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Abla N, Marrast AC, Jambert E, Richardson N, Duparc S, Almond L, Rowland Yeo K, Pan X, Tarning J, Zhao P, Culpepper J, Waitt C, Koldeweij C, Cole S, Butler AS, Khier S, Möhrle JJ, El Gaaloul M. Addressing health equity for breastfeeding women: primaquine for Plasmodium vivax radical cure. Malar J 2024; 23:287. [PMID: 39334094 PMCID: PMC11438061 DOI: 10.1186/s12936-024-05112-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024] Open
Abstract
Plasmodium vivax malaria remains a global health challenge, with approximately 6.9 million estimated cases in 2022. The parasite has a dormant liver stage, the hypnozoite, which reactivates to cause repeated relapses over weeks, months, or years. These relapses erode patient health, contribute to the burden of malaria, and promote transmission. Radical cure to prevent relapses requires administration of an 8-aminoquinoline, either primaquine or tafenoquine. However, malaria treatment guidelines updated by the World Health Organization (WHO) in October 2023 restrict primaquine use for women breastfeeding children < 6 months of age, or women breastfeeding older children if their child is G6PD deficient or if the child's G6PD status is unknown. Primaquine restrictions assume that 8-aminoquinoline exposures in breast milk would be sufficient to cause haemolysis in the nursing infant should they be G6PD deficient. WHO recommendations for tafenoquine are awaited. Notably, the WHO recommends that infants are breastfed for the first 2 years of life, and exclusively until 6 months old. Repeated pregnancies, followed by extended breastfeeding leaves women in P. vivax endemic regions potentially vulnerable to relapses for many years. This puts women's health at risk, increases the malaria burden, and perpetuates transmission, hindering malaria control and elimination. The benefits of lifting restrictions on primaquine administration to breastfeeding women are significant, avoiding the adverse consequences of repeated episodes of acute malaria, such as severe anaemia. Recent data challenge the restriction of primaquine in breastfeeding women. Clinical pharmacokinetic data in breastfeeding infants ≥ 28 days old show that the exposure to primaquine is very low and less than 1% of the maternal exposure, indicating negligible risk to infants, irrespective of their G6PD status. Physiologically-based pharmacokinetic modelling complements the clinical data, predicting minimal primaquine exposure to infants and neonates via breast milk from early post-partum. This article summarizes the clinical and modelling evidence for a favourable benefit:risk evaluation of P. vivax radical cure with primaquine for breastfeeding women without the need for infant G6PD testing, supporting a change in policy. This adjustment to current treatment guidelines would support health equity in regard to effective interventions to protect women and their children, enhance malaria control strategies, and advance P. vivax elimination.
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Affiliation(s)
- Nada Abla
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland.
| | - Anne Claire Marrast
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
| | - Elodie Jambert
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
| | | | - Stephan Duparc
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
| | - Lisa Almond
- Certara Predictive Technologies, Simcyp Division, Sheffield, UK
| | | | - Xian Pan
- Certara Predictive Technologies, Simcyp Division, Sheffield, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Ping Zhao
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | | | - Catriona Waitt
- Department of Pharmacology and Therapeutics, University of Liverpool, Liverpool, UK
- Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda
| | - Charlotte Koldeweij
- Division of Pharmacology Toxicology, Department of Pharmacy, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Susan Cole
- Medicines and Healthcare products Regulatory Agency (MHRA), 10 South Colonnade, London, UK
| | - Andrew S Butler
- Medicines and Healthcare products Regulatory Agency (MHRA), 10 South Colonnade, London, UK
| | - Sonia Khier
- Pharmacokinetic and Modelling Department, School of Pharmacy, IMAG, CNRS, INRIA, UMR 5149, University of Montpellier, Montpellier, France
| | - Jörg J Möhrle
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
| | - Myriam El Gaaloul
- MMV Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
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2
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Sanna A, Lambert Y, Jimeno Maroto I, Galindo MS, Plessis L, Bardon T, Carboni C, Bordalo J, Hiwat H, Cairo H, Musset L, Lazrek Y, Pelleau S, White M, Suárez Mutis M, Vreden S, Douine M. CUREMA project: a further step towards malaria elimination among hard-to-reach and mobile populations. Malar J 2024; 23:271. [PMID: 39256842 PMCID: PMC11385508 DOI: 10.1186/s12936-024-05040-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 07/09/2024] [Indexed: 09/12/2024] Open
Abstract
BACKGROUND In most countries engaged on the last mile towards malaria elimination, residual transmission mainly persists among vulnerable populations represented by isolated and mobile (often cross-border) communities. These populations are sometimes involved in informal or even illegal activities. In regions with Plasmodium vivax transmission, the specific biology of this parasite poses additional difficulties related to the need for a radical treatment against hypnozoites to prevent relapses. Among hard-to-reach communities, case management, a pillar of elimination strategy, is deficient: acute malaria attacks often occur in remote areas, where there is limited access to care, and drugs acquired outside formal healthcare are often inadequately used for treatment, which typically does not include radical treatment against P. vivax. For these reasons, P. vivax circulation among these communities represents one of the main challenges for malaria elimination in many non-African countries. The objective of this article is to describe the protocol of the CUREMA study, which aims to meet the challenge of targeting malaria in hard-to-reach populations with a focus on P. vivax. RESULTS CUREMA is a multi-centre, international public health intervention research project. The study population is represented by persons involved in artisanal and small-scale gold mining who are active and mobile in the Guiana Shield, deep inside the Amazon Forest. The CUREMA project includes a complex intervention composed of a package of actions: (1) health education activities; (2) targeted administration of treatment against P. vivax after screening against G6PD deficiency to asymptomatic persons considered at risk of silently carrying the parasite; (3) distribution of a self-testing and self-treatment kit (malakit) associated with user training for self-management of malaria symptoms occurring while in extreme isolation. These actions are offered by community health workers at settlements and neighbourhoods (often cross-border) that represent transit and logistic bases of gold miners. The study relies on hybrid design, aiming to evaluate both the effectiveness of the intervention on malaria transmission with a pre/post quasi-experimental design, and its implementation with a mixed methods approach. CONCLUSIONS The purpose of this study is to experiment an intervention that addresses both Plasmodium falciparum and P. vivax malaria elimination in a mobile and isolated population and to produce results that can be transferred to many contexts facing the same challenges around the world.
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Affiliation(s)
- Alice Sanna
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France.
| | - Yann Lambert
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Irene Jimeno Maroto
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Muriel Suzanne Galindo
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Lorraine Plessis
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Teddy Bardon
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Carlotta Carboni
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
| | - Jane Bordalo
- Associação Desenvolvimento, Prevenção, Acompanhamento e Cooperação de Fronteiras (DPAC), Oiapoque, Brazil
| | - Helene Hiwat
- National Malaria Programme, Ministry of Health, Paramaribo, Suriname
| | - Hedley Cairo
- National Malaria Programme, Ministry of Health, Paramaribo, Suriname
| | - Lise Musset
- Laboratoire de Parasitologie, Institut Pasteur de la Guyane, Centre National de Référence du Paludisme, Cayenne, French Guiana, France
| | - Yassamine Lazrek
- Laboratoire de Parasitologie, Institut Pasteur de la Guyane, Centre National de Référence du Paludisme, Cayenne, French Guiana, France
| | - Stéphane Pelleau
- Infectious Disease Epidemiology and Analytics, Institut Pasteur, Université Paris Cité, Paris, France
| | - Michael White
- Infectious Disease Epidemiology and Analytics, Institut Pasteur, Université Paris Cité, Paris, France
| | - Martha Suárez Mutis
- Laboratory of Parasitic Diseases, Graduate Program in Tropical Medicine, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Stephen Vreden
- Foundation for the Advancement of Scientific Research in Suriname (SWOS), Paramaribo, Suriname
| | - Maylis Douine
- French West Indies-French Guiana Center for Clinical Investigation (CIC Inserm 1424), Department of Research, Innovation, and Public Health, Cayenne Hospital, Cayenne, French Guiana, France
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Anwar MN, McCaw JM, Zarebski AE, Hickson RI, Flegg JA. Investigation of P. vivax elimination via mass drug administration: A simulation study. Epidemics 2024; 48:100789. [PMID: 39255654 DOI: 10.1016/j.epidem.2024.100789] [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: 05/30/2024] [Revised: 08/05/2024] [Accepted: 08/22/2024] [Indexed: 09/12/2024] Open
Abstract
Plasmodium vivax is the most geographically widespread malaria parasite. P. vivax has the ability to remain dormant (as a hypnozoite) in the human liver and subsequently reactivate, which makes control efforts more difficult. Given the majority of P. vivax infections are due to hypnozoite reactivation, targeting the hypnozoite reservoir with a radical cure is crucial for achieving P. vivax elimination. Stochastic effects can strongly influence dynamics when disease prevalence is low or when the population size is small. Hence, it is important to account for this when modelling malaria elimination. We use a stochastic multiscale model of P. vivax transmission to study the impacts of multiple rounds of mass drug administration (MDA) with a radical cure, accounting for superinfection and hypnozoite dynamics. Our results indicate multiple rounds of MDA with a high-efficacy drug are needed to achieve a substantial probability of elimination. This work has the potential to help guide P. vivax elimination strategies by quantifying elimination probabilities for an MDA approach.
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Affiliation(s)
- Md Nurul Anwar
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.
| | - James M McCaw
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia
| | - Alexander E Zarebski
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Roslyn I Hickson
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia; CSIRO, Townsville, Australia
| | - Jennifer A Flegg
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
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Nguyen Ngoc Pouplin J, Kaendiao T, Rahimi BA, Soni M, Basopia H, Shah D, Patil J, Dholakia V, Suthar Y, Tarning J, Mukaka M, Taylor WR. Bioequivalence of a new coated 15 mg primaquine formulation for malaria elimination. Malar J 2024; 23:176. [PMID: 38840151 PMCID: PMC11155120 DOI: 10.1186/s12936-024-04947-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/12/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND With only one 15 mg primaquine tablet registered by a stringent regulatory authority and marketed, more quality-assured primaquine is needed to meet the demands of malaria elimination. METHODS A classic, two sequence, crossover study, with a 10-day wash out period, of 15 mg of IPCA-produced test primaquine tablets and 15 mg of Sanofi reference primaquine tablets was conducted. Healthy volunteers, aged 18-45 years, without glucose-6-phosphate dehydrogenase deficiency, a baseline haemoglobin ≥ 11 g/dL, creatinine clearance ≥ 70 mL/min/1.73 ms, and body mass index of 18.5-30 kg/m2 were randomized to either test or reference primaquine, administered on an empty stomach with 240 mL of water. Plasma primaquine and carboxyprimaquine concentrations were measured at baseline, then 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.333, 2.667, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 8.0, 10.0, 12.0, 16.0, 24.0, 36.0, 48.0 and 72.0 h by liquid chromatography coupled to tandem mass spectrometry. Primaquine pharmacokinetic profiles were evaluated by non-compartmental analysis and bioequivalence concluded if the 90% confidence intervals (CI) of geometric mean (GM) ratios of test vs. reference formulation for the peak concentrations (Cmax) and area under the drug concentration-time (AUC0-t) were within 80.00 to 125.00%. RESULTS 47 of 50 volunteers, median age 33 years, completed both dosing rounds and were included in the bioequivalence analysis. For primaquine, GM Cmax values for test and reference formulations were 62.12 vs. 59.63 ng/mL, resulting in a GM ratio (90% CI) of 104.17% (96.92-111.96%); the corresponding GM AUC0-t values were 596.56 vs. 564.09 ngxh/mL, for a GM ratio of 105.76% (99.76-112.08%). Intra-subject coefficient of variation was 20.99% for Cmax and 16.83% for AUC0-t. Median clearances and volumes of distribution were similar between the test and reference products: 24.6 vs. 25.2 L/h, 189.4 vs. 191.0 L, whilst the median half-lives were the same, 5.2 h. CONCLUSION IPCA primaquine was bioequivalent to the Sanofi primaquine. This opens the door to prequalification, registration in malaria endemic countries, and programmatic use for malaria elimination. Trial registration The trial registration reference is ISRCTN 54640699.
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Affiliation(s)
- Julie Nguyen Ngoc Pouplin
- Réseau Médicaments et Développement, 21Bis Avenue du Commandant l'Herminier, 44600, Saint-Nazaire, France.
| | - Thoopmanee Kaendiao
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
| | - Bilal Ahmad Rahimi
- Department of Paediatrics, Faculty of Medicine, Kandahar University, Kandahar, Afghanistan
| | - Mayur Soni
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Hensi Basopia
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Darshana Shah
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Jitendra Patil
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Vyom Dholakia
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Yash Suthar
- Cliantha Research Limited, Cliantha Corporate, Ahmedabad, Gujarat, India
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Walter R Taylor
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Wattanakul T, Gilder ME, McGready R, Hanpithakpong W, Day NPJ, White NJ, Nosten F, Tarning J, Hoglund RM. Population pharmacokinetic modelling of primaquine exposures in lactating women and breastfed infants. Nat Commun 2024; 15:3851. [PMID: 38719803 PMCID: PMC11078975 DOI: 10.1038/s41467-024-47908-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 04/16/2024] [Indexed: 05/12/2024] Open
Abstract
Current guidelines advise against primaquine treatment for breastfeeding mothers to avoid the potential for haemolysis in infants with G6PD deficiency. To predict the haemolytic risk, the amount of drug received from the breast milk and the resulting infant drug exposure need to be characterised. Here, we develop a pharmacokinetic model to describe the drug concentrations in breastfeeding women using venous, capillary, and breast milk data. A mother-to-infant model is developed to mimic the infant feeding pattern and used to predict their drug exposures. Primaquine and carboxyprimaquine exposures in infants are <1% of the exposure in mothers. Therefore, even in infants with the most severe G6PD deficiency variants, it is highly unlikely that standard doses of primaquine (0.25-1 mg base/kg once daily given to the mother for 1-14 days) would cause significant haemolysis. After the neonatal period, primaquine should not be restricted for breastfeeding women (Clinical Trials Registration: NCT01780753).
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Affiliation(s)
- Thanaporn Wattanakul
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mary Ellen Gilder
- Shoklo Malaria Research Unit, Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Mae Sot, Thailand
| | - Rose McGready
- 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, Oxford University, Oxford, UK
| | - Warunee Hanpithakpong
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - 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 Medicine, Oxford University, 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, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - François 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, Oxford University, Oxford, UK
| | - 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 Medicine, Oxford University, 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 Medicine, Oxford University, Oxford, UK.
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Yongvanitchit K, Kum-Arb U, Limsalakpetch A, Im-Erbsin R, Ubalee R, Spring MD, Vesely BA, Waters N, Pichyangkul S. Superior protection in a relapsing Plasmodium cynomolgi rhesus macaque model by a chemoprophylaxis with sporozoite immunization regimen with atovaquone-proguanil followed by primaquine. Malar J 2024; 23:106. [PMID: 38632607 PMCID: PMC11022453 DOI: 10.1186/s12936-024-04933-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND To gain a deeper understanding of protective immunity against relapsing malaria, this study examined sporozoite-specific T cell responses induced by a chemoprophylaxis with sporozoite (CPS) immunization in a relapsing Plasmodium cynomolgi rhesus macaque model. METHODS The animals received three CPS immunizations with P. cynomolgi sporozoites, administered by mosquito bite, while under two anti-malarial drug regimens. Group 1 (n = 6) received artesunate/chloroquine (AS/CQ) followed by a radical cure with CQ plus primaquine (PQ). Group 2 (n = 6) received atovaquone-proguanil (AP) followed by PQ. After the final immunization, the animals were challenged with intravenous injection of 104 P. cynomolgi sporozoites, the dose that induced reliable infection and relapse rate. These animals, along with control animals (n = 6), were monitored for primary infection and subsequent relapses. Immunogenicity blood draws were done after each of the three CPS session, before and after the challenge, with liver, spleen and bone marrow sampling and analysis done after the challenge. RESULTS Group 2 animals demonstrated superior protection, with two achieving protection and two experiencing partial protection, while only one animal in group 1 had partial protection. These animals displayed high sporozoite-specific IFN-γ T cell responses in the liver, spleen, and bone marrow after the challenge with one protected animal having the highest frequency of IFN-γ+ CD8+, IFN-γ+ CD4+, and IFN-γ+ γδ T cells in the liver. Partially protected animals also demonstrated a relatively high frequency of IFN-γ+ CD8+, IFN-γ+ CD4+, and IFN-γ+ γδ T cells in the liver. It is important to highlight that the second animal in group 2, which experienced protection, exhibited deficient sporozoite-specific T cell responses in the liver while displaying average to high T cell responses in the spleen and bone marrow. CONCLUSIONS This research supports the notion that local liver T cell immunity plays a crucial role in defending against liver-stage infection. Nevertheless, there is an instance where protection occurs independently of T cell responses in the liver, suggesting the involvement of the liver's innate immunity. The relapsing P. cynomolgi rhesus macaque model holds promise for informing the development of vaccines against relapsing P. vivax.
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Affiliation(s)
- Kosol Yongvanitchit
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Utaiwan Kum-Arb
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Rawiwan Im-Erbsin
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Ratawan Ubalee
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Michele D Spring
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Brian A Vesely
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Norman Waters
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Sathit Pichyangkul
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand.
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Anwar MN, Smith L, Devine A, Mehra S, Walker CR, Ivory E, Conway E, Mueller I, McCaw JM, Flegg JA, Hickson RI. Mathematical models of Plasmodium vivax transmission: A scoping review. PLoS Comput Biol 2024; 20:e1011931. [PMID: 38483975 DOI: 10.1371/journal.pcbi.1011931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 03/26/2024] [Accepted: 02/19/2024] [Indexed: 03/27/2024] Open
Abstract
Plasmodium vivax is one of the most geographically widespread malaria parasites in the world, primarily found across South-East Asia, Latin America, and parts of Africa. One of the significant characteristics of the P. vivax parasite is its ability to remain dormant in the human liver as hypnozoites and subsequently reactivate after the initial infection (i.e. relapse infections). Mathematical modelling approaches have been widely applied to understand P. vivax dynamics and predict the impact of intervention outcomes. Models that capture P. vivax dynamics differ from those that capture P. falciparum dynamics, as they must account for relapses caused by the activation of hypnozoites. In this article, we provide a scoping review of mathematical models that capture P. vivax transmission dynamics published between January 1988 and May 2023. The primary objective of this work is to provide a comprehensive summary of the mathematical models and techniques used to model P. vivax dynamics. In doing so, we aim to assist researchers working on mathematical epidemiology, disease transmission, and other aspects of P. vivax malaria by highlighting best practices in currently published models and highlighting where further model development is required. We categorise P. vivax models according to whether a deterministic or agent-based approach was used. We provide an overview of the different strategies used to incorporate the parasite's biology, use of multiple scales (within-host and population-level), superinfection, immunity, and treatment interventions. In most of the published literature, the rationale for different modelling approaches was driven by the research question at hand. Some models focus on the parasites' complicated biology, while others incorporate simplified assumptions to avoid model complexity. Overall, the existing literature on mathematical models for P. vivax encompasses various aspects of the parasite's dynamics. We recommend that future research should focus on refining how key aspects of P. vivax dynamics are modelled, including spatial heterogeneity in exposure risk and heterogeneity in susceptibility to infection, the accumulation of hypnozoite variation, the interaction between P. falciparum and P. vivax, acquisition of immunity, and recovery under superinfection.
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Affiliation(s)
- Md Nurul Anwar
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Department of Mathematics, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, Bangladesh
| | - Lauren Smith
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Angela Devine
- Division of Global and Tropical Health, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Health Economics Unit, Centre for Health Policy, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia
| | - Somya Mehra
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Camelia R Walker
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Elizabeth Ivory
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Eamon Conway
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - James M McCaw
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia
| | - Jennifer A Flegg
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Roslyn I Hickson
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Australia
- Commonwealth Scientific and Industrial Research Organisation, Townsville, Australia
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8
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Pan X, Abduljalil K, Almond LM, Pansari A, Yeo KR. Supplementing clinical lactation studies with PBPK modeling to inform drug therapy in lactating mothers: Prediction of primaquine exposure as a case example. CPT Pharmacometrics Syst Pharmacol 2024; 13:386-395. [PMID: 38084656 PMCID: PMC10941563 DOI: 10.1002/psp4.13090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 10/28/2023] [Accepted: 11/20/2023] [Indexed: 03/16/2024] Open
Abstract
Evaluating the safety of primaquine (PQ) during breastfeeding requires an understanding of its pharmacokinetics (PKs) in breast milk and its exposure in the breastfed infant. Physiologically-based PK (PBPK) modeling is primed to assess the complex interplay of factors affecting the exposure of PQ in both the mother and the nursing infant. A published PBPK model for PQ describing the metabolism by monoamine oxidase A (MAO-A; 90% contribution) and cytochrome P450 2D6 (CYP2D6; 10%) in adults was applied to predict the exposure of PQ in mothers and their breastfeeding infants. Plasma exposures following oral daily dosing of 0.5 mg/kg in the nursing mothers in a clinical lactation study were accurately captured, including the observed ranges. Reported infant daily doses based on milk data from the clinical study were used to predict the exposure of PQ in breastfeeding infants greater than or equal to 28 days. On average, the predicted exposures were less than or equal to 0.13% of the mothers. Furthermore, in simulations involving neonates less than 28 days, PQ exposures remain less than 0.16% of the mothers. Assuming that MAO-A increases slowly with age, the predicted relative exposure of PQ remains low in neonates (<0.46%). Thus, the findings of our study support the recommendation made by the authors who reported the results of the clinical lactation study, that is, that when put into context of safety data currently available in children, PQ should not be withheld in lactating women as it is unlikely to cause adverse events in breastfeeding infants greater than or equal to 28 days old.
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Affiliation(s)
- Xian Pan
- Certara UK Limited (Simcyp Division)SheffieldUK
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Parvatkar P, Maher SP, Zhao Y, Cooper CA, de Castro ST, Péneau J, Vantaux A, Witkowski B, Kyle DE, Manetsch R. In Vitro Antimalarial Activity of Trichothecenes against Liver and Blood Stages of Plasmodium Species. JOURNAL OF NATURAL PRODUCTS 2024; 87:315-321. [PMID: 38262446 PMCID: PMC10897926 DOI: 10.1021/acs.jnatprod.3c01019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 01/25/2024]
Abstract
Trichothecenes (TCNs) are a large group of tricyclic sesquiterpenoid mycotoxins that have intriguing structural features and remarkable biological activities. Herein, we focused on three TCNs (anguidine, verrucarin A, and verrucarol) and their ability to target both the blood and liver stages of Plasmodium species, the parasite responsible for malaria. Anguidine and verrucarin A were found to be highly effective against the blood and liver stages of malaria, while verrucarol had no effect at the highest concentration tested. However, these compounds were also found to be cytotoxic and, thus, not selective, making them unsuitable for drug development. Nonetheless, they could be useful as chemical probes for protein synthesis inhibitors due to their direct impact on parasite synthesis processes.
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Affiliation(s)
- Prakash
T. Parvatkar
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Steven P. Maher
- Center
for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, United States
| | - Yingzhao Zhao
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Caitlin A. Cooper
- Center
for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, United States
| | - Sagan T. de Castro
- Center
for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, United States
| | - Julie Péneau
- Malaria
Molecular Epidemiology Unit, Institut Pasteur
du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 120 210, Cambodia
| | - Amélie Vantaux
- Malaria
Molecular Epidemiology Unit, Institut Pasteur
du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 120 210, Cambodia
| | - Benoît Witkowski
- Malaria
Molecular Epidemiology Unit, Institut Pasteur
du Cambodge, 5 Boulevard Monivong, PO Box 983, Phnom Penh, 120 210, Cambodia
| | - Dennis E. Kyle
- Center
for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, United States
| | - Roman Manetsch
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
- Department
of Pharmaceutical Sciences, Northeastern
University, Boston, Massachusetts 02115, United States
- Center
for Drug Discovery, Northeastern University, Boston, Massachusetts 02115, United States
- Barnett
Institute
of Chemical and Biological Analysis, Northeastern
University, Boston, Massachusetts 02115, United States
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Rajasekhar M, Simpson JA, Ley B, Edler P, Chu CS, Abreha T, Awab GR, Baird JK, Bancone G, Barber BE, Grigg MJ, Hwang J, Karunajeewa H, Lacerda MVG, Ladeia-Andrade S, Llanos-Cuentas A, Pukrittayakamee S, Rijal KR, Saravu K, Sutanto I, Taylor WRJ, Thriemer K, Watson JA, Guerin PJ, White NJ, Price RN, Commons RJ. Primaquine dose and the risk of haemolysis in patients with uncomplicated Plasmodium vivax malaria: a systematic review and individual patient data meta-analysis. THE LANCET. INFECTIOUS DISEASES 2024; 24:184-195. [PMID: 37748497 PMCID: PMC7615565 DOI: 10.1016/s1473-3099(23)00431-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/24/2023] [Accepted: 06/29/2023] [Indexed: 09/27/2023]
Abstract
BACKGROUND Primaquine radical cure is used to treat dormant liver-stage parasites and prevent relapsing Plasmodium vivax malaria but is limited by concerns of haemolysis. We undertook a systematic review and individual patient data meta-analysis to investigate the haematological safety of different primaquine regimens for P vivax radical cure. METHODS For this systematic review and individual patient data meta-analysis, we searched MEDLINE, Web of Science, Embase, and Cochrane Central for prospective clinical studies of uncomplicated P vivax from endemic countries published between Jan 1, 2000, and June 8, 2023. We included studies if they had active follow-up of at least 28 days, if they included a treatment group with daily primaquine given over multiple days where primaquine was commenced within 3 days of schizontocidal treatment and was given alone or coadministered with chloroquine or one of four artemisinin-based combination therapies (ie, artemether-lumefantrine, artesunate-mefloquine, artesunate-amodiaquine, or dihydroartemisinin-piperaquine), and if they recorded haemoglobin or haematocrit concentrations on day 0. We excluded studies if they were on prevention, prophylaxis, or patients with severe malaria, or if data were extracted retrospectively from medical records outside of a planned trial. For the meta-analysis, we contacted the investigators of eligible trials to request individual patient data and we then pooled data that were made available by Aug 23, 2021. The main outcome was haemoglobin reduction of more than 25% to a concentration of less than 7 g/dL by day 14. Haemoglobin concentration changes between day 0 and days 2-3 and between day 0 and days 5-7 were assessed by mixed-effects linear regression for patients with glucose-6-phosphate dehydrogenase (G6PD) activity of (1) 30% or higher and (2) between 30% and less than 70%. The study was registered with PROSPERO, CRD42019154470 and CRD42022303680. FINDINGS Of 226 identified studies, 18 studies with patient-level data from 5462 patients from 15 countries were included in the analysis. A haemoglobin reduction of more than 25% to a concentration of less than 7 g/dL occurred in one (0·1%) of 1208 patients treated without primaquine, none of 893 patients treated with a low daily dose of primaquine (<0·375 mg/kg per day), five (0·3%) of 1464 patients treated with an intermediate daily dose (0·375 mg/kg per day to <0·75 mg/kg per day), and six (0·5%) of 1269 patients treated with a high daily dose (≥0·75 mg/kg per day). The covariate-adjusted mean estimated haemoglobin changes at days 2-3 were -0·6 g/dL (95% CI -0·7 to -0·5), -0·7 g/dL (-0·8 to -0·5), -0·6 g/dL (-0·7 to -0·4), and -0·5 g/dL (-0·7 to -0·4), respectively. In 51 patients with G6PD activity between 30% and less than 70%, the adjusted mean haemoglobin concentration on days 2-3 decreased as G6PD activity decreased; two patients in this group who were treated with a high daily dose of primaquine had a reduction of more than 25% to a concentration of less than 7 g/dL. 17 of 18 included studies had a low or unclear risk of bias. INTERPRETATION Treatment of patients with G6PD activity of 30% or higher with 0·25-0·5 mg/kg per day primaquine regimens and patients with G6PD activity of 70% or higher with 0·25-1 mg/kg per day regimens were associated with similar risks of haemolysis to those in patients treated without primaquine, supporting the safe use of primaquine radical cure at these doses. FUNDING Australian National Health and Medical Research Council, Bill & Melinda Gates Foundation, and Medicines for Malaria Venture.
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Affiliation(s)
- Megha Rajasekhar
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia; WorldWide Antimalarial Resistance Network (WWARN), Asia-Pacific Regional Centre, Melbourne, VIC, Australia
| | - Benedikt Ley
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Peta Edler
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia; Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tesfay Abreha
- ICAP, Columbia University Mailman School of Public Health, Addis Ababa, Ethiopia
| | - Ghulam R Awab
- MORU, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Nangarhar Medical Faculty, Nangarhar University, Jalalabad, Afghanistan
| | - J Kevin Baird
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Oxford University Clinical Research Unit Indonesia, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Germana Bancone
- Shoklo Malaria Research Unit, Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Bridget E Barber
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Matthew J Grigg
- Global Health Division, Menzies 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, Malaysia
| | - Jimee Hwang
- US President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA; Institute for Global Health Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Harin Karunajeewa
- Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, VIC, Australia
| | - Marcus V G Lacerda
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil; Instituto Leônidas e Maria Deane, Fiocruz, Manaus, Brazil; University of Texas Medical Branch, Galveston, TX, USA
| | - Simone Ladeia-Andrade
- Laboratory of Parasitic Diseases, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil; Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Lisbon, Portugal
| | - Alejandro Llanos-Cuentas
- Unit of Leishmaniasis and Malaria, Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Komal R Rijal
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal
| | - Kavitha Saravu
- Department of Infectious Diseases, Kasturba Medical College, and Manipal Center for Infectious Diseases, Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, India
| | - Inge Sutanto
- Department of Parasitology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Walter R J Taylor
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; ICAP, Columbia University Mailman School of Public Health, Addis Ababa, Ethiopia
| | - Kamala Thriemer
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - James A Watson
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam; WWARN, Oxford, UK
| | - Philippe J Guerin
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; WWARN, Oxford, UK; Infectious Diseases Data Observatory (IDDO), Oxford, UK
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; MORU, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Ric N Price
- WorldWide Antimalarial Resistance Network (WWARN), Asia-Pacific Regional Centre, Melbourne, VIC, Australia; Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Robert J Commons
- WorldWide Antimalarial Resistance Network (WWARN), Asia-Pacific Regional Centre, Melbourne, VIC, Australia; Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; General and Subspecialty Medicine, Grampians Health-Ballarat, Ballarat, VIC, Australia.
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11
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Bancone G, Poe DD, Gornsawun G, Htway PP, Gilder ME, Archasuksan L, Chotivanich K, McGready R, Nosten F. Reference spectrophotometric values for glucose-6-phosphate dehydrogenase activity in two-to six-month-old infants on the Thailand-Myanmar border. Wellcome Open Res 2024; 7:273. [PMID: 38406309 PMCID: PMC10884598 DOI: 10.12688/wellcomeopenres.18417.2] [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] [Accepted: 01/08/2024] [Indexed: 02/27/2024] Open
Abstract
Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency represents a barrier to the full deployment of anti-malarial drugs for vivax malaria elimination and of first-line antibiotics. Lack of established reference ranges for G6PD activity in breast-fed infants puts them at risk of drug-induced haemolysis and restricts access to safe treatment of their mothers. Methods The present work was undertaken to establish age-specific G6PD normal values using the gold standard spectrophotometric assay to support the future clinical use of tafenoquine in lactating women and safer antibiotic treatment in infants. Results Spectrophotometric results collected at the Thai-Myanmar border from 78 healthy infants between the ages of 2 and 6 months showed a trend of decreased enzymatic activity with increasing age (which did not reach statistical significance when comparing 2-3 months old against 4-6 months old infants) and provided a reference normal value of 100% activity for infants 2-6 months old of 10.18IU/gHb. Conclusions Normal reference G6PD activity in 2-6-month-old infants was approximately 140% of that observed in G6PD normal adults from the same population. Age specific G6PD activity thresholds should be used in paediatric populations to avoid drug-induced haemolysis.
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Affiliation(s)
- Germana Bancone
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Day Day Poe
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Gornpan Gornsawun
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Phyu Phyu Htway
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Mary Ellen Gilder
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Laypaw Archasuksan
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
| | - Kesinee Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Rose McGready
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK
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12
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Kunkeaw N, Nguitragool W, Takashima E, Kangwanrangsan N, Muramatsu H, Tachibana M, Ishino T, Lin PJC, Tam YK, Pichyangkul S, Tsuboi T, Pardi N, Sattabongkot J. A Pvs25 mRNA vaccine induces complete and durable transmission-blocking immunity to Plasmodium vivax. NPJ Vaccines 2023; 8:187. [PMID: 38092803 PMCID: PMC10719277 DOI: 10.1038/s41541-023-00786-9] [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] [Received: 06/28/2023] [Accepted: 10/09/2023] [Indexed: 12/17/2023] Open
Abstract
Plasmodium vivax (P. vivax) is the major malaria parasite outside of Africa and no vaccine is available against it. A vaccine that interrupts parasite transmission (transmission-blocking vaccine, TBV) is considered highly desirable to reduce the spread of P. vivax and to accelerate its elimination. However, the development of a TBV against this pathogen has been hampered by the inability to culture the parasite as well as the low immunogenicity of the vaccines developed to date. Pvs25 is the most advanced TBV antigen candidate for P. vivax. However, in previous phase I clinical trials, TBV vaccines based on Pvs25 yielded low antibody responses or had unacceptable safety profiles. As the nucleoside-modified mRNA-lipid nanoparticle (mRNA-LNP) vaccine platform proved to be safe and effective in humans, we generated and tested mRNA-LNP vaccines encoding several versions of Pvs25 in mice. We found that in a prime-boost vaccination schedule, all Pvs25 mRNA-LNP vaccines elicited robust antigen-specific antibody responses. Furthermore, when compared with a Pvs25 recombinant protein vaccine formulated with Montanide ISA-51 adjuvant, the full-length Pvs25 mRNA-LNP vaccine induced a stronger and longer-lasting functional immunity. Seven months after the second vaccination, vaccine-induced antibodies retained the ability to fully block P. vivax transmission in direct membrane feeding assays, whereas the blocking activity induced by the protein/ISA-51 vaccine dropped significantly. Taken together, we report on mRNA vaccines targeting P. vivax and demonstrate that Pvs25 mRNA-LNP outperformed an adjuvanted Pvs25 protein vaccine suggesting that it is a promising candidate for further testing in non-human primates.
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Affiliation(s)
- Nawapol Kunkeaw
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wang Nguitragool
- Mahidol Vivax 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
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Niwat Kangwanrangsan
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Hiromi Muramatsu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Tomoko Ishino
- Department of Parasitology and Tropical Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Paulo J C Lin
- Acuitas Therapeutics, Vancouver, BC, V6T 1Z3, Canada
| | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC, V6T 1Z3, Canada
| | - Sathit Pichyangkul
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Norbert Pardi
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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13
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Anwar MN, Hickson RI, Mehra S, Price DJ, McCaw JM, Flegg MB, Flegg JA. Optimal Interruption of P. vivax Malaria Transmission Using Mass Drug Administration. Bull Math Biol 2023; 85:43. [PMID: 37076740 PMCID: PMC10115738 DOI: 10.1007/s11538-023-01153-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/30/2023] [Indexed: 04/21/2023]
Abstract
Plasmodium vivax is the most geographically widespread malaria-causing parasite resulting in significant associated global morbidity and mortality. One of the factors driving this widespread phenomenon is the ability of the parasites to remain dormant in the liver. Known as 'hypnozoites', they reside in the liver following an initial exposure, before activating later to cause further infections, referred to as 'relapses'. As around 79-96% of infections are attributed to relapses from activating hypnozoites, we expect it will be highly impactful to apply treatment to target the hypnozoite reservoir (i.e. the collection of dormant parasites) to eliminate P. vivax. Treatment with radical cure, for example tafenoquine or primaquine, to target the hypnozoite reservoir is a potential tool to control and/or eliminate P. vivax. We have developed a deterministic multiscale mathematical model as a system of integro-differential equations that captures the complex dynamics of P. vivax hypnozoites and the effect of hypnozoite relapse on disease transmission. Here, we use our multiscale model to study the anticipated effect of radical cure treatment administered via a mass drug administration (MDA) program. We implement multiple rounds of MDA with a fixed interval between rounds, starting from different steady-state disease prevalences. We then construct an optimisation model with three different objective functions motivated on a public health basis to obtain the optimal MDA interval. We also incorporate mosquito seasonality in our model to study its effect on the optimal treatment regime. We find that the effect of MDA interventions is temporary and depends on the pre-intervention disease prevalence (and choice of model parameters) as well as the number of MDA rounds under consideration. The optimal interval between MDA rounds also depends on the objective (combinations of expected intervention outcomes). We find radical cure alone may not be enough to lead to P. vivax elimination under our mathematical model (and choice of model parameters) since the prevalence of infection eventually returns to pre-MDA levels.
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Affiliation(s)
- Md Nurul Anwar
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Department of Mathematics, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, 8100, Bangladesh
| | - Roslyn I Hickson
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Australian Institute of Tropical Health and Medicine, and College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia
- CSIRO, Townsville, Australia
| | - Somya Mehra
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - David J Price
- Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia
| | - James M McCaw
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia
| | - Mark B Flegg
- School of Mathematics, Monash University, Melbourne, Australia
| | - Jennifer A Flegg
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.
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14
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Bancone G, Poe DD, Gornsawun G, Htway PP, Gilder ME, Archasuksan L, Chotivanich K, McGready R, Nosten F. Reference spectrophotometric values for glucose-6-phosphate dehydrogenase activity in two-to six-month-old infants on the Thailand-Myanmar border. Wellcome Open Res 2022. [DOI: 10.12688/wellcomeopenres.18417.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency represents a barrier to the full deployment of anti-malarial drugs for vivax malaria elimination and of first-line antibiotics. Lack of established reference ranges for G6PD activity in breast-fed infants puts them at risk of drug-induced haemolysis and restricts access to safe treatment of their mothers. Methods: The present work was undertaken to establish age-specific G6PD normal values using the gold standard spectrophotometric assay to support the future clinical use of tafenoquine in lactating women and safer antibiotic treatment in infants. Results: Spectrophotometric results from 78 healthy infants between the ages of 2 and 6 months showed a trend of decreased enzymatic activity with increasing age and provided a reference normal value of 100% activity for infants 2-6 months old of 10.18IU/gHb. Conclusions: Normal reference G6PD activity in 2–6-month-old infants was approximately 140% of that observed in G6PD normal adults from the same population. Age specific G6PD activity thresholds should be used in paediatric populations to avoid drug-induced haemolysis.
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15
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Anwar MN, Hickson RI, Mehra S, McCaw JM, Flegg JA. A Multiscale Mathematical Model of Plasmodium Vivax Transmission. Bull Math Biol 2022; 84:81. [PMID: 35778540 PMCID: PMC9249727 DOI: 10.1007/s11538-022-01036-0] [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: 12/12/2021] [Accepted: 05/26/2022] [Indexed: 11/29/2022]
Abstract
Malaria is caused by Plasmodium parasites which are transmitted to humans by the bite of an infected Anopheles mosquito. Plasmodium vivax is distinct from other malaria species in its ability to remain dormant in the liver (as hypnozoites) and activate later to cause further infections (referred to as relapses). Mathematical models to describe the transmission dynamics of P. vivax have been developed, but most of them fail to capture realistic dynamics of hypnozoites. Models that do capture the complexity tend to involve many governing equations, making them difficult to extend to incorporate other important factors for P. vivax, such as treatment status, age and pregnancy. In this paper, we have developed a multiscale model (a system of integro-differential equations) that involves a minimal set of equations at the population scale, with an embedded within-host model that can capture the dynamics of the hypnozoite reservoir. In this way, we can gain key insights into dynamics of P. vivax transmission with a minimum number of equations at the population scale, making this framework readily scalable to incorporate more complexity. We performed a sensitivity analysis of our multiscale model over key parameters and found that prevalence of P. vivax blood-stage infection increases with both bite rate and number of mosquitoes but decreases with hypnozoite death rate. Since our mathematical model captures the complex dynamics of P. vivax and the hypnozoite reservoir, it has the potential to become a key tool to inform elimination strategies for P. vivax.
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Affiliation(s)
- Md Nurul Anwar
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.,Department of Mathematics, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, 8100, Bangladesh
| | - Roslyn I Hickson
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.,Australian Institute of Tropical Health and Medicine, and College of Public Health, Medical & Veterinary Sciences, James Cook University, Townsville, Australia.,Health and Biosecurity, CSIRO, Townsville, Australia
| | - Somya Mehra
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - James M McCaw
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia.,Peter Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital and The University of Melbourne, Parkville, Australia
| | - Jennifer A Flegg
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.
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16
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Zhou Y, Lauschke VM. Population pharmacogenomics: an update on ethnogeographic differences and opportunities for precision public health. Hum Genet 2022; 141:1113-1136. [PMID: 34652573 PMCID: PMC9177500 DOI: 10.1007/s00439-021-02385-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/05/2021] [Indexed: 11/25/2022]
Abstract
Both safety and efficacy of medical treatment can vary depending on the ethnogeographic background of the patient. One of the reasons underlying this variability is differences in pharmacogenetic polymorphisms in genes involved in drug disposition, as well as in drug targets. Knowledge and appreciation of these differences is thus essential to optimize population-stratified care. Here, we provide an extensive updated analysis of population pharmacogenomics in ten pharmacokinetic genes (CYP2D6, CYP2C19, DPYD, TPMT, NUDT15 and SLC22A1), drug targets (CFTR) and genes involved in drug hypersensitivity (HLA-A, HLA-B) or drug-induced acute hemolytic anemia (G6PD). Combined, polymorphisms in the analyzed genes affect the pharmacology, efficacy or safety of 141 different drugs and therapeutic regimens. The data reveal pronounced differences in the genetic landscape, complexity and variant frequencies between ethnogeographic groups. Reduced function alleles of CYP2D6, SLC22A1 and CFTR were most prevalent in individuals of European descent, whereas DPYD and TPMT deficiencies were most common in Sub-Saharan Africa. Oceanian populations showed the highest frequencies of CYP2C19 loss-of-function alleles while their inferred CYP2D6 activity was among the highest worldwide. Frequencies of HLA-B*15:02 and HLA-B*58:01 were highest across Asia, which has important implications for the risk of severe cutaneous adverse reactions upon treatment with carbamazepine and allopurinol. G6PD deficiencies were most frequent in Africa, the Middle East and Southeast Asia with pronounced differences in variant composition. These variability data provide an important resource to inform cost-effectiveness modeling and guide population-specific genotyping strategies with the goal of optimizing the implementation of precision public health.
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Affiliation(s)
- Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden.
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.
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17
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Llanos-Cuentas A, Manrrique P, Rosas-Aguirre A, Herrera S, Hsiang MS. Tafenoquine for the treatment of Plasmodium vivax malaria. Expert Opin Pharmacother 2022; 23:759-768. [PMID: 35379070 DOI: 10.1080/14656566.2022.2058394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Plasmodium vivax malaria causes significant disease burden worldwide, especially in Latin America, Southeast Asia, and Oceania. P. vivax is characterized by the production of liver hypnozoites that cause clinical relapses upon periodic activation. Primaquine, an 8-aminoquinoline drug, has been the standard of care for decades to treat liver-stage P. vivax malaria; however, it requires long treatment regimens (one to two weeks) that lead to poor adherence and thus clinical relapses. Tafenoquine (TFQ), a newly available and efficacious single-dose 8-aminoquinoline, aims to address this challenge. Safe administration is possible when paired with the use of glucose-6-phosphate dehydrogenase (G6PD) diagnostics to prevent 8-aminoquinoline-induced hemolysis in patients with underlying G6PD deficiency (G6PDd). AREAS COVERED In this review, the authors present the recent literature regarding the pharmacology, efficacy, safety, and tolerability of TFQ and highlight regional differences in these areas. The authors also discuss the potential for TFQ, complemented with primaquine PQ and effective screening for G6PDd, to improve P. vivax clinical management and facilitate targeted mass drug administration in communities to decrease transmission. EXPERT OPINION Clinical studies show therapeutic efficacy of TFQ as well as a good performance in terms of safety and tolerability. Additional research regarding the effectiveness and safety TFQ in malaria elimination strategies such as targeted or mass drug administration are needed.
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Affiliation(s)
| | - Paulo Manrrique
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, PA, USA
| | - Angel Rosas-Aguirre
- Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Sonia Herrera
- Department of Epidemiology, Division of Infectious Diseases and Global Health, Department of Pediatrics, Division of Pediatric Infectious Diseases, University of California San Francisco, San Francisco, CA, United States
| | - Michelle S Hsiang
- Department of Epidemiology, Division of Infectious Diseases and Global Health, Department of Pediatrics, Division of Pediatric Infectious Diseases, University of California San Francisco, San Francisco, CA, United States.,Department of Epidemiology and Biostatistics, University of California San Francisco (UCSF), San Francisco, CA, USA.,Department of PediatricsUniversity of California San Francisco (UCSF), San Francisco, CA, USA
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18
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Taylor WR, Hoglund RM, Peerawaranun P, Nguyen TN, Hien TT, Tarantola A, von Seidlein L, Tripura R, Peto TJ, Dondorp AM, Landier J, H Nosten F, Smithuis F, Phommasone K, Mayxay M, Kheang ST, Say C, Neeraj K, Rithea L, Dysoley L, Kheng S, Muth S, Roca-Feltrer A, Debackere M, Fairhurst RM, Song N, Buchy P, Menard D, White NJ, Tarning J, Mukaka M. Development of weight and age-based dosing of daily primaquine for radical cure of vivax malaria. Malar J 2021; 20:366. [PMID: 34503519 PMCID: PMC8427859 DOI: 10.1186/s12936-021-03886-w] [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: 03/30/2021] [Accepted: 08/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In many endemic areas, Plasmodium vivax malaria is predominantly a disease of young adults and children. International recommendations for radical cure recommend fixed target doses of 0.25 or 0.5 mg/kg/day of primaquine for 14 days in glucose-6-phosphate dehydrogenase normal patients of all ages. However, for many anti-malarial drugs, including primaquine, there is evidence that children have lower exposures than adults for the same weight-adjusted dose. The aim of the study was to develop 14-day weight-based and age-based primaquine regimens against high-frequency relapsing tropical P. vivax. METHODS The recommended adult target dose of 0.5 mg/kg/day (30 mg in a 60 kg patient) is highly efficacious against tropical P. vivax and was assumed to produce optimal drug exposure. Primaquine doses were calculated using allometric scaling to derive a weight-based primaquine regimen over a weight range from 5 to 100 kg. Growth curves were constructed from an anthropometric database of 53,467 individuals from the Greater Mekong Subregion (GMS) to define weight-for-age relationships. The median age associated with each weight was used to derive an age-based dosing regimen from the weight-based regimen. RESULTS The proposed weight-based regimen has 5 dosing bands: (i) 5-7 kg, 5 mg, resulting in 0.71-1.0 mg/kg/day; (ii) 8-16 kg, 7.5 mg, 0.47-0.94 mg/kg/day; (iii) 17-40 kg, 15 mg, 0.38-0.88 mg/kg/day; (iv) 41-80 kg, 30 mg, 0.37-0.73 mg/kg/day; and (v) 81-100 kg, 45 mg, 0.45-0.56 mg/kg/day. The corresponding age-based regimen had 4 dosing bands: 6-11 months, 5 mg, 0.43-1.0 mg/kg/day; (ii) 1-5 years, 7.5 mg, 0.35-1.25 mg/kg/day; (iii) 6-14 years, 15 mg, 0.30-1.36 mg/kg/day; and (iv) ≥ 15 years, 30 mg, 0.35-1.07 mg/kg/day. CONCLUSION The proposed weight-based regimen showed less variability around the primaquine dose within each dosing band compared to the age-based regimen and is preferred. Increased dose accuracy could be achieved by additional dosing bands for both regimens. The age-based regimen might not be applicable to regions outside the GMS, which must be based on local anthropometric data. Pharmacokinetic data in small children are needed urgently to inform the proposed regimens.
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Affiliation(s)
- Walter Robert Taylor
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Richard M Hoglund
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pimnara Peerawaranun
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
| | - Thuy Nhien Nguyen
- Oxford University Clinical Research Unit, Wellcome Trust Major Oversea Programme, Ho Chi Minh City, Vietnam
| | - Tran Tinh Hien
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Oxford University Clinical Research Unit, Wellcome Trust Major Oversea Programme, Ho Chi Minh City, Vietnam
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
| | - Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rupam Tripura
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Department of Global Health, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Thomas J Peto
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, 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, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jordi Landier
- Shoklo Malaria Research Unit, Mae Sot, Thailand
- Aix-Marseille Université, IRD, INSERM, SESSTIM, Marseille, France
| | - Francois H Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mae Sot, Thailand
| | | | - Koukeo Phommasone
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
- Amsterdam Institute for Global Health & Development, Amsterdam, The Netherlands
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
- Institute of Research and Education Development, University of Health Sciences, Vientiane, Lao PDR
| | - Soy Ty Kheang
- Center for Health and Social Development (HSD), National Institute for Public Health (NIPH) and University Research Co., LLC (URC), Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
- AQUITY Global Inc, 987 Avenel Farm Dr, Potomac, MD, 20854, USA
| | - Chy Say
- Center for Health and Social Development (HSD), National Institute for Public Health (NIPH) and University Research Co., LLC (URC), Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
| | - Kak Neeraj
- University Research Co., LLC Washington DC, 7200 Wisconsin Ave, Bethesda, MD, 20814, USA
| | - Leang Rithea
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | - Lek Dysoley
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
- Institute of Public Health, Phnom Penh, Cambodia
| | - Sim Kheng
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | - Sinoun Muth
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | | | - Mark Debackere
- MSF Belgium Cambodia Malaria Program, Khan Chamkarmon, Phnom Penh, Cambodia
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Ngak Song
- FHI 360 Cambodia Office, Keng Kang III Khan Chamkamon, Phnom Penh, Cambodia
| | - Philippe Buchy
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
- GSK Vaccines, 23 Rochester Park, Singapore, Singapore
| | - Didier Menard
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
- Unité Génétique du Paludisme Et Résistance, Département Parasites Et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Singh L, Singh K. Ivermectin: A Promising Therapeutic for Fighting Malaria. Current Status and Perspective. J Med Chem 2021; 64:9711-9731. [PMID: 34242031 DOI: 10.1021/acs.jmedchem.1c00498] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Finding new chemotherapeutic interventions to treat malaria through repurposing of time-tested drugs and rigorous design of new drugs using tools of rational drug design remains one of the most sought strategies at the disposal of medicinal chemists. Ivermectin, a semisynthetic derivative of avermectin B1, is among the efficacious drugs used in mass drug administration drives employed against onchocerciasis, lymphatic filariasis, and several other parasitic diseases in humans. In this review, we present the prowess of ivermectin, a potent endectocide, in the control of malaria through vector control to reduce parasite transmission combined with efficacious chemoprevention to reduce malaria-related fatalities.
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Affiliation(s)
- Lovepreet Singh
- Department of Chemistry, UGC Centre for Advanced Studies-II, Guru Nanak Dev University, Amritsar-143 005, India
| | - Kamaljit Singh
- Department of Chemistry, UGC Centre for Advanced Studies-II, Guru Nanak Dev University, Amritsar-143 005, India
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20
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Ahmad SS, Rahi M, Sharma A. Relapses of Plasmodium vivax malaria threaten disease elimination: time to deploy tafenoquine in India? BMJ Glob Health 2021; 6:bmjgh-2020-004558. [PMID: 33619041 PMCID: PMC7903102 DOI: 10.1136/bmjgh-2020-004558] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/30/2021] [Accepted: 02/02/2021] [Indexed: 12/21/2022] Open
Affiliation(s)
- Sundus Shafat Ahmad
- Parasite and Host Biology, National Institute of Malaria Research, New Delhi, Delhi, India
| | - Manju Rahi
- Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi, Delhi, India
| | - Amit Sharma
- Parasite and Host Biology, National Institute of Malaria Research, New Delhi, Delhi, India
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21
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Abstract
Cindy S Chu and co-authors review options for diagnosis, safe and radical cure, and relapse prevention of Plasmodium Vivax.
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Affiliation(s)
- Cindy S. Chu
- Shoklo Malaria Research Unit-Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Headington, Oxford, United Kingdom
- * E-mail:
| | - Nicholas J. White
- Shoklo Malaria Research Unit-Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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22
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Abstract
In this review for the Vivax malaria collection, Kamala Thriemer and colleagues explore efforts to eliminate P. vivax malaria.
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Affiliation(s)
- Kamala Thriemer
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Lorenz von Seidlein
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), 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
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23
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Nekkab N, Lana R, Lacerda M, Obadia T, Siqueira A, Monteiro W, Villela D, Mueller I, White M. Estimated impact of tafenoquine for Plasmodium vivax control and elimination in Brazil: A modelling study. PLoS Med 2021; 18:e1003535. [PMID: 33891582 PMCID: PMC8064585 DOI: 10.1371/journal.pmed.1003535] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 01/06/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite recent intensification of control measures, Plasmodium vivax poses a major challenge for malaria elimination efforts. Liver-stage hypnozoite parasites that cause relapsing infections can be cleared with primaquine; however, poor treatment adherence undermines drug effectiveness. Tafenoquine, a new single-dose treatment, offers an alternative option for preventing relapses and reducing transmission. In 2018, over 237,000 cases of malaria were reported to the Brazilian health system, of which 91.5% were due to P. vivax. METHODS AND FINDINGS We evaluated the impact of introducing tafenoquine into case management practices on population-level transmission dynamics using a mathematical model of P. vivax transmission. The model was calibrated to reflect the transmission dynamics of P. vivax endemic settings in Brazil in 2018, informed by nationwide malaria case reporting data. Parameters for treatment pathways with chloroquine, primaquine, and tafenoquine with glucose-6-phosphate dehydrogenase deficiency (G6PDd) testing were informed by clinical trial data and the literature. We assumed 71.3% efficacy for primaquine and tafenoquine, a 66.7% adherence rate to the 7-day primaquine regimen, a mean 5.5% G6PDd prevalence, and 8.1% low metaboliser prevalence. The introduction of tafenoquine is predicted to improve effective hypnozoite clearance among P. vivax cases and reduce population-level transmission over time, with heterogeneous levels of impact across different transmission settings. According to the model, while achieving elimination in only few settings in Brazil, tafenoquine rollout in 2021 is estimated to improve the mean effective radical cure rate from 42% (95% uncertainty interval [UI] 41%-44%) to 62% (95% UI 54%-68%) among clinical cases, leading to a predicted 38% (95% UI 7%-99%) reduction in transmission and over 214,000 cumulative averted cases between 2021 and 2025. Higher impact is predicted in settings with low transmission, low pre-existing primaquine adherence, and a high proportion of cases in working-aged males. High-transmission settings with a high proportion of cases in children would benefit from a safe high-efficacy tafenoquine dose for children. Our methodological limitations include not accounting for the role of imported cases from outside the transmission setting, relying on reported clinical cases as a measurement of community-level transmission, and implementing treatment efficacy as a binary condition. CONCLUSIONS In our modelling study, we predicted that, provided there is concurrent rollout of G6PDd diagnostics, tafenoquine has the potential to reduce P. vivax transmission by improving effective radical cure through increased adherence and increased protection from new infections. While tafenoquine alone may not be sufficient for P. vivax elimination, its introduction will improve case management, prevent a substantial number of cases, and bring countries closer to achieving malaria elimination goals.
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Affiliation(s)
- Narimane Nekkab
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Raquel Lana
- Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Marcus Lacerda
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- Instituto Leônidas e Maria Deane, Fundação Oswaldo Cruz, Manaus, Brazil
| | - Thomas Obadia
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - André Siqueira
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Wuelton Monteiro
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- School of Health Sciences, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Daniel Villela
- Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Ivo Mueller
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
- Population Health & Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Michael White
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
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Disrupting Plasmodium UIS3-host LC3 interaction with a small molecule causes parasite elimination from host cells. Commun Biol 2020; 3:688. [PMID: 33214643 PMCID: PMC7677311 DOI: 10.1038/s42003-020-01422-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 10/17/2020] [Indexed: 01/12/2023] Open
Abstract
The malaria parasite Plasmodium obligatorily infects and replicates inside hepatocytes surrounded by a parasitophorous vacuole membrane (PVM), which is decorated by the host-cell derived autophagy protein LC3. We have previously shown that the parasite-derived, PVM-resident protein UIS3 sequesters LC3 to avoid parasite elimination by autophagy from hepatocytes. Here we show that a small molecule capable of disrupting this interaction triggers parasite elimination in a host cell autophagy-dependent manner. Molecular docking analysis of more than 20 million compounds combined with a phenotypic screen identified one molecule, C4 (4-{[4-(4-{5-[3-(trifluoromethyl) phenyl]-1,2,4-oxadiazol-3-yl}benzyl)piperazino]carbonyl}benzonitrile), capable of impairing infection. Using biophysical assays, we established that this impairment is due to the ability of C4 to disrupt UIS3-LC3 interaction, thus inhibiting the parasite's ability to evade the host autophagy response. C4 impacts infection in autophagy-sufficient cells without harming the normal autophagy pathway of the host cell. This study, by revealing the disruption of a critical host-parasite interaction without affecting the host's normal function, uncovers an efficient anti-malarial strategy to prevent this deadly disease.
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25
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Primaquine elicits Foxp3+ regulatory T cells with a superior ability to limit CNS autoimmune inflammation. J Autoimmun 2020; 114:102505. [DOI: 10.1016/j.jaut.2020.102505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 12/16/2022]
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Abstract
PURPOSE OF REVIEW This is a review of tafenoquine, a new antimalarial drug. Here we examine the recent literature supporting the use of tafenoquine and summarize the opportunities and challenges for its well tolerated use worldwide. RECENT FINDINGS Tafenoquine was recently approved by the US Food and Drug Administration for the treatment of dormant liver stage (hypnozoite) in Plasmodium vivax and for malaria prophylaxis. Single-dose tafenoquine provides equivalent efficacy to 14 days of primaquine for radical cure in P. vivax, and it can be dosed weekly to prevent malaria. However, tafenoquine can only be used in patients with normal G6PD activity and is contraindicated in children and during pregnancy or in lactating mothers with infants of deficient or unknown G6PD status. SUMMARY Tafenoquine's long half-life allows a single dose to achieve radical cure, and weekly dosing for chemoprophylaxis to provide an exciting therapeutic option for patient care and as a new weapon for malaria control/eradication programs. Global implementation of tafenoquine will require the development and validation of a robust, low-cost diagnostic to reliably identify G6PD-deficient individuals. In addition, studies on tafenoquine safety in children are needed.
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Calvaresi EC, Genzen JR. Evaluating Percentage-Based Reporting of Glucose-6-Phosphate Dehydrogenase (G6PD) Enzymatic Activity. Am J Clin Pathol 2020; 154:248-254. [PMID: 32405645 DOI: 10.1093/ajcp/aqaa040] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVES The World Health Organization recommends measurement of glucose-6-phosphate dehydrogenase (G6PD) activity before initiation of 8-aminoquinoline therapy. A new drug for malaria prophylaxis and treatment (tafenoquine) is contraindicated in patients with G6PD deficiency or unknown G6PD status given its prolonged half-life. Assessments of percentage of normal G6PD activity using laboratory-specific result distributions are not widely available, making tafenoquine-eligibility decisions potentially challenging. METHODS Using an institutional review board-exempt protocol, a data set of quantitative G6PD results was retrieved from a national reference laboratory. G6PD testing was previously performed at 37 °C using an automated enzymatic assay configured on a Roche cobas c501 chemistry analyzer. RESULTS Overall, 52,216 results from patients 18 years and older and 6,397 results from patients younger than 18 years were obtained. A modified adjusted male median of 12.7 U/g Hb was derived for adult males in this assay configuration. Result distributions showed higher G6PD activity in neonates. CONCLUSIONS Retrospective data analysis can be used to determine laboratory-specific normal G6PD activity values in clinical populations and thus can assist in clinical-eligibility considerations for 8-aminoquinoline treatment.
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Affiliation(s)
| | - Jonathan R Genzen
- Department of Pathology, University of Utah, Salt Lake City
- ARUP Laboratories, Salt Lake City, UT
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Singh L, Fontinha D, Francisco D, Mendes AM, Prudêncio M, Singh K. Molecular Design and Synthesis of Ivermectin Hybrids Targeting Hepatic and Erythrocytic Stages of Plasmodium Parasites. J Med Chem 2020; 63:1750-1762. [PMID: 32011136 DOI: 10.1021/acs.jmedchem.0c00033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ivermectin is a powerful endectocide, which reduces the incidence of vector-borne diseases. Besides its strong insecticidal effect on mosquito vectors of the disease, ivermectin inhibits Plasmodium falciparum sporogonic and blood stage development and impairs Plasmodium berghei development inside hepatocytes, both in vitro and in vivo. Herein, we present the first report on structural modification of ivermectin to produce dual-action molecular hybrids with good structure-dependent in vitro activity against both the hepatic and erythrocytic stages of P. berghei and P. falciparum infection, suggesting inclusion of ivermectin antimalarial hybrids in malaria control strategies. The most active hybrid displayed over threefold and 10-fold higher in vitro activity than ivermectin against hepatic and blood stage infections, respectively. Although an overwhelming insecticidal effect against Anopheles stephensi mosquitoes in laboratory conditions was not noticed, in silico docking analysis supports allosteric binding to glutamate-gated chloride channels similar to ivermectin.
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Affiliation(s)
- Lovepreet Singh
- Department of Chemistry , Guru Nanak Dev University , Amritsar 143 005 , India
| | - Diana Fontinha
- Instituto de Medicina Molecular , Faculdade de Medicina da Universidade de Lisboa , Av. Prof. Egas Moniz , Lisboa 1649-028 , Portugal
| | - Denise Francisco
- Instituto de Medicina Molecular , Faculdade de Medicina da Universidade de Lisboa , Av. Prof. Egas Moniz , Lisboa 1649-028 , Portugal
| | - Antonio M Mendes
- Instituto de Medicina Molecular , Faculdade de Medicina da Universidade de Lisboa , Av. Prof. Egas Moniz , Lisboa 1649-028 , Portugal
| | - Miguel Prudêncio
- Instituto de Medicina Molecular , Faculdade de Medicina da Universidade de Lisboa , Av. Prof. Egas Moniz , Lisboa 1649-028 , Portugal
| | - Kamaljit Singh
- Department of Chemistry , Guru Nanak Dev University , Amritsar 143 005 , India
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Brummaier T, Gilder ME, Gornsawun G, Chu CS, Bancone G, Pimanpanarak M, Chotivanich K, Nosten F, McGready R. Vivax malaria in pregnancy and lactation: a long way to health equity. Malar J 2020; 19:40. [PMID: 31969155 PMCID: PMC6977346 DOI: 10.1186/s12936-020-3123-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 01/13/2020] [Indexed: 12/30/2022] Open
Abstract
Background The Sustainable Development Goals (SDG) call for increased gender equity and reduction in malaria-related mortality and morbidity. Plasmodium vivax infections in pregnancy are associated with maternal anaemia and increased adverse perinatal outcomes. Providing radical cure for women with 8-aminoquinolines (e.g., primaquine) is hindered by gender-specific complexities. Case presentation A symptomatic episode of vivax malaria at 18 weeks of gestation in a primigravid woman was associated with maternal anaemia, a recurrent asymptomatic P. vivax episode, severe intra-uterine growth restriction with no other identifiable cause and induction to reduce the risk of stillbirth. At 5 months postpartum a qualitative glucose-6-phosphate dehydrogenase (G6PD) point-of-care test was normal and radical cure with primaquine was prescribed to the mother. A 33% fractional decrease in haematocrit on day 7 of primaquine led to further testing which showed intermediate phenotypic G6PD activity; the G6PD genotype could not be identified. Her infant daughter was well throughout maternal treatment and found to be heterozygous for Mahidol variant. Conclusion Adverse effects of vivax malaria in pregnancy, ineligibility of radical cure for pregnant and postpartum women, and difficulties in diagnosing intermediate levels of G6PD activity multiplied morbidity in this woman. Steps towards meeting the SDG include prevention of malaria in pregnancy, reducing unnecessary exclusion of women from radical cure, and accessible quantitative G6PD screening in P. vivax-endemic settings.
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Affiliation(s)
- Tobias Brummaier
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand. .,Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, UK.
| | - Mary Ellen Gilder
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand
| | - Gornpan Gornsawun
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand
| | - Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, UK
| | - Germana Bancone
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, UK
| | - Mupawjay Pimanpanarak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand
| | - Kesinee Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, UK
| | - Rose McGready
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, P.O. Box 46, 68/31 Bann Tung Road, Mae Sot, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, UK
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30
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Thawnashom K, Kaneko M, Xangsayarath P, Chaiyawong N, Yahata K, Asada M, Adams JH, Kaneko O. Validation of Plasmodium vivax centromere and promoter activities using Plasmodium yoelii. PLoS One 2019; 14:e0226884. [PMID: 31860644 PMCID: PMC6924662 DOI: 10.1371/journal.pone.0226884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/06/2019] [Indexed: 11/18/2022] Open
Abstract
Plasmodium vivax is the leading cause of malaria outside Africa and represents a significant health and economic burden on affected countries. A major obstacle for P. vivax eradication is the dormant hypnozoite liver stage that causes relapse infections and the limited antimalarial drugs that clear this stage. Advances in studying the hypnozoite and other unique biological aspects of this parasite are hampered by the lack of a continuous in vitro laboratory culture system and poor availability of molecular tools for genetic manipulation. In this study, we aim to develop molecular tools that can be used for genetic manipulation of P. vivax. A putative P. vivax centromere sequence (PvCEN) was cloned and episomal centromere based plasmids expressing a GFP marker were constructed. Centromere activity was evaluated using a rodent malaria parasite Plasmodium yoelii. A plasmid carrying PvCEN was stably maintained in asexual-stage parasites in the absence of drug pressure, and approximately 45% of the parasites retained the plasmid four weeks later. The same retention rate was observed in parasites possessing a native P. yoelii centromere (PyCEN)-based control plasmid. The segregation efficiency of the plasmid per nuclear division was > 99% in PvCEN parasites, compared to ~90% in a control parasite harboring a plasmid without a centromere. In addition, we observed a clear GFP signal in both oocysts and salivary gland sporozoites isolated from mosquitoes. In blood-stage parasites after liver stage development, GFP positivity in PvCEN parasites was comparable to control PyCEN parasites. Thus, PvCEN plasmids were maintained throughout the parasite life cycle. We also validated several P. vivax promoter activities and showed that hsp70 promoter (~1 kb) was active throughout the parasite life cycle. This is the first data for the functional characterization of a P. vivax centromere that can be used in future P. vivax biological research.
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Affiliation(s)
- Kittisak Thawnashom
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
- Department of Medical Technology, Faculty of Allied Health Sciences, Naresuan University, Mueang, Phitsanulok, Thailand
| | - Miho Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Phonepadith Xangsayarath
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Nattawat Chaiyawong
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
- Leading Program, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Masahito Asada
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
- Leading Program, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto, Nagasaki, Japan
- Leading Program, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan
- * E-mail:
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31
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Vera IM, Grilo Ruivo MT, Lemos Rocha LF, Marques S, Bhatia SN, Mota MM, Mancio-Silva L. Targeting liver stage malaria with metformin. JCI Insight 2019; 4:127441. [PMID: 31852843 DOI: 10.1172/jci.insight.127441] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 11/13/2019] [Indexed: 12/29/2022] Open
Abstract
Despite an unprecedented 2 decades of success, the combat against malaria - the mosquito-transmitted disease caused by Plasmodium parasites - is no longer progressing. Efforts toward eradication are threatened by the lack of an effective vaccine and a rise in antiparasite drug resistance. Alternative approaches are urgently needed. Repurposing of available, approved drugs with distinct modes of action are being considered as viable and immediate adjuncts to standard antimicrobial treatment. Such strategies may be well suited to the obligatory and clinically silent first phase of Plasmodium infection, where massive parasite replication occurs within hepatocytes in the liver. Here, we report that the widely used antidiabetic drug, metformin, impairs parasite liver stage development of both rodent-infecting Plasmodium berghei and human-infecting P. falciparum parasites. Prophylactic treatment with metformin curtails parasite intracellular growth in vitro. An additional effect was observed in mice with a decrease in the numbers of infected hepatocytes. Moreover, metformin provided in combination with conventional liver- or blood-acting antimalarial drugs further reduced the total burden of P. berghei infection and substantially lessened disease severity in mice. Together, our findings indicate that repurposing of metformin in a prophylactic regimen could be considered for malaria chemoprevention.
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Affiliation(s)
- Iset Medina Vera
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Margarida T Grilo Ruivo
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Leonardo F Lemos Rocha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Sofia Marques
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Sangeeta N Bhatia
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts, USA.,Howard Hughes Medical Institute, Cambridge, Masschusetts, USA
| | - Maria M Mota
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal
| | - Liliana Mancio-Silva
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina Universidade de Lisboa, Lisboa, Portugal.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Koch Institute for Integrative Cancer Research, Cambridge, Massachusetts, USA
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32
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Taylor AR, Watson JA, Chu CS, Puaprasert K, Duanguppama J, Day NPJ, Nosten F, Neafsey DE, Buckee CO, Imwong M, White NJ. Resolving the cause of recurrent Plasmodium vivax malaria probabilistically. Nat Commun 2019; 10:5595. [PMID: 31811128 PMCID: PMC6898227 DOI: 10.1038/s41467-019-13412-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 10/29/2019] [Indexed: 11/23/2022] Open
Abstract
Relapses arising from dormant liver-stage Plasmodium vivax parasites (hypnozoites) are a major cause of vivax malaria. However, in endemic areas, a recurrent blood-stage infection following treatment can be hypnozoite-derived (relapse), a blood-stage treatment failure (recrudescence), or a newly acquired infection (reinfection). Each of these requires a different prevention strategy, but it was not previously possible to distinguish between them reliably. We show that individual vivax malaria recurrences can be characterised probabilistically by combined modelling of time-to-event and genetic data within a framework incorporating identity-by-descent. Analysis of pooled patient data on 1441 recurrent P. vivax infections in 1299 patients on the Thailand-Myanmar border observed over 1000 patient follow-up years shows that, without primaquine radical curative treatment, 3 in 4 patients relapse. In contrast, after supervised high-dose primaquine only 1 in 40 relapse. In this region of frequent relapsing P. vivax, failure rates after supervised high-dose primaquine are significantly lower (∼3%) than estimated previously.
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Affiliation(s)
- Aimee R Taylor
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
| | - James A Watson
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK.
| | - Cindy S Chu
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
- Shoklo Malaria Research Unit, Mae Sot, Tak Province, 63110, Thailand
| | - Kanokpich Puaprasert
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Jureeporn Duanguppama
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Francois Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
- Shoklo Malaria Research Unit, Mae Sot, Tak Province, 63110, Thailand
| | - Daniel E Neafsey
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Caroline O Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Mallika Imwong
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK.
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Plewes K, Leopold SJ, Kingston HWF, Dondorp AM. Malaria: What's New in the Management of Malaria? Infect Dis Clin North Am 2019; 33:39-60. [PMID: 30712767 DOI: 10.1016/j.idc.2018.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The global burden of malaria remains high, with 216 million cases causing 445,000 deaths in 2016 despite first-line treatment with artemisinin-based combination therapy. Decreasing transmission in Africa shifts the risk for severe malaria to older age groups as premunition wanes. Prompt diagnosis and treatment with intravenous artesunate in addition to appropriate supportive management are critical to reduce deaths from severe malaria. Effective individual management is challenging in settings with limited resources for higher-level care. Adjunctive therapies targeting the underlying pathophysiological pathways have the potential to reduce mortality. Resistance to artemisinin derivatives and their partner drugs threaten malaria management and control.
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Affiliation(s)
- Katherine Plewes
- Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand; Department of Medicine, University of British Columbia, Vancouver General Hospital, 452D Heather Pavilion East, 2733 Heather Street, Vancouver, British Columbia V5Z 3J5, Canada
| | - Stije J Leopold
- Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand
| | - Hugh W F Kingston
- Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Headington, Oxford OX3 7BN, UK; Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand
| | - Arjen M Dondorp
- Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Headington, Oxford OX3 7BN, UK; Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand.
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34
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Tafenoquine. Curr Opin Infect Dis 2019. [DOI: 10.1097/qco.0000000000000574 and 21=21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
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Sabiá Júnior EF, Menezes LFS, de Araújo IFS, Schwartz EF. Natural Occurrence in Venomous Arthropods of Antimicrobial Peptides Active against Protozoan Parasites. Toxins (Basel) 2019; 11:E563. [PMID: 31557900 PMCID: PMC6832604 DOI: 10.3390/toxins11100563] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/31/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023] Open
Abstract
Arthropoda is a phylum of invertebrates that has undergone remarkable evolutionary radiation, with a wide range of venomous animals. Arthropod venom is a complex mixture of molecules and a source of new compounds, including antimicrobial peptides (AMPs). Most AMPs affect membrane integrity and produce lethal pores in microorganisms, including protozoan pathogens, whereas others act on internal targets or by modulation of the host immune system. Protozoan parasites cause some serious life-threatening diseases among millions of people worldwide, mostly affecting the poorest in developing tropical regions. Humans can be infected with protozoan parasites belonging to the genera Trypanosoma, Leishmania, Plasmodium, and Toxoplasma, responsible for Chagas disease, human African trypanosomiasis, leishmaniasis, malaria, and toxoplasmosis. There is not yet any cure or vaccine for these illnesses, and the current antiprotozoal chemotherapeutic compounds are inefficient and toxic and have been in clinical use for decades, which increases drug resistance. In this review, we will present an overview of AMPs, the diverse modes of action of AMPs on protozoan targets, and the prospection of novel AMPs isolated from venomous arthropods with the potential to become novel clinical agents to treat protozoan-borne diseases.
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Affiliation(s)
- Elias Ferreira Sabiá Júnior
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Luis Felipe Santos Menezes
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Israel Flor Silva de Araújo
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Elisabeth Ferroni Schwartz
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
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36
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Abstract
The technical genesis and practice of 8-aminoquinoline therapy of latent malaria offer singular scientific, clinical, and public health insights. The 8-aminoquinolines brought revolutionary scientific discoveries, dogmatic practices, benign neglect, and, finally, enduring promise against endemic malaria. The clinical use of plasmochin-the first rationally synthesized blood schizontocide and the first gametocytocide, tissue schizontocide, and hypnozoitocide of any kind-commenced in 1926. Plasmochin became known to sometimes provoke fatal hemolytic crises. World War II delivered a newer 8-aminoquinoline, primaquine, and the discovery of glucose-6-phosphate dehydrogenase (G6PD) deficiency as the basis of its hemolytic toxicity came in 1956. Primaquine nonetheless became the sole therapeutic option against latent malaria. After 40 years of fitful development, in 2018 the U.S. Food and Drug Administration registered the 8-aminoquinoline called tafenoquine for the prevention of all malarias and the treatment of those that relapse. Tafenoquine also cannot be used in G6PD-unknown or -deficient patients. The hemolytic toxicity of the 8-aminoquinolines impedes their great potential, but this problem has not been a research priority. This review explores the complex technical dimensions of the history of 8-aminoquinolines. The therapeutic principles thus examined may be leveraged in improved practice and in understanding the bright prospect of discovery of newer drugs that cannot harm G6PD-deficient patients.
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Affiliation(s)
- J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Djigo OKM, Bollahi MA, Hasni Ebou M, Ould Ahmedou Salem MS, Tahar R, Bogreau H, Basco L, Ould Mohamed Salem Boukhary A. Assessment of glucose-6-phosphate dehydrogenase activity using CareStart G6PD rapid diagnostic test and associated genetic variants in Plasmodium vivax malaria endemic setting in Mauritania. PLoS One 2019; 14:e0220977. [PMID: 31525211 PMCID: PMC6746352 DOI: 10.1371/journal.pone.0220977] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 07/26/2019] [Indexed: 02/06/2023] Open
Abstract
Background Primaquine is recommended by the World Health Organization (WHO) for radical treatment of Plasmodium vivax malaria. This drug is known to provoke acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Due to lack of data on G6PD deficiency, the use of primaquine has been limited in Africa. In the present study, G6PD deficiency was investigated in blood donors of various ethnic groups living in Nouakchott, a P. vivax endemic area in Mauritania. Methodology/Principal findings Venous blood samples from 443 healthy blood donors recruited at the National Transfusion Center in Nouakchott were screened for G6PD activity using the CareStart G6PD deficiency rapid diagnostic test. G6PD allelic variants were investigated using DiaPlexC G6PD genotyping kit that detects African (A-) and Mediterranean (B-) variants. Overall, 50 of 443 (11.3%) individuals (49 [11.8%] men and 1 [3.7%] woman) were phenotypically deficient. Amongst men, Black Africans had the highest prevalence of G6PD deficiency (15 of 100 [15%]) and White Moors the lowest (10 of 168, [5.9%]). The most commonly observed G6PD allelic variants among 44 tested G6PD-deficient men were the African variant A- (202A/376G) in 14 (31.8%), the Mediterranean variant B- (563T) in 13 (29.5%), and the Betica-Selma A- (376G/968C) allelic variant in 6 (13.6%). The Santamaria A- variant (376G/542T) and A variant (376G) were observed in only one and two individuals, respectively. None of the expected variants was observed in 8 (18.2%) of the tested phenotypically G6PD-deficient men. Conclusion This is the first published data on G6PD deficiency in Mauritanians. The prevalence of phenotypic G6PD deficiency was relatively high (11.3%). It was mostly associated with either African or Mediterranean variants, in agreement with diverse Arab and Black African origins of the Mauritanian population.
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Affiliation(s)
- Oum kelthoum Mamadou Djigo
- Unité de recherche Génomes et Milieux, Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouveau Campus Universitaire, Nouakchott, Mauritania
| | | | - Moina Hasni Ebou
- Unité de recherche Génomes et Milieux, Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouveau Campus Universitaire, Nouakchott, Mauritania
| | - Mohamed Salem Ould Ahmedou Salem
- Unité de recherche Génomes et Milieux, Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouveau Campus Universitaire, Nouakchott, Mauritania
| | - Rachida Tahar
- UMR 216 MERIT, IRD, Faculté de Pharmacie, Univ. Paris Descartes, Paris, France
| | - Hervé Bogreau
- Unité de Parasitologie et d’Entomologie, Institut de Recherche Biomédicale des Armées, IHU-Méditerranée Infection, Marseille, France
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
- Centre National de Référence du Paludisme, Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Marseille, France
| | - Leonardo Basco
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Ali Ould Mohamed Salem Boukhary
- Unité de recherche Génomes et Milieux, Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouveau Campus Universitaire, Nouakchott, Mauritania
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- * E-mail:
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Mayence A, Vanden Eynde JJ. Tafenoquine: A 2018 Novel FDA-Approved Prodrug for the Radical Cure of Plasmodium vivax Malaria and Prophylaxis of Malaria. Pharmaceuticals (Basel) 2019; 12:ph12030115. [PMID: 31366060 PMCID: PMC6789594 DOI: 10.3390/ph12030115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 07/25/2019] [Accepted: 07/27/2019] [Indexed: 12/18/2022] Open
Abstract
Tafenoquine (an 8-aminoquinoline) was approved by the Food and Drug Administration (FDA) in 2018 for the radical cure of Plasmodium vivax malaria and preventive action against malaria. Despite the fact that the mechanism of action of the drug remains unclear, all studies indicated that a metabolite is responsible for its efficacy. Routes for the preparation of the drug are described.
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Affiliation(s)
- Annie Mayence
- Haute Ecole Provinciale de Hainaut-Condorcet, 7330 Saint-Ghislain, Belgium
| | - Jean Jacques Vanden Eynde
- Formerly head of the Department of Organic Chemistry (FS), University of Mons-UMONS, 7000 Mons, Belgium.
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Chu CS, Freedman DO. Tafenoquine and G6PD: a primer for clinicians. J Travel Med 2019; 26:taz023. [PMID: 30941413 PMCID: PMC6542331 DOI: 10.1093/jtm/taz023] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND Tafenoquine, an 8-aminoquinoline, is now indicated for causal prophylaxis against all human malarias and as radical curative (anti-relapse) treatment against Plasmodium vivax and Plasmodium ovale. As with other 8-aminoquinolines, tafenoquine causes hemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency (hemizygous males and homozygous females) and is contraindicated in this population. Those with intermediate G6PD activity (heterozygous females) are also at risk for hemolysis. Awareness of how to prescribe tafenoquine in relation to G6PD status is needed so it can be used safely. METHODS A standard literature search was performed on varying combinations of the terms tafenoquine, Arakoda, Kodatef, Krintafel, Kozenis, primaquine, G6PD deficiency, malaria prophylaxis and radical cure. The data were gathered and interpreted to review how tafenoquine should be prescribed in consideration of the G6PD status of an individual and traveller. RESULTS Tafenoquine should only be given to those with G6PD activity >70% of the local population median. Qualitative G6PD tests are sufficient for diagnosing G6PD deficiency in males. However, in females quantitative G6PD testing is necessary to differentiate deficient, intermediate and normal G6PD statuses. Testing for G6PD deficiency is mandatory before tafenoquine prescription. Measures can be taken to avoid tafenoquine administration to ineligible individuals (i.e. due to G6PD status, age, pregnancy and lactation). Primaquine is still necessary for some of these cases. This review provides actions that can be taken to diagnose and manage hemolysis when tafenoquine is given inadvertently to ineligible individuals. CONCLUSION Attention to G6PD status is required for safe prescription of tafenoquine. A high index of suspicion is needed if hemolysis occurs. Clinicians should seek evidence-based information for the management and treatment of iatrogenicy hemolysis caused by 8-aminoquinolines.
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Affiliation(s)
- Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol–Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - David O Freedman
- William C. Gorgas Center for Geographic Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, USA
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40
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Yahiya S, Rueda-Zubiaurre A, Delves MJ, Fuchter MJ, Baum J. The antimalarial screening landscape-looking beyond the asexual blood stage. Curr Opin Chem Biol 2019; 50:1-9. [PMID: 30875617 PMCID: PMC6591700 DOI: 10.1016/j.cbpa.2019.01.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 12/20/2022]
Abstract
In recent years, the research agenda to tackle global morbidity and mortality from malaria disease has shifted towards innovation, in the hope that efforts at the frontiers of scientific research may re-invigorate gains made towards eradication. Discovery of new antimalarial drugs with novel chemotypes or modes of action lie at the heart of these efforts. There is a particular interest in drug candidates that target stages of the malaria parasite lifecycle beyond the symptomatic asexual blood stages. This is especially important given the spectre of emerging drug resistance to all current frontline antimalarials. One approach gaining increased interest is the potential of designing novel drugs that target parasite passage from infected individual to feeding mosquito and back again. Action of such therapeutics is geared much more at the population level rather than just concerned with the infected individual. The search for novel drugs active against these stages has been helped by improvements to in vitro culture of transmission and pre-erythrocytic parasite lifecycle stages, robotic automation and high content imaging, methodologies that permit the high-throughput screening (HTS) of compound libraries for drug discovery. Here, we review recent advances in the antimalarial screening landscape, focussed on transmission blocking as a key aim for drug-treatment campaigns of the future.
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Affiliation(s)
- Sabrina Yahiya
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Ainoa Rueda-Zubiaurre
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Michael J Delves
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Matthew J Fuchter
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK.
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41
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Hounkpatin AB, Kreidenweiss A, Held J. Clinical utility of tafenoquine in the prevention of relapse of Plasmodium vivax malaria: a review on the mode of action and emerging trial data. Infect Drug Resist 2019; 12:553-570. [PMID: 30881061 PMCID: PMC6411314 DOI: 10.2147/idr.s151031] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Tafenoquine is an 8-aminoquinoline with activity against all human life cycle stages of Plasmodium vivax, including dormant liver stages – so called hypnozoites. Its long half-life of ~15 days is allowing for a single exposure regimen. It has been under development since 1980 and received approval by the US Food and Drug Administration in summer 2018 as an anti-relapse drug for P. vivax malaria in patients aged 16 years and older and for prophylaxis of malaria caused by any Plasmodium species in adults. Prior to tafenoquine administration, glucose-6-phosphate dehydrogenase (G6PD) deficiency needs to be excluded by testing. Individuals with a deficient G6PD activity are at risk of tafenoquine-induced hemolysis – as is the case for primaquine, the mainstay drug for P. vivax radical cure. A wealth of clinical studies have been conducted and are still ongoing to assess the safety, tolerability, and efficacy of tafenoquine. This review focuses on data emerging from the latest clinical trials on P. vivax radical cure with tafenoquine, the key studies for regulatory approval of tafenoquine, and elucidates the latest hypothesis on the mode of action.
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Affiliation(s)
- Aurore B Hounkpatin
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany, .,German Centre for Infection Research, Partner Site Tübingen, Tübingen, Germany, .,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon,
| | - Andrea Kreidenweiss
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany, .,German Centre for Infection Research, Partner Site Tübingen, Tübingen, Germany,
| | - Jana Held
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany, .,German Centre for Infection Research, Partner Site Tübingen, Tübingen, Germany, .,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon,
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42
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Beiter KJ, Wentlent ZJ, Hamouda AR, Thomas BN. Nonconventional opponents: a review of malaria and leishmaniasis among United States Armed Forces. PeerJ 2019; 7:e6313. [PMID: 30701136 PMCID: PMC6348955 DOI: 10.7717/peerj.6313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/19/2018] [Indexed: 01/10/2023] Open
Abstract
As the United States military engage with different countries and cultures throughout the world, personnel become exposed to new biospheres as well. There are many infectious pathogens that are not endemic to the US, but two of particular importance are Plasmodium and Leishmania, which respectively cause malaria and leishmaniasis. These parasites are both known to cause significant disease burden in their endemic locales, and thus pose a threat to military travelers. This review introduces readers to basic life cycle and disease mechanisms for each. Local and military epidemiology are described, as are the specific actions taken by the US military for prevention and treatment purposes. Complications of such measures with regard to human health are also discussed, including possible chemical toxicities. Additionally, poor recognition of these diseases upon an individual's return leading to complications and treatment delays in the United States are examined. Information about canine leishmaniasis, poorly studied relative to its human manifestation, but of importance due to the utilization of dogs in military endeavors is presented. Future implications for the American healthcare system regarding malaria and leishmaniasis are also presented.
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Affiliation(s)
- Kaylin J Beiter
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States of America
| | - Zachariah J Wentlent
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States of America
| | - Adrian R Hamouda
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States of America
| | - Bolaji N Thomas
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States of America
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43
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Linares M, Postigo M, Cuadrado D, Ortiz-Ruiz A, Gil-Casanova S, Vladimirov A, García-Villena J, Nuñez-Escobedo JM, Martínez-López J, Rubio JM, Ledesma-Carbayo MJ, Santos A, Bassat Q, Luengo-Oroz M. Collaborative intelligence and gamification for on-line malaria species differentiation. Malar J 2019; 18:21. [PMID: 30678733 PMCID: PMC6345056 DOI: 10.1186/s12936-019-2662-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/19/2019] [Indexed: 11/28/2022] Open
Abstract
Background Current World Health Organization recommendations for the management of malaria include the need for a parasitological confirmation prior to triggering appropriate treatment. The use of rapid diagnostic tests (RDTs) for malaria has contributed to a better infection recognition and a more targeted treatment. Nevertheless, low-density infections and parasites that fail to produce HRP2 can cause false-negative RDT results. Microscopy has traditionally been the methodology most commonly used to quantify malaria and characterize the infecting species, but the wider use of this technique remains challenging, as it requires trained personnel and processing capacity. Objective In this study, the feasibility of an on-line system for remote malaria species identification and differentiation has been investigated by crowdsourcing the analysis of digitalized infected thin blood smears by non-expert observers using a mobile app. Methods An on-line videogame in which players learned how to differentiate the young trophozoite stage of the five Plasmodium species has been designed. Images were digitalized with a smartphone camera adapted to the ocular of a conventional light microscope. Images from infected red blood cells were cropped and puzzled into an on-line game. During the game, players had to decide the malaria species (Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, Plasmodium ovale, Plasmodium knowlesi) of the infected cells that were shown in the screen. After 2 months, each player’s decisions were analysed individually and collectively. Results On-line volunteers playing the game made more than 500,000 assessments for species differentiation. Statistically, when the choice of several players was combined (n > 25), they were able to significantly discriminate Plasmodium species, reaching a level of accuracy of 99% for all species combinations, except for P. knowlesi (80%). Non-expert decisions on which Plasmodium species was shown in the screen were made in less than 3 s. Conclusion These findings show that it is possible to train malaria-naïve non-experts to identify and differentiate malaria species in digitalized thin blood samples. Although the accuracy of a single player is not perfect, the combination of the responses of multiple casual gamers can achieve an accuracy that is within the range of the diagnostic accuracy made by a trained microscopist. Electronic supplementary material The online version of this article (10.1186/s12936-019-2662-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- María Linares
- Research Institute Hospital 12 de Octubre/CNIO, Universidad Complutense de Madrid, Ciudad Universitaria, 28040, Madrid, Spain.
| | - María Postigo
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - Daniel Cuadrado
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - Alejandra Ortiz-Ruiz
- Research Institute Hospital 12 de Octubre/CNIO, Universidad Complutense de Madrid, Ciudad Universitaria, 28040, Madrid, Spain
| | - Sara Gil-Casanova
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - Alexander Vladimirov
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - Jaime García-Villena
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - José María Nuñez-Escobedo
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain
| | - Joaquín Martínez-López
- Research Institute Hospital 12 de Octubre/CNIO, Universidad Complutense de Madrid, Ciudad Universitaria, 28040, Madrid, Spain
| | - José Miguel Rubio
- Malaria and Emerging Parasitic Diseases Laboratory, National Microbiology Centre, Instituto de Salud Carlos III, Madrid, Spain
| | - María Jesús Ledesma-Carbayo
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain
| | - Andrés Santos
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain
| | - Quique Bassat
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Miguel Luengo-Oroz
- Biomedical Image Technologies Group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain. .,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain.
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44
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Bancone G, Menard D, Khim N, Kim S, Canier L, Nguong C, Phommasone K, Mayxay M, Dittrich S, Vongsouvath M, Fievet N, Le Hesran JY, Briand V, Keomany S, Newton PN, Gorsawun G, Tardy K, Chu CS, Rattanapalroj O, Dong LT, Quang HH, Tam-Uyen N, Thuy-Nhien N, Hien TT, Kalnoky M, Nosten F. Molecular characterization and mapping of glucose-6-phosphate dehydrogenase (G6PD) mutations in the Greater Mekong Subregion. Malar J 2019; 18:20. [PMID: 30674319 PMCID: PMC6343352 DOI: 10.1186/s12936-019-2652-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/16/2019] [Indexed: 12/31/2022] Open
Abstract
Background Plasmodium vivax malaria elimination can only be achieved by the deployment of 8-aminoquinolines (primaquine and tafenoquine) in combination with ACT to kill both blood and liver-stage parasites. However, primaquine and the other 8-aminoquinolines cause dose-dependent haemolysis in subjects with G6PD deficiency, an X-linked disorder of red blood cells that is very common in populations living in tropical and subtropical areas. In order to inform safer use of 8-aminoquinolines in the Greater Mekong Subregion, a multi-centre study was carried out to assess the prevalence of G6PD deficiency and to identify the main G6PD variants in samples collected in Cambodia, Lao PDR, Myanmar, Thailand and Vietnam. Methods Blood samples were collected in the five countries during National Malaria Surveys or during Population Surveys. During Population Surveys samples were characterized for G6PD phenotype using the Fluorescent Spot Test. Samples were then genotyped for a panel of G6PD mutations. Results G6PD deficiency was found to be common in the region with an overall mean prevalence of deficient or mutated hemizygous males of 14.0%, ranging from a mean 7.3% in Thailand, 8.1% in Lao PDR, 8.9% in Vietnam, 15.8% in Myanmar and 18.8% in Cambodia. Mahidol and Viangchan mutations were the most common and widespread variants found among the nine investigated. Conclusions Owing to the high prevalence of G6PD deficiency in the Greater Mekong Subregion, strategies for vivax malaria elimination should include point-of-care G6PD testing (both qualitative and quantitative) to allow safe and wide treatment with 8-aminoquinolines. Electronic supplementary material The online version of this article (10.1186/s12936-019-2652-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Germana Bancone
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand. .,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Didier Menard
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia.,Malaria Genetics and Resistance Group, Institut Pasteur, Paris, France
| | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Lydie Canier
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Chea Nguong
- National Centre for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Koukeo Phommasone
- Microbiology Laboratory, Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic
| | - Mayfong Mayxay
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Microbiology Laboratory, Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic.,Institute of Research and Education Development, University of Health Sciences, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Sabine Dittrich
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Microbiology Laboratory, Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic.,Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Malavanh Vongsouvath
- Microbiology Laboratory, Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic
| | - Nadine Fievet
- UMR216-MERIT, French National Research Institute for Sustainable Development (IRD), Paris-5 University, Sorbonne Paris Cité, Paris, France
| | - Jean-Yves Le Hesran
- UMR216-MERIT, French National Research Institute for Sustainable Development (IRD), Paris-5 University, Sorbonne Paris Cité, Paris, France
| | - Valerie Briand
- UMR216-MERIT, French National Research Institute for Sustainable Development (IRD), Paris-5 University, Sorbonne Paris Cité, Paris, France
| | - Sommay Keomany
- Salavan Provincial Hospital, Salavan, Lao People's Democratic Republic
| | - Paul N Newton
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Microbiology Laboratory, Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Vientiane, Lao People's Democratic Republic
| | - Gornpan Gorsawun
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Kaelan Tardy
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Le Thanh Dong
- Institute of Malariology, Parasitology and Entomology - Ho Chi Minh City (IMPE-HCM), Ho Chi Minh City, Vietnam
| | - Huynh Hong Quang
- Institute of Malariology, Parasitology and Entomology - Quy Nhon (IMPE-QN), Quy Nhon, Vietnam
| | - Nguyen Tam-Uyen
- Oxford University Clinical Research Unit, Wellcome Trust Asia Program, in partnership with Hospital For Tropical Diseases (HTD), Ho Chi Minh City, Vietnam
| | - Nguyen Thuy-Nhien
- Oxford University Clinical Research Unit, Wellcome Trust Asia Program, in partnership with Hospital For Tropical Diseases (HTD), Ho Chi Minh City, Vietnam
| | - Tran Tinh Hien
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Oxford University Clinical Research Unit, Wellcome Trust Asia Program, in partnership with Hospital For Tropical Diseases (HTD), Ho Chi Minh City, Vietnam
| | | | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Grignard L, Mair C, Curry J, Mahey L, Bastiaens GJH, Tiono AB, Okebe J, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Lanke KHW, Sirima SB, d'Alessandro U, Clark TG, Campino S, Bousema T, Drakeley C. Bead-based assays to simultaneously detect multiple human inherited blood disorders associated with malaria. Malar J 2019; 18:14. [PMID: 30665411 PMCID: PMC6341711 DOI: 10.1186/s12936-019-2648-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/12/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Glucose-6-phosphate dehydrogenase deficiency (G6PDd), haemoglobin C (HbC) and S (HbS) are inherited blood disorders (IBD) common in populations in malaria endemic areas. All are associated to some degree with protection against clinical malaria whilst additionally G6PDd is associated with haemolysis following treatment with 8-aminoquinolines. Measuring the prevalence of these inherited blood disorders in affected populations can improve understanding of disease epidemiology. Current methodologies in epidemiological studies commonly rely on individual target amplification and visualization; here a method is presented to simultaneously detect the polymorphisms and that can be expanded to include other single nucleotide polymorphisms (SNPs) of interest. METHODS Human DNA from whole blood samples was amplified in a novel, multiplex PCR reaction and extended with SNP-specific probes in an allele specific primer extension (ASPE) to simultaneously detect four epidemiologically important human markers including G6PD SNPs (G202A and A376G) and common haemoglobin mutations (HbS and HbC). The products were hybridized to magnetic beads and the median fluorescence intensity (MFI) was read on MAGPIX® (Luminex corp.). Genotyping data was compared to phenotypical data generated by flow cytometry and to established genotyping methods. RESULTS Seventy-five samples from Burkina Faso (n = 75/78, 96.2%) and 58 samples from The Gambia (n = 58/61, 95.1%) had a G6PD and a HBB genotype successfully assigned by the bead-based assay. Flow cytometry data available for n = 61 samples further supported the concordance between % G6PD normal/deficient cells and genotype. CONCLUSIONS The bead based assay compares well to alternative measures of genotyping and phenotyping for G6PD. The screening is high throughput, adaptable to inclusion of multiple targets of interest and easily standardized.
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Affiliation(s)
- Lynn Grignard
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
| | - Catherine Mair
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | | | | | - Guide J H Bastiaens
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Sam A Coulibaly
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Muna Affara
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Edith C Bougouma
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Guillaume S Sanou
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Kjerstin H W Lanke
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Sodiomon B Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Umberto d'Alessandro
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Taane G Clark
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Susana Campino
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
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Spectrophotometry assays to determine G6PD activity from Trinity Biotech and Pointe Scientific G6PD show good correlation. BMC Res Notes 2018; 11:855. [PMID: 30514365 PMCID: PMC6278131 DOI: 10.1186/s13104-018-3964-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 11/29/2018] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVES Spectrophotometry kits from Pointe Scientific (PS; USA) were compared to kits from Trinity Biotech (Trinity; Ireland) in 50 venous blood samples from purposively selected individuals in Bangladesh. Repeatability and inter-assay variability were assessed by Students t-test, Bland-Altman plot and Pearson correlation coefficient (r). The median glucose-6-phosphate dehydrogenase (G6PD) activity of all G6PD normal participants was calculated per assay and defined as 100% activity. Performance was calculated considering 30% and 70% cut off activities and Trinity as reference. RESULTS The intra-assay correlation of Trinity (r = 0.9841, p < 0.001) and PS (r = 0.9833, p < 0.001) did not differ significantly (p = 0.904). Both assays were closely correlated (r = 0.9799, p < 0.001), with a mean difference of 0.1 U/gHb (95% limit of agreement: - 1.32 to 1.57). At 30% cut off PS had a sensitivity of 100% (95% confidence interval (95 CI) 59.0-100.0) and specificity of 100% (95% CI 91.8 to 100.0), at 70% cut-off of 100% (95% CI 79.4-100.0) and 97.1% (95% CI 84.7-99.9) respectively. The G6PD assay from PS is a reliable alternative to the assay from Trinity.
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Bourke BP, Conn JE, de Oliveira TMP, Chaves LSM, Bergo ES, Laporta GZ, Sallum MAM. Exploring malaria vector diversity on the Amazon Frontier. Malar J 2018; 17:342. [PMID: 30261932 PMCID: PMC6161421 DOI: 10.1186/s12936-018-2483-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 09/10/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Deforestation in the Amazon and the social vulnerability of its settler communities has been associated with increased malaria incidence. The feeding biology of the most important malaria vectors in the region, notably Nyssorhynchus darlingi, compounds efforts to control vectors and reduce transmission of what has become known as "Frontier Malaria". Exploring Anophelinae mosquito diversity is fundamental to understanding the species responsible for transmission and developing appropriate management and intervention strategies for malaria control in the Amazon River basin. METHODS This study describes Anophelinae mosquito diversity from settler communities affected by Frontier Malaria in the states of Acre, Amazonas and Rondônia by analysing COI gene data using cluster and tree-based species delimitation approaches. RESULTS In total, 270 specimens from collection sites were sequenced and these were combined with 151 reference (GenBank) sequences in the analysis to assist in species identification. Conservative estimates found that the number of species collected at these sites was between 23 (mPTP partition) and 27 (strict ABGD partition) species, up to 13 of which appeared to be new. Nyssorhynchus triannulatus and Nyssorhynchus braziliensis displayed exceptional levels of intraspecific genetic diversity but there was little to no support for putative species complex status. CONCLUSIONS This study demonstrates that Anophelinae mosquito diversity continues to be underestimated in poorly sampled areas where frontier malaria is a major public health concern. The findings will help shape future studies of vector incrimination and transmission dynamics in these areas and support efforts to develop more effective vector control and transmission reduction strategies in settler communities in the Amazon River basin.
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Affiliation(s)
- Brian P Bourke
- Department of Epidemiology, Faculty of Public Health, University of São Paulo, São Paulo, SP, Brazil.
| | - Jan E Conn
- Wadsworth Center, New York State Department of Health, Slingerlands, NY, 12159, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Albany, NY, 12222, USA
| | - Tatiane M P de Oliveira
- Department of Epidemiology, Faculty of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | - Leonardo S M Chaves
- Department of Epidemiology, Faculty of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | - Eduardo S Bergo
- Superintendência de Controle de Endemias, Secretaria de Estado da Saúde de São Paulo, Araraquara, SP, Brazil
| | - Gabriel Z Laporta
- Setor de Pós-graduação, Pesquisa e Inovação, Faculdade de Medicina do ABC, Santo André, SP, Brazil
| | - Maria A M Sallum
- Department of Epidemiology, Faculty of Public Health, University of São Paulo, São Paulo, SP, Brazil
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Mathews ES, Odom John AR. Tackling resistance: emerging antimalarials and new parasite targets in the era of elimination. F1000Res 2018; 7. [PMID: 30135714 PMCID: PMC6073090 DOI: 10.12688/f1000research.14874.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2018] [Indexed: 12/27/2022] Open
Abstract
Malaria remains a significant contributor to global human mortality, and roughly half the world’s population is at risk for infection with
Plasmodium spp. parasites. Aggressive control measures have reduced the global prevalence of malaria significantly over the past decade. However, resistance to available antimalarials continues to spread, including resistance to the widely used artemisinin-based combination therapies. Novel antimalarial compounds and therapeutic targets are greatly needed. This review will briefly discuss several promising current antimalarial development projects, including artefenomel, ferroquine, cipargamin, SJ733, KAF156, MMV048, and tafenoquine. In addition, we describe recent large-scale genetic and resistance screens that have been instrumental in target discovery. Finally, we highlight new antimalarial targets, which include essential transporters and proteases. These emerging antimalarial compounds and therapeutic targets have the potential to overcome multi-drug resistance in ongoing efforts toward malaria elimination.
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Affiliation(s)
- Emily S Mathews
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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