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam; Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Chea Nguon
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nguyen Thi Huyen Thuong
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Rob W van der Pluijm
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Nguyen Thi Phuong Dung
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Meas Sokha
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Vo Van Luong
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Le Thanh Long
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Yok Sovann
- Pailin Provincial Health Department, Pailin, Cambodia
| | | | - Naomi Waithira
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Richard M Hoglund
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Palang Chotsiri
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nguyen Hoang Chau
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Andrea Ruecker
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Chanaki Amaratunga
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Mehul Dhorda
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; WorldWide Antimalarial Resistance Network, Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Olivo Miotto
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Wellcome Trust Sanger Institute, Hinxton, UK
| | - 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 Clinical Medicine, University of Oxford, Oxford, UK; Harvard T H Chan School of Public Health, Harvard University, Boston, MA, USA; The Open University, Milton Keynes, UK
| | - Huy Rekol
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Kesinee Chotivanich
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Clinical Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Tran Tinh Hien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
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16
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O’Flaherty K, Chan JA, Cutts JC, Zaloumis SG, Ashley EA, Phyo AP, Drew DR, Dondorp AM, Day NP, Dhorda M, Fairhurst RM, Lim P, Amaratunga C, Pukrittayakamee S, Hien TT, Htut Y, Mayxay M, Faiz MA, Mokuolu OA, Onyamboko MA, Fanello C, Takashima E, Tsuboi T, Theisen M, Nosten F, Beeson JG, Simpson JA, White NJ, Fowkes FJI. Anti-Gametocyte Antigen Humoral Immunity and Gametocytemia During Treatment of Uncomplicated Falciparum Malaria: A Multi-National Study. Front Cell Infect Microbiol 2022; 12:804470. [PMID: 35463638 PMCID: PMC9022117 DOI: 10.3389/fcimb.2022.804470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/11/2022] [Indexed: 11/16/2022] Open
Abstract
Introduction Understanding the human immune response to Plasmodium falciparum gametocytes and its association with gametocytemia is essential for understanding the transmission of malaria as well as progressing transmission blocking vaccine candidates. Methods In a multi-national clinical efficacy trial of artemisinin therapies (13 sites of varying transmission over South-East Asia and Africa), we measured Immunoglobulin G (IgG) responses to recombinant P. falciparum gametocyte antigens expressed on the gametocyte plasma membrane and leading transmission blocking vaccine candidates Pfs230 (Pfs230c and Pfs230D1M) and Pfs48/45 at enrolment in 1,114 participants with clinical falciparum malaria. Mixed effects linear and logistic regression were used to determine the association between gametocyte measures (gametocytemia and gametocyte density) and antibody outcomes at enrolment. Results Microscopy detectable gametocytemia was observed in 11% (127/1,114) of participants at enrolment, and an additional 9% (95/1,114) over the follow-up period (up to day 42) (total 20% of participants [222/1,114]). IgG levels in response to Pfs230c, Pfs48/45 and Pfs230D1M varied across study sites at enrolment (p < 0.001), as did IgG seroprevalence for anti-Pfs230c and D1M IgG (p < 0.001), but not for anti-Pfs48/45 IgG (p = 0.159). In adjusted analyses, microscopy detectable gametocytemia at enrolment was associated with an increase in the odds of IgG seropositivity to the three gametocyte antigens (Pfs230c OR [95% CI], p: 1.70 [1.10, 2.62], 0.017; Pfs48/45: 1.45 [0.85, 2.46], 0.174; Pfs230D1M: 1.70 [1.03, 2.80], 0.037), as was higher gametocyte density at enrolment (per two-fold change in gametocyte density Pfs230c OR [95% CI], p: 1.09 [1.02, 1.17], 0.008; Pfs48/45: 1.05 [0.98, 1.13], 0.185; Pfs230D1M: 1.07 [0.99, 1.14], 0.071). Conclusion Pfs230 and Pfs48/45 antibodies are naturally immunogenic targets associated with patent gametocytemia and increasing gametocyte density across multiple malaria endemic settings, including regions with emerging artemisinin-resistant P. falciparum.
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Affiliation(s)
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- Department of Immunology, Monash University, Melbourne, VIC, Australia
| | - Julia C. Cutts
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
| | - Sophie G. Zaloumis
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Elizabeth A. Ashley
- 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, United Kingdom
| | | | - Damien R. Drew
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | - Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas P. Day
- 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, United Kingdom
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- WorldWide Antimalarial Resistance Network, Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Pharath Lim
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | | | - Tran Tinh Hien
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ye Htut
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust-Research Unit, Mahosot Hospital, Vientiane, Laos
- Institute of Research and Education Development, University of Health Sciences, Vientiane, Laos
| | - M. Abul Faiz
- Malaria Research Group and Dev Care Foundation, Chittagong, Bangladesh
| | - Olugbenga A. Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Marie A. Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Caterina Fanello
- 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, United Kingdom
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Francois Nosten
- 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, United Kingdom
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - James G. Beeson
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- Department of Immunology, Monash University, Melbourne, VIC, Australia
- Department of Microbiology and Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Nicholas J. White
- 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, United Kingdom
| | - Freya J. I. Fowkes
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
- Department of Infectious Diseases and Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, VIC, Australia
- *Correspondence: Freya J. I. Fowkes,
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Wamae K, Ndwiga L, Kharabora O, Kimenyi K, Osoti V, de Laurent Z, Wambua J, Musyoki J, Ngetsa C, Kalume P, Mwambingu G, Hamaluba M, van der Pluijm R, Dondorp A, Bailey J, Juliano J, Bejon P, Ochola-Oyier L. Targeted Amplicon deep sequencing of ama1 and mdr1 to track within-host P. falciparum diversity throughout treatment in a clinical drug trial. Wellcome Open Res 2022. [DOI: 10.12688/wellcomeopenres.17736.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimalarial therapeutic efficacy studies are routinely conducted in malaria-endemic countries to assess the effectiveness of antimalarial treatment strategies. Targeted amplicon deep sequencing (TADS) uniquely identifies and quantifies genetically distinct parasites within an infection. In this study, TADS Plasmodium falciparum apical membrane antigen 1 (ama1), and multidrug resistance gene 1 (mdr1), were used to characterize the complexity of infection (COI) and drug-resistance genotypes, respectively. P. falciparum positive samples were obtained from a triple artemisinin combination therapy clinical trial conducted in 30 children under 13 years of age between 2018 and 2019 in Kilifi, Kenya. Of the 30 participants, 9 presented with recurrent parasitemia from day 26 (624h) onwards. The ama1 and mdr1 genes were amplified and sequenced, while msp1, msp2 and glurp data were obtained from the original clinical study. The COI was comparable between ama1 and msp1, msp2 and glurp, however, overall ama1 detected more haplotypes. Based on ama1, a stable number of haplotypes were detected throughout treatment up until day 3. Additionally, a recrudescent infection was identified with an ama1 haplotype initially observed at 30h and later in an unscheduled follow-up visit. Using the relative frequencies of ama1 haplotypes and parasitaemia, we identified a fast (<1h) and slow (>5h) clearing haplotype. As expected, only two mdr1 haplotypes (NF and NY) were identified based on the combination of amino acid polymorphisms at codons 86 and 184. This study highlights TADS as a sensitive tool for tracking parasite haplotypes throughout treatment and can detect variation in haplotype clearance estimates. TADS can also identify slow clearing haplotypes, a potential early sign of selection during treatment. Consequently, TADS has the capability of improving the discriminatory power to accurately distinguish recrudescences from reinfections.
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Assessment of Plasmodium falciparum Artemisinin Resistance Independent of kelch13 Polymorphisms and with Escalating Malaria in Bangladesh. mBio 2022; 13:e0344421. [PMID: 35073756 PMCID: PMC8787467 DOI: 10.1128/mbio.03444-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Emerging resistance to artemisinin drugs threatens the elimination of malaria. Resistance is widespread in South East Asia (SEA) and Myanmar. Neighboring Bangladesh, where 90% of infections occur in the Chittagong Hill Tracts (CHTs), lacks recent assessment. We undertook a prospective study in the sole district-level hospital in Bandarban, a CHT district with low population densities but 60% of reported malaria cases. Thirty patients presented with malaria in 2018. An increase to 68 patients in 2019 correlated with the district-level rise in malaria, rainfall, humidity, and temperature. Twenty-four patients (7 in 2018 and 17 in 2019) with uncomplicated Plasmodium falciparum monoinfection were assessed for clearing parasites after starting artemisinin combination therapy (ACT). The median (range) time to clear half of the initial parasites was 5.6 (1.5 to 9.6) h, with 20% of patients showing a median of 8 h. There was no correlation between parasite clearance and initial parasitemia, blood cell counts, or mutations of P. falciparum gene Pfkelch13 (the molecular marker of artemisinin resistance [AR]). The in vitro ring-stage survival assay (RSA) revealed one (of four) culture-adapted strains with a quantifiable resistance of 2.01% ± 0.1% (mean ± standard error of the mean [SEM]). Regression analyses of in vivo and in vitro measurements of the four CHT strains and WHO-validated K13 resistance mutations yielded good correlation (R2 = 0.7; ρ = 0.9, P < 0.005), strengthening evaluation of emerging AR with small sample sizes, a challenge in many low/moderate-prevalence sites. There is an urgent need to deploy multiple, complementary approaches to understand the evolutionary dynamics of the emergence of P. falciparum resistant to artemisinin derivatives in countries where malaria is endemic. IMPORTANCE Malaria elimination is a Millennium Development Goal. Artemisinins, fast-acting antimalarial drugs, have played a key role in malaria elimination. Emergence of artemisinin resistance threatens the global elimination of malaria. Over the last decade, advanced clinical and laboratory methods have documented its spread throughout South East Asia and Myanmar. Neighboring Bangladesh lies in the historical path of dissemination of antimalarial resistance to the rest of the world, yet it has not been evaluated by combinations of leading methods, particularly in the highland Chittagong Hill Tracts adjacent to Myanmar which contain >90% of malaria in Bangladesh. We show the first establishment of capacity to assess clinical artemisinin resistance directly in patients in the hilltops and laboratory adaptation of Bangladeshi parasite strains from a remote, sparsely populated malaria frontier that is responsive to climate. Our study also provides a generalized model for comprehensive monitoring of drug resistance for countries where malaria is endemic.
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Antimalarial drug candidates in phase I and II drug development: a scoping review. Antimicrob Agents Chemother 2021; 66:e0165921. [PMID: 34843390 PMCID: PMC8846400 DOI: 10.1128/aac.01659-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence and spread of parasite resistance to currently available antimalarials has highlighted the importance of developing novel antimalarials. This scoping review provides an overview of antimalarial drug candidates undergoing phase I and II studies between 1 January 2016 and 28 April 2021. PubMed, Web of Science, Embase, clinical trial registries, and reference lists were searched for relevant studies. Information regarding antimalarial compound details, clinical trial characteristics, study population, and drug pharmacokinetics and pharmacodynamics (PK-PD) were extracted. A total of 50 studies were included, of which 24 had published their results and 26 were unpublished. New antimalarial compounds were evaluated as monotherapy (28 studies, 14 drug candidates) and combination therapy (9 studies, 10 candidates). Fourteen active compounds were identified in the current antimalarial drug development pipeline together with 11 compounds that are inactive, 6 due to insufficient efficacy. PK-PD data were available from 24 studies published as open-access articles. Four unpublished studies have made their results publicly available on clinical trial registries. The terminal elimination half-life of new antimalarial compounds ranged from 14.7 to 483 h. The log10 parasite reduction ratio over 48 h and parasite clearance half-life for Plasmodium falciparum following a single-dose monotherapy were 1.55 to 4.1 and 3.4 to 9.4 h, respectively. The antimalarial drug development landscape has seen a number of novel compounds, with promising PK-PD properties, evaluated in phase I and II studies over the past 5 years. Timely public disclosure of PK-PD data is crucial for informative decision-making and drug development strategy.
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Marwa KJ, Konje ET, Kapesa A, Kamugisha E, Mwita S, Swedberg G. Artemether-lumefantrine and dihydroartemisinin-piperaquine treatment outcomes among children infected with uncomplicated Plasmodium falciparum malaria in Mwanza, Tanzania. Trop Med Health 2021; 49:94. [PMID: 34838151 PMCID: PMC8627025 DOI: 10.1186/s41182-021-00383-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/10/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Artemisinin based combination therapies (ACTs) have been a cornerstone in the treatment of malaria in the world. A rapid decline in dihydroartemisinin piperaquine (DHP) and artemether lumefantrine (ALU) efficacies has been reported in some parts of South East Asia, the historical epicenter for the antimalarial drug resistance. Prolonged drug use is associated with selection of resistant parasites due to exposure to inadequate drug levels hence effects on treatment outcomes in malaria. ALU and DHP are used as first line and alternative first line, respectively, in Tanzania. This study was carried in Igombe, Tanzania to assess the efficacies of ALU and DHP in routine treatment of uncomplicated malaria among children. METHODS This was a prospective study involving children up to 10 years and followed up for 28 and 35 days as per the WHO protocol, 2015 for monitoring antimalarial drug efficacy. The primary end points were crude and adjusted Adequate Clinical and Parasitological Response (ACPR), parasite clearance rate and reported adverse events. RESULTS A total of 205 children with uncomplicated malaria were enrolled. One hundred and sixteen participants were treated with ALU, while 89 participants were treated with DHP. Two participants in the ALU group were lost within the 24 h of follow-up. The PCR unadjusted ACPR was108 (94.7%) for ALU and 88 (98.9%) for DHP, while the PCR adjusted ACPR was 109(95.6%) and 88(98.9%) for ALU and DHP, respectively, at 28 day follow-up. No treatment failure was observed in both groups. Cumulative risk of recurrent parasitemia was similar in both groups (p = 0.32). Age and parasite density were strong predictors for persistent day 1 parasitemia (p = 0.034 and 0.026, respectively). Nausea and vomiting, abdominal pain and headache were the most clinical adverse events reported in both groups of patients. CONCLUSION The present study shows that ALU and DHP are still efficacious after more than a decade of use with PCR corrected efficacies greater than 95% implying a failure rate less than 5% which is below the WHO minimum threshold requirement for recommendation of a change in the treatment policy. Both drugs were well tolerated with no major adverse events reported.
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Affiliation(s)
- Karol J Marwa
- Department of Pharmacology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania.
| | - Eveline T Konje
- Department of Epidemiology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Anthony Kapesa
- Department of Community Medicine, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Erasmus Kamugisha
- Department of Biochemistry, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Stanley Mwita
- School of Pharmacy, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Göte Swedberg
- Institute of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Pyronaridine-Artesunate (Pyramax) for Treatment of Artemisinin- and Piperaquine-Resistant Plasmodium falciparum in the Central Highlands of Vietnam. Antimicrob Agents Chemother 2021; 65:e0027621. [PMID: 34570647 DOI: 10.1128/aac.00276-21] [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] [Indexed: 01/25/2023] Open
Abstract
The rise in Plasmodium falciparum resistance to dihydroartemisinin-piperaquine in Vietnam justifies the need to evaluate alternative artemisinin-based combination therapies. Between July 2018 and October 2019, a single-arm trial of pyronaridine-artesunate (Pyramax, PA) was conducted in Dak Nong province, Vietnam. PA (3-day course) was administered to adults and children infected with P. falciparum. PA was well tolerated by the participants. The proportion of patients with Day 42 PCR-corrected adequate clinical and parasitological response was 95.2% (95% confidence interval [CI], 82.3 to 98.8, n = 40/42) for treating falciparum malaria. The median parasite clearance half-life was 6.7 h (range, 2.6 to 11.9) and the median parasite clearance time was 72 h (range, 12 to 132) with 44.9% (22/49) of patients having positive blood films at 72 h. The two patients that recrudesced had comparable Day 7 blood pyronaridine concentrations (39.5 and 39.0 ng/ml) to the 40 patients who did not recrudesce (median 43.4 ng/ml, 95% CI, 35.1 to 54.9). Ring-stage and piperaquine survival assays revealed that of the 29 P. falciparum isolates collected from the patients before PA treatment, 22 (75.9%) had reduced susceptibility to artemisinins and 17 (58.6%) were resistant to piperaquine. Genotyping confirmed that 92.0% (46/50) of falciparum patients were infected with parasites bearing the Pfkelch13 C580Y mutation associated with artemisinin resistance. Of these, 56.0% (28/50) of the isolates also had multiple copies of the plasmepsin 2/3 genes responsible for piperaquine resistance. Overall, PA was effective in treating P. falciparum in the Central Highlands of Vietnam. (This study has been registered at AustralianClinicalTrials.gov.au under trial ID ACTRN12618001429246.).
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Lee WC, Russell B, Lee B, Chu CS, Phyo AP, Sriprawat K, Lau YL, Nosten F, Rénia L. Plasmodium falciparum rosetting protects schizonts against artemisinin. EBioMedicine 2021; 73:103680. [PMID: 34749300 PMCID: PMC8586750 DOI: 10.1016/j.ebiom.2021.103680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/04/2021] [Accepted: 10/25/2021] [Indexed: 11/24/2022] Open
Abstract
Background Artemisinin (ART) resistance in Plasmodium falciparum is thought to occur during the early stage of the parasite's erythrocytic cycle. Here, we identify a novel factor associated with the late stage parasite development that contributes to ART resistance. Methods Rosetting rates of clinical isolates pre- and post- brief (one hour) exposure to artesunate (AS, an ART derivative) were evaluated. The effects of AS-mediated rosetting on the post-AS-exposed parasite's replication and survival, as well as the extent of protection by AS-mediated rosetting on different parasite stages were investigated. The rosetting ligands, mechanisms, and gene mutations involved were studied. Findings Brief AS exposure stimulated rosetting, with AS-resistant isolates forming more rosettes in a more rapid manner. AS-mediated rosetting enabled infected erythrocytes (IRBC) to withstand AS exposure for several hours and protected the IRBC from phagocytosis. When their rosetting ability was blocked experimentally, the post-AS exposure survival advantage by the AS-resistant parasites was abrogated. Deletions in two genes coding for PfEMP1 exon 2 (PF3D7_0200300 and PF3D7_0223300) were found to be associated with AS-mediated rosetting, and these mutations were significantly selected through time in the parasite population under study, along with the K13 mutations, a molecular marker of ART-resistance. Interpretation Rapid ART parasite clearance is driven by the direct oxidative damages on IRBC by ART and the phagocytic destruction of the damaged IRBC. Rosetting serves as a rapid ‘buying time’ strategy that allows more parasites to complete schizont maturation, reinvasion and subsequent development into the intrinsically less ART-susceptible ring stage. Funding A*STAR, NMRC-OF-YIRG, HRC e-ASIA, Wellcome.
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Affiliation(s)
- Wenn-Chyau Lee
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A*STAR), Singapore; Singapore Immunology Network (SIgN), A*STAR, Singapore.
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, Otago, New Zealand
| | - Bernett Lee
- Singapore Immunology Network (SIgN), A*STAR, Singapore
| | - Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand; Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand; Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand; Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A*STAR), Singapore; Singapore Immunology Network (SIgN), A*STAR, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore.
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23
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Saidi AM, Guenther G, Izem R, Chen X, Seydel K, Postels D. Plasmodium falciparum clearance time in Malawian children with cerebral malaria: a retrospective cohort study. Malar J 2021; 20:408. [PMID: 34663346 PMCID: PMC8524966 DOI: 10.1186/s12936-021-03947-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 10/07/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Standard treatment for both uncomplicated and severe malaria is artemisinin derivatives. Delayed parasite clearance times preceded the appearance of artemisinin treatment failures in Southeast Asia. Most worldwide malaria cases are in sub-Saharan Africa (SSA), where clinically significant artemisinin resistance or treatment failure has not yet been detected. The recent emergence of a resistance-conferring genetic mutation in the Plasmodium falciparum parasite in Africa warrants continued monitoring throughout the continent. METHODS An analysis was performed on data from a retrospective cohort study of Malawian children with cerebral malaria admitted between 2010 and 2019 to a public referral hospital, ascertaining parasite clearance times across years. Data were collected from patients treated for severe malaria with quinine or artesunate, an artemisinin derivative. Parasite density was determined at admission and every subsequent 6 h until parasitaemia was below 1000 parasites/µl.The mean parasite clearance time in all children admitted in any one year was compared to the parasite clearance time in 2014, the first year of artesunate use in Malawi. RESULTS The median population parasite clearance time was slower from 2010 to 2013 (quinine-treated patients) compared to 2014, the first year of artesunate use in Malawi (30 h (95% CI: 30-30) vs 18 h (95% CI: 18-24)). After adjustment for admission parasite count, there was no statistically significant difference in the median population parasite clearance time when comparing 2014 with any subsequent year. CONCLUSION Malaria parasite clearance times in Malawian children with cerebral malaria remained constant between 2014 and 2019, arguing against evolving artemisinin resistance in parasites in this region.
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Affiliation(s)
- Alexuse M Saidi
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Geoffrey Guenther
- Department of Pediatrics, Children's National Medical Center, Washington, DC, USA
| | - Rima Izem
- Division of Biostatistics and Study Methodology, Children's National Research Institute, Washington, DC, USA
- Department of Epidemiology, The George Washington University School of Public Health, Washington, DC, USA
- Statistical Methods and Consulting, Novartis, Basel, Switzerland
| | - Xiaojun Chen
- Department of Biostatistics and Bioinformatics, The George Washington University, Washington, DC, USA
| | - Karl Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Douglas Postels
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Division of Neurology, The George Washington University/Children's National Medical Center, Washington, DC, USA
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24
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Hamaluba M, van der Pluijm RW, Weya J, Njuguna P, Ngama M, Kalume P, Mwambingu G, Ngetsa C, Wambua J, Boga M, Mturi N, Lal AA, Khuroo A, Taylor WRJ, Gonçalves S, Miotto O, Dhorda M, Mutinda B, Mukaka M, Waithira N, Hoglund RM, Imwong M, Tarning J, Day NPJ, White NJ, Bejon P, Dondorp AM. Arterolane-piperaquine-mefloquine versus arterolane-piperaquine and artemether-lumefantrine in the treatment of uncomplicated Plasmodium falciparum malaria in Kenyan children: a single-centre, open-label, randomised, non-inferiority trial. THE LANCET. INFECTIOUS DISEASES 2021; 21:1395-1406. [PMID: 34111412 PMCID: PMC8461080 DOI: 10.1016/s1473-3099(20)30929-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/04/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Triple antimalarial combination therapies combine potent and rapidly cleared artemisinins or related synthetic ozonides, such as arterolane, with two, more slowly eliminated partner drugs to reduce the risk of resistance. We aimed to assess the safety, tolerability, and efficacy of arterolane-piperaquine-mefloquine versus arterolane-piperaquine and artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in Kenyan children. METHODS In this single-centre, open-label, randomised, non-inferiority trial done in Kilifi County Hospital, Kilifi, coastal Kenya, children with uncomplicated Plasmodium falciparum malaria were recruited. Eligible patients were aged 2-12 years and had an asexual parasitaemia of 5000-250 000 parasites per μL. The exclusion criteria included the presence of an acute illness other than malaria, the inability to tolerate oral medications, treatment with an artemisinin derivative in the previous 7 days, a known hypersensitivity or contraindication to any of the study drugs, and a QT interval corrected for heart rate (QTc interval) longer than 450 ms. Patients were randomly assigned (1:1:1), by use of blocks of six, nine, and 12, and opaque, sealed, and sequentially numbered envelopes, to receive either arterolane-piperaquine, arterolane-piperaquine-mefloquine, or artemether-lumefantrine. Laboratory staff, but not the patients, the patients' parents or caregivers, clinical or medical officers, nurses, or trial statistician, were masked to the intervention groups. For 3 days, oral artemether-lumefantrine was administered twice daily (target dose 5-24 mg/kg of bodyweight of artemether and 29-144 mg/kg of bodyweight of lumefantrine), and oral arterolane-piperaquine (arterolane dose 4 mg/kg of bodyweight; piperaquine dose 20 mg/kg of bodyweight) and oral arterolane-piperaquine-mefloquine (mefloquine dose 8 mg/kg of bodyweight) were administered once daily. All patients received 0·25 mg/kg of bodyweight of oral primaquine at hour 24. All patients were admitted to Kilifi County Hospital for at least 3 consecutive days and followed up at day 7 and, thereafter, weekly for up to 42 days. The primary endpoint was 42-day PCR-corrected efficacy, defined as the absence of treatment failure in the first 42 days post-treatment, of arterolane-piperaquine-mefloquine versus artemether-lumefantrine, and, along with safety, was analysed in the intention-to-treat population, which comprised all patients who received at least one dose of a study drug. The 42-day PCR-corrected efficacy of arterolane-piperaquine-mefloquine versus arterolane-piperaquine was an important secondary endpoint and was also analysed in the intention-to-treat population. The non-inferiority margin for the risk difference between treatments was -7%. The study is registered in ClinicalTrials.gov, NCT03452475, and is completed. FINDINGS Between March 7, 2018, and May 2, 2019, 533 children with P falciparum were screened, of whom 217 were randomly assigned to receive either arterolane-piperaquine (n=73), arterolane-piperaquine-mefloquine (n=72), or artemether-lumefantrine (n=72) and comprised the intention-to-treat population. The 42-day PCR-corrected efficacy after treatment with arterolane-piperaquine-mefloquine (100%, 95% CI 95-100; 72/72) was non-inferior to that after treatment with artemether-lumefantrine (96%, 95% CI 88-99; 69/72; risk difference 4%, 95% CI 0-9; p=0·25). The 42-day PCR-corrected efficacy of arterolane-piperaquine-mefloquine was non-inferior to that of arterolane-piperaquine (100%, 95% CI 95-100; 73/73; risk difference 0%). Vomiting rates in the first hour post-drug administration were significantly higher in patients treated with arterolane-piperaquine (5%, 95% CI 2-9; ten of 203 drug administrations; p=0·0013) or arterolane-piperaquine-mefloquine (5%, 3-9; 11 of 209 drug administrations; p=0·0006) than in patients treated with artemether-lumefantrine (1%, 0-2; three of 415 drug administrations). Upper respiratory tract complaints (n=26 for artemether-lumefantrine; n=19 for arterolane-piperaquine-mefloquine; n=23 for arterolane-piperaquine), headache (n=13; n=4; n=5), and abdominal pain (n=7; n=5; n=5) were the most frequently reported adverse events. There were no deaths. INTERPRETATION This study shows that arterolane-piperaquine-mefloquine is an efficacious and safe treatment for uncomplicated falciparum malaria in children and could potentially be used to prevent or delay the emergence of antimalarial resistance. FUNDING UK Department for International Development, The Wellcome Trust, The Bill & Melinda Gates Foundation, Sun Pharmaceutical Industries.
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Affiliation(s)
- Mainga Hamaluba
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Rob W van der Pluijm
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joseph Weya
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Patricia Njuguna
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Peter Kalume
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | | | | | - Neema Mturi
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Altaf A Lal
- Sun Pharmaceutical Industries, Gurugram, India
| | | | - Walter R J Taylor
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Olivo Miotto
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Wellcome Sanger Institute, Hinxton, UK
| | - Mehul Dhorda
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Asia-Pacific Regional Centre, WorldWide Antimalarial Resistance Network, Bangkok, Thailand
| | - Brian Mutinda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mavuto Mukaka
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Naomi Waithira
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Richard M Hoglund
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Philip Bejon
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Dhorda M, Amaratunga C, Dondorp AM. Artemisinin and multidrug-resistant Plasmodium falciparum - a threat for malaria control and elimination. Curr Opin Infect Dis 2021; 34:432-439. [PMID: 34267045 PMCID: PMC8452334 DOI: 10.1097/qco.0000000000000766] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE OF REVIEW Artemisinin-based combination therapies (ACTs) are globally the first-line treatment for uncomplicated falciparum malaria and new compounds will not be available within the next few years. Artemisinin-resistant Plasmodium falciparum emerged over a decade ago in the Greater Mekong Subregion (GMS) and, compounded by ACT partner drug resistance, has caused significant ACT treatment failure. This review provides an update on the epidemiology, and mechanisms of artemisinin resistance and approaches to counter multidrug-resistant falciparum malaria. RECENT FINDINGS An aggressive malaria elimination programme in the GMS has helped prevent the spread of drug resistance to neighbouring countries. However, parasites carrying artemisinin resistance-associated mutations in the P. falciparum Kelch13 gene (pfk13) have now emerged independently in multiple locations elsewhere in Asia, Africa and South America. Notably, artemisinin-resistant infections with parasites carrying the pfk13 R561H mutation have emerged and spread in Rwanda. SUMMARY Enhancing the geographic coverage of surveillance for resistance will be key to ensure prompt detection of emerging resistance in order to implement effective countermeasures without delay. Treatment strategies designed to prevent the emergence and spread of multidrug resistance must be considered, including deployment of triple drug combination therapies and multiple first-line therapies.
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Affiliation(s)
- Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chanaki Amaratunga
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Gbessi EA, Toure OA, Gnondjui A, Koui TS, Coulibaly B, Ako BA, Tiacoh NL, Assi SB, Sanogo I, Sokouri DP, Jambou R. Artemisinin derivative-containing therapies and abnormal hemoglobin: Do we need to adapt the treatment? ACTA ACUST UNITED AC 2021; 28:67. [PMID: 34569928 PMCID: PMC8475499 DOI: 10.1051/parasite/2021063] [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: 03/19/2021] [Accepted: 08/31/2021] [Indexed: 11/23/2022]
Abstract
Background: Artemisinin-based treatment in malaria patients with abnormal hemoglobin may be ineffective because of their genetic particularity, which could lead to resistance. The main purpose of this study was to assess the effect of artemisinin derivatives on in vivo parasite clearance according to erythrocyte variants. In vivo response was investigated through retrospective data obtained over a 42-day artemether-lumefantrine/artesunate amodiaquine efficacy protocol conducted from 2012 to 2016. Results: A total of 770 patients in Côte d’Ivoire attending the hospitals of Anonkoua-koute (Abidjan), Petit Paris (Korhogo), Libreville (Man), Dar es salam (Bouaké), Ayamé and Yamoussoukro with acute uncomplicated falciparum malaria were selected for successful hemoglobin typing. HbAS, HbSS, HbAC, and HbSC genotypes were found. Parasite clearance time was obtained for 414 patients. In the population with abnormal hemoglobin, parasite densities on admission and parasite clearance rates were significantly lower in the HbSC group compared to HbAA (p = 0.02 and p = 0.007, respectively). After PCR correction on day 42, the acute treatment rate was 100% for each group. Parasite half-life and time for initial parasitaemia to decline by 50 and 99% were longer for the HbSC group (p < 0.05). The study also investigated the prevalence of K13-propeller polymorphisms across different hemoglobin genotype groups. A total of 185 and 63 samples were sequenced in the HbAA group and patients with abnormal Hb, respectively. Only two nonsynonymous mutations D559N and V510M were found in the HbAA group. Conclusion: Although this study proved good efficacy of artemether-lumefantrine and artesunate amodiaquine in the treatment of uncomplicated Plasmodium falciparum malaria in patients with abnormal hemoglobin, the increased delay of parasite clearance may represent a threat to health in these patients in relation with sickle cell crisis, which could support selection of parasites resistant to artemisinin.
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Affiliation(s)
- Eric A Gbessi
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Offianan A Toure
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Albert Gnondjui
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Tossea S Koui
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Baba Coulibaly
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Berenger A Ako
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Nguessan L Tiacoh
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Serge-Brice Assi
- Institut Pierre Richet/Programme National de Lutte contre le Paludisme, BP 1500 Bouaké, Côte d'Ivoire
| | - Ibrahima Sanogo
- Service d'Hématologie, CHU Youpougon, Abidjan, Côte d'Ivoire
| | - Didier-Paulin Sokouri
- Université Félix-Houphouet Boigny, Unité de Formation et de Recherche, Biosciences, Abidjan, Côte d'Ivoire
| | - Ronan Jambou
- Unité de Paludologie, Institut Pasteur Côte d'Ivoire, 01 BP 490, Abidjan 01, Côte d'Ivoire - Département de santé globale, Institut Pasteur Paris, 25 rue du Dr Roux, 75015 Paris, France
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Balikagala B, Fukuda N, Ikeda M, Katuro OT, Tachibana SI, Yamauchi M, Opio W, Emoto S, Anywar DA, Kimura E, Palacpac NMQ, Odongo-Aginya EI, Ogwang M, Horii T, Mita T. Evidence of Artemisinin-Resistant Malaria in Africa. N Engl J Med 2021; 385:1163-1171. [PMID: 34551228 DOI: 10.1056/nejmoa2101746] [Citation(s) in RCA: 370] [Impact Index Per Article: 123.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND In the six Southeast Asian countries that make up the Greater Mekong Subregion, Plasmodium falciparum has developed resistance to derivatives of artemisinin, the main component of first-line treatments for malaria. Clinical resistance to artemisinin monotherapy in other global regions, including Africa, would be problematic. METHODS In this longitudinal study conducted in Northern Uganda, we treated patients who had P. falciparum infection with intravenous artesunate (a water-soluble artemisinin derivative) and estimated the parasite clearance half-life. We evaluated ex vivo susceptibility of the parasite using a ring-stage survival assay and genotyped resistance-related genes. RESULTS From 2017 through 2019, a total of 14 of 240 patients who received intravenous artesunate had evidence of in vivo artemisinin resistance (parasite clearance half-life, >5 hours). Of these 14 patients, 13 were infected with P. falciparum parasites with mutations in the A675V or C469Y allele in the kelch13 gene. Such mutations were associated with prolonged parasite clearance half-lives (geometric mean, 3.95 hours for A675V and 3.30 hours for C469Y, vs. 1.78 hours for wild-type allele; P<0.001 and P = 0.05, respectively). The ring-stage survival assay showed a higher frequency of parasite survival among organisms with the A675V allele than among those with the wild-type allele. The prevalence of parasites with kelch13 mutations increased significantly, from 3.9% in 2015 to 19.8% in 2019, due primarily to the increased frequency of the A675V and C469Y alleles (P<0.001 and P = 0.004, respectively). Single-nucleotide polymorphisms flanking the A675V mutation in Uganda were substantially different from those in Southeast Asia. CONCLUSIONS The independent emergence and local spread of clinically artemisinin-resistant P. falciparum has been identified in Africa. The two kelch13 mutations may be markers for detection of these resistant parasites. (Funded by the Japan Society for the Promotion of Science and others.).
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Affiliation(s)
- Betty Balikagala
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Naoyuki Fukuda
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Mie Ikeda
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Osbert T Katuro
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Shin-Ichiro Tachibana
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Masato Yamauchi
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Walter Opio
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Sakurako Emoto
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Denis A Anywar
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Eisaku Kimura
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Nirianne M Q Palacpac
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Emmanuel I Odongo-Aginya
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Martin Ogwang
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Toshihiro Horii
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
| | - Toshihiro Mita
- From the Department of Tropical Medicine and Parasitology, School of Medicine (B.B., N.F., M.I., S.-I.T., M.Y., S.E., T.M.), and the Atopy Research Center, Graduate School of Medicine (B.B.), Juntendo University, Tokyo, the School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki (E.K.), and the Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka (N.M.Q.P., T.H.) - all in Japan; and Mildmay Uganda, Nazibwa Hill, Kampala (O.T.K.), and St. Mary's Hospital Lacor (W.O., M.O.) and the Faculty of Medicine, Gulu University (D.A.A., E.I.O.-A.), Gulu - all in Uganda
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White NJ, Watson JA. Questioning the Claimed Superiority of Malaria Parasite Ex Vivo Viability Reduction Over Observed Parasite Clearance Rate? J Infect Dis 2021; 224:738-739. [PMID: 34398241 PMCID: PMC8366431 DOI: 10.1093/infdis/jiaa790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 12/22/2020] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nicholas J White
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - James A Watson
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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High Proportion of Genome-Wide Homology and Increased Pretreatment pvcrt Levels in Plasmodium vivax Late Recurrences: a Chloroquine Therapeutic Efficacy Study. Antimicrob Agents Chemother 2021; 65:e0009521. [PMID: 34031050 DOI: 10.1128/aac.00095-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chloroquine (CQ) is the first-line treatment for Plasmodium vivax malaria in most countries where malaria is endemic. Monitoring P. vivax CQ resistance (CQR) is critical but remains challenged by the difficulty to distinguish real treatment failure from reinfection or liver relapse. The therapeutic efficacy of CQ against uncomplicated P. vivax malaria was evaluated in Gia Lai Province, Vietnam. Sixty-seven patients were enrolled and followed for 42 days using microscopy and quantitative PCR. Adequate clinical and parasitological response (ACPR) was 100% (66/66) on day 28 but 75.4% (49/65) on day 42. Eighteen recurrences (27.7%) were detected, with a median time to recurrence of 42 days (interquartile range [IQR], 35 to 42) and blood CQ concentration of <100 ng/ml. Primary infections leading to recurrence occurred in younger individuals (median age for ACPR = 25 years [IQR, 20 to 28]; recurrences = 18 [16 to 21]; P = 0.002) had a longer parasite clearance time (PCT for ACPR = 47.5 h [IQR, 36.2 to 59.8 h]; recurrences = 54.2 [48.4 to 62.0]; P = 0.035) and higher pvcrt gene expression (median relative expression ratio for ACPR = 0.09 [IQR, 0.05 to 0.22]; recurrences = 0.20 [0.15 to 0.56]; P = 0.002), but showed no differences in ex vivo CQ sensitivity. Parasite genotyping by microsatellites, single nucleotide polymorphism (SNP) barcoding, and whole-genome sequencing (WGS) identified a majority of homologous recurrences, with 80% (8/10) showing >98% identity by descent to paired day 0 samples. This study shows that CQ remained largely efficacious to treat P. vivax in Gia Lai; i.e., recurrences occurred late (>day 28) and in the presence of low blood CQ concentrations. However, the combination of both WGS and gene expression analysis (pvcrt) data with clinical data (PCT) allowed us to identify potential emergence of low-grade CQR, which should be closely monitored. (This study has been registered at ClinicalTrials.gov under identifier NCT02610686.).
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30
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Rovira-Vallbona E, Van Hong N, Kattenberg JH, Huan RM, Hien NTT, Ngoc NTH, Guetens P, Hieu NL, Mai TT, Duong NTT, Duong TT, Phuc BQ, Xa NX, Erhart A, Rosanas-Urgell A. Efficacy of dihydroartemisinin/piperaquine and artesunate monotherapy for the treatment of uncomplicated Plasmodium falciparum malaria in Central Vietnam. J Antimicrob Chemother 2021; 75:2272-2281. [PMID: 32437557 DOI: 10.1093/jac/dkaa172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 03/20/2020] [Accepted: 04/03/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Artemisinin-based combination therapies (ACTs) have significantly contributed to reduce Plasmodium falciparum malaria burden in Vietnam, but their efficacy is challenged by treatment failure of dihydroartemisinin/piperaquine ACT in Southern provinces. OBJECTIVES To assess the efficacy of dihydroartemisinin/piperaquine for uncomplicated P. falciparum malaria in Gia Lai, Central Vietnam, and determine parasite resistance to artemisinin (ClinicalTrials.gov identifier NCT02604966). METHODS Sixty patients received either dihydroartemisinin/piperaquine (4 mg/kg/day, 3 days; n = 33) or artesunate monotherapy (4 mg/kg/day, 3 days; n = 27) followed by dihydroartemisinin/piperaquine (AS + DHA/PPQ). Clinical phenotypes were determined during a 42 day follow-up and analysed together with ex vivo susceptibility to antimalarials and molecular markers of drug resistance. RESULTS Day 3 positivity rate was significantly higher in the AS + DHA/PPQ arm compared with dihydroartemisinin/piperaquine (70.4% versus 39.4%, P = 0.016). Parasite clearance time was 95.2 h (AS + DHA/PPQ) versus 71.9 h (dihydroartemisinin/piperaquine, P = 0.063) and parasite clearance half-life was 7.4 h (AS + DHA/PPQ) versus 7.0 h (dihydroartemisinin/piperaquine, P = 0.140). Adequate clinical and parasitological response at Day 42 was 100% in both arms. By RT-qPCR, 36% (19/53) patients remained positive until Day 7. No recurrences were detected. kelch13 artemisinin resistance mutations were found in 87% (39/45) of isolates and 50% (20/40) were KEL1/C580Y. The piperaquine resistance marker plasmepsin-2 was duplicated in 10.4% (5/48). Isolates from Day 3-positive patients (n = 18) had higher ex vivo survival rates to artemisinin compounds (P < 0.048) and prevalence of kelch13 mutations (P = 0.005) than Day 3-negative patients (n = 5). The WHO definition of artemisinin resistance was fulfilled in 60% (24/40) of cases. CONCLUSIONS Although dihydroartemisinin/piperaquine remained effective to treat P. falciparum, the high Day 3 positivity rate and prevalence of KEL1 strains calls for continuous monitoring of dihydroartemisinin/piperaquine efficacy in Central Vietnam.
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Affiliation(s)
| | - Nguyen Van Hong
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Johanna H Kattenberg
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Ro Mah Huan
- Centre for Disease Control and Prevention, Gia Lai Province, Vietnam
| | - Nguyen Thi Thu Hien
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | | | - Pieter Guetens
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Nguyen Luong Hieu
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Tran Tuyet Mai
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | | | - Tran Thanh Duong
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Bui Quang Phuc
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Nguyen Xuan Xa
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Annette Erhart
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.,Medical Research Council Unit The Gambia (MRCG) at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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31
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Das S, Kar A, Manna S, Mandal S, Mandal S, Das S, Saha B, Hati AK. Artemisinin combination therapy fails even in the absence of Plasmodium falciparum kelch13 gene polymorphism in Central India. Sci Rep 2021; 11:9946. [PMID: 33976269 PMCID: PMC8113598 DOI: 10.1038/s41598-021-89295-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/23/2021] [Indexed: 11/25/2022] Open
Abstract
Artemisinin is the frontline fast-acting anti-malarial against P. falciparum. Emergence and spread of resistant parasite in eastern-India poses a threat to national malaria control programs. Therefore, the objective of our study is to evaluate the artesunate-sulfadoxine-pyrimethamine efficacy in Central India. 180 monoclonal P. falciparum-infected patients received standard ASSP therapy during August 2015–January 2017, soon after diagnosis and monitored over next 42-days. Artemisinin-resistance was assessed through in-vivo parasite clearance half-life (PC1/2), ex-vivo ring-stage survivability (RSA), and genome analysis of kelch13 and other candidate gene (pfcrt, pfmdr1, pfatpase 6, pfdhfr and pfdhps). Of 180 P. falciparum positive patients, 9.5% showed increased PC1/2 (> 5.5 h), among them eleven isolates (6.1%) showed reduced sensitivity to RSA. In 4.4% of cases, parasites were not cleared by 72 h and showed prolonged PC1/2(5.6 h) (P < 0.005) along with significantly higher RSA (2.2%) than cured patients (0.4%). None of day-3 positive isolates contained the pfkelch13 mutation implicated in artemisinin resistance. Parasite recrudescence was observed in 5.6% patients, which was associated with triple dhfr–dhps (A16I51R59N108I164–S436G437K540G581T613) combination mutation. Emergence of reduced sensitivity to artesunate-sulfadoxine-pyrimethamine, in central India highlighted the risk toward spread of resistant parasite across different parts of India. Day-3 positive parasite, featuring the phenotype of artemisinin-resistance without pfkelch13 mutation, suggested kelch13-independent artemisinin-resistance.
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Affiliation(s)
- Sabyasachi Das
- Department of Physiology, Faculty of Medicine, Manipal University College Malaysia, Jalan Batu Hampar, Bukit Baru, 75150, Melaka, Malaysia. .,Department of Physiology, Faculty of Medicine, Lincoln University College, Petaling Jaya, Selangor, Malaysia. .,Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
| | - Amrita Kar
- Department of Biotechnology, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology, Sastra University, Thanjavur, Tamil Nadu, India
| | - Subhankar Manna
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | - Samaresh Mandal
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | | | | | - Bhaskar Saha
- Lab 5, National Centre for Cell Science, Ganeshkhind, Pune, India
| | - Amiya Kumar Hati
- Department of Medical Entomology and Parasitology, Calcutta School of Tropical Medicine, Kolkata, West Bengal, India
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Parasite-Host Dynamics throughout Antimalarial Drug Development Stages Complicate the Translation of Parasite Clearance. Antimicrob Agents Chemother 2021; 65:AAC.01539-20. [PMID: 33526486 PMCID: PMC8097426 DOI: 10.1128/aac.01539-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 01/20/2021] [Indexed: 11/21/2022] Open
Abstract
Ensuring continued success against malaria depends on a pipeline of new antimalarials. Antimalarial drug development utilizes preclinical murine and experimental human malaria infection studies to evaluate drug efficacy. Ensuring continued success against malaria depends on a pipeline of new antimalarials. Antimalarial drug development utilizes preclinical murine and experimental human malaria infection studies to evaluate drug efficacy. A sequential approach is typically adapted, with results from each stage informing the design of the next stage of development. The validity of this approach depends on confidence that results from murine malarial studies predict the outcome of clinical trials in humans. Parasite clearance rates following treatment are key parameters of drug efficacy. To investigate the validity of forward predictions, we developed a suite of mathematical models to capture parasite growth and drug clearance along the drug development pathway and estimated parasite clearance rates. When comparing the three infection experiments, we identified different relationships of parasite clearance with dose and different maximum parasite clearance rates. In Plasmodium berghei-NMRI mouse infections, we estimated a maximum parasite clearance rate of 0.2 (1/h); in Plasmodium falciparum-SCID mouse infections, 0.05 (1/h); and in human volunteer infection studies with P. falciparum, we found a maximum parasite clearance rate of 0.12 (1/h) and 0.18 (1/h) after treatment with OZ439 and MMV048, respectively. Sensitivity analysis revealed that host-parasite driven processes account for up to 25% of variance in parasite clearance for medium-high doses of antimalarials. Although there are limitations in translating parasite clearance rates across these experiments, they provide insight into characterizing key parameters of drug action and dose response and assist in decision-making regarding dosage for further drug development.
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33
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Fanello C, Hoglund RM, Lee SJ, Kayembe D, Ndjowo P, Kabedi C, Badjanga BB, Niamyim P, Tarning J, Woodrow C, Gomes M, Day NP, White NJ, Onyamboko MA. Pharmacokinetic Study of Rectal Artesunate in Children with Severe Malaria in Africa. Antimicrob Agents Chemother 2021; 65:e02223-20. [PMID: 33526485 PMCID: PMC8097454 DOI: 10.1128/aac.02223-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/14/2021] [Indexed: 11/20/2022] Open
Abstract
When severe malaria is suspected in children, the WHO recommends pretreatment with a single rectal dose of artesunate before referral to an appropriate facility. This was an individually randomized, open-label, 2-arm, crossover clinical trial in 82 Congolese children with severe falciparum malaria to characterize the pharmacokinetics of rectal artesunate. At admission, children received a single dose of rectal artesunate (10 mg/kg of body weight) followed 12 h later by intravenous artesunate (2.4 mg/kg) or the reverse order. All children also received standard doses of intravenous quinine. Artesunate and dihydroartemisinin were measured at 11 fixed intervals, following 0- and 12-h drug administrations. Clinical, laboratory, and parasitological parameters were measured. After rectal artesunate, artesunate and dihydroartemisinin showed large interindividual variability (peak concentrations of dihydroartemisinin ranged from 5.63 to 8,090 nM). The majority of patients, however, reached previously suggested in vivo IC50 and IC90 values (98.7% and 92.5%, respectively) of combined concentrations of artesunate and dihydroartemisinin between 15 and 30 min after drug administration. The median (interquartile range [IQR]) time above IC50 and IC90 was 5.68 h (2.90 to 6.08) and 2.74 h (1.52 to 3.75), respectively. The absolute rectal bioavailability (IQR) was 25.6% (11.7 to 54.5) for artesunate and 19.8% (10.3 to 35.3) for dihydroartemisinin. The initial 12-h parasite reduction ratio was comparable between rectal and intravenous artesunate: median (IQR), 84.3% (50.0 to 95.4) versus 69.2% (45.7 to 93.6), respectively (P = 0.49). Despite large interindividual variability, rectal artesunate can initiate and sustain rapid parasiticidal activity in most children with severe falciparum malaria while they are transferred to a facility where parenteral artesunate is available. (This study has been registered at ClinicalTrials.gov under identifier NCT02492178.).
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Affiliation(s)
- Caterina Fanello
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Richard M Hoglund
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sue J Lee
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Daddy Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Pauline Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Charlie Kabedi
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Benjamin B Badjanga
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Phettree Niamyim
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles Woodrow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Melba Gomes
- World Health Organization, Geneva, Switzerland
| | - Nick P Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
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Monitoring of the Sensitivity In Vivo of Plasmodium falciparum to Artemether-Lumefantrine in Mali. Trop Med Infect Dis 2021; 6:tropicalmed6010013. [PMID: 33498803 PMCID: PMC7838931 DOI: 10.3390/tropicalmed6010013] [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: 12/22/2020] [Revised: 01/17/2021] [Accepted: 01/19/2021] [Indexed: 11/17/2022] Open
Abstract
In Mali, since 2007, artemether-lumefantrine has been the first choice against uncomplicated malaria. Despite its effectiveness, a rapid selection of markers of resistance to partner drugs has been documented. This work evaluated the treatment according to the World Health Organization's standard 28-day treatment method. The primary endpoint was the clinical and parasitological response corrected by a polymerase chain reaction. It was more than 99.9 percent, the proportion of patients with anemia significantly decrease compared to baseline (p < 0.001), and no serious events were recorded. Plasmodium falciparum remains sensitive to artemether-lumefantrine in Mali.
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Abstract
BACKGROUND The World Health Organization (WHO) in 2015 stated atovaquone-proguanil can be used in travellers, and is an option in malaria-endemic areas in combination with artesunate, as an alternative treatment where first-line artemisinin-based combination therapy (ACT) is not available or effective. This review is an update of a Cochrane Review undertaken in 2005. OBJECTIVES To assess the efficacy and safety of atovaquone-proguanil (alone and in combination with artemisinin drugs) versus other antimalarial drugs for treating uncomplicated Plasmodium falciparum malaria in adults and children. SEARCH METHODS The date of the last trial search was 30 January 2020. Search locations for published trials included the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, Embase, and LILACS. To include recently published and unpublished trials, we also searched ClinicalTrials.gov, the metaRegister of Controlled Trials and the WHO International Clinical Trials Registry Platform Search Portal. SELECTION CRITERIA Randomized controlled trials (RCTs) reporting efficacy and safety data for atovaquone-proguanil or atovaquone-proguanil with a partner drug compared with at least one other antimalarial drug for treating uncomplicated Plasmodium falciparum infection. DATA COLLECTION AND ANALYSIS For this update, two review authors re-extracted data and assessed certainty of evidence. We meta-analyzed data to calculate risk ratios (RRs) with 95% confidence intervals (CI) for treatment failures between comparisons, and for safety outcomes between and across comparisons. Outcome measures include unadjusted treatment failures and polymerase chain reaction (PCR)-adjusted treatment failures. PCR adjustment differentiates new infection from recrudescent infection. MAIN RESULTS Seventeen RCTs met our inclusion criteria providing 4763 adults and children from Africa, South-America, and South-East Asia. Eight trials reported PCR-adjusted data to distinguish between new and recrudescent infection during the follow-up period. In this abstract, we report only the comparisons against the three WHO-recommended antimalarials which were included within these trials. There were two comparisons with artemether-lumefantrine, one trial from 2008 in Ethiopia with 60 participants had two failures with atovaquone-proguanil compared to none with artemether-lumefantrine (PCR-adjusted treatment failures at day 28). A second trial from 2012 in Colombia with 208 participants had one failure in each arm (PCR-adjusted treatment failures at day 42). There was only one comparison with artesunate-amodiaquine from a 2014 trial conducted in Cameroon. There were six failures with atovaquone-proguanil at day 28 and two with artesunate-amodiaquine (PCR-adjusted treatment failures at day 28: 9.4% with atovaquone-proguanil compared to 2.9% with artesunate-amodiaquine; RR 3.19, 95% CI 0.67 to 15.22; 1 RCT, 132 participants; low-certainty evidence), although there was a similar number of PCR-unadjusted treatment failures (9 (14.1%) with atovaquone-proguanil and 8 (11.8%) with artesunate-amodiaquine; RR 1.20, 95% CI 0.49 to 2.91; 1 RCT, 132 participants; low-certainty evidence). There were two comparisons with artesunate-mefloquine from a 2012 trial in Colombia and a 2002 trial in Thailand where there are high levels of multi-resistant malaria. There were similar numbers of PCR-adjusted treatment failures between groups at day 42 (2.7% with atovaquone-proguanil compared to 2.4% with artesunate-mefloquine; RR 1.15, 95% CI 0.57 to 2.34; 2 RCTs, 1168 participants; high-certainty evidence). There were also similar PCR-unadjusted treatment failures between groups (5.3% with atovaquone-proguanil compared to 6.6% with artesunate-mefloquine; RR 0.8, 95% CI 0.5 to 1.3; 1 RCT, 1063 participants; low-certainty evidence). When atovaquone-proguanil was combined with artesunate, there were fewer treatment failures with and without PCR-adjustment at day 28 (PCR-adjusted treatment failures at day 28: 2.16% with atovaquone-proguanil compared to no failures with artesunate-atovaquone-proguanil; RR 5.14, 95% CI 0.61 to 43.52; 2 RCTs, 375 participants, low-certainty evidence) and day 42 (PCR-adjusted treatment failures at day 42: 3.82% with atovaquone-proguanil compared to 2.05% with artesunate-atovaquone-proguanil (RR 1.84, 95% CI 0.95 to 3.56; 2 RCTs, 1258 participants, moderate-certainty evidence). In the 2002 trial in Thailand, there were fewer treatment failures in the artesunate-atovaquone-proguanil group compared to the atovaquone-proguanil group at day 42 with PCR-adjustment. Whilst there were some small differences in which adverse events were more frequent in the atovaquone-proguanil groups compared to comparator drugs, there were no recurrent associations to suggest that atovaquone-proguanil is strongly associated with any specific adverse event. AUTHORS' CONCLUSIONS Atovaquone-proguanil was effective against uncomplicated P falciparum malaria, although in some instances treatment failure rates were between 5% and 10%. The addition of artesunate to atovaquone-proguanil may reduce treatment failure rates. Artesunate-atovaquone-proguanil and the development of parasite resistance may represent an area for further research.
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Affiliation(s)
- Andrew Blanshard
- Department of Medicine, Norfolk and Norwich University Hospital, Norwich, UK
| | - Paul Hine
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
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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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Plasmodium berghei K13 Mutations Mediate In Vivo Artemisinin Resistance That Is Reversed by Proteasome Inhibition. mBio 2020; 11:mBio.02312-20. [PMID: 33173001 PMCID: PMC7667033 DOI: 10.1128/mbio.02312-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Recent successes in malaria control have been seriously threatened by the emergence of Plasmodium falciparum parasite resistance to the frontline artemisinin drugs in Southeast Asia. P. falciparum artemisinin resistance is associated with mutations in the parasite K13 protein, which associates with a delay in the time required to clear the parasites upon drug treatment. Gene editing technologies have been used to validate the role of several candidate K13 mutations in mediating P. falciparum artemisinin resistance in vitro under laboratory conditions. Nonetheless, the causal role of these mutations under in vivo conditions has been a matter of debate. Here, we have used CRISPR/Cas9 gene editing to introduce K13 mutations associated with artemisinin resistance into the related rodent-infecting parasite, Plasmodium berghei. Phenotyping of these P. berghei K13 mutant parasites provides evidence of their role in mediating artemisinin resistance in vivo, which supports in vitro artemisinin resistance observations. However, we were unable to introduce some of the P. falciparum K13 mutations (C580Y and I543T) into the corresponding amino acid residues, while other introduced mutations (M476I and R539T equivalents) carried pronounced fitness costs. Our study provides evidence of a clear causal role of K13 mutations in modulating susceptibility to artemisinins in vitro and in vivo using the well-characterized P. berghei model. We also show that inhibition of the P. berghei proteasome offsets parasite resistance to artemisinins in these mutant lines. The recent emergence of Plasmodium falciparum parasite resistance to the first line antimalarial drug artemisinin is of particular concern. Artemisinin resistance is primarily driven by mutations in the P. falciparum K13 protein, which enhance survival of early ring-stage parasites treated with the artemisinin active metabolite dihydroartemisinin in vitro and associate with delayed parasite clearance in vivo. However, association of K13 mutations with in vivo artemisinin resistance has been problematic due to the absence of a tractable model. Herein, we have employed CRISPR/Cas9 genome editing to engineer selected orthologous P. falciparum K13 mutations into the K13 gene of an artemisinin-sensitive Plasmodium berghei rodent model of malaria. Introduction of the orthologous P. falciparum K13 F446I, M476I, Y493H, and R539T mutations into P. berghei K13 yielded gene-edited parasites with reduced susceptibility to dihydroartemisinin in the standard 24-h in vitro assay and increased survival in an adapted in vitro ring-stage survival assay. Mutant P. berghei K13 parasites also displayed delayed clearance in vivo upon treatment with artesunate and achieved faster recrudescence upon treatment with artemisinin. Orthologous C580Y and I543T mutations could not be introduced into P. berghei, while the equivalents of the M476I and R539T mutations resulted in significant growth defects. Furthermore, a Plasmodium-selective proteasome inhibitor strongly synergized dihydroartemisinin action in these P. berghei K13 mutant lines, providing further evidence that the proteasome can be targeted to overcome artemisinin resistance. Taken together, our findings provide clear experimental evidence for the involvement of K13 polymorphisms in mediating susceptibility to artemisinins in vitro and, most importantly, under in vivo conditions.
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38
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Kayiba NK, Yobi DM, Tshibangu-Kabamba E, Tuan VP, Yamaoka Y, Devleesschauwer B, Mvumbi DM, Okitolonda Wemakoy E, De Mol P, Mvumbi GL, Hayette MP, Rosas-Aguirre A, Speybroeck N. Spatial and molecular mapping of Pfkelch13 gene polymorphism in Africa in the era of emerging Plasmodium falciparum resistance to artemisinin: a systematic review. THE LANCET. INFECTIOUS DISEASES 2020; 21:e82-e92. [PMID: 33125913 DOI: 10.1016/s1473-3099(20)30493-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 03/29/2020] [Accepted: 04/21/2020] [Indexed: 12/19/2022]
Abstract
The spread of Plasmodium falciparum isolates carrying mutations in the kelch13 (Pfkelch13) gene associated with artemisinin resistance (PfART-R) in southeast Asia threatens malaria control and elimination efforts. Emergence of PfART-R in Africa would result in a major public health problem. In this systematic review, we investigate the frequency and spatial distribution of Pfkelch13 mutants in Africa, including mutants linked to PfART-R in southeast Asia. Seven databases were searched (PubMed, Embase, Scopus, African Journal Online, African Index Medicus, Bioline, and Web of Science) for relevant articles about polymorphisms of the Pfkelch13 gene in Africa before January, 2019. Following PRISMA guidelines, 53 studies that sequenced the Pfkelch13 gene of 23 100 sample isolates in 41 sub-Saharan African countries were included. The Pfkelch13 sequence was highly polymorphic (292 alleles, including 255 in the Pfkelch13-propeller domain) but with mutations occurring at very low relative frequencies. Non-synonymous mutations were found in only 626 isolates (2·7%) from west, central, and east Africa. According to WHO, nine different mutations linked to PfART-R in southeast Asia (Phe446Ile, Cys469Tyr, Met476Ile, Arg515Lys, Ser522Cys, Pro553Leu, Val568Gly, Pro574Leu, and Ala675Val) were detected, mainly in east Africa. Several other Pfkelch13 mutations, such as those structurally similar to southeast Asia PfART-R mutations, were also identified, but their relevance for drug resistance is still unknown. This systematic review shows that Africa, thought to not have established PfART-R, reported resistance-related mutants in the past 5 years. Surveillance using PfART-R molecular markers can provide valuable decision-making information to sustain the effectiveness of artemisinin in Africa.
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Affiliation(s)
- Nadine K Kayiba
- Institute of Health and Society, Université catholique de Louvain, Brussels, Belgium; Department of Public Health, University of Mbujimayi, Mbujimayi, DR Congo; Department of Epidemiology and Biostatistics, University of Kinshasa, Kinshasa, DR Congo
| | - Doudou M Yobi
- Department of Basic Sciences, University of Kinshasa, Kinshasa, DR Congo
| | - Evariste Tshibangu-Kabamba
- Department of Basic Sciences, University of Mbujimayi, Mbujimayi, DR Congo; Department of Environmental and Preventive Medicine, Oita University, Yufu, Japan
| | - Vo P Tuan
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh, Vietnam; Department of Environmental and Preventive Medicine, Oita University, Yufu, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University, Yufu, Japan
| | - Brecht Devleesschauwer
- Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium; Department of Veterinary Public Health and Food Safety, Ghent University, Merelbeke, Belgium
| | - Dieudonné M Mvumbi
- Department of Basic Sciences, University of Kinshasa, Kinshasa, DR Congo
| | | | - Patrick De Mol
- Department of Parasitology and Mycology, University Hospital of Liège, Liège, Belgium
| | - Georges L Mvumbi
- Department of Basic Sciences, University of Kinshasa, Kinshasa, DR Congo
| | - Marie-Pierre Hayette
- Department of Parasitology and Mycology, University Hospital of Liège, Liège, Belgium
| | - Angel Rosas-Aguirre
- Institute of Health and Society, Université catholique de Louvain, Brussels, Belgium
| | - Niko Speybroeck
- Institute of Health and Society, Université catholique de Louvain, Brussels, Belgium.
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Ippolito MM, Pringle JC, Siame M, Katowa B, Aydemir O, Oluoch PO, Huang L, Aweeka FT, Bailey JA, Juliano JJ, Meshnick SR, Shapiro TA, Moss WJ, Thuma PE. Therapeutic Efficacy of Artemether-Lumefantrine for Uncomplicated Falciparum Malaria in Northern Zambia. Am J Trop Med Hyg 2020; 103:2224-2232. [PMID: 33078701 DOI: 10.4269/ajtmh.20-0852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Artemether-lumefantrine (AL) is a first-line agent for uncomplicated malaria caused by Plasmodium falciparum. The WHO recommends periodic therapeutic efficacy studies of antimalarial drugs for the detection of malaria parasite drug resistance and to inform national malaria treatment policies. We conducted a therapeutic efficacy study of AL in a high malaria transmission region of northern Zambia from December 2014 to July 2015. One hundred children of ages 6 to 59 months presenting to a rural health clinic with uncomplicated falciparum malaria were admitted for treatment with AL (standard 6-dose regimen) and followed weekly for 5 weeks. Parasite counts were taken every 6 hours during treatment to assess parasite clearance. Recurrent episodes during follow-up (n = 14) were genotyped to distinguish recrudescence from reinfection and to identify drug resistance single nucleotide polymorphisms (SNPs) and multidrug resistance protein 1 (mdr1) copy number variation. Day 7 lumefantrine concentrations were measured for correspondence with posttreatment reinfection. All children who completed the parasite clearance portion of the study (n = 94) were microscopy-negative by 72 hours. The median parasite elimination half-life was 2.7 hours (interquartile range: 2.1-3.3). Genotype-corrected therapeutic efficacy was 98.8% (95% CI: 97.6-100). Purported artemisinin and lumefantrine drug resistance SNPs in atp6, 3D7_1451200, and mdr1 were detected but did not correlate with parasite recurrence, nor did day 7 lumefantrine concentrations. In summary, AL was highly effective for the treatment of uncomplicated falciparum malaria in northern Zambia during the study period. The high incidence of recurrent parasitemia was consistent with reinfection due to high, perennial malaria transmission.
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Affiliation(s)
- Matthew M Ippolito
- The Johns Hopkins Malaria Research Institute, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland.,Division of Clinical Pharmacology, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Julia C Pringle
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland
| | - Mwiche Siame
- Ministry of Health, Government of the Republic of Zambia, Lusaka, Zambia
| | | | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island
| | - Peter O Oluoch
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.,Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island
| | - Liusheng Huang
- Department of Clinical Pharmacology, University of California San Francisco School of Pharmacy, San Francisco, California
| | - Francesca T Aweeka
- Department of Clinical Pharmacology, University of California San Francisco School of Pharmacy, San Francisco, California
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island
| | - Jonathan J Juliano
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Steven R Meshnick
- Department of Epidemiology, University of North Carolina Gillings School of Global Public Health, Chapel Hill, North Carolina
| | - Theresa A Shapiro
- The Johns Hopkins Malaria Research Institute, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland.,Division of Clinical Pharmacology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - William J Moss
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland.,The Johns Hopkins Malaria Research Institute, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland.,W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland
| | - Philip E Thuma
- Macha Research Trust, Macha, Zambia.,The Johns Hopkins Malaria Research Institute, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland
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40
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van der Pluijm RW, Amaratunga C, Dhorda M, Dondorp AM. Triple Artemisinin-Based Combination Therapies for Malaria - A New Paradigm? Trends Parasitol 2020; 37:15-24. [PMID: 33060063 DOI: 10.1016/j.pt.2020.09.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 01/31/2023]
Abstract
Recent gains in the fight against malaria are threatened by the emergence and spread of artemisinin and partner drug resistance in Plasmodium falciparum in the Greater Mekong Subregion (GMS). When artemisinins are combined with a single partner drug, all recommended artemisinin-based combination therapies have shown reduced efficacy in some countries in the GMS at some point. Novel drugs are not available for the near future. Triple artemisinin-based combination therapies, combining artemisinins with two currently available partner drugs, will provide one of the last remaining safe and effective treatments for falciparum malaria that can be deployed rapidly in the GMS, whereas their deployment beyond the GMS could delay or prevent the global emergence and spread of resistance to currently available drugs.
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Affiliation(s)
- Rob W van der Pluijm
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chanaki Amaratunga
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; WorldWide Antimalarial Resistance Network - Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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41
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O'Flaherty K, Ataíde R, Zaloumis SG, Ashley EA, Powell R, Feng G, Reiling L, Dondorp AM, Day NP, Dhorda M, Fairhurst RM, Lim P, Amaratunga C, Pukrittayakamee S, Hien TT, Htut Y, Mayxay M, Faiz MA, Beeson JG, Nosten F, Simpson JA, White NJ, Fowkes FJI. Contribution of Functional Antimalarial Immunity to Measures of Parasite Clearance in Therapeutic Efficacy Studies of Artemisinin Derivatives. J Infect Dis 2020; 220:1178-1187. [PMID: 31075171 PMCID: PMC6735958 DOI: 10.1093/infdis/jiz247] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/09/2019] [Indexed: 12/15/2022] Open
Abstract
Background Antibodies to the blood stages of malaria parasites enhance parasite clearance and antimalarial efficacy. The antibody subclass and functions that contribute to parasite clearance during antimalarial treatment and their relationship to malaria transmission intensity have not been characterized. Methods Levels of immunoglobulin G (IgG) subclasses and C1q fixation in response to Plasmodium falciparum merozoite antigens (erythrocyte-binding antigen [EBA] 175RIII-V, merozoite surface protein 2 [MSP-2], and MSP-142) and opsonic phagocytosis of merozoites were measured in a multinational trial assessing the efficacy of artesunate therapy across 11 Southeast Asian sites. Regression analyses assessed the effects of antibody seropositivity on the parasite clearance half-life (PC½), having a PC½ of ≥5 hours, and having parasitemia 3 days after treatment. Results IgG3, followed by IgG1, was the predominant IgG subclass detected (seroprevalence range, 5%–35% for IgG1 and 27%–41% for IgG3), varied across study sites, and was lowest in study sites with the lowest transmission intensity and slowest mean PC½. IgG3, C1q fixation, and opsonic-phagocytosis seropositivity were associated with a faster PC½ (range of the mean reduction in PC½, 0.47–1.16 hours; P range, .001–.03) and a reduced odds of having a PC½ of ≥5 hours and having parasitemia 3 days after treatment. Conclusions The prevalence of IgG3, complement-fixing antibodies, and merozoite phagocytosis vary according to transmission intensity, are associated with faster parasite clearance, and may be sensitive surrogates of an augmented clearance capacity of infected erythrocytes. Determining the functional immune mechanisms associated with parasite clearance will improve characterization of artemisinin resistance.
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Affiliation(s)
- Katherine O'Flaherty
- Burnet Institute, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, Melbourne, Australia
| | - Ricardo Ataíde
- Burnet Institute, Melbourne, Australia.,Department of Immunology, Monash University, Melbourne, Australia
| | - Sophie G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, Melbourne, Australia
| | - Elizabeth A Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | | | - Gaoqian Feng
- Burnet Institute, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia
| | | | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Nicholas P Day
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Worldwide Antimalarial Resistance Network, University of Oxford, United Kingdom.,Howard Hughes Medical Institute, Chevy Chase, Baltimore.,Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Pharath Lim
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | | | - Tran Tinh Hien
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ye Htut
- Department of Medical Research, Yangon, Myanmar
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom.,Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit, Mahosot Hospital, Lao People's Democratic Republic.,Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Lao People's Democratic Republic
| | - M Abul Faiz
- Malaria Research Group, Chittagong, Bangladesh.,Dev Care Foundation, Chittagong, Bangladesh
| | - James G Beeson
- Burnet Institute, Melbourne, Australia.,Department of Microbiology, Monash University, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
| | - Francois Nosten
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Shoklo Malaria Research Unit, Mae Sot, Thailand
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, Melbourne, Australia
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok.,Centre for Tropical Medicine and Global Health, University of Oxford, United Kingdom
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, Melbourne, Australia.,Department of Infectious Diseases, Monash University, Melbourne, Australia.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
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Wanjala CNL, Bergmann-Leitner E, Akala HM, Odhiambo G, Ogutu BR, Andagalu B, Kamau E, Ochiel D. The role of complement immune response on artemisinin-based combination therapy in a population from malaria endemic region of Western Kenya. Malar J 2020; 19:168. [PMID: 32349765 PMCID: PMC7191791 DOI: 10.1186/s12936-020-03242-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/18/2020] [Indexed: 02/05/2023] Open
Abstract
Background Naturally acquired immunity (NAI), which is characterized by protection against overt clinical disease and high parasitaemia, is acquired with age and transmission intensity. The role of NAI on the efficacy of anti-malarial drugs, including artemisinin-based combinations used as the first-line treatment for uncomplicated Plasmodium falciparum, has not been fully demonstrated. This study investigated the role of NAI in response to artemisinin-based combination therapy (ACT), in symptomatic patients living in western Kenya, a high malaria transmission area. Methods Sera samples from malaria immune participants (n = 105) in a therapeutic efficacy study were assessed for in vitro growth inhibitory activity against the 3D7 strain of P. falciparum using a fluorescent-based growth inhibition assay (GIA). Participants’ age and parasite clearance parameters were used in the analysis. Pooled sera from malaria naïve participants (n = 6) with no Plasmodium infection from malaria non-endemic regions of Kenya was used as negative control. Results The key observations of the study were as follows: (1) Sera with intact complement displayed higher GIA activity at lower (1%) serum dilutions (p < 0.0001); (2) there was significant relationship between GIA activity, parasite clearance rate (p = 0.05) and slope half-life (p = 0.025); and (3) age was a confounding factor when comparing the GIA activity with parasite clearance kinetics. Conclusion This study demonstrates for the first time there is synergy of complement, pre-existing immunity, and drug treatment in younger patients with symptomatic malaria in a high-transmission area.
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Affiliation(s)
- Christine N L Wanjala
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya.,School of Physical and Biological Sciences Zoology Department, Maseno University, Maseno, Kenya
| | - Elke Bergmann-Leitner
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Hoseah M Akala
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya
| | - Geoffrey Odhiambo
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya.,School of Physical and Biological Sciences Zoology Department, Maseno University, Maseno, Kenya
| | - Bernhards R Ogutu
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya.,KEMRI, Nairobi, Kenya
| | - Ben Andagalu
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya
| | - Edwin Kamau
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya. .,U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | - Daniel Ochiel
- Department of Emerging and Infectious Diseases (DEID), United States Army Medical Research Directorate-Africa (USAMRD-A), Kenya Medical Research Institute (KEMRI)/Walter Reed Project (WRP), Kisumu, Kenya.,School of Physical and Biological Sciences Zoology Department, Maseno University, Maseno, Kenya
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43
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van der Pluijm RW, Tripura R, Hoglund RM, Pyae Phyo A, Lek D, Ul Islam A, Anvikar AR, Satpathi P, Satpathi S, Behera PK, Tripura A, Baidya S, Onyamboko M, Chau NH, Sovann Y, Suon S, Sreng S, Mao S, Oun S, Yen S, Amaratunga C, Chutasmit K, Saelow C, Runcharern R, Kaewmok W, Hoa NT, Thanh NV, Hanboonkunupakarn B, Callery JJ, Mohanty AK, Heaton J, Thant M, Gantait K, Ghosh T, Amato R, Pearson RD, Jacob CG, Gonçalves S, Mukaka M, Waithira N, Woodrow CJ, Grobusch MP, van Vugt M, Fairhurst RM, Cheah PY, Peto TJ, von Seidlein L, Dhorda M, Maude RJ, Winterberg M, Thuy-Nhien NT, Kwiatkowski DP, Imwong M, Jittamala P, Lin K, Hlaing TM, Chotivanich K, Huy R, Fanello C, Ashley E, Mayxay M, Newton PN, Hien TT, Valecha N, Smithuis F, Pukrittayakamee S, Faiz A, Miotto O, Tarning J, Day NPJ, White NJ, Dondorp AM. Triple artemisinin-based combination therapies versus artemisinin-based combination therapies for uncomplicated Plasmodium falciparum malaria: a multicentre, open-label, randomised clinical trial. Lancet 2020; 395:1345-1360. [PMID: 32171078 PMCID: PMC8204272 DOI: 10.1016/s0140-6736(20)30552-3] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 02/20/2020] [Accepted: 03/02/2020] [Indexed: 10/25/2022]
Abstract
BACKGROUND Artemisinin and partner-drug resistance in Plasmodium falciparum are major threats to malaria control and elimination. Triple artemisinin-based combination therapies (TACTs), which combine existing co-formulated ACTs with a second partner drug that is slowly eliminated, might provide effective treatment and delay emergence of antimalarial drug resistance. METHODS In this multicentre, open-label, randomised trial, we recruited patients with uncomplicated P falciparum malaria at 18 hospitals and health clinics in eight countries. Eligible patients were aged 2-65 years, with acute, uncomplicated P falciparum malaria alone or mixed with non-falciparum species, and a temperature of 37·5°C or higher, or a history of fever in the past 24 h. Patients were randomly assigned (1:1) to one of two treatments using block randomisation, depending on their location: in Thailand, Cambodia, Vietnam, and Myanmar patients were assigned to either dihydroartemisinin-piperaquine or dihydroartemisinin-piperaquine plus mefloquine; at three sites in Cambodia they were assigned to either artesunate-mefloquine or dihydroartemisinin-piperaquine plus mefloquine; and in Laos, Myanmar, Bangladesh, India, and the Democratic Republic of the Congo they were assigned to either artemether-lumefantrine or artemether-lumefantrine plus amodiaquine. All drugs were administered orally and doses varied by drug combination and site. Patients were followed-up weekly for 42 days. The primary endpoint was efficacy, defined by 42-day PCR-corrected adequate clinical and parasitological response. Primary analysis was by intention to treat. A detailed assessment of safety and tolerability of the study drugs was done in all patients randomly assigned to treatment. This study is registered at ClinicalTrials.gov, NCT02453308, and is complete. FINDINGS Between Aug 7, 2015, and Feb 8, 2018, 1100 patients were given either dihydroartemisinin-piperaquine (183 [17%]), dihydroartemisinin-piperaquine plus mefloquine (269 [24%]), artesunate-mefloquine (73 [7%]), artemether-lumefantrine (289 [26%]), or artemether-lumefantrine plus amodiaquine (286 [26%]). The median age was 23 years (IQR 13 to 34) and 854 (78%) of 1100 patients were male. In Cambodia, Thailand, and Vietnam the 42-day PCR-corrected efficacy after dihydroartemisinin-piperaquine plus mefloquine was 98% (149 of 152; 95% CI 94 to 100) and after dihydroartemisinin-piperaquine was 48% (67 of 141; 95% CI 39 to 56; risk difference 51%, 95% CI 42 to 59; p<0·0001). Efficacy of dihydroartemisinin-piperaquine plus mefloquine in the three sites in Myanmar was 91% (42 of 46; 95% CI 79 to 98) versus 100% (42 of 42; 95% CI 92 to 100) after dihydroartemisinin-piperaquine (risk difference 9%, 95% CI 1 to 17; p=0·12). The 42-day PCR corrected efficacy of dihydroartemisinin-piperaquine plus mefloquine (96% [68 of 71; 95% CI 88 to 99]) was non-inferior to that of artesunate-mefloquine (95% [69 of 73; 95% CI 87 to 99]) in three sites in Cambodia (risk difference 1%; 95% CI -6 to 8; p=1·00). The overall 42-day PCR-corrected efficacy of artemether-lumefantrine plus amodiaquine (98% [281 of 286; 95% CI 97 to 99]) was similar to that of artemether-lumefantrine (97% [279 of 289; 95% CI 94 to 98]; risk difference 2%, 95% CI -1 to 4; p=0·30). Both TACTs were well tolerated, although early vomiting (within 1 h) was more frequent after dihydroartemisinin-piperaquine plus mefloquine (30 [3·8%] of 794) than after dihydroartemisinin-piperaquine (eight [1·5%] of 543; p=0·012). Vomiting after artemether-lumefantrine plus amodiaquine (22 [1·3%] of 1703) and artemether-lumefantrine (11 [0·6%] of 1721) was infrequent. Adding amodiaquine to artemether-lumefantrine extended the electrocardiogram corrected QT interval (mean increase at 52 h compared with baseline of 8·8 ms [SD 18·6] vs 0·9 ms [16·1]; p<0·01) but adding mefloquine to dihydroartemisinin-piperaquine did not (mean increase of 22·1 ms [SD 19·2] for dihydroartemisinin-piperaquine vs 20·8 ms [SD 17·8] for dihydroartemisinin-piperaquine plus mefloquine; p=0·50). INTERPRETATION Dihydroartemisinin-piperaquine plus mefloquine and artemether-lumefantrine plus amodiaquine TACTs are efficacious, well tolerated, and safe treatments of uncomplicated P falciparum malaria, including in areas with artemisinin and ACT partner-drug resistance. FUNDING UK Department for International Development, Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and US National Institutes of Health.
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Affiliation(s)
- Rob W van der Pluijm
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Rupam Tripura
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Richard M Hoglund
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - Dysoley Lek
- National Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia; School of Public Health, National Institute of Public Health, Phnom Penh, Cambodia
| | | | - Anupkumar R Anvikar
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, India
| | | | | | | | | | | | - Marie Onyamboko
- Kinshasa Mahidol Oxford Research Unit (KIMORU), Kinshasa, Democratic Republic of the Congo; Kinshasa School of Public Health, Kinshasa, Democratic Republic of the Congo
| | - Nguyen Hoang Chau
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Yok Sovann
- Pailin Provincial Health Department, Pailin, Cambodia
| | - Seila Suon
- National Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Sokunthea Sreng
- National Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Sivanna Mao
- Sampov Meas Referral Hospital, Pursat, Cambodia
| | - Savuth Oun
- Ratanakiri Referral Hospital, Ratanakiri, Cambodia
| | | | - Chanaki Amaratunga
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | | | | | | | - Nhu Thi Hoa
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ngo Viet Thanh
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Borimas Hanboonkunupakarn
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - James J Callery
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Akshaya Kumar Mohanty
- Infectious Disease Biology Unit, IGH, Rourkela Research Unit of ILS, Bhubeneswar, DBT, Rourkela, India
| | - James Heaton
- Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar
| | - Myo Thant
- Defence Services Medical Research Centre, Yangon, Myanmar
| | | | | | - Roberto Amato
- Nuffield Department of Medicine and MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK; Wellcome Sanger Institute, Hinxton, UK
| | - Richard D Pearson
- Nuffield Department of Medicine and MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK; Wellcome Sanger Institute, Hinxton, UK
| | | | | | - Mavuto Mukaka
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Naomi Waithira
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Charles J Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Martin P Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Michele van Vugt
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA; AstraZeneca, Gaithersburg, MD, USA
| | - Phaik Yeong Cheah
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Thomas J Peto
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Lorenz von Seidlein
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; WorldWide Antimalarial Resistance Network - Asia Regional Centre, Bangkok, Thailand
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; The Open University, Milton Keynes, UK; Harvard T H Chan School of Public Health, Harvard University, Boston, MA USA
| | - Markus Winterberg
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Nguyen Thanh Thuy-Nhien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Dominic P Kwiatkowski
- Nuffield Department of Medicine and MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK; Wellcome Sanger Institute, Hinxton, UK
| | - Mallika Imwong
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Podjanee Jittamala
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Khin Lin
- Department of Medical Research, Pyin Oo Lwin, Myanmar
| | | | - Kesinee Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rekol Huy
- National Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Caterina Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Kinshasa Mahidol Oxford Research Unit (KIMORU), Kinshasa, Democratic Republic of the Congo
| | - Elizabeth Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit (LOMWRU), Vientiane, Laos
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit (LOMWRU), Vientiane, Laos; Institute of Research and Education Development (IRED), University of Health Sciences, Ministry of Health, Vientiane, Laos
| | - Paul N Newton
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit (LOMWRU), Vientiane, Laos
| | - Tran Tinh Hien
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Neena Valecha
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, India
| | - Frank Smithuis
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar
| | - Sasithon Pukrittayakamee
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; The Royal Society of Thailand, Dusit, Bangkok, Thailand
| | - Abul Faiz
- Malaria Research Group and Dev Care Foundation, Dhaka, Bangladesh
| | - Olivo Miotto
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Nuffield Department of Medicine and MRC Centre for Genomics and Global Health, Big Data Institute, University of Oxford, Oxford, UK; Wellcome Sanger Institute, Hinxton, UK
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
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Khoury DS, Zaloumis SG, Grigg MJ, Haque A, Davenport MP. Malaria Parasite Clearance: What Are We Really Measuring? Trends Parasitol 2020; 36:413-426. [PMID: 32298629 DOI: 10.1016/j.pt.2020.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 02/11/2020] [Accepted: 02/24/2020] [Indexed: 01/22/2023]
Abstract
Antimalarial drugs are vital for treating malaria and controlling transmission. Measuring drug efficacy in the field requires large clinical trials and thus we have identified proxy measures of drug efficacy such as the parasite clearance curve. This is often assumed to measure the rate of drug activity against parasites and is used to predict optimal treatment regimens required to completely clear a blood-stage infection. We discuss evidence that the clearance curve is not measuring the rate of drug killing. This has major implications for how we assess optimal treatment regimens, as well as how we prioritise new drugs in the drug development pipeline.
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Affiliation(s)
- David S Khoury
- Kirby Institute, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Sophie G Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
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45
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Burgert L, Rottmann M, Wittlin S, Gobeau N, Krause A, Dingemanse J, Möhrle JJ, Penny MA. Ensemble modeling highlights importance of understanding parasite-host behavior in preclinical antimalarial drug development. Sci Rep 2020; 10:4410. [PMID: 32157151 PMCID: PMC7064600 DOI: 10.1038/s41598-020-61304-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 02/20/2020] [Indexed: 11/23/2022] Open
Abstract
Emerging drug resistance and high-attrition rates in early and late stage drug development necessitate accelerated development of antimalarial compounds. However, systematic and meaningful translation of drug efficacy and host-parasite dynamics between preclinical testing stages is missing. We developed an ensemble of mathematical within-host parasite growth and antimalarial action models, fitted to extensive data from four antimalarials with different modes of action, to assess host-parasite interactions in two preclinical drug testing systems of murine parasite P. berghei in mice, and human parasite P. falciparum in immune-deficient mice. We find properties of the host-parasite system, namely resource availability, parasite maturation and virulence, drive P. berghei dynamics and drug efficacy, whereas experimental constraints primarily influence P. falciparum infection and drug efficacy. Furthermore, uninvestigated parasite behavior such as dormancy influences parasite recrudescence following non-curative treatment and requires further investigation. Taken together, host-parasite interactions should be considered for meaningful translation of pharmacodynamic properties between murine systems and for predicting human efficacious treatment.
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Affiliation(s)
- Lydia Burgert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Andreas Krause
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jasper Dingemanse
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jörg J Möhrle
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Medicines for Malaria Venture, Geneva, Switzerland
| | - Melissa A Penny
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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46
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Odhiambo G, Bergmann-Leitner E, Maraka M, Wanjala CNL, Duncan E, Waitumbi J, Andagalu B, Jura WGZO, Dutta S, Angov E, Ogutu BR, Kamau E, Ochiel D. Correlation Between Malaria-Specific Antibody Profiles and Responses to Artemisinin Combination Therapy for Treatment of Uncomplicated Malaria in Western Kenya. J Infect Dis 2020; 219:1969-1979. [PMID: 30649381 DOI: 10.1093/infdis/jiz027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/11/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The impact of preexisting immunity on the efficacy of artemisinin combination therapy must be examined to monitor resistance, and for implementation of new treatment strategies. METHODS Serum samples obtained from a clinical trial in Western Kenya randomized to receive artemether-lumefantrine (AL) or artesunate-mefloquine (ASMQ) were screened for total immunoglobulin G against preerythrocytic and erythrocytic antigens. The association and correlation between different variables, and impact of preexisting immunity on parasite slope half-life (t½) was determined. RESULTS There was no significant difference in t½, but the number of individuals with lag phase was significantly higher in the AL than in the ASMQ arm (29 vs 13, respectively; P < .01). Circumsporozoite protein-specific antibodies correlate positively with t½ (AL, P = .03; ASMQ, P = .09), but negatively with clearance rate in both study arms (AL, P = .16; ASMQ, P = .02). The t½ correlated negatively with age in ASMQ group. When stratified based on t½, the antibody titers against circumsporozoite protein and merozoite surface protein 1 were significantly higher in participants who cleared parasites rapidly in the AL group (P = .01 and P = .02, respectively). CONCLUSION Data presented here define immunoprofiles associated with distinct responses to 2 different antimalarial drugs, revealing impact of preexisting immunity on the efficacy of artemisinin combination therapy regimens in a malaria-holoendemic area. CLINICAL TRIALS REGISTRATION NCT01976780.
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Affiliation(s)
- Geoffrey Odhiambo
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu.,Maseno University School of Physical and Biological Sciences Zoology Department, Maseno, Kenya
| | - Elke Bergmann-Leitner
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Moureen Maraka
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu
| | - Christine N L Wanjala
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu.,Maseno University School of Physical and Biological Sciences Zoology Department, Maseno, Kenya
| | - Elizabeth Duncan
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - John Waitumbi
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu
| | - Ben Andagalu
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu
| | - Walter G Z O Jura
- Maseno University School of Physical and Biological Sciences Zoology Department, Maseno, Kenya
| | - Sheetij Dutta
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Evelina Angov
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Bernhards R Ogutu
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu.,Kenya Medical Research Institute, Nairobi
| | - Edwin Kamau
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu.,Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Daniel Ochiel
- Department of Emerging and Infectious Diseases, United States Army Medical Research Directorate-Africa, Kenya Medical Research Institute/Walter Reed Project , Kisumu.,Maseno University School of Physical and Biological Sciences Zoology Department, Maseno, Kenya
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A Randomized Controlled Trial of Three- versus Five-Day Artemether-Lumefantrine Regimens for Treatment of Uncomplicated Plasmodium falciparum Malaria in Pregnancy in Africa. Antimicrob Agents Chemother 2020; 64:AAC.01140-19. [PMID: 31818818 PMCID: PMC7038309 DOI: 10.1128/aac.01140-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/24/2019] [Indexed: 01/09/2023] Open
Abstract
Artemether-lumefantrine antimalarial efficacy in pregnancy could be compromised by reduced drug exposure. Population-based simulations suggested that therapeutic efficacy would be improved if the treatment duration was increased. Artemether-lumefantrine antimalarial efficacy in pregnancy could be compromised by reduced drug exposure. Population-based simulations suggested that therapeutic efficacy would be improved if the treatment duration was increased. We assessed the efficacy, tolerability, and pharmacokinetics of an extended 5-day regimen of artemether-lumefantrine compared to the standard 3-day treatment in 48 pregnant women and 48 nonpregnant women with uncomplicated falciparum malaria in an open-label, randomized clinical trial. Babies were assessed at birth and 1, 3, 6, and 12 months. Nonlinear mixed-effects modeling was used to characterize the plasma concentration-time profiles of artemether and lumefantrine and their metabolites. Both regimens were highly efficacious (100% PCR-corrected cure rates) and well tolerated. Babies followed up to 1 year had normal development. Parasite clearance half-lives were longer in pregnant women (median [range], 3.30 h [1.39 to 7.83 h]) than in nonpregnant women (2.43 h [1.05 to 6.00 h]) (P=0.005). Pregnant women had lower exposures to artemether and dihydroartemisinin than nonpregnant women, resulting in 1.2% decreased exposure for each additional week of gestational age. By term, these exposures were reduced by 48% compared to nonpregnant patients. The overall exposure to lumefantrine was improved with the extended regimen, with no significant differences in exposures to lumefantrine or desbutyl-lumefantrine between pregnant and nonpregnant women. The extended artemether-lumefantrine regimen was well tolerated and safe and increased the overall antimalarial drug exposure and so could be a promising treatment option in pregnancy in areas with lower rates of malaria transmission and/or emerging drug resistance. (This study has been registered at ClinicalTrials.gov under identifier NCT01916954.)
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Davis SZ, Singh PP, Vendrely KM, Shoue DA, Checkley LA, McDew-White M, Button-Simons KA, Cassady Z, Sievert MAC, Foster GJ, Nosten FH, Anderson TJC, Ferdig MT. The extended recovery ring-stage survival assay provides a superior association with patient clearance half-life and increases throughput. Malar J 2020; 19:54. [PMID: 32005233 PMCID: PMC6995136 DOI: 10.1186/s12936-020-3139-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/24/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Tracking and understanding artemisinin resistance is key for preventing global setbacks in malaria eradication efforts. The ring-stage survival assay (RSA) is the current gold standard for in vitro artemisinin resistance phenotyping. However, the RSA has several drawbacks: it is relatively low throughput, has high variance due to microscopy readout, and correlates poorly with the current benchmark for in vivo resistance, patient clearance half-life post-artemisinin treatment. Here a modified RSA is presented, the extended Recovery Ring-stage Survival Assay (eRRSA), using 15 cloned patient isolates from Southeast Asia with a range of patient clearance half-lives, including parasite isolates with and without kelch13 mutations. METHODS Plasmodium falciparum cultures were synchronized with single layer Percoll during the schizont stage of the intraerythrocytic development cycle. Cultures were left to reinvade to early ring-stage and parasitaemia was quantified using flow cytometry. Cultures were diluted to 2% haematocrit and 0.5% parasitaemia in a 96-well plate to start the assay, allowing for increased throughput and decreased variability between biological replicates. Parasites were treated with 700 nM of dihydroartemisinin or 0.02% dimethyl sulfoxide (DMSO) for 6 h, washed three times in drug-free media, and incubated for 66 or 114 h, when samples were collected and frozen for PCR amplification. A SYBR Green-based quantitative PCR method was used to quantify the fold-change between treated and untreated samples. RESULTS 15 cloned patient isolates from Southeast Asia with a range of patient clearance half-lives were assayed using the eRRSA. Due to the large number of pyknotic and dying parasites at 66 h post-exposure (72 h sample), parasites were grown for an additional cell cycle (114 h post-exposure, 120 h sample), which drastically improved correlation with patient clearance half-life compared to the 66 h post-exposure sample. A Spearman correlation of - 0.8393 between fold change and patient clearance half-life was identified in these 15 isolates from Southeast Asia, which is the strongest correlation reported to date. CONCLUSIONS eRRSA drastically increases the efficiency and accuracy of in vitro artemisinin resistance phenotyping compared to the traditional RSA, which paves the way for extensive in vitro phenotyping of hundreds of artemisinin resistant parasites.
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Affiliation(s)
- Sage Z Davis
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.,Molecular, Cell, and Systems Biology Department, University of California Riverside, Riverside, CA, USA
| | - Puspendra P Singh
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Katelyn M Vendrely
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Douglas A Shoue
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Lisa A Checkley
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | | | - Katrina A Button-Simons
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Zione Cassady
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Mackenzie A C Sievert
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Gabriel J Foster
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - François H Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford Old Road Campus, Oxford, UK
| | | | - Michael T Ferdig
- Eck Institute for Global Health, Dept. of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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Shija KM, Nondo RSO, Mloka D, Sangeda RZ, Bwire GM. Effects of lemon decoction on malaria parasite clearance and selected hematological parameters in Plasmodium berghei ANKA infected mice. BMC Complement Med Ther 2020; 20:24. [PMID: 32020885 PMCID: PMC7076818 DOI: 10.1186/s12906-020-2820-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 01/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Citrus plants particularly lemon (Citrus limon L.) concoctions are ethno-medically used for treatment of infectious diseases including malaria. Therefore, we set an experiment to investigate the effects of lemon decoction in mice infected with Plasmodium berghei ANKA parasites. METHODS Antimalarial activity was determined using Rane's curative test on 25 Theiler's albino mice. Twenty mice were each injected with 2 × 107 infected red blood cells (iRBCs). The mice were divided into four groups, consisting of five mice per group. Each group received an oral dose of either 5% carboxymethyl cellulose/placebo (negative infected control), lemon decoction (Citrus limon [CILI extract]) alone or a combination of artemether/lumefantrine (A/LU, 28 mg/kg) and CILI extract and A/LU alone. A fifth group of mice consisted of uninfected mice as parasite-negative control. RESULTS Within 72 hours after initiation of treatment, the mean percentage parasitemia ± standard deviation of the CILI extract group (24.2% ± 9.83%) was lower compared to placebo group (40.0% ± 14.78%), p = 0.037. CILI extract group was found to have an increased survival rate (11 days ± 1.6 days) as compared to placebo group (8.6 days ± 3.4 days), p = 0.226. Mice in the combination group (A/LU + CILI extract) had the highest mean counts in terms of hemato-immunological parameters, whereas those in the CILI extract alone had the lowest hematocrit levels. The study also found that mice that received a combination of CILI extract and A/LU exhibited a decreased lag time with regards to time required to clear 99% of parasites (58.8 h vs. 64.2 h, p = 0.681) as compared to the A/LU alone group. CONCLUSION Lemon decoction demonstrated antimalarial activity in mice infected with P. berghei ANKA through parasites suppression by 39% as compared to those received placebo. However, when used alone, lemons did not suffice as a cure but in combination with standard antimalarials, lemons promoted early parasite clearance with an improved hematological parameters.
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Affiliation(s)
- Kelvin M Shija
- Department of Pharmaceutical Microbiology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. Box 65013, Dar es salaam, Tanzania
| | - Ramadhani S O Nondo
- Department of Biological and Pre-Clinical Studies, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, P.O. Box 65001, Dar es Salaam, Tanzania
| | - Doreen Mloka
- Department of Pharmaceutical Microbiology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. Box 65013, Dar es salaam, Tanzania
| | - Raphael Z Sangeda
- Department of Pharmaceutical Microbiology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. Box 65013, Dar es salaam, Tanzania
| | - George M Bwire
- Department of Pharmaceutical Microbiology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. Box 65013, Dar es salaam, Tanzania.
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50
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Yeka A, Wallender E, Mulebeke R, Kibuuka A, Kigozi R, Bosco A, Kyambadde P, Opigo J, Kalyesubula S, Senzoga J, Vinden J, Conrad M, Rosenthal PJ. Comparative Efficacy of Artemether-Lumefantrine and Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Malaria in Ugandan Children. J Infect Dis 2020; 219:1112-1120. [PMID: 30418593 DOI: 10.1093/infdis/jiy637] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/01/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In Uganda, artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DHA-PQ) showed excellent treatment efficacy for uncomplicated malaria in prior trials. Because the frequency of resistance to artemisinins and piperaquine is increasing in Southeast Asia and the prevalence of Plasmodium falciparum polymorphisms associated with resistance has changed, we reassessed treatment efficacies at 3 sites in Uganda. METHODS For this randomized, single-blinded clinical trial, children aged 6-59 months with uncomplicated falciparum malaria were assigned treatment with AL or DHA-PQ and followed for 42 days. Primary end points were risks of recurrent parasitemia, either unadjusted or adjusted to distinguish recrudescence from new infection. We assessed selection by study regimens of relevant P. falciparum genetic polymorphisms associated with drug resistance. RESULTS Of 599 patients enrolled, 578 completed follow-up. There were no early treatment failures. The risk of recurrent parasitemia was lower with DHA-PQ as compared to AL at all 3 sites at 42 days (26.0% vs 47.0%; P < .001). Recrudescent infections were uncommon in both the DHA-PQ and AL arms (1.1% and 2.2%, respectively; P = .25). Neither regimen selected for pfcrt or pfmdr1 polymorphisms associated with drug resistance. CONCLUSIONS AL and DHA-PQ remain effective for the treatment of malaria in Uganda. Neither regimen selected for genetic polymorphisms associated with drug resistance. CLINICAL TRIALS REGISTRATION ISRCTN15793046.
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Affiliation(s)
- Adoke Yeka
- School of Public Health, Makerere University College of Health Sciences
| | - Erika Wallender
- Department of Medicine, University of California, San Francisco
| | - Ronald Mulebeke
- School of Public Health, Makerere University College of Health Sciences
| | - Afizi Kibuuka
- School of Public Health, Makerere University College of Health Sciences
| | - Ruth Kigozi
- Malaria Action Programme for Districts, Malaria Consortium
| | - Agaba Bosco
- National Malaria Control Program, Ministry of Health, Uganda
| | - Paul Kyambadde
- National Malaria Control Program, Ministry of Health, Uganda
| | - Jimmy Opigo
- National Malaria Control Program, Ministry of Health, Uganda
| | - Simeon Kalyesubula
- East African Public Health Laboratories Networking Project, Kampala, Uganda
| | - Joseph Senzoga
- East African Public Health Laboratories Networking Project, Kampala, Uganda
| | - Joanna Vinden
- School of Public Health, University of California, Berkeley
| | - Melissa Conrad
- Department of Medicine, University of California, San Francisco
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