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Anstey NM, Tham WH, Shanks GD, Poespoprodjo JR, Russell BM, Kho S. The biology and pathogenesis of vivax malaria. Trends Parasitol 2024; 40:573-590. [PMID: 38749866 DOI: 10.1016/j.pt.2024.04.015] [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: 03/20/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 07/06/2024]
Abstract
Plasmodium vivax contributes significantly to global malaria morbidity. Key advances include the discovery of pathways facilitating invasion by P. vivax merozoites of nascent reticulocytes, crucial for vaccine development. Humanized mouse models and hepatocyte culture systems have enhanced understanding of hypnozoite biology. The spleen has emerged as a major reservoir for asexual vivax parasites, replicating in an endosplenic life cycle, and contributing to recurrent and chronic infections, systemic inflammation, and anemia. Splenic accumulation of uninfected red cells is the predominant cause of anemia. Recurring and chronic infections cause progressive anemia, malnutrition, and death in young children in high-transmission regions. Endothelial activation likely contributes to vivax-associated organ dysfunction. The many recent advances in vivax pathobiology should help guide new approaches to prevention and management.
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Affiliation(s)
- Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia.
| | - Wai-Hong Tham
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia; Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - G Dennis Shanks
- School of Public Health, University of Queensland, Brisbane, Queensland, Australia
| | - Jeanne R Poespoprodjo
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia; Centre for Child Health and Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia; Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Timika, Central Papua, Indonesia; Mimika District Hospital and District Health Authority, Timika, Central Papua, Indonesia
| | - Bruce M Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Steven Kho
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia; Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Timika, Central Papua, Indonesia
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2
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Acharya S, Shrestha M, Thang ND, Wini L, Habib MN, Neukom J, Lhazeen K, Lynch CA, Thriemer K. Optimizing test and treat options for vivax malaria: An options assessment toolkit (OAT) for Asia Pacific national malaria control programs. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002970. [PMID: 38776349 PMCID: PMC11111040 DOI: 10.1371/journal.pgph.0002970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 04/19/2024] [Indexed: 05/24/2024]
Abstract
Designing policy in public health is a complex process requiring decision making that incorporates available evidence and is suitable to a country's epidemiological and health system context. The main objective of this study was to develop an options assessment toolkit (OAT) to provide a pragmatic and evidence-based approach to the development of policies for the radical cure (prevention of relapse) of vivax malaria for national malaria control programs in the Asia-Pacific region. The OAT was developed using participatory research methods and a Delphi process using a sequential multi-phase design, adapted with a pre-development phase, a development phase, and a final development phase. In the pre-development phase, a literature review was conducted to inform the toolkit development. Data collection in the development phase consisted of core research team discussions, multiple rounds of consultation with participants from National Malaria Control Programs (NMP) (online and in person), and two separate modified e-Delphi processes with experts. The final development phase was the piloting of the toolkit during the annual meeting of the Asia Pacific Malaria Elimination Network (APMEN) Vivax Working Group. We developed a tool kit containing the following elements: i) Baseline Assessment Tool (BAT) to assess the readiness of NMPs for new or improved coverage of radical cure, ii) eight scenarios representative of Asia Pacific region, iii) matching test and treat options based on available options for G6PD testing and radical cure for the given scenarios, iv) an approaches tool to allow NMPs to visualize considerations for policy change process and different implementation strategies/approaches for each test and treat option. The OAT can support vivax radical cure policy formulation among NMPs and stakeholders tailoring for their unique country context. Future studies are needed to assess the utility and practicality of using the OAT for specific country context.
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Affiliation(s)
- Sanjaya Acharya
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Manash Shrestha
- Asia Pacific Malaria Elimination Network (APMEN) Vivax Working Group, Singapore, Singapore
- MMV Medicines for Malaria Venture (MMV), Geneva, Switzerland
| | - Ngo Duc Thang
- National Institute of Malariology, Parasitology and Entomology (NIMPE), Ministry of Health, Hanoi, Viet Nam
| | - Lyndes Wini
- National Vector Borne Disease Control Programme, Ministry of Health and Medical Services, Honiara, The Solomon Islands
| | - M. Naeem Habib
- National Malaria Control Program, Ministry of Public Health, Kabul, Afghanistan
| | | | - Karma Lhazeen
- Asia Pacific Malaria Elimination Network (APMEN) Vivax Working Group, Singapore, Singapore
| | - Caroline A. Lynch
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Asia Pacific Malaria Elimination Network (APMEN) Vivax Working Group, Singapore, Singapore
- MMV Medicines for Malaria Venture (MMV), Geneva, Switzerland
| | - Kamala Thriemer
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
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3
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Mehra S, Taylor PG, McCaw JM, Flegg JA. A hybrid transmission model for Plasmodium vivax accounting for superinfection, immunity and the hypnozoite reservoir. J Math Biol 2024; 89:7. [PMID: 38772937 PMCID: PMC11108905 DOI: 10.1007/s00285-024-02088-7] [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: 08/24/2022] [Revised: 10/12/2023] [Accepted: 03/25/2024] [Indexed: 05/23/2024]
Abstract
Malaria is a vector-borne disease that exacts a grave toll in the Global South. The epidemiology of Plasmodium vivax, the most geographically expansive agent of human malaria, is characterised by the accrual of a reservoir of dormant parasites known as hypnozoites. Relapses, arising from hypnozoite activation events, comprise the majority of the blood-stage infection burden, with implications for the acquisition of immunity and the distribution of superinfection. Here, we construct a novel model for the transmission of P. vivax that concurrently accounts for the accrual of the hypnozoite reservoir, (blood-stage) superinfection and the acquisition of immunity. We begin by using an infinite-server queueing network model to characterise the within-host dynamics as a function of mosquito-to-human transmission intensity, extending our previous model to capture a discretised immunity level. To model transmission-blocking and antidisease immunity, we allow for geometric decay in the respective probabilities of successful human-to-mosquito transmission and symptomatic blood-stage infection as a function of this immunity level. Under a hybrid approximation-whereby probabilistic within-host distributions are cast as expected population-level proportions-we couple host and vector dynamics to recover a deterministic compartmental model in line with Ross-Macdonald theory. We then perform a steady-state analysis for this compartmental model, informed by the (analytic) distributions derived at the within-host level. To characterise transient dynamics, we derive a reduced system of integrodifferential equations, likewise informed by our within-host queueing network, allowing us to recover population-level distributions for various quantities of epidemiological interest. In capturing the interplay between hypnozoite accrual, superinfection and acquired immunity-and providing, to the best of our knowledge, the most complete population-level distributions for a range of epidemiological values-our model provides insights into important, but poorly understood, epidemiological features of P. vivax.
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Affiliation(s)
- Somya Mehra
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia.
| | - Peter G Taylor
- 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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Sekine S, Chan CW, Kalkoa M, Yamar S, Iata H, Taleo G, Kc A, Kagaya W, Kido Y, Kaneko A. Tracing the origins of Plasmodium vivax resurgence after malaria elimination on Aneityum Island in Vanuatu. COMMUNICATIONS MEDICINE 2024; 4:91. [PMID: 38762604 PMCID: PMC11102431 DOI: 10.1038/s43856-024-00524-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 05/08/2024] [Indexed: 05/20/2024] Open
Abstract
BACKGROUND Five years after successful malaria elimination, Aneityum Island in Vanuatu experienced an outbreak of Plasmodium vivax of unknown origin in 2002. Epidemiological investigations revealed several potential sources of P. vivax. We aimed to identify the genetic origin of P. vivax responsible for the resurgence. METHODS Five P. vivax microsatellite markers were genotyped using DNA extracted from archived blood samples. A total of 69 samples from four P. vivax populations was included: 29 from the outbreak in 2002, seven from Aneityum in 1999 and 2000, 18 from visitors to Aneityum in 2000, and 15 from nearby Tanna Island in 2002. A neighbour-joining phylogenetic tree was constructed to elucidate the relationships among P. vivax isolates. STRUCTURE and principal component analysis were used to assess patterns of genetic structure. RESULTS Here we show distinct genetic origins of P. vivax during the outbreak on Aneityum. While the origin of most P. vivax lineages found during the outbreak remains unidentified, limited genetic diversity among these lineages is consistent with a rapid expansion from a recent common ancestor. Contemporaneous P. vivax from neighboring Tanna and potential relapse of P. vivax acquired from other islands in 1999 and 2000 are also identified as minor contributors to the outbreak. CONCLUSIONS Multiple reintroductions of P. vivax after elimination highlight the high receptivity and vulnerability to malaria resurgence in island settings of Vanuatu, despite robust surveillance and high community compliance to control measures.
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Affiliation(s)
- Sho Sekine
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
- Department of Medical Technology, Morinomiya University of Medical Sciences, Osaka, Japan
| | - Chim W Chan
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Morris Kalkoa
- National Malaria and other Vector Borne Diseases Control Program (NVBDCP), Ministry of Health, Port Vila, Vanuatu
| | - Sam Yamar
- National Malaria and other Vector Borne Diseases Control Program (NVBDCP), Ministry of Health, Port Vila, Vanuatu
| | - Harry Iata
- National Malaria and other Vector Borne Diseases Control Program (NVBDCP), Ministry of Health, Port Vila, Vanuatu
| | - George Taleo
- National Malaria and other Vector Borne Diseases Control Program (NVBDCP), Ministry of Health, Port Vila, Vanuatu
| | - Achyut Kc
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Wataru Kagaya
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
- Department of Eco-epidemiology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Yasutoshi Kido
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Akira Kaneko
- Department of Virology, Graduate School of Medicine, and Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan.
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
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5
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Manen-Freixa L, Moliner-Cubel S, Gamo FJ, Crespo B, Borrell JI, Teixidó J, Estrada-Tejedor R. Exploring the unexplored chemical space: Rational identification of new Tafenoquine analogs with antimalarial properties. Bioorg Chem 2024; 148:107472. [PMID: 38788364 DOI: 10.1016/j.bioorg.2024.107472] [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: 03/21/2024] [Revised: 05/07/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024]
Abstract
Patents tend to define a huge chemical space described by the combinatorial nature of Markush structures. However, the optimization of new principal active ingredient is frequently driven by a simple Free Wilson approach. This procedure leads to a highly focused study on the chemical space near a hit compound leaving many unexplored regions that may present highly biological active reservoirs. This study aims to demonstrate that this unveiled chemical space can hide compounds with interesting potential biological activity that would be worth pursuing. This underlines the value and necessity of broadening an approach beyond conventional strategies. Hence, we advocate for an alternative methodology that may be more efficient in the early drug discovery stages. We have selected the case of Tafenoquine, a single-dose treatment for the radical cure of P. vivax malaria approved by the FDA in 2018, as an example to illustrate the process. Through the deep exploration of the Tafenoquine chemical space, seven compounds with potential antimalarial activity have been rationally identified and synthesized. This small set is representative of the chemical diversity unexplored by the 58 analogs reported to date. After biological assessment, results evidence that our approach for rational design has proven to be a very efficient exploratory methodology suitable for the early drug discovery stages.
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Affiliation(s)
- Leticia Manen-Freixa
- IQS School of Engineering, Universitat Ramon Llull, Via Augusta, 390, 08017 Barcelona, Spain
| | | | | | - Benigno Crespo
- Global Health Medicines R&D, GSK, Severo Ochoa, 2, 28760 Tres Cantos, Spain
| | - José I Borrell
- IQS School of Engineering, Universitat Ramon Llull, Via Augusta, 390, 08017 Barcelona, Spain
| | - Jordi Teixidó
- IQS School of Engineering, Universitat Ramon Llull, Via Augusta, 390, 08017 Barcelona, Spain
| | - Roger Estrada-Tejedor
- IQS School of Engineering, Universitat Ramon Llull, Via Augusta, 390, 08017 Barcelona, Spain.
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Popkin-Hall ZR, Seth MD, Madebe RA, Budodo R, Bakari C, Francis F, Pereus D, Giesbrecht DJ, Mandara CI, Mbwambo D, Aaron S, Lusasi A, Lazaro S, Bailey JA, Juliano JJ, Ishengoma DS. Malaria Species Positivity Rates Among Symptomatic Individuals Across Regions of Differing Transmission Intensities in Mainland Tanzania. J Infect Dis 2024; 229:959-968. [PMID: 37992117 PMCID: PMC11011190 DOI: 10.1093/infdis/jiad522] [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: 09/20/2023] [Revised: 11/09/2023] [Accepted: 11/20/2023] [Indexed: 11/24/2023] Open
Abstract
BACKGROUND Recent data indicate that non-Plasmodium falciparum species may be more prevalent than thought in sub-Saharan Africa. Although Plasmodium malariae, Plasmodium ovale spp., and Plasmodium vivax are less severe than P. falciparum, treatment and control are more challenging, and their geographic distributions are not well characterized. METHODS We randomly selected 3284 of 12 845 samples collected from cross-sectional surveys in 100 health facilities across 10 regions of Mainland Tanzania and performed quantitative real-time PCR to determine presence and parasitemia of each malaria species. RESULTS P. falciparum was most prevalent, but P. malariae and P. ovale were found in all but 1 region, with high levels (>5%) of P. ovale in 7 regions. The highest P. malariae positivity rate was 4.5% in Mara and 8 regions had positivity rates ≥1%. We only detected 3 P. vivax infections, all in Kilimanjaro. While most nonfalciparum malaria-positive samples were coinfected with P. falciparum, 23.6% (n = 13 of 55) of P. malariae and 14.7% (n = 24 of 163) of P. ovale spp. were monoinfections. CONCLUSIONS P. falciparum remains by far the largest threat, but our data indicate that malaria elimination efforts in Tanzania will require increased surveillance and improved understanding of the biology of nonfalciparum species.
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Affiliation(s)
- Zachary R Popkin-Hall
- Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Misago D Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rashid A Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rule Budodo
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Filbert Francis
- National Institute for Medical Research, Tanga Center, Tanga, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - David J Giesbrecht
- Department of Entomology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA
| | - Celine I Mandara
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | | | - Samwel Lazaro
- National Malaria Control Programme, Dodoma, Tanzania
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, USA
| | - Jonathan J Juliano
- Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
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7
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Habtemariam Y, Asnake M, Alemu M, Shash EP, Tessema TW, Tesso ZG, Hawlet M. Plasmodium Vivax as a Causative Agent for Cerebral Malaria in a Group of Adults at Mizan Tepi Teaching Hospital: Case Series. Int Med Case Rep J 2024; 17:161-166. [PMID: 38504722 PMCID: PMC10949269 DOI: 10.2147/imcrj.s440800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/07/2024] [Indexed: 03/21/2024] Open
Abstract
In 2022, there were 249 million cases of malaria globally, resulting in 608,000 deaths. The majority of cases and deaths occurred in the WHO (World Health Organization) African Region. A study in our region found that, out of 263,476 individuals, 148,734 had P. falciparum, 106,946 had P. vivax, and 7,796 had mixed infections. The prevalence of P. falciparum (Plasmodium falciparum) was 8.97% and P. vivax (Plasmodium Vivax) was 7.94%. Although there have been a few reported cases of cerebral malaria caused by P. vivax, there is currently no comprehensive analysis of such cases. All the cases that have been reported so far involved individuals living in malaria-endemic areas, who presented with symptoms characteristic of cerebral malaria. Cerebral malaria was diagnosed based on the clinical algorithm which WHO used except we used P. vivax instead of P. falciparum The diagnosis of these cases was confirmed through thin blood film examination and Rapid Diagnostic Tests (RDTs). Therefore, this report aims to provide additional data on the occurrence of P. vivax as a cause of cerebral malaria. It also recommends further studies to reassess the current clinical case definition of cerebral malaria mainly in endemic areas as it affects patient treatment outcome.
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Affiliation(s)
- Yosef Habtemariam
- School of Medicine, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Molla Asnake
- School of Medicine, Adult ICU Unit, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Misikr Alemu
- School of Medicine, Department of Internal Medicine, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Erkyehun Pawlos Shash
- School of Medicine, Department of Internal Medicine, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Tsegaw Worku Tessema
- School of Medicine, Adult ICU Unit, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Zerubabel Girma Tesso
- School of Medicine, College of Medicine and Health Sciences, Mizan-Tepi University, Mizan Aman, Ethiopia
| | - Michael Hawlet
- Department of Pediatrics and Child Health, School of Medicine, College of Medicine and Health Sciences, Wolkite University, Wolkite, Ethiopia
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8
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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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9
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Obaldía N, Da Silva Filho JL, Núñez M, Glass KA, Oulton T, Achcar F, Wirjanata G, Duraisingh M, Felgner P, Tetteh KK, Bozdech Z, Otto TD, Marti M. Sterile protection against P. vivax malaria by repeated blood stage infection in the Aotus monkey model. Life Sci Alliance 2024; 7:e202302524. [PMID: 38158220 PMCID: PMC10756917 DOI: 10.26508/lsa.202302524] [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: 12/13/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024] Open
Abstract
The malaria parasite Plasmodium vivax remains a major global public health challenge, and no vaccine is approved for use in humans. Here, we assessed whether P. vivax strain-transcendent immunity can be achieved by repeated infection in Aotus monkeys. Sterile immunity was achieved after two homologous infections, whereas subsequent heterologous challenge provided only partial protection. IgG levels based on P. vivax lysate ELISA and protein microarray increased with repeated infections and correlated with the level of homologous protection. Parasite transcriptional profiles provided no evidence of major antigenic switching upon homologous or heterologous challenge. However, we observed significant sequence diversity and transcriptional differences in the P. vivax core gene repertoire between the two strains used in the study, suggesting that partial protection upon heterologous challenge is due to molecular differences between strains rather than immune evasion by antigenic switching. Our study demonstrates that sterile immunity against P. vivax can be achieved by repeated homologous blood stage infection in Aotus monkeys, thus providing a benchmark to test the efficacy of candidate blood stage P. vivax malaria vaccines.
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Affiliation(s)
- Nicanor Obaldía
- Departamento de Investigaciones en Parasitologia, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Republic of Panamá
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA
- https://ror.org/00vtgdb53 Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Joao Luiz Da Silva Filho
- https://ror.org/00vtgdb53 Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- https://ror.org/02crff812 Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zurich, Zurich, Switzerland
| | - Marlon Núñez
- Departamento de Investigaciones en Parasitologia, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Republic of Panamá
| | - Katherine A Glass
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Tate Oulton
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Fiona Achcar
- https://ror.org/00vtgdb53 Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- https://ror.org/02crff812 Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zurich, Zurich, Switzerland
| | - Grennady Wirjanata
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Manoj Duraisingh
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Philip Felgner
- Institute for Immunology, University of California, Irvine, CA, USA
| | - Kevin Ka Tetteh
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Thomas D Otto
- https://ror.org/00vtgdb53 Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA
- https://ror.org/00vtgdb53 Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- https://ror.org/02crff812 Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zurich, Zurich, Switzerland
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10
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Winnicki AC, Dietrich MH, Yeoh LM, Carias LL, Roobsoong W, Drago CL, Malachin AN, Redinger KR, Feufack-Donfack LB, Baldor L, Jung NC, McLaine OS, Skomorovska-Prokvolit Y, Orban A, Opi DH, Sattabongkot J, Tham WH, Popovici J, Beeson JG, Bosch J, King CL. Potent AMA1-specific human monoclonal antibody against P. vivax Pre-erythrocytic and Blood Stages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.07.579302. [PMID: 38370683 PMCID: PMC10871283 DOI: 10.1101/2024.02.07.579302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
New therapeutics are a priority for preventing and eliminating Plasmodium vivax (Pv) malaria because of its easy transmissibility and dormant stages in the liver. Relapses due to the dormant liver stages are the major contributor to reoccurring Pv. Therefore, therapies that reduce the establishment of dormant parasites and blood-stage infection are important for controlling this geographically widespread parasite. Here, we isolated 12 human monoclonal antibodies (humAbs) from the plasma of a Pv-exposed individual that recognized Pv apical membrane antigen 1 (PvAMA1). PvAMA1 is important for both sporozoite invasion of hepatocytes and merozoite invasion of reticulocytes. We identified one humAb, 826827, that blocked invasion of human erythrocytes using a transgenic P. falciparum line expressing PvAMA1 (IC 50 = 3 µg/mL) and all Pv clinical isolates in vitro . This humAb also inhibited sporozoite invasion of a human hepatocyte cell line and primary human hepatocytes (IC 50 of 0.3 - 3.7 µg/mL). The crystal structure of recombinant PvAMA1 with the antigen-binding fragment of 826827 at 2.4 Å resolution shows that the humAb partially occupies the highly conserved hydrophobic groove in PvAMA1 that binds its known receptor, RON2. HumAb 826827 binds to PvAMA1 with higher affinity than RON2, accounting for its potency. To our knowledge, this is the first reported humAb specific to PvAMA1, and the PvAMA1 residues it binds to are highly conserved across different isolates, explaining its strain-transcendent properties.
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11
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Tajudeen YA, Oladipo HJ, Oladunjoye IO, Oladipo MK, Shittu HD, Abdulmumeen IF, Afolabi AO, El-Sherbini MS. Transforming malaria prevention and control: the prospects and challenges of gene drive technology for mosquito management. Ann Med 2024; 55:2302504. [PMID: 38232762 PMCID: PMC10795774 DOI: 10.1080/07853890.2024.2302504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/02/2024] [Indexed: 01/19/2024] Open
Abstract
Background: In the era of insecticides and anti-malarial drug resistance, gene drive technology holds considerable promise for malaria control. Gene drive technology deploys genetic modifications into mosquito populations to impede their ability to transmit the malaria parasite. This can be either through the disruption of an essential mosquito gene or the association of gene drive with a desirable effector gene. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a gene editing tool that precisely modifies mosquito vector DNA sequences and curtails the rate of pathogen transmission.Methods: A comprehensive search was conducted in the SCOPUS and MEDLINE databases (via PubMed) until October 2023. The keywords used were related to the principles and mechanisms of gene drive technology, its advantages, and disadvantages, and its ethical and regulatory considerations in sustainable malaria eradication.Results: The development of gene drive enables the preferential inheritance of specific genes in targeted mosquitoes, potentially obstructing the transmission of the Plasmodium parasite. This technology was also studied for the control of other vector-borne diseases such as dengue and chikungunya viruses. Despite its experimental superiority over other traditional methods such as insecticide-treated nets and insecticide sprays, the long-term dynamic interplay of mutation and resistance poses challenges for gene drive efficiency in sustainable malaria control.Conclusions: This commentary elucidates the underlying mechanisms and principles of gene drive technology, underscoring its promise and challenges as a novel strategy to curtail malaria prevalence. Although the release of such genetically modified mosquitoes into the natural environment would result in the eradication of the locally targeted species of mosquitoes, the complete eradication of the entire species remains questionable. Thus, the practical application raises significant ethical and regulatory concerns for further research and risk assessment, including the risk of gene drive spreading to nontarget species in the wider theatre of biodiverse species.
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Affiliation(s)
- Yusuf Amuda Tajudeen
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria
- Department of Microbiology, Faculty of Life Sciences, University of Ilorin, Ilorin, Nigeria
| | - Habeebullah Jayeola Oladipo
- Department of Microbiology, Faculty of Life Sciences, University of Ilorin, Ilorin, Nigeria
- Faculty of Pharmaceutical Sciences, University of Ilorin, Ilorin, Nigeria
| | | | | | | | - Imam-Fulani Abdulmumeen
- Faculty of health science, Department of Public health, Alhikmah University Ilorin, Ilorin, Nigeria
| | - Abdullateef Opeyemi Afolabi
- Faculty of Biomedical Sciences, Department of Microbiology and Immunology, Kampala International University, Bushenyi, Uganda
| | - Mona Said El-Sherbini
- Department of Medical Parasitology, Faculty of Medicine, Cairo University, Cairo, Egypt
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12
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Mehra S, McCaw JM, Taylor PG. Superinfection and the hypnozoite reservoir for Plasmodium vivax: a general framework. J Math Biol 2023; 88:7. [PMID: 38040981 PMCID: PMC10692056 DOI: 10.1007/s00285-023-02014-3] [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: 06/26/2023] [Revised: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 12/03/2023]
Abstract
A characteristic of malaria in all its forms is the potential for superinfection (that is, multiple concurrent blood-stage infections). An additional characteristic of Plasmodium vivax malaria is a reservoir of latent parasites (hypnozoites) within the host liver, which activate to cause (blood-stage) relapses. Here, we present a model of hypnozoite accrual and superinfection for P. vivax. To couple host and vector dynamics for a homogeneously-mixing population, we construct a density-dependent Markov population process with countably many types, for which disease extinction is shown to occur almost surely. We also establish a functional law of large numbers, taking the form of an infinite-dimensional system of ordinary differential equations that can also be recovered by coupling expected host and vector dynamics (i.e. a hybrid approximation) or through a standard compartment modelling approach. Recognising that the subset of these equations that model the infection status of the human hosts has precisely the same form as the Kolmogorov forward equations for a Markovian network of infinite server queues with an inhomogeneous batch arrival process, we use physical insight into the evolution of the latter process to write down a time-dependent multivariate generating function for the solution. We use this characterisation to collapse the infinite-compartment model into a single integrodifferential equation (IDE) governing the intensity of mosquito-to-human transmission. Through a steady state analysis, we recover a threshold phenomenon for this IDE in terms of a parameter [Formula: see text] expressible in terms of the primitives of the model, with the disease-free equilibrium shown to be uniformly asymptotically stable if [Formula: see text] and an endemic equilibrium solution emerging if [Formula: see text]. Our work provides a theoretical basis to explore the epidemiology of P. vivax, and introduces a strategy for constructing tractable population-level models of malarial superinfection that can be generalised to allow for greater biological realism in a number of directions.
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Affiliation(s)
- 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 G Taylor
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
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13
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Kotepui KU, Mahittikorn A, Wilairatana P, Masangkay FR, Kotepui M. A Systematic Review and Meta-Analysis Exploring Variations in Copper Levels between Individuals with Malaria and Uninfected Controls. Nutrients 2023; 15:4749. [PMID: 38004142 PMCID: PMC10675583 DOI: 10.3390/nu15224749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/14/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Micronutrient insufficiency has been implicated in malaria pathogenesis. However, the role of copper in malaria remains inconclusive. This study aimed to investigate the association between copper levels and malaria pathogenesis, providing a deeper understanding of copper's role in the disease. A systematic review was conducted following the registered protocol in PROSPERO (CRD42023439732). Multiple databases, including Embase, MEDLINE, Ovid, PubMed, Scopus, and Google Scholar, were searched for relevant studies reporting blood copper levels in patients with malaria. The Joanna Briggs Institute critical appraisal checklist was used for assessing methodological quality. Qualitative and quantitative syntheses were employed, organizing, and summarizing the findings of the included studies. To calculate the standardized mean difference (Hedge's g) and 95% confidence intervals (CIs), a random-effects model was used. After screening the databases, 16 studies were included. Most studies (52.9%) reported that individuals with malaria had significantly higher copper levels than uninfected controls. The meta-analysis, based on 16 studies, showed no significant difference in copper levels between patients with malaria and uninfected controls overall (p = 0.39; Hedges' g, 0.38; 95% CI, -0.48 to 1.25; I2, 98.73%). Subgroup analysis showed a significant difference in copper levels between patients with malaria and uninfected controls among studies conducted in Asia (p < 0.01; Hedges' g, 1.74; 95% CI, 1.04 to 2.44; I2, 90.88%; five studies) and studies employing plasma blood samples (p < 0.01; Hedges' g, 1.13; 95% CI, 0.60 to 2.07; I2, 93.11%; four studies). The qualitative synthesis of the reviewed studies suggests a complex relationship between copper levels and malaria. The meta-analysis results showed no significant difference in copper levels between patients with malaria and uninfected controls overall. However, subgroup analyses based on various factors, including continent and blood sample type, showed copper level variations. These findings highlight the need for further research to better understand the role of copper in malaria pathogenesis by considering geographical factors and the blood sample type used for copper level measurement.
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Affiliation(s)
- Kwuntida Uthaisar Kotepui
- Medical Technology Program, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat 80160, Thailand;
| | - Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand;
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | - Manas Kotepui
- Medical Technology Program, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat 80160, Thailand;
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14
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Bradley L, Yewhalaw D, Hemming-Schroeder E, Embury P, Lee MC, Zemene E, Degefa T, King C, Kazura J, Yan G, Dent A. Determination of Plasmodium vivax and Plasmodium falciparum Malaria Exposure in Two Ethiopian Communities and Its Relationship to Duffy Expression. Am J Trop Med Hyg 2023; 109:1028-1035. [PMID: 37918005 PMCID: PMC10622468 DOI: 10.4269/ajtmh.22-0644] [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: 10/07/2022] [Accepted: 07/16/2023] [Indexed: 11/04/2023] Open
Abstract
Despite historical dogma that Duffy blood group negativity of human erythrocytes confers resistance to Plasmodium vivax blood stage infection, cases of P. vivax malaria and asymptomatic blood stage infection (subclinical malaria) have recently been well documented in Duffy-negative individuals throughout Africa. However, the impact of Duffy negativity on the development of naturally acquired immunity to P. vivax remains poorly understood. We examined antibody reactivity to P. vivax and P. falciparum antigens at two field sites in Ethiopia and assessed Duffy gene expression by polymerase chain reaction amplification and sequencing of the GATA-1 transcription factor-binding site of the Duffy antigen receptor for chemokines (DARC) gene promotor region that is associated with silencing of erythroid cell transcription and absent protein expression. Antibodies to three of the four P. vivax blood stage antigens examined, RBP2b, EBP2, and DBPIISal-1, were significantly lower (P < 0.001) in Duffy-negative individuals relative to Duffy-positive individuals. In stark contrast, no clear pattern was found across Duffy-negative and Duffy-positive genotypes for P. falciparum antibodies. We conclude that lack of erythroid Duffy expression is associated with reduced serologic responses, indicative of less naturally acquired immunity and less cumulative exposure to blood stage P. vivax parasites relative to Duffy positive individuals living in the same communities.
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Affiliation(s)
- Lauren Bradley
- Department of Ecology and Evolutionary Biology, School of Biological Sciences, University of California, Irvine, California
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | | | - Paula Embury
- Center for Global Health and Disease, Case Western Reserve University, Cleveland, Ohio
| | - Ming-Chieh Lee
- Program in Public Health, College of Health Sciences, University of California, Irvine, California
| | - Endalew Zemene
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Teshome Degefa
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Christopher King
- Center for Global Health and Disease, Case Western Reserve University, Cleveland, Ohio
| | - James Kazura
- Center for Global Health and Disease, Case Western Reserve University, Cleveland, Ohio
| | - Guiyun Yan
- Department of Ecology and Evolutionary Biology, School of Biological Sciences, University of California, Irvine, California
- Program in Public Health, College of Health Sciences, University of California, Irvine, California
| | - Arlene Dent
- Center for Global Health and Disease, Case Western Reserve University, Cleveland, Ohio
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15
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van Loon W, Oliveira R, Bergmann C, Habarugira F, Tacoli C, Jäger J, Savelsberg D, Mbarushimana D, Ndoli JM, Sendegeya A, Bayingana C, Mockenhaupt FP. Plasmodium vivax Malaria in Duffy-Positive Patients in Rwanda. Am J Trop Med Hyg 2023; 109:621-623. [PMID: 37549894 PMCID: PMC10484245 DOI: 10.4269/ajtmh.23-0143] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/21/2023] [Indexed: 08/09/2023] Open
Abstract
Plasmodium vivax is the second-most common malaria pathogen globally, but is considered very rare in the predominantly Duffy-negative sub-Saharan African population. In 259 malaria patients from highland southern Rwanda, we assessed Plasmodium species and Duffy blood group status by polymerase chain reaction (PCR). Plasmodium falciparum, P. vivax, Plasmodium malariae, and Plasmodium ovale were seen in 90.7%, 8.1%, 11.6%, and 5.0%, respectively. Plasmodium vivax occurred more frequently as a monoinfection than in combination with P. falciparum. All P. vivax-infected individuals showed heterozygous Duffy positivity, whereas this was the case for only 3.1% of patients with P. falciparum monoinfection and malaria-negative control subjects (P < 0.01). Based on PCR diagnosis, P. vivax is not rare in southern Rwanda. All episodes of P. vivax were observed in heterozygous Duffy-positive patients, whereas elsewhere in Africa, P. vivax is also reported in Duffy-negative individuals. Refined mapping of Plasmodium species is required to establish control and elimination strategies including all malaria species.
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Affiliation(s)
- Welmoed van Loon
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Rafael Oliveira
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
- John Curtin School of Medical Research, Australian National University, Canberra, Australia
| | - Clara Bergmann
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Felix Habarugira
- Pathology Department, University Teaching Hospital of Butare, Huye, Rwanda
| | - Costanza Tacoli
- Malaria Molecular Epidemiology Unit Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Julia Jäger
- Associatid Group Immune Ontogeny and Viral Infections, Leibniz Institute of Virology, Hamburg, Germany
| | - Darius Savelsberg
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | | | - Jules M. Ndoli
- Clinical Education and Research Division, University Teaching Hospital of Butare, Huye, Rwanda
| | | | | | - Frank P. Mockenhaupt
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
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16
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Moore BR, Salman S, Tobe R, Benjamin J, Yadi G, Kasian B, Laman M, Robinson LJ, Page-Sharp M, Betuela I, Batty KT, Manning L, Mueller I, Davis TME. Short-course, high-dose primaquine regimens for the treatment of liver-stage vivax malaria in children. Int J Infect Dis 2023; 134:114-122. [PMID: 37269941 DOI: 10.1016/j.ijid.2023.05.063] [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: 03/10/2023] [Revised: 05/23/2023] [Accepted: 05/23/2023] [Indexed: 06/05/2023] Open
Abstract
OBJECTIVES To assess the pharmacokinetics, safety, and tolerability of two high-dose, short-course primaquine (PQ) regimens compared with standard care in children with Plasmodium vivax infections. METHODS We performed an open-label pediatric dose-escalation study in Madang, Papua New Guinea (Clinicaltrials.gov NCT02364583). Children aged 5-10 years with confirmed blood-stage vivax malaria and normal glucose-6-phosphate dehydrogenase activity were allocated to one of three PQ treatment regimens in a stepwise design (group A: 0.5 mg/kg once daily for 14 days, group B: 1 mg/kg once daily for 7 days, and group C: 1 mg/kg twice daily for 3.5-days). The study assessments were completed at each treatment time point and fortnightly for 2 months after PQ administration. RESULTS Between August 2013 and May 2018, 707 children were screened and 73 met the eligibility criteria (15, 40, and 16 allocated to groups A, B, and C, respectively). All children completed the study procedures. The three regimens were safe and generally well tolerated. The pharmacokinetic analysis indicated that an additional weight adjustment of the conventionally recommended milligram per kilogram PQ doses is not necessary to ensure the therapeutic plasma concentrations in pediatric patients. CONCLUSIONS A novel, ultra-short 3.5-day PQ regimen has potential benefits for improving the treatment outcomes in children with vivax malaria that warrants further investigation in a large-scale clinical trial.
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Affiliation(s)
- Brioni R Moore
- Curtin Medical School, Curtin University, Perth, Australia; Curtin Health Innovation Research Institute, Curtin University, Perth, Australia; Medical School, The University of Western Australia, Perth, Australia; Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Australia.
| | - Sam Salman
- Medical School, The University of Western Australia, Perth, Australia; Clinical Pharmacology and Toxicology Unit, PathWest, Perth, Australia
| | - Roselyn Tobe
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - John Benjamin
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Gumul Yadi
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Bernadine Kasian
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Moses Laman
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Leanne J Robinson
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Australia; Burnet Institute, Melbourne, Australia
| | | | - Inoni Betuela
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Kevin T Batty
- Curtin Medical School, Curtin University, Perth, Australia; Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Laurens Manning
- Medical School, The University of Western Australia, Perth, Australia; Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Australia
| | - Ivo Mueller
- Department of Medical Biology, University of Melbourne, Melbourne, Australia; Burnet Institute, Melbourne, Australia
| | - Timothy M E Davis
- Medical School, The University of Western Australia, Perth, Australia
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17
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Anjani QK, Volpe-Zanutto F, Hamid KA, Sabri AHB, Moreno-Castellano N, Gaitán XA, Calit J, Bargieri DY, Donnelly RF. Primaquine and chloroquine nano-sized solid dispersion-loaded dissolving microarray patches for the improved treatment of malaria caused by Plasmodium vivax. J Control Release 2023; 361:385-401. [PMID: 37562555 DOI: 10.1016/j.jconrel.2023.08.009] [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: 06/03/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
Malaria is a global parasitic infection that leads to substantial illness and death. The most commonly-used drugs for treatment of malaria vivax are primaquine and chloroquine, but they have limitations, such as poor adherence due to frequent oral administration and gastrointestinal side effects. To overcome these limitations, we have developed nano-sized solid dispersion-based dissolving microarray patches (MAPs) for the intradermal delivery of these drugs. In vitro testing showed that these systems can deliver to skin and receiver compartment up to ≈60% of the payload for CQ-based dissolving MAPs and a total of ≈42% of drug loading for PQ-based dissolving MAPs. MAPs also displayed acceptable biocompatibility in cell tests. Pharmacokinetic studies in rats showed that dissolving MAPs could deliver sustained plasma levels of both PQ and CQ for over 7 days. Efficacy studies in a murine model for malaria showed that mice treated with PQ-MAPs and CQ-MAPs had reduced parasitaemia by up to 99.2%. This pharmaceutical approach may revolutionise malaria vivax treatment, especially in developing countries where the disease is endemic. The development of these dissolving MAPs may overcome issues associated with current pharmacotherapy and improve patient outcomes.
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Affiliation(s)
- Qonita Kurnia Anjani
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK; Fakultas Farmasi, Universitas Megarezky, Jl. Antang Raya No. 43, Makassar 90234, Indonesia
| | - Fabiana Volpe-Zanutto
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Khuriah Abdul Hamid
- Department of Pharmaceutics, Faculty of Pharmacy, Universiti Teknologi MARA Cawangan Selangor, 42300, Puncak Alam, Malaysia
| | - Akmal Hidayat Bin Sabri
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Natalia Moreno-Castellano
- Basic Science Department, Faculty of Health, Universidad Industrial de Santander, Bucaramanga 680001, Colombia
| | - Xiomara A Gaitán
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Juliana Calit
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Daniel Y Bargieri
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ryan F Donnelly
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
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18
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Pirahmadi S, Afzali S, Mehrizi AA, Raz A, Raeisi A. Molecular epidemiology of potential candidate markers for chloroquine resistance in imported Plasmodium vivax malaria cases in Iran. Malar J 2023; 22:118. [PMID: 37038137 PMCID: PMC10084653 DOI: 10.1186/s12936-023-04553-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/04/2023] [Indexed: 04/12/2023] Open
Abstract
BACKGROUND The spread of Plasmodium vivax strains resistant to chloroquine (CQ) has posed a challenge to control strategies aimed at eliminating malaria. Molecular analysis of candidate resistance markers is very important for monitoring the P. vivax resistance to CQ in different endemic regions. In the present study, the multidrug resistance 1 (pvmdr1) gene, a possible marker for CQ resistance in P. vivax, was evaluated by molecular methods. METHODS A simple PCR-RFLP method was developed for mutation analysis in pvmdr1 gene. A number of 120 blood spots were obtained from patients with P. vivax mono-infection in 2021. All of the samples were collected from Pakistani patients who travelled to Iran. RESULTS None of the samples had any mutation at codon 976 of pvmdr1, while the 1076 mutation was detected in 96.2% of the examined isolates. Only two pvmdr1 haplotypes were identified, including the single mutant (Y976/1076L) as the most prevalent haplotype (with 96.2% frequency) and the wild type (Y976/F1076; with 3.8% frequency). CONCLUSIONS In this study, the major CQ resistance-mediating mutation and multiple mutant haplotypes of the pvmdr1 gene was not detected. However, continuous monitoring of drug resistance markers and close supervision of the efficacy of CQ is essential to detect the potential emergence of CQ-resistant P. vivax isolates in Iran. This data is important for performing future epidemiological surveillance to monitor CQ resistance in this endemic area and the bordering regions.
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Affiliation(s)
- Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Shima Afzali
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Abbasali Raz
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Ahmad Raeisi
- National Programme Manager for Malaria Control, Ministry of Health and Medical Education, Tehran, Iran
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19
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Le Goff M, Kendjo E, Thellier M, Piarroux R, Boelle PY, Jauréguiberry S. Impact of Chemoprophylaxis on Plasmodium vivax and Plasmodium ovale Infection Among Civilian Travelers: A Nested Case-Control Study With a Counterfactual Approach on 862 Patients. Clin Infect Dis 2023; 76:e884-e893. [PMID: 35962785 DOI: 10.1093/cid/ciac641] [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: 04/18/2022] [Revised: 07/28/2022] [Accepted: 08/02/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The impact of chemoprophylaxis targeting Plasmodium falciparum on Plasmodium vivax and Plasmodium ovale, which may remain quiescent as hypnozoites in the liver, is debated. METHODS We conducted a nested case-control analysis of the outcomes of P. vivax and P. ovale infections in imported malaria cases in France among civilian travelers from 1 January 2006, to 31 December 2017. Using adjusted logistic regression, we assessed the effect of chemoprophylaxis on the incubation period, time from symptoms to diagnosis, management, blood results, symptoms, and hospitalization duration. We analyzed the effect of blood-stage drugs (doxycycline, mefloquine, chloroquine, chloroquine-proguanil) or atovaquone-proguanil on the incubation period. We used a counterfactual approach to ascertain the causal effect of chemoprophylaxis on postinfection characteristics. RESULTS Among 247 P. vivax- and 615 P. ovale-infected travelers, 30% and 47%, respectively, used chemoprophylaxis, and 7 (3%) and 8 (1%) were severe cases. Chemoprophylaxis users had a greater risk of presenting symptoms >2 months after returning for both species (P. vivax odds ratio [OR], 2.91 [95% confidence interval {CI}, 1.22-6.95], P = .02; P. ovale OR, 2.28 [95% CI, 1.47-3.53], P < .001). Using drugs only acting on the blood stage was associated with delayed symptom onset after 60 days, while using atovaquone-proguanil was not. CONCLUSIONS Civilian travelers infected with P. vivax or P. ovale reporting chemoprophylaxis use, especially of blood-stage agents, had a greater risk of delayed onset of illness. The impact of chemoprophylaxis on the outcomes of infection with relapse-causing species calls for new chemoprophylaxis acting against erythrocytic and liver stages.
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Affiliation(s)
- Maëlle Le Goff
- Université de Bretagne Occidentale, Service des maladies infectieuses et tropicales, Centre Hospitalier Régional Universitaire La Cavale Blanche, Brest, France.,Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique, Inserm, Paris, France
| | - Eric Kendjo
- Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique, Inserm, Paris, France.,Centre National de Référence du Paludisme, Paris, France
| | - Marc Thellier
- Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique, Inserm, Paris, France.,Centre National de Référence du Paludisme, Paris, France.,Sorbonne Université, Service de parasitologie, Hôpital Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Renaud Piarroux
- Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique, Inserm, Paris, France.,Centre National de Référence du Paludisme, Paris, France.,Sorbonne Université, Service de parasitologie, Hôpital Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Pierre-Yves Boelle
- Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique, Inserm, Paris, France
| | - Stéphane Jauréguiberry
- Centre National de Référence du Paludisme, Paris, France.,Université de Paris Saclay, Service des maladies infectieuses et tropicales, Hôpital Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin Bicêtre, France.,Société Française de Médecine des Voyages, Paris, France.,Université de Paris Saclay, Centre de Recherche en Epidémiologie et Santé des Populations, Inserm, Villejuif, France
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20
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Carlucci R, Di Gresia G, Mediavilla MG, Cricco JA, Tekwani BL, Khan SI, Labadie GR. Expanding the scope of novel 1,2,3-triazole derivatives as new antiparasitic drug candidates. RSC Med Chem 2023; 14:122-134. [PMID: 36760749 PMCID: PMC9890560 DOI: 10.1039/d2md00324d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that prenyl and aliphatic triazoles are interesting motifs to prepare new chemical entities for antiparasitic and antituberculosis drug development. In this opportunity a new series of prenyl-1,2,3-triazoles were prepared from isoprenyl azides and different alkynes looking for new antimalarial drug candidates. The compounds were prepared by copper(i) catalyzed dipolar cycloaddition of the isoprenyl azide equilibrium mixture providing exclusively 1,4-disubstituted 1,2,3-triazoles in a regiospecific fashion. The complete collection of 64 compounds was tested on chloroquine-sensitive (CQ sensitive), Sierra Leone (D6), and the chloroquine-resistant, Indochina (W2), strains of Plasmodium falciparum and those compounds which were not previously reported were also tested against Leishmania donovani, the causative agent for visceral leishmaniasis. Thirteen analogs displayed antimalarial activity with IC50 below 10 μM, while the antileishmanial activity of the newly reported analogs could not improve upon those previously reported. Compounds 1o and 1r were identified as the most promising antimalarial drug leads with IC50 below 3.0 μM for both CQ-sensitive and resistant P. falciparum strains with high selectivity index. Finally, a chemoinformatic in silico analysis was performed to evaluate physicochemical parameters, cytotoxicity risk and drug score. The validation of a bifunctional farnesyl/geranylgeranyl diphosphate synthase PfFPPS/GGPPS as the potential target of the antimalarial activity of selected analogs should be further investigated.
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Affiliation(s)
- Renzo Carlucci
- Instituto de Química Rosario (IQUIR) UNR, CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54 341 4370477 +54 341 4370477
| | - Gabriel Di Gresia
- Instituto de Química Rosario (IQUIR) UNR, CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54 341 4370477 +54 341 4370477
| | - María Gabriela Mediavilla
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Rosario (UNR) Suipacha 531 S2002LRK Rosario Argentina
| | - Julia A Cricco
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Rosario (UNR) Suipacha 531 S2002LRK Rosario Argentina
| | - Babu L Tekwani
- Department of Infectious Diseases, Division of Scientific Platforms, Southern Research Birmingham AL 35205 USA
| | - Shabana I Khan
- National Center for Natural Products Research & Department of Biomolecular Sciences, School of Pharmacy, University of Mississippi University MS 38677 USA
| | - Guillermo R Labadie
- Instituto de Química Rosario (IQUIR) UNR, CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54 341 4370477 +54 341 4370477
- Departamento de Química Orgánica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina
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21
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Reddy V, Weiss DJ, Rozier J, Ter Kuile FO, Dellicour S. Global estimates of the number of pregnancies at risk of malaria from 2007 to 2020: a demographic study. Lancet Glob Health 2023; 11:e40-e47. [PMID: 36521951 PMCID: PMC9764451 DOI: 10.1016/s2214-109x(22)00431-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/19/2022] [Accepted: 09/29/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND The most recent global estimates of the number of pregnancies at risk of Plasmodium falciparum and Plasmodium vivax malaria infection are from 2007. To inform global malaria prevention and control efforts, we aimed to estimate the global distribution of pregnancies at risk of malaria infection from 2007 to 2020. METHODS We used estimates from the Malaria Atlas Project on the total population living in areas of P falciparum and P vivax transmission, combined with country-specific demographic data on women of reproductive age, fertility rates, induced abortions, and stillbirths, to derive the annual number of pregnancies overall, by parasite species, and by endemicity strata from 2007 to 2020. The definition of endemicity strata was based on the parasite point prevalence in individuals aged 2-10 years for P falciparum and 1-99 years for P vivax. We also did a sensitivity analysis in which we considered most of sub-Saharan Africa endemic for P vivax. FINDINGS In 2020, 121·9 million pregnancies occurred in malaria transmission areas, resulting in an estimated 70·9 million (58·1%) livebirths. The total number of pregnancies at risk of malaria was 52·9 million in the WHO South-East Asia (SEARO) region, 5·1 million in the Western Pacific (WPRO) region, 46·1 million in the Africa (AFRO) region, 11·1 million in the Eastern Mediterranean (EMRO) region, and 6·7 million in the Americas (AMRO) region. Between 2007 and 2020, pregnancies in areas of P falciparum transmission declined by 11·4% globally, despite an overall 7·0% increase in pregnancies, representing a decrease of 100·0% in the WHO Europe (EURO) region, 52·6% in WPRO, 51·5% in AMRO, 23·9% in EMRO, and 17·2% in SEARO, and a 25·4% increase in AFRO. Pregnancies in P vivax transmission areas fell by 42·8%, representing a decrease of 100·0% in EURO, 89·8% in WPRO, 48·4% in AMRO, 32·4% in EMRO, and 10·0% in SEARO, and a 25·8% increase in AFRO. Our sensitivity analysis suggests that the number of pregnancies at risk of P vivax infection could be seven-fold higher for AFRO if the whole of sub-Saharan Africa was considered endemic for P vivax. INTERPRETATION Between 2007 and 2020, substantial declines in the number of pregnancies at risk of malaria were seen globally. However, in AFRO, 25·4% more pregnancies were at risk of P falciparum or P vivax malaria than in 2007. This increase in the number at risk in AFRO comes despite the decline in malaria rates due to the rapidly rising population and the corresponding number of pregnancies in endemic areas. These estimates should guide priority setting for resource allocation to control malaria in pregnancy. FUNDING Bill & Melinda Gates Foundation and Telethon Trust.
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Affiliation(s)
- Valentina Reddy
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Daniel J Weiss
- Telethon Kids Institute, Perth Children's Hospital, Perth, WA, Australia; Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Jennifer Rozier
- Telethon Kids Institute, Perth Children's Hospital, Perth, WA, Australia; Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Stephanie Dellicour
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
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22
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Habtamu K, Petros B, Yan G. Plasmodium vivax: the potential obstacles it presents to malaria elimination and eradication. Trop Dis Travel Med Vaccines 2022; 8:27. [PMID: 36522671 PMCID: PMC9753897 DOI: 10.1186/s40794-022-00185-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
Initiatives to eradicate malaria have a good impact on P. falciparum malaria worldwide. P. vivax, however, still presents significant difficulties. This is due to its unique biological traits, which, in comparison to P. falciparum, pose serious challenges for malaria elimination approaches. P. vivax's numerous distinctive characteristics and its ability to live for weeks to years in liver cells in its hypnozoite form, which may elude the human immune system and blood-stage therapy and offer protection during mosquito-free seasons. Many malaria patients are not fully treated because of contraindications to primaquine use in pregnant and nursing women and are still vulnerable to P. vivax relapses, although there are medications that could radical cure P. vivax. Additionally, due to CYP2D6's highly variable genetic polymorphism, the pharmacokinetics of primaquine may be impacted. Due to their inability to metabolize PQ, some CYP2D6 polymorphism alleles can cause patients to not respond to treatment. Tafenoquine offers a radical treatment in a single dose that overcomes the potentially serious problem of poor adherence to daily primaquine. Despite this benefit, hemolysis of the early erythrocytes continues in individuals with G6PD deficiency until all susceptible cells have been eliminated. Field techniques such as microscopy or rapid diagnostic tests (RDTs) miss the large number of submicroscopic and/or asymptomatic infections brought on by reticulocyte tropism and the low parasitemia levels that accompany it. Moreover, P. vivax gametocytes grow more quickly and are much more prevalent in the bloodstream. P. vivax populations also have a great deal of genetic variation throughout their genome, which ensures evolutionary fitness and boosts adaptation potential. Furthermore, P. vivax fully develops in the mosquito faster than P. falciparum. These characteristics contribute to parasite reservoirs in the human population and facilitate faster transmission. Overall, no genuine chance of eradication is predicted in the next few years unless new tools for lowering malaria transmission are developed (i.e., malaria elimination and eradication). The challenging characteristics of P. vivax that impede the elimination and eradication of malaria are thus discussed in this article.
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Affiliation(s)
- Kassahun Habtamu
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
- Menelik II Medical & Health Science College, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA 92697 USA
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23
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Shankar VS, Purti N, Stephen LC, Mohan PM, Narshimulu G, Satyakeerthy TR, Jacob S. Elucidating the status of malaria in Andaman and Nicobar Islands post-millennium 2000. J Parasit Dis 2022; 46:1062-1069. [PMID: 36457779 PMCID: PMC9606159 DOI: 10.1007/s12639-022-01528-9] [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: 06/09/2022] [Accepted: 08/22/2022] [Indexed: 11/29/2022] Open
Abstract
Malaria is a major vector-borne disease in the Indian sub-continent and has been pestering Andaman and Nicobar islands (ANI's) as well since British colonial times. A retrospective data mining technique has been adhered to assess the status of malaria for nineteen years from 2000 to 2019 in ANI's. The altered environment due to 2004 tsunami had increased malaria incidence significantly during (2005-2010). The Nicobar district recorded high incidence of malaria while the least in the north and middle Andaman district. Comparative high incidence of malaria was documented due to Plasmodium falciparum than Plasmodium vivax in the Nicobar district between 2005 and 2009. The declining trend of malaria-positive cases in ANI's was observed post 2010, articulating various initiatives taken by the local Andaman and Nicobar administration to curb this vector-borne disease. The initiatives were like (1) large-scale release of larvivorous fish, Gambusia affinis in the transient water pools, (2) outdoor application of DDT, (3) indoor application of Pyrethrum, (4) malaria awareness drive that led to the curbing of the proliferation not only the malaria vector but also other potential mosquito vector species as well, and (5) implementation of revised drug policy.
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Affiliation(s)
- Venkatesan Shiva Shankar
- Faculty of Environmental Science, ANCOL, Chakargaon, Port Blair, Andaman and Nicobar Islands 744112 India
| | - Neelam Purti
- Department of Environment and Forest, Manglutan Range, Port Balir, Andaman and Nicobar Islands 744105 India
| | - Lena Charlette Stephen
- Department of Community and Family Medicine, All India Institute of Medical Sciences, Madurai, 625008 India
| | - P. M. Mohan
- Department of Ocean Studies and Marine Biology, Brookashabad Campus, Pondicherry University, Port Blair, 744112 India
| | - G. Narshimulu
- Department of Geography, JNRM, Port Blair, 744102 India
| | | | - Sunil Jacob
- Department of Chemistry, Catholicate College, Mahatma Gandhi University, Pathanamthitta, 689695 India
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24
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Abstract
PURPOSE OF REVIEW This is a review of Plasmodium vivax epidemiology, pathogenesis, disease presentation, treatment and innovations in control and elimination. Here, we examine the recent literature and summarize new advances and ongoing challenges in the management of P. vivax . RECENT FINDINGS P. vivax has a complex life cycle in the human host which impacts disease severity and treatment regimens. There is increasing data for the presence of cryptic reservoirs in the spleen and bone marrow which may contribute to chronic vivax infections and possibly disease severity. Methods to map the geospatial epidemiology of P. vivax chloroquine resistance are advancing, and they will inform local treatment guidelines. P. vivax treatment requires an 8-aminoquinoline to eradicate the dormant liver stage. Evidence suggests that higher doses of 8-aminoquinolines may be needed for radical cure of tropical frequent-relapsing strains. SUMMARY P. vivax is a significant global health problem. There have been recent developments in understanding the complexity of P. vivax biology and optimization of antimalarial therapy. Studies toward the development of best practices for P. vivax control and elimination programs are ongoing.
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Affiliation(s)
- Nazia Khan
- Department of Medicine (Infectious Diseases), Albert Einstein College of Medicine, Bronx, New York
| | - Johanna P. Daily
- Department of Medicine (Infectious Diseases), Albert Einstein College of Medicine, Bronx, New York
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25
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De Meulenaere K, Prajapati SK, Villasis E, Cuypers B, Kattenberg JH, Kasian B, Laman M, Robinson LJ, Gamboa D, Laukens K, Rosanas-Urgell A. Band 3–mediated Plasmodium vivax invasion is associated with transcriptional variation in PvTRAg genes. Front Cell Infect Microbiol 2022; 12:1011692. [PMID: 36250048 PMCID: PMC9563252 DOI: 10.3389/fcimb.2022.1011692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/09/2022] [Indexed: 11/13/2022] Open
Abstract
The Plasmodium vivax reticulocyte invasion process is still poorly understood, with only a few receptor-ligand interactions identified to date. Individuals with the Southeast Asian ovalocytosis (SAO) phenotype have a deletion in the band 3 protein on the surface of erythrocytes, and are reported to have a lower incidence of clinical P. vivax malaria. Based on this observation, band 3 has been put forward as a receptor for P. vivax invasion, although direct proof is still lacking. In this study, we combined functional ex vivo invasion assays and transcriptome sequencing to uncover a band 3–mediated invasion pathway in P. vivax and potential band 3 ligands. Invasion by P. vivax field isolates was 67%-71% lower in SAO reticulocytes compared with non-SAO reticulocytes. Reticulocyte invasion was decreased by 40% and 27%-31% when blocking with an anti-band 3 polyclonal antibody and a PvTRAg38 peptide, respectively. To identify new band 3 receptor candidates, we mRNA-sequenced schizont-stage isolates used in the invasion assays, and observed high transcriptional variability in multigene and invasion-related families. Transcriptomes of isolates with low or high dependency on band 3 for invasion were compared by differential expression analysis, which produced a list of band 3 ligand candidates with high representation of PvTRAg genes. Our ex vivo invasion assays have demonstrated that band 3 is a P. vivax invasion receptor and confirm previous in vitro studies showing binding between PvTRAg38 and band 3, although the lower and variable inhibition levels observed suggest the involvement of other ligands. By coupling transcriptomes and invasion phenotypes from the same isolates, we identified a list of band 3 ligand candidates, of which the overrepresented PvTRAg genes are the most promising for future research.
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Affiliation(s)
- Katlijn De Meulenaere
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- Department of Computer Science, University of Antwerp, Antwerp, Belgium
- *Correspondence: Anna Rosanas-Urgell, ; Katlijn De Meulenaere,
| | - Surendra Kumar Prajapati
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Elizabeth Villasis
- Laboratorio de Malaria, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Bart Cuypers
- Department of Computer Science, University of Antwerp, Antwerp, Belgium
| | | | - Bernadine Kasian
- Vector-borne Diseases Unit, Papua New Guinea Institute for Medical Research, Madang, Papua New Guinea
| | - Moses Laman
- Vector-borne Diseases Unit, Papua New Guinea Institute for Medical Research, Madang, Papua New Guinea
| | - Leanne J. Robinson
- Vector-borne Diseases Unit, Papua New Guinea Institute for Medical Research, Madang, Papua New Guinea
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
- Health Security and Disease Elimination, Burnet Institute, Melbourne, VIC, Australia
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Kris Laukens
- Department of Computer Science, University of Antwerp, Antwerp, Belgium
| | - Anna Rosanas-Urgell
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- *Correspondence: Anna Rosanas-Urgell, ; Katlijn De Meulenaere,
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26
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Pfeffer DA, Satyagraha AW, Sadhewa A, Alam MS, Bancone G, Boum Y, Brito M, Cui L, Deng Z, Domingo GJ, He Y, Khan WA, Kibria MG, Lacerda M, Menard D, Monteiro W, Pal S, Parikh S, Roca-Feltrer A, Roh M, Sirdah MM, Wang D, Huang Q, Howes RE, Price RN, Ley B. Genetic Variants of Glucose-6-Phosphate Dehydrogenase and Their Associated Enzyme Activity: A Systematic Review and Meta-Analysis. Pathogens 2022; 11:1045. [PMID: 36145477 PMCID: PMC9502867 DOI: 10.3390/pathogens11091045] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/05/2022] [Accepted: 09/10/2022] [Indexed: 01/12/2023] Open
Abstract
Low glucose-6-phosphate dehydrogenase enzyme (G6PD) activity is a key determinant of drug-induced haemolysis. More than 230 clinically relevant genetic variants have been described. We investigated the variation in G6PD activity within and between different genetic variants. In this systematic review, individual patient data from studies reporting G6PD activity measured by spectrophotometry and corresponding the G6PD genotype were pooled (PROSPERO: CRD42020207448). G6PD activity was converted into percent normal activity applying study-specific definitions of 100%. In total, 4320 individuals from 17 studies across 10 countries were included, where 1738 (40.2%) had one of the 24 confirmed G6PD mutations, and 61 observations (3.5%) were identified as outliers. The median activity of the hemi-/homozygotes with A-(c.202G>A/c.376A>G) was 29.0% (range: 1.7% to 76.6%), 10.2% (range: 0.0% to 32.5%) for Mahidol, 16.9% (range 3.3% to 21.3%) for Mediterranean, 9.0% (range: 2.9% to 23.2%) for Vanua Lava, and 7.5% (range: 0.0% to 18.3%) for Viangchan. The median activity in heterozygotes was 72.1% (range: 16.4% to 127.1%) for A-(c.202G>A/c.376A>G), 54.5% (range: 0.0% to 112.8%) for Mahidol, 37.9% (range: 20.7% to 80.5%) for Mediterranean, 53.8% (range: 10.9% to 82.5%) for Vanua Lava, and 52.3% (range: 4.8% to 78.6%) for Viangchan. A total of 99.5% of hemi/homozygotes with the Mahidol mutation and 100% of those with the Mediterranean, Vanua Lava, and Viangchan mutations had <30% activity. For A-(c.202G>A/c.376A>G), 55% of hemi/homozygotes had <30% activity. The G6PD activity for each variant spanned the current classification thresholds used to define clinically relevant categories of enzymatic deficiency.
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Affiliation(s)
- Daniel A. Pfeffer
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | | | - Arkasha Sadhewa
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
| | - Mohammad Shafiul Alam
- Infectious Diseases Division, International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka 1212, Bangladesh
| | - 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 & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, UK
| | - Yap Boum
- Médecins sans Frontières Epicentre, Mbarara Research Centre, Mbarara, Uganda
- Mbarara University of Science and Technology, Mbarara 1956, Uganda
| | - Marcelo Brito
- Fundaçāo de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus 69040-000, AM, Brazil
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, Tampa, FL 33620, USA
| | - Zeshuai Deng
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming 650032, China
| | | | - Yongshu He
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming 650032, China
| | - Wasif A. Khan
- Infectious Diseases Division, International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka 1212, Bangladesh
| | - Mohammad Golam Kibria
- Infectious Diseases Division, International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka 1212, Bangladesh
| | - Marcus Lacerda
- Fundaçāo de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus 69040-000, AM, Brazil
| | - Didier Menard
- Malaria Genetics and Resistance Unit, Institut Pasteur, INSERM U1201, 75015 Paris, France
- Institute of Parasitology and Tropical Diseases, UR7292 Dynamics of Host-Pathogen Interactions, Federation of Translational Medicine, University of Strasbourg, 67081 Strasbourg, France
| | - Wuelton Monteiro
- Fundaçāo de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus 69040-000, AM, Brazil
| | - Sampa Pal
- Diagnostics Program, PATH, Seattle, WA 98121, USA
| | - Sunil Parikh
- Yale School of Public Health, New Haven, CT 06520, USA
| | - Arantxa Roca-Feltrer
- Malaria Consortium, Phnom Penh Center, Street Sothearos, Tonle Basac, Chamkarmorn, Building “H”, 1st Floor, Room No. 192, Phnom Penh, Cambodia
| | - Michelle Roh
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Duoquan Wang
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention, Chinese Centre for Tropical Diseases Research, WHO Collaborating Centre for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai 200000, China
- Chinese Center for Tropical Diseases Research, School of Global Health, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiuying Huang
- School of Life Sciences, Xiamen University, Xiamen 361005, China
| | | | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin 0810, Australia
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Health and economic burden due to malaria in Peru over 30 years (1990-2019): Findings from the global burden of diseases study 2019. LANCET REGIONAL HEALTH. AMERICAS 2022; 15:100347. [PMID: 36778067 PMCID: PMC9903979 DOI: 10.1016/j.lana.2022.100347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background Malaria is one of the biggest impediments to global progress. In Peru, it is still a major public health problem. Measures of health and economic burden due to malaria are relevant considerations for the assessment of current policies. Methods We used estimates from the Global Burden of Diseases Study 2019 for malaria in Peru, grouped by gender and age, from 1990 to 2019. Results are presented as absolute numbers and age-standardized rates with 95% uncertainty intervals (UI). We collected economic data from the World Bank and The National Institute of Statistics and Informatics of Peru and Loreto to calculate the economic burden of productivity loss (EBPL) using the human capital approach. Economic values were presented in constant dollars, soles, and percentages. Findings Rates of deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs), as well as the EBPL, were drastically reduced from 1990 to 2019. DALYs had a greater percentage of YLDs in 2019 than in 1990. DALYs rates showed no preference between sexes, but the "< 1 year" age group had the highest DALYs values over the study period. We found that the EBPL due to malaria for Loreto was considerably higher than Peru's in terms of GDP percentage. Interpretation Our study shows that the fight against malaria in Peru reduced remarkably the impact of the disease since 1990; however, during the last decade the estimates were stable or even increased. Our results help to measure the malaria impact on the health status of the Peruvian population as well as the economic pressure that it exerts, constituting remarkable tools for policymaking aimed at reducing the burden of this disease. Strengthening the malaria elimination program is important to achieve the elimination of the disease in the coming years. Funding This study was supported by the Universidad Nacional Toribio Rodríguez de Mendoza and FONDECYT: Contrato Nº 09-2019-FONDECYT-BMINC.INV and FONDECYT-BM, Perú (Program INCORPORACIÓN DE INVESTIGADORES E038-2019-01, Registry Number: 64007).
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Kattenberg JH, Nguyen HV, Nguyen HL, Sauve E, Nguyen NTH, Chopo-Pizarro A, Trimarsanto H, Monsieurs P, Guetens P, Nguyen XX, Esbroeck MV, Auburn S, Nguyen BTH, Rosanas-Urgell A. Novel highly-multiplexed AmpliSeq targeted assay for Plasmodium vivax genetic surveillance use cases at multiple geographical scales. Front Cell Infect Microbiol 2022; 12:953187. [PMID: 36034708 PMCID: PMC9403277 DOI: 10.3389/fcimb.2022.953187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/19/2022] [Indexed: 11/17/2022] Open
Abstract
Although the power of genetic surveillance tools has been acknowledged widely, there is an urgent need in malaria endemic countries for feasible and cost-effective tools to implement in national malaria control programs (NMCPs) that can generate evidence to guide malaria control and elimination strategies, especially in the case of Plasmodium vivax. Several genetic surveillance applications (‘use cases’) have been identified to align research, technology development, and public health efforts, requiring different types of molecular markers. Here we present a new highly-multiplexed deep sequencing assay (Pv AmpliSeq). The assay targets the 33-SNP vivaxGEN-geo panel for country-level classification, and a newly designed 42-SNP within-country barcode for analysis of parasite dynamics in Vietnam and 11 putative drug resistance genes in a highly multiplexed NGS protocol with easy workflow, applicable for many different genetic surveillance use cases. The Pv AmpliSeq assay was validated using: 1) isolates from travelers and migrants in Belgium, and 2) routine collections of the national malaria control program at sentinel sites in Vietnam. The assay targets 229 amplicons and achieved a high depth of coverage (mean 595.7 ± 481) and high accuracy (mean error-rate of 0.013 ± 0.007). P. vivax parasites could be characterized from dried blood spots with a minimum of 5 parasites/µL and 10% of minority-clones. The assay achieved good spatial specificity for between-country prediction of origin using the 33-SNP vivaxGEN-geo panel that targets rare alleles specific for certain countries and regions. A high resolution for within-country diversity in Vietnam was achieved using the designed 42-SNP within-country barcode that targets common alleles (median MAF 0.34, range 0.01-0.49. Many variants were detected in (putative) drug resistance genes, with different predominant haplotypes in the pvmdr1 and pvcrt genes in different provinces in Vietnam. The capacity of the assay for high resolution identity-by-descent (IBD) analysis was demonstrated and identified a high rate of shared ancestry within Gia Lai Province in the Central Highlands of Vietnam, as well as between the coastal province of Binh Thuan and Lam Dong. Our approach performed well in geographically differentiating isolates at multiple spatial scales, detecting variants in putative resistance genes, and can be easily adjusted to suit the needs in other settings in a country or region. We prioritize making this tool available to researchers and NMCPs in endemic countries to increase ownership and ensure data usage for decision-making and malaria policy.
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Affiliation(s)
- Johanna Helena Kattenberg
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
- *Correspondence: Johanna Helena Kattenberg, ; Anna Rosanas-Urgell,
| | - Hong Van Nguyen
- Department of Clinical Research, National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Hieu Luong Nguyen
- Department of Clinical Research, National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Erin Sauve
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Ngoc Thi Hong Nguyen
- Department of Molecular Biology, National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Ana Chopo-Pizarro
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Hidayat Trimarsanto
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Pieter Monsieurs
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Pieter Guetens
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Xa Xuan Nguyen
- Department of Epidemiology, National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Marjan Van Esbroeck
- Clinical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sarah Auburn
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- Mahidol‐Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Binh Thi Huong Nguyen
- Department of Clinical Research, National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | - Anna Rosanas-Urgell
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
- *Correspondence: Johanna Helena Kattenberg, ; Anna Rosanas-Urgell,
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Ruberto AA, Bourke C, Vantaux A, Maher SP, Jex A, Witkowski B, Snounou G, Mueller I. Single-cell RNA sequencing of Plasmodium vivax sporozoites reveals stage- and species-specific transcriptomic signatures. PLoS Negl Trop Dis 2022; 16:e0010633. [PMID: 35926062 PMCID: PMC9380936 DOI: 10.1371/journal.pntd.0010633] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 08/16/2022] [Accepted: 07/04/2022] [Indexed: 11/24/2022] Open
Abstract
Background Plasmodium vivax sporozoites reside in the salivary glands of a mosquito before infecting a human host and causing malaria. Previous transcriptome-wide studies in populations of these parasite forms were limited in their ability to elucidate cell-to-cell variation, thereby masking cellular states potentially important in understanding malaria transmission outcomes. Methodology/Principal findings In this study, we performed transcription profiling on 9,947 P. vivax sporozoites to assess the extent to which they differ at single-cell resolution. We show that sporozoites residing in the mosquito’s salivary glands exist in distinct developmental states, as defined by their transcriptomic signatures. Additionally, relative to P. falciparum, P. vivax displays overlapping and unique gene usage patterns, highlighting conserved and species-specific gene programs. Notably, distinguishing P. vivax from P. falciparum were a subset of P. vivax sporozoites expressing genes associated with translational regulation and repression. Finally, our comparison of single-cell transcriptomic data from P. vivax sporozoite and erythrocytic forms reveals gene usage patterns unique to sporozoites. Conclusions/Significance In defining the transcriptomic signatures of individual P. vivax sporozoites, our work provides new insights into the factors driving their developmental trajectory and lays the groundwork for a more comprehensive P. vivax cell atlas. Plasmodium vivax is the second most common cause of malaria worldwide. It is particularly challenging for malaria elimination as it forms both active blood-stage infections, as well as asymptomatic liver-stage infections that can persist for extended periods of time. The activation of persister forms in the liver (hypnozoites) are responsible for relapsing infections occurring weeks or months following primary infection via a mosquito bite. How P. vivax persists in the liver remains a major gap in understanding of this organism. It has been hypothesized that there is pre-programming of the infectious sporozoite while it is in the salivary-glands that determines if the cell’s fate once in the liver is to progress towards immediate liver stage development or persist for long-periods as a hypnozoite. The aim of this study was to see if such differences were distinguishable at the transcript level in salivary-gland sporozoites. While we found significant variation amongst sporozoites, we did not find clear evidence that they are transcriptionally pre-programmed as has been suggested. Nevertheless, we highlight several intriguing patterns that appear to be P. vivax specific relative to non-relapsing species that cause malaria prompting further investigation.
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Affiliation(s)
- Anthony A. Ruberto
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Caitlin Bourke
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Amélie Vantaux
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Kingdom of Cambodia
| | - Steven P. Maher
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Aaron Jex
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Kingdom of Cambodia
| | - Georges Snounou
- Commissariat à l’Énergie Atomique et aux Énergies Alternatives-Université Paris Sud 11-INSERM U1184, Immunology of Viral Infections and Autoimmune Diseases (IMVA-HB), Infectious Disease Models and Innovative Therapies (IDMIT) Department, Institut de Biologie François Jacob (IBFJ), Direction de la Recherche Fondamentale (DRF), Fontenay-aux-Roses, France
| | - Ivo Mueller
- Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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Boonyarangka P, Phontham K, Sriwichai S, Poramathikul K, Harncharoenkul K, Kuntawunginn W, Maneesrikhum N, Srisawath S, Seenuan C, Thanyakait C, Inkabajan K, Pludpiem S, Pidtana K, Demons S, Vesely B, Wojnarski M, Griesenbeck JS, Spring M. Co-Infection with Plasmodium vivax and COVID-19 in Thailand. Trop Med Infect Dis 2022; 7:tropicalmed7080145. [PMID: 35893653 PMCID: PMC9332623 DOI: 10.3390/tropicalmed7080145] [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: 06/28/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 02/06/2023] Open
Abstract
With the emergence of SARS-CoV-2, healthcare systems not only had to address the pressing clinical needs of the COVID-19 pandemic but anticipate the effect on and of other conditions and diseases. This was of particular concern in areas of the world endemic with malaria, a disease which takes hundreds of thousands of lives each year. This case report from Thailand describes a 25-year-old man diagnosed with Plasmodium vivax, who was then found to be co-infected with COVID-19. Both conditions can have overlapping acute febrile illness symptoms which may delay or complicate diagnoses. He had no prior history of malaria and had received two vaccinations against COVID-19. His clinical course was mild with no pulmonary complications or oxygen requirement, and he responded well to treatments for both conditions. Three months after cure, he again contracted COVID-19 but did not experience any P. vivax relapse. Review of the available literature produced less than 10 publications describing co-infections with P. vivax and COVID-19; nonetheless, in endemic areas, vigilance for both diseases should continue, as co-infections could significantly alter the course of clinical management and prognosis as well as affect the healthcare staff caring for these patients.
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Affiliation(s)
- Parat Boonyarangka
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Kittijarankon Phontham
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Sabaithip Sriwichai
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Kamonporn Poramathikul
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Krit Harncharoenkul
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Worachet Kuntawunginn
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Napat Maneesrikhum
- Suan Phueng Hospital, Ratchaburi 70180, Thailand; (N.M.); (S.S.); (C.S.); (C.T.); (K.I.)
| | - Sarayouth Srisawath
- Suan Phueng Hospital, Ratchaburi 70180, Thailand; (N.M.); (S.S.); (C.S.); (C.T.); (K.I.)
| | - Chanida Seenuan
- Suan Phueng Hospital, Ratchaburi 70180, Thailand; (N.M.); (S.S.); (C.S.); (C.T.); (K.I.)
| | - Chattakorn Thanyakait
- Suan Phueng Hospital, Ratchaburi 70180, Thailand; (N.M.); (S.S.); (C.S.); (C.T.); (K.I.)
| | - Kanjana Inkabajan
- Suan Phueng Hospital, Ratchaburi 70180, Thailand; (N.M.); (S.S.); (C.S.); (C.T.); (K.I.)
| | - Suda Pludpiem
- Division of Health Promotion and Prevention, Suan Phueng District Health Office, Ratchaburi 70180, Thailand;
| | - Kingkan Pidtana
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Samandra Demons
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Brian Vesely
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Mariusz Wojnarski
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - John S. Griesenbeck
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
| | - Michele Spring
- Department of Bacterial and Parasitic Diseases, US Army Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand; (P.B.); (K.P.); (S.S.); (K.P.); (K.H.); (W.K.); (K.P.); (S.D.); (B.V.); (M.W.); (J.S.G.)
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, USA
- Correspondence:
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A framework for evaluating health system surveillance sensitivity to support public health decision-making for malaria elimination: a case study from Indonesia. BMC Infect Dis 2022; 22:619. [PMID: 35840923 PMCID: PMC9288013 DOI: 10.1186/s12879-022-07581-2] [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: 11/22/2021] [Accepted: 06/30/2022] [Indexed: 12/01/2022] Open
Abstract
Background The effectiveness of a surveillance system to detect infections in the population is paramount when confirming elimination. Estimating the sensitivity of a surveillance system requires identifying key steps in the care-seeking cascade, from initial infection to confirmed diagnosis, and quantifying the probability of appropriate action at each stage. Using malaria as an example, a framework was developed to estimate the sensitivity of key components of the malaria surveillance cascade.
Methods Parameters to quantify the sensitivity of the surveillance system were derived from monthly malaria case data over a period of 36 months and semi-quantitative surveys in 46 health facilities on Java Island, Indonesia. Parameters were informed by the collected empirical data and estimated by modelling the flow of an infected individual through the system using a Bayesian framework. A model-driven health system survey was designed to collect empirical data to inform parameter estimates in the surveillance cascade. Results Heterogeneity across health facilities was observed in the estimated probability of care-seeking (range = 0.01–0.21, mean ± sd = 0.09 ± 0.05) and testing for malaria (range = 0.00–1.00, mean ± sd = 0.16 ± 0.29). Care-seeking was higher at facilities regularly providing antimalarial drugs (Odds Ratio [OR] = 2.98, 95% Credible Intervals [CI]: 1.54–3.16). Predictably, the availability of functioning microscopy equipment was associated with increased odds of being tested for malaria (OR = 7.33, 95% CI = 20.61). Conclusions The methods for estimating facility-level malaria surveillance sensitivity presented here can help provide a benchmark for what constitutes a strong system. The proposed approach also enables programs to identify components of the health system that can be improved to strengthen surveillance and support public-health decision-making.
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Baird JK, Warsame M, Recht J. Survey and Analysis of Chemoprophylaxis Policies for Domestic Travel in Malaria-Endemic Countries. Trop Med Infect Dis 2022; 7:tropicalmed7070121. [PMID: 35878133 PMCID: PMC9325288 DOI: 10.3390/tropicalmed7070121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/23/2022] [Accepted: 05/31/2022] [Indexed: 02/04/2023] Open
Abstract
The prevention of malaria in travelers with the use of antimalarials often occurs in connection with international travel to areas of significant risk of infection. Although these travelers sometimes cause outbreaks in their malaria-free home countries, the cardinal objective of prescribed chemoprophylaxis is to protect the traveler from patent malaria during travel. Here we consider the chemoprophylaxis of domestic travelers from malaria-free but -receptive areas within malaria-endemic countries. The main objective in this setting is the protection of those areas from reintroduced malaria transmission. In order to better understand policy and practices in this regard, we surveyed malaria prevention and treatment guidelines of 36 malaria-endemic countries and 2 that have recently eliminated malaria (Sri Lanka, China) for recommendations regarding malaria chemoprophylaxis for domestic travel. Among them, just 8 provided specific and positive recommendations, 1 recommended without specific guidance, and 4 advised against the practice. Most nations (25/38; 66%) did not mention chemoprophylaxis for domestic travel, though many of those did offer guidance for international travel. The few positive recommendations for domestic travel were dominated by the suppressive prophylaxis options of daily doxycycline or atovaquone-proguanil or weekly mefloquine. The incomplete protection afforded by these strategies, along with impractical dosing in connection with the typically brief domestic travel, may in part explain the broad lack of policies and practices across malaria-endemic nations regarding chemoprophylaxis.
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Affiliation(s)
- John Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Jakarta 10430, Indonesia
- The Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
- Correspondence:
| | - Marian Warsame
- School of Public Health and Social Medicine, Institute of Medicine, Gothenburg University, 41390 Gothenburg, Sweden;
| | - Judith Recht
- Independent Researcher, North Bethesda, MD 20852, USA;
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Abstract
"The Primate Malarias" book has been a uniquely important resource for multiple generations of scientists, since its debut in 1971, and remains pertinent to the present day. Indeed, nonhuman primates (NHPs) have been instrumental for major breakthroughs in basic and pre-clinical research on malaria for over 50 years. Research involving NHPs have provided critical insights and data that have been essential for malaria research on many parasite species, drugs, vaccines, pathogenesis, and transmission, leading to improved clinical care and advancing research goals for malaria control, elimination, and eradication. Whilst most malaria scientists over the decades have been studying Plasmodium falciparum, with NHP infections, in clinical studies with humans, or using in vitro culture or rodent model systems, others have been dedicated to advancing research on Plasmodium vivax, as well as on phylogenetically related simian species, including Plasmodium cynomolgi, Plasmodium coatneyi, and Plasmodium knowlesi. In-depth study of these four phylogenetically related species over the years has spawned the design of NHP longitudinal infection strategies for gathering information about ongoing infections, which can be related to human infections. These Plasmodium-NHP infection model systems are reviewed here, with emphasis on modern systems biological approaches to studying longitudinal infections, pathogenesis, immunity, and vaccines. Recent discoveries capitalizing on NHP longitudinal infections include an advanced understanding of chronic infections, relapses, anaemia, and immune memory. With quickly emerging new technological advances, more in-depth research and mechanistic discoveries can be anticipated on these and additional critical topics, including hypnozoite biology, antigenic variation, gametocyte transmission, bone marrow dysfunction, and loss of uninfected RBCs. New strategies and insights published by the Malaria Host-Pathogen Interaction Center (MaHPIC) are recapped here along with a vision that stresses the importance of educating future experts well trained in utilizing NHP infection model systems for the pursuit of innovative, effective interventions against malaria.
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Affiliation(s)
- Mary R Galinski
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
- Emory Vaccine Center, Emory University, Atlanta, GA, USA.
- Emory National Primate Research Center (Yerkes National Primate Research Center), Emory University, Atlanta, GA, USA.
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Obaldía N, Barahona I, Lasso J, Avila M, Quijada M, Nuñez M, Marti M. Comparison of PvLAP5 and Pvs25 qRT-PCR assays for the detection of Plasmodium vivax gametocytes in field samples preserved at ambient temperature from remote malaria endemic regions of Panama. PLoS Negl Trop Dis 2022; 16:e0010327. [PMID: 35394999 PMCID: PMC9020738 DOI: 10.1371/journal.pntd.0010327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 04/20/2022] [Accepted: 03/14/2022] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND As the elimination of malaria in Mesoamerica progresses, detection of Plasmodium vivax using light microscopy (LM) becomes more difficult. Highly sensitive molecular tools have been developed to help determine the hidden reservoir of malaria transmission in low transmission settings. In this study we compare the performance of PvLAP5 and Pvs25 qRT-PCR assays to LM for the detection of Plasmodium vivax gametocytes in field samples preserved at ambient temperature from malaria endemic regions of Panama. METHODS For this purpose, we collected a total of 83 malaria field samples during 2017-2020 preserved in RNAprotect (RNAp) of which 63 (76%) were confirmed P. vivax by LM and selected for further analysis. Additionally, 16 blood samples from local healthy malaria smear negative volunteers, as well as, from 15 malaria naïve lab-bred Aotus monkeys were used as controls. To optimize the assays, we first determined the minimum blood volume sufficient for detection of PvLAP5 and Pv18SrRNA using P. vivax infected Aotus blood that was preserved in RNAp and kept either at ambient temperature for up to 8 days before freezing or was snap-frozen at -80° Celsius at the time of bleeding. We then compared the mean differences in gametocyte detection rates of both qRT-PCR assays to LM and performed a multivariate correlation analysis of study variables. Finally, we determined the sensitivity (Se) and specificity (Sp) of the assays at detecting gametocytes compared to LM. RESULTS Blood volume optimization indicated that a blood volume of at least 60 μL was sufficient for detection of PvLAP5 and Pv18SrRNA and no significant differences were found between RNA storage conditions. Both PvLAP5 and Pvs25 qRT-PCR assays showed a 37-39% increase in gametocyte detection rate compared to LM respectively. Strong positive correlations were found between gametocytemia and parasitemia and both PvLAP5 and Pvs25 gametocyte markers. However, no significant differences were detected in the Se and Sp of the Pvs25 and PvLAP5 qRT-PCR assays, even though data from control samples suggested Pvs25 to be more abundant than PvLAP5. CONCLUSIONS This study shows that the PvLAP5 qRT-PCR assay is as Se and Sp as the gold standard Pvs25 assay and is at least 37% more sensitive than LM at detecting P. vivax gametocytes in field samples preserved in RNAp at ambient temperature from malaria endemic regions of Panama. AUTHOR SUMMARY Plasmodium vivax is one of the five species of malaria (P. falciparum, P. malariae, P. ovale and P. knowlesi) that are transmitted to man by the bite of female anopheles mosquitoes. It causes ~14.3 million cases mainly in Southeast Asia, India, the Western Pacific and the Americas annually. In the Americas, malaria remains a major problem in underdeveloped areas and indigenous communities in the Amazon region and eastern Panama, where it is endemic and difficult to eliminate. As malaria elimination progresses, detection of P. vivax by light microscopy (LM) becomes more difficult. Therefore, highly sensitive molecular tools have been developed that use genetic markers for the parasite to help determine the hidden reservoir of malaria transmission. This study compares the performance of two molecular assays based on the genetic markers of mature gametocytes PvLAP5 and Pvs25 with LM. The study shows that the PvLAP5 qRT-PCR assay is as sensitive and specific as the gold standard Pvs25 assay and is at least 37% more sensitive than LM at detecting P. vivax gametocytes. These data suggest that the PvLAP5 qRT-PCR assay can be a useful tool to help determine the hidden reservoir of transmission in endemic foci approaching elimination.
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Affiliation(s)
- Nicanor Obaldía
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
- Department of Immunology and Infectious Diseases, Harvard T.H. CHAN School of Public Health, Boston, Massachusetts, United States of America
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Itza Barahona
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - José Lasso
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - Mario Avila
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - Mario Quijada
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
| | - Marlon Nuñez
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard T.H. CHAN School of Public Health, Boston, Massachusetts, United States of America
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
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