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Rosenthal PJ, Asua V, Bailey JA, Conrad MD, Ishengoma DS, Kamya MR, Rasmussen C, Tadesse FG, Uwimana A, Fidock DA. The emergence of artemisinin partial resistance in Africa: how do we respond? THE LANCET. INFECTIOUS DISEASES 2024:S1473-3099(24)00141-5. [PMID: 38552654 DOI: 10.1016/s1473-3099(24)00141-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 04/21/2024]
Abstract
Malaria remains one of the most important infectious diseases in the world, with the greatest burden in sub-Saharan Africa, primarily from Plasmodium falciparum infection. The treatment and control of malaria is challenged by resistance to most available drugs, but partial resistance to artemisinins (ART-R), the most important class for the treatment of malaria, was until recently confined to southeast Asia. This situation has changed, with the emergence of ART-R in multiple countries in eastern Africa. ART-R is mediated primarily by single point mutations in the P falciparum kelch13 protein, with several mutations present in African parasites that are now validated resistance mediators based on clinical and laboratory criteria. Major priorities at present are the expansion of genomic surveillance for ART-R mutations across the continent, more frequent testing of the efficacies of artemisinin-based regimens against uncomplicated and severe malaria in trials, more regular assessment of ex-vivo antimalarial drug susceptibilities, consideration of changes in treatment policy to deter the spread of ART-R, and accelerated development of new antimalarial regimens to overcome the impacts of ART-R. The emergence of ART-R in Africa is an urgent concern, and it is essential that we increase efforts to characterise its spread and mitigate its impact.
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Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, USA.
| | - Victor Asua
- Infectious Diseases Research Collaboration, Kampala, Uganda; University of Tübingen, Tübingen, Germany
| | - Jeffrey A Bailey
- Center for Computational Molecular Biology, Brown University, Providence, RI, USA; Departments of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Melissa D Conrad
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania; Department of Biochemistry, Kampala International University in Tanzania, Dar es Salaam, Tanzania; School of Public Health, Harvard University, Boston, MA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda; Department of Medicine, Makerere University, Kampala, Uganda
| | | | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia; London School of Hygiene and Tropical Medicine, London, UK
| | - Aline Uwimana
- Rwanda Biomedical Center, Kigali, Rwanda; Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - David A Fidock
- Department of Microbiology and Immunology and Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
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2
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Werling K, Itoe MA, Shaw WR, Hien RD, Bazié BJ, Aminata F, Adams KL, Ouattara BS, Sanou M, Peng D, Dabiré RK, Da DF, Yerbanga RS, Diabaté A, Lefèvre T, Catteruccia F. Development of circulating isolates of Plasmodium falciparum is accelerated in Anopheles vectors with reduced reproductive output. PLoS Negl Trop Dis 2024; 18:e0011890. [PMID: 38206958 PMCID: PMC10807765 DOI: 10.1371/journal.pntd.0011890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/24/2024] [Accepted: 12/28/2023] [Indexed: 01/13/2024] Open
Abstract
Anopheles gambiae and its sibling species Anopheles coluzzii are the most efficient vectors of the malaria parasite Plasmodium falciparum. When females of these species feed on an infected human host, oogenesis and parasite development proceed concurrently, but interactions between these processes are not fully understood. Using multiple natural P. falciparum isolates from Burkina Faso, we show that in both vectors, impairing steroid hormone signaling to disrupt oogenesis leads to accelerated oocyst growth and in a manner that appears to depend on both parasite and mosquito genotype. Consistently, we find that egg numbers are negatively linked to oocyst size, a metric for the rate of oocyst development. Oocyst growth rates are also strongly accelerated in females that are in a pre-gravid state, i.e. that fail to develop eggs after an initial blood meal. Overall, these findings advance our understanding of mosquito-parasite interactions that influence P. falciparum development in malaria-endemic regions.
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Affiliation(s)
- Kristine Werling
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Maurice A. Itoe
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - W. Robert Shaw
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | | | - Bali Jean Bazié
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Fofana Aminata
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Kelsey L. Adams
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | | | - Mathias Sanou
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Duo Peng
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Roch K. Dabiré
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Dari F. Da
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | | | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Thierry Lefèvre
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
- MIVEGEC, IRD, CNRS, University of Montpellier, Montpellier, France
| | - Flaminia Catteruccia
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
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Siqueira-Neto JL, Wicht KJ, Chibale K, Burrows JN, Fidock DA, Winzeler EA. Antimalarial drug discovery: progress and approaches. Nat Rev Drug Discov 2023; 22:807-826. [PMID: 37652975 PMCID: PMC10543600 DOI: 10.1038/s41573-023-00772-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2023] [Indexed: 09/02/2023]
Abstract
Recent antimalarial drug discovery has been a race to produce new medicines that overcome emerging drug resistance, whilst considering safety and improving dosing convenience. Discovery efforts have yielded a variety of new molecules, many with novel modes of action, and the most advanced are in late-stage clinical development. These discoveries have led to a deeper understanding of how antimalarial drugs act, the identification of a new generation of drug targets, and multiple structure-based chemistry initiatives. The limited pool of funding means it is vital to prioritize new drug candidates. They should exhibit high potency, a low propensity for resistance, a pharmacokinetic profile that favours infrequent dosing, low cost, preclinical results that demonstrate safety and tolerability in women and infants, and preferably the ability to block Plasmodium transmission to Anopheles mosquito vectors. In this Review, we describe the approaches that have been successful, progress in preclinical and clinical development, and existing challenges. We illustrate how antimalarial drug discovery can serve as a model for drug discovery in diseases of poverty.
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Affiliation(s)
| | - Kathryn J Wicht
- Holistic Drug Discovery and Development (H3D) Centre, University of Cape Town, Rondebosch, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, South Africa
| | - Kelly Chibale
- Holistic Drug Discovery and Development (H3D) Centre, University of Cape Town, Rondebosch, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, South Africa
| | | | - David A Fidock
- Department of Microbiology and Immunology and Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
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Namayanja C, Eregu EEI, Ongodia P, Okalebo CB, Okiror W, Okello F, Okibure A, Paasi G, Kakungulu H, Grace A, Muhindo R, Banks D, Martin C, Taylor-Robinson S, Olupot-Olupot P. Unusual clinical spectra of childhood severe malaria during malaria epidemic in eastern Uganda: a prospective study. Malar J 2023; 22:169. [PMID: 37259110 DOI: 10.1186/s12936-023-04586-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND In sub-Saharan Africa (SSA), malaria remains a public health problem despite recent reports of declining incidence. Severe malaria is a multiorgan disease with wide-ranging clinical spectra and outcomes that have been reported to vary by age, geographical location, transmission intensity over time. There are reports of recent malaria epidemics or resurgences, but few data, if any, focus on the clinical spectrum of severe malaria during epidemics. This describes the clinical spectrum and outcomes of childhood severe malaria during the disease epidemic in Eastern Uganda. METHODS This prospective cohort study from October 1, 2021, to September 7, 2022, was nested within the 'Malaria Epidemiological, Pathophysiological and Intervention studies in Highly Endemic Eastern Uganda' (TMA2016SF-1514-MEPIE Study) at Mbale Regional Referral Hospital, Uganda. Children aged 60 days to 12 years who at admission tested positive for malaria and fulfilled the clinical WHO criteria for surveillance of severe malaria were enrolled on the study. Follow-up was performed until day 28. Data were collected using a customized proforma on social demographic characteristics, clinical presentation, treatment, and outcomes. Laboratory analyses included complete blood counts, malaria RDT (SD BIOLINE Malaria Ag P.f/Pan, Ref. 05FK60-40-1) and blood slide, lactate, glucose, blood gases and electrolytes. In addition, urinalysis using dipsticks (Multistix® 10 SG, SIEMENS, Ref.2300) at the bedside was done. Data were analysed using STATA V15.0. The study had prior ethical approval. RESULTS A total of 300 participants were recruited. The median age was 4.6 years, mean of 57.2 months and IQR of 44.5 months. Many children, 164/300 (54.7%) were under 5 years, and 171/300 (57.0%) were males. The common clinical features were prostration 236/300 (78.7%), jaundice in 205/300 (68.3%), severe malarial anaemia in 158/300 (52.7%), black water fever 158/300 (52.7%) and multiple convulsions 51/300 (17.0%), impaired consciousness 50/300(16.0%), acidosis 41/300(13.7%), respiratory distress 26/300(6.7%) and coma in 18/300(6.0%). Prolonged hospitalization was found in 56/251 (22.3%) and was associated with acidosis, P = 0.041. The overall mortality was 19/300 (6.3%). Day 28 follow-up was achieved in 247/300 (82.3%). CONCLUSION During the malaria epidemic in Eastern Uganda, severe malaria affected much older children and the spectrum had more of prostration, jaundice severe malarial anaemia, black water fever and multiple convulsions with less of earlier reported respiratory distress and cerebral malaria.
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Affiliation(s)
- Cate Namayanja
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda.
- Department of Pediatrics and Child Health, Busitema University Faculty of Health Sciences, Mbale, Uganda.
| | - Egiru Emma Isaiah Eregu
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Pediatrics and Child Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
| | - Paul Ongodia
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
| | - Charles Benard Okalebo
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
| | - William Okiror
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
| | - Francis Okello
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
- Varimetrics Group Limited, Mbale, Uganda
| | | | - George Paasi
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
| | - Hellen Kakungulu
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
- Varimetrics Group Limited, Mbale, Uganda
| | - Abongo Grace
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
| | - Rita Muhindo
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
| | - Duncan Banks
- Busitema University, TORORO, Uganda
- The Open University, Milton Keynes, UK
| | - Chebet Martin
- Department of Pediatrics and Child Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
| | - Simon Taylor-Robinson
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
- Imperial College London, London, UK
| | - Peter Olupot-Olupot
- Mbale Clinical Research Institute, P.O. Box 1966, Mbale, Uganda
- Department of Community and Public Health, Busitema University Faculty of Health Sciences, Mbale, Uganda
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Chilot D, Mondelaers A, Alem AZ, Asres MS, Yimer MA, Toni AT, Ayele TA. Pooled prevalence and risk factors of malaria among children aged 6-59 months in 13 sub-Saharan African countries: A multilevel analysis using recent malaria indicator surveys. PLoS One 2023; 18:e0285265. [PMID: 37256889 DOI: 10.1371/journal.pone.0285265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 04/19/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND Every 75 seconds, a child under five dies of malaria. Mainly children, aged between six months and five years, are at the highest risk for malaria. These children lost maternal immunity and did not yet developed specific immunity to the infection. Under the age of five, children bear the highest burden of malaria in Sub-Saharan Africa (SSA). Many individual and community level factors could contribute to malaria prevalence remaining high among under-five children in the region. Thus, this study aimed to assess the pooled prevalence of malaria among children aged 6-59 months and identify potential factors associated with malaria by using recent Malaria Indicator Surveys in 13 SSA countries. METHODS Data for this study were drawn from recent 13 Sub-Saharan African countries Malaria Indicator Surveys (MIS). A total weighted sample of 60,541 children aged 6-59 months was included. STATA version 14.2 was used to clean, code and analyze the data. Multilevel logistic regression was employed to identify factors associated with malaria. Adjusted odds ratio with 95% CI and a P value <0.05 was reported to indicate statistical association. Model fitness and comparison were done using Inter cluster correlation coefficient, Median odds ratio, proportional change in variance, and deviance. RESULTS The pooled prevalence of malaria among children aged 6-59 months was found to be 27.41% (95% CI: 17.94%-36.88%). It ranges from 5.04% in Senegal to 62.57% in Sierra Leone. Aged 36-47 months (AOR = 3.54, 95% CI 3.21-3.91), and 48-59 months (AOR = 4.32, 95% CI 3.91-4.77), mothers attended primary education (AOR = 0.78, 95% CI 0.73-0.84), richer (AOR = 0.35, 95% CI 0.32-0.39), and richest household (AOR = 0.16, 95% CI 0.14-0.19), number of three and more under-five children (AOR = 1.35, 95% CI 1.26-1.45), improved floor material (AOR = 0.65, 95% CI 0.57-0.73), improved wall material (AOR = 0.73, 95% CI 0.64-0.84), improved roof material (AOR = 0.70, 95% CI 0.51-0.93), insecticide-treated bed net (ITN) use (0.56, 95% CI 0.51-0.62), not anemic (AOR = 0.05, 95% CI 0.04-0.06), rural resident (AOR = 2.16, 95% CI 2.06-2.27), high community ITN use (AOR = 0.40, 95% CI 0.24-0.63) and high community poverty (AOR = 2.66, 95% CI 2.53-2.84) were strongly associated with malaria. CONCLUSIONS AND RECOMMENDATIONS Almost 3 out of 10 children were infected by malaria in 13 SSA countries. Malaria infection remains one of the main killers of children aged 6-59 months in the SSA. This study revealed that older under-five children living in large families with low incomes in rural areas are most vulnerable to malaria infection. Our results clearly indicate that ITN utilization and improved housing are promising means to effectively prevent malaria infection among children aged 6-59 months. It is therefore important to note that households with low wealth quintiles and rural residents should be prioritized in any mass distribution of ITNs. This has to be accompanied by education using mass media to enhance community awareness.
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Affiliation(s)
- Dagmawi Chilot
- Department of Human Physiology, University of Gondar, College of Medicine and Health Science, School of Medicine, Gondar, Ethiopia
| | - Annelies Mondelaers
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Adugnaw Zeleke Alem
- Department of Epidemiology & Biostatistics, Institute of Public Health, University of Gondar, College of Medicine and Health Science, Gondar, Ethiopia
| | - Mezgebu Selamsew Asres
- Department of Internal Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Mulugeta Ayalew Yimer
- Department of Pediatrics and Child Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Alemayehu Teklu Toni
- Department of Pediatrics and Child Health, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Tadesse Awoke Ayele
- Department of Epidemiology & Biostatistics, Institute of Public Health, University of Gondar, College of Medicine and Health Science, Gondar, Ethiopia
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Kamiya T, Paton DG, Catteruccia F, Reece SE. Targeting malaria parasites inside mosquitoes: ecoevolutionary consequences. Trends Parasitol 2022; 38:1031-1040. [PMID: 36209032 PMCID: PMC9815470 DOI: 10.1016/j.pt.2022.09.004] [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: 07/12/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 11/05/2022]
Abstract
Proof-of-concept studies demonstrate that antimalarial drugs designed for human treatment can also be applied to mosquitoes to interrupt malaria transmission. Deploying a new control tool is ideally undertaken within a stewardship programme that maximises a drug's lifespan by minimising the risk of resistance evolution and slowing its spread once emerged. We ask: what are the epidemiological and evolutionary consequences of targeting parasites within mosquitoes? Our synthesis argues that targeting parasites inside mosquitoes (i) can be modelled by readily expanding existing epidemiological frameworks; (ii) provides a functionally novel control method that has potential to be more robust to resistance evolution than targeting parasites in humans; and (iii) could extend the lifespan and clinical benefit of antimalarials used exclusively to treat humans.
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Affiliation(s)
- Tsukushi Kamiya
- Centre for Interdisciplinary Research in Biology, Collège de France, Paris, France; HRB Clinical Research Facility, National University of Ireland, Galway, Ireland; Institute of Ecology and Evolution, and Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
| | - Douglas G Paton
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Flaminia Catteruccia
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA; Howard Hughes Medical Institute, Boston, MA, USA
| | - Sarah E Reece
- Institute of Ecology and Evolution, and Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
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Epigenetic and Epitranscriptomic Gene Regulation in Plasmodium falciparum and How We Can Use It against Malaria. Genes (Basel) 2022; 13:genes13101734. [PMID: 36292619 PMCID: PMC9601349 DOI: 10.3390/genes13101734] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/15/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
Malaria, caused by Plasmodium parasites, is still one of the biggest global health challenges. P. falciparum is the deadliest species to humans. In this review, we discuss how this parasite develops and adapts to the complex and heterogenous environments of its two hosts thanks to varied chromatin-associated and epigenetic mechanisms. First, one small family of transcription factors, the ApiAP2 proteins, functions as master regulators of spatio-temporal patterns of gene expression through the parasite life cycle. In addition, chromatin plasticity determines variable parasite cell phenotypes that link to parasite growth, virulence and transmission, enabling parasite adaptation within host conditions. In recent years, epitranscriptomics is emerging as a new regulatory layer of gene expression. We present evidence of the variety of tRNA and mRNA modifications that are being characterized in Plasmodium spp., and the dynamic changes in their abundance during parasite development and cell fate. We end up outlining that new biological systems, like the mosquito model, to decipher the unknowns about epigenetic mechanisms in vivo; and novel methodologies, to study the function of RNA modifications; are needed to discover the Achilles heel of the parasite. With this new knowledge, future strategies manipulating the epigenetics and epitranscriptomic machinery of the parasite have the potential of providing new weapons against malaria.
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