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Lokole PB, Byamungu GG, Mutwale PK, Ngombe NK, Mudogo CN, Krause RWM, Nkanga CI. Plant-based nanoparticles targeting malaria management. Front Pharmacol 2024; 15:1440116. [PMID: 39185312 PMCID: PMC11341498 DOI: 10.3389/fphar.2024.1440116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 07/18/2024] [Indexed: 08/27/2024] Open
Abstract
Malaria is one of the most devastating diseases across the globe, particularly in low-income countries in Sub-Saharan Africa. The increasing incidence of malaria morbidity is mainly due to the shortcomings of preventative measures such as the lack of vaccines and inappropriate control over the parasite vector. Additionally, high mortality rates arise from therapeutic failures due to poor patient adherence and drug resistance development. Although the causative pathogen (Plasmodium spp.) is an intracellular parasite, the recommended antimalarial drugs show large volumes of distribution and low-to no-specificity towards the host cell. This leads to severe side effects that hamper patient compliance and promote the emergence of drug-resistant strains. Recent research efforts are promising to enable the discovery of new antimalarial agents; however, the lack of efficient means to achieve targeted delivery remains a concern, given the risk of further resistance development. New strategies based on green nanotechnologies are a promising avenue for malaria management due to their potential to eliminate malaria vectors (Anopheles sp.) and to encapsulate existing and emerging antimalarial agents and deliver them to different target sites. In this review we summarized studies on the use of plant-derived nanoparticles as cost-effective preventative measures against malaria parasites, starting from the vector stage. We also reviewed plant-based nanoengineering strategies to target malaria parasites, and further discussed the site-specific delivery of natural products using ligand-decorated nanoparticles that act through receptors on the host cells or malaria parasites. The exploration of traditionally established plant medicines, surface-engineered nanoparticles and the molecular targets of parasite/host cells may provide valuable insights for future discovery of antimalarial drugs and open new avenues for advancing science toward the goal of malaria eradication.
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Affiliation(s)
- Pathy B. Lokole
- Centre de Recherche en Nanotechnologies Appliquées aux Produits Naturels (CReNAPN), Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Centre d’Etudes des Substances Naturelles d’Origine Végétale (CESNOV), Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Center for Chemico- and Bio-Medicinal Research (CCBR), Department of Chemistry, Faculty of Sciences, Rhodes University, Grahamstown, Eastern Cape, South Africa
| | - Galilée G. Byamungu
- Centre de Recherche en Nanotechnologies Appliquées aux Produits Naturels (CReNAPN), Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Center for Chemico- and Bio-Medicinal Research (CCBR), Department of Chemistry, Faculty of Sciences, Rhodes University, Grahamstown, Eastern Cape, South Africa
- Department of Chemistry, Faculty of Sciences and Technology, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Paulin K. Mutwale
- Centre de Recherche en Nanotechnologies Appliquées aux Produits Naturels (CReNAPN), Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Centre d’Etudes des Substances Naturelles d’Origine Végétale (CESNOV), Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Nadège K. Ngombe
- Centre de Recherche en Nanotechnologies Appliquées aux Produits Naturels (CReNAPN), Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Centre d’Etudes des Substances Naturelles d’Origine Végétale (CESNOV), Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Celestin N. Mudogo
- Unit of Molecular Biology, Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Rui W. M. Krause
- Center for Chemico- and Bio-Medicinal Research (CCBR), Department of Chemistry, Faculty of Sciences, Rhodes University, Grahamstown, Eastern Cape, South Africa
| | - Christian I. Nkanga
- Centre de Recherche en Nanotechnologies Appliquées aux Produits Naturels (CReNAPN), Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
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Abstract
Severe malaria is a medical emergency. It is a major cause of preventable childhood death in tropical countries. Severe malaria justifies considerable global investment in malaria control and elimination yet, increasingly, international agencies, funders and policy makers are unfamiliar with it, and so it is overlooked. In sub-Saharan Africa, severe malaria is overdiagnosed in clinical practice. Approximately one third of children diagnosed with severe malaria have another condition, usually sepsis, as the cause of their severe illness. But these children have a high mortality, contributing substantially to the number of deaths attributed to ‘severe malaria’. Simple well-established tests, such as examination of the thin blood smear and the full blood count, improve the specificity of diagnosis and provide prognostic information in severe malaria. They should be performed more widely. Early administration of artesunate and broad-spectrum antibiotics to all children with suspected severe malaria would reduce global malaria mortality.
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Affiliation(s)
- Nicholas J White
- Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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3
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Watson JA, Uyoga S, Wanjiku P, Makale J, Nyutu GM, Mturi N, George EC, Woodrow CJ, Day NPJ, Bejon P, Opoka RO, Dondorp AM, John CC, Maitland K, Williams TN, White NJ. Improving the diagnosis of severe malaria in African children using platelet counts and plasma PfHRP2 concentrations. Sci Transl Med 2022; 14:eabn5040. [PMID: 35857826 PMCID: PMC7613613 DOI: 10.1126/scitranslmed.abn5040] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Severe malaria caused by Plasmodium falciparum is difficult to diagnose accurately in children in high-transmission settings. Using data from 2649 pediatric and adult patients enrolled in four studies of severe illness in three countries (Bangladesh, Kenya, and Uganda), we fitted Bayesian latent class models using two diagnostic markers: the platelet count and the plasma concentration of P. falciparum histidine-rich protein 2 (PfHRP2). In severely ill patients with clinical features consistent with severe malaria, the combination of a platelet count of ≤150,000/μl and a plasma PfHRP2 concentration of ≥1000 ng/ml had an estimated sensitivity of 74% and specificity of 93% in identifying severe falciparum malaria. Compared with misdiagnosed children, pediatric patients with true severe malaria had higher parasite densities, lower hematocrits, lower rates of invasive bacterial disease, and a lower prevalence of both sickle cell trait and sickle cell anemia. We estimate that one-third of the children enrolled into clinical studies of severe malaria in high-transmission settings in Africa had another cause of their severe illness.
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Affiliation(s)
- James A. Watson
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK,Corresponding author.
| | - Sophie Uyoga
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Perpetual Wanjiku
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Johnstone Makale
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Gideon M. Nyutu
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Neema Mturi
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Elizabeth C. George
- Medical Research Council Clinical Trials Unit, University College London, London, UK
| | - Charles J. Woodrow
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas P. J. Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Philip Bejon
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK,KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya
| | - Robert O. Opoka
- Makerere University, Department of Paediatrics and Child Health, Kampala, Uganda
| | - Arjen M. Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chandy C. John
- Department of Pediatrics, Indiana University, Indiana, IN, USA
| | - Kathryn Maitland
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya,Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College, London, UK
| | - Thomas N. Williams
- KEMRI Wellcome Trust Research Programme, Centre for Geographic Medicine Research, Coast, Kilifi 80108, Kenya,Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College, London, UK
| | - Nicholas J. White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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4
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Uyoga S, Wanjiku P, Rop JC, Makale J, Macharia AW, Nyutu GM, Shebe M, Awuondo KA, Mturi N, Woodrow CJ, Dondorp AM, Maitland K, Williams TN. Plasma Plasmodium falciparum Histidine-Rich Protein-2 concentrations in children with malaria infections of differing severity in Kilifi, Kenya. Clin Infect Dis 2020; 73:e2415-e2423. [PMID: 32772115 PMCID: PMC8492128 DOI: 10.1093/cid/ciaa1141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Indexed: 11/13/2022] Open
Abstract
Background Most previous studies support a direct link between total parasite load and the clinical severity of Plasmodium falciparum malaria infections. Methods We estimated P. falciparum parasite loads in 3 groups of children with malaria infections of differing severity: (1) children with World Health Organization–defined severe malaria (n = 1544), (2) children admitted with malaria but without features of severity (n = 200), and (3) children in the community with asymptomatic parasitemia (n = 33). Results Peripheral parasitemias were highest in those with uncomplicated malaria (geometric mean [GM] parasite count, 111 064/μL; 95% confidence interval, CI, 86 798–141 819/μL), almost 3 times higher than in those with severe malaria (39 588/μL; 34 990–44 791/μL) and >100 times higher than in those with asymptomatic malaria (1092/μL; 523–2280/μL). However, the GM P. falciparum histidine-rich protein 2 (PfHRP2) values (95% CI) increased with severity, being 7 (4–12) ng/mL in asymptomatic malaria, 843 (655–1084) ng/mL in uncomplicated malaria, and 1369 (1244–1506) ng/mL in severe malaria. PfHRP2 concentrations were markedly lower in the subgroup of patients with severe malaria and concomitant invasive bacterial infections of blood or cerebrospinal fluid (GM concentration, 312 ng/mL; 95% CI, 175–557 ng/mL; P < .001) than in those without such infections (1439 ng/mL; 1307–1584; P < .001). Conclusions The clinical severity of malaria infections related strongly to the total burden of P. falciparum parasites. A quantitative test for plasma concentrations of PfHRP2 could be useful in identifying children at the greatest clinical risk and identifying critically ill children in whom malaria is not the primary cause.
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Affiliation(s)
- Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Jesse C Rop
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | | | | | | | - Neema Mturi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Charles J Woodrow
- Mahidol-Oxford Research Unit,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health,Nuffield Department of Medicine,University of Oxford, UK
| | - Arjen M Dondorp
- Mahidol-Oxford Research Unit,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health,Nuffield Department of Medicine,University of Oxford, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Infectious Diseases, Imperial College, London, UK
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Infectious Diseases, Imperial College, London, UK
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5
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HRP2: Transforming Malaria Diagnosis, but with Caveats. Trends Parasitol 2020; 36:112-126. [DOI: 10.1016/j.pt.2019.12.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 11/23/2022]
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Njuguna P, Maitland K, Nyaguara A, Mwanga D, Mogeni P, Mturi N, Mohammed S, Mwambingu G, Ngetsa C, Awuondo K, Lowe B, Adetifa I, Scott JAG, Williams TN, Atkinson S, Osier F, Snow RW, Marsh K, Tsofa B, Peshu N, Hamaluba M, Berkley JA, Newton CRJ, Fondo J, Omar A, Bejon P. Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya. BMC Med 2019; 17:124. [PMID: 31280724 PMCID: PMC6613255 DOI: 10.1186/s12916-019-1359-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 06/04/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of reductions in transmission. We examined the clinical spectrum of disease and predictors of mortality after sustained changes in transmission intensity, using data collected from 1989 to 2016. METHODS We conducted a temporal observational analysis of 18,000 children, aged 14 days to 14 years old, who were admitted to Kilifi County Hospital, Kenya, from 1989 to 2016 with malaria. We describe the trends over time of the clinical and laboratory criteria for severe malaria and associated risk of mortality. RESULTS During the time periods 1989-2003, 2004-2008, and 2009-2016, Kilifi County Hospital admitted averages of 657, 310, and 174 cases of severe malaria per year including averages of 48, 14, and 12 malaria-associated deaths per year, respectively. The median ages in years of children admitted with cerebral malaria, severe anaemia, and malaria-associated mortality were 3.0 (95% confidence interval (CI) 2.2-3.9), 1.1 (95% CI 0.9-1.4), and 1.1 (95% CI 0.3-2.2) in the year 1989, rising to 4.9 (95% CI 3.9-5.9), 3.8 (95% CI 2.5-7.1), and 5 (95% CI 3.3-6.3) in the year 2016. The ratio of children with cerebral malaria to severe anaemia rose from 1:2 before 2004 to 3:2 after 2009. Hyperparasitaemia was a risk factor for death after 2009 but not in earlier time periods. CONCLUSION Despite the evidence of slower acquisition of immunity, continued reductions in the numbers of cases of severe malaria resulted in lower overall mortality. Our temporal data are limited to a single site, albeit potentially applicable to a secular trend present in many parts of Africa.
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Affiliation(s)
- Patricia Njuguna
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Department of Paediatrics, Faculty of Medicine, Imperial College, London, UK
| | - Amek Nyaguara
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Daniel Mwanga
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Polycarp Mogeni
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Neema Mturi
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Shebe Mohammed
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Gabriel Mwambingu
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Caroline Ngetsa
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Kenedy Awuondo
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Brett Lowe
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ifedayo Adetifa
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,London School of Hygiene and Tropical Medicine, London, UK
| | - J Anthony G Scott
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,London School of Hygiene and Tropical Medicine, London, UK
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Department of Paediatrics, Faculty of Medicine, Imperial College, London, UK
| | - Sarah Atkinson
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Department of Paediatrics, University of Oxford, Oxford, UK
| | - Faith Osier
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Robert W Snow
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kevin Marsh
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Benjamin Tsofa
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Norbert Peshu
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - Mainga Hamaluba
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya
| | - James A Berkley
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Charles R J Newton
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.,Department of Psychiatry, University of Oxford, Oxford, UK
| | - John Fondo
- Kilifi County Department of Health, Kilifi, Kenya
| | - Anisa Omar
- Kilifi County Department of Health, Kilifi, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRI, PO Box 230, Kilifi, Kenya.
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Abstract
Cerebral malaria is one of the most severe complications of human infection by the Plasmodium falciparum parasite. In this issue of Cell Host & Microbe, Kessler et al. (2017) provide valuable insights into the diagnosis and pathogenesis of this poorly understood manifestation of malaria.
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Affiliation(s)
- Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
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8
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Plucinski MM, Dimbu PR, Fortes F, Abdulla S, Ahmed S, Gutman J, Kachur SP, Badiane A, Ndiaye D, Talundzic E, Lucchi N, Aidoo M, Udhayakumar V, Halsey E, Rogier E. Posttreatment HRP2 Clearance in Patients with Uncomplicated Plasmodium falciparum Malaria. J Infect Dis 2018; 217:685-692. [PMID: 29220497 PMCID: PMC11023016 DOI: 10.1093/infdis/jix622] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/04/2017] [Indexed: 11/13/2022] Open
Abstract
Background The response to antimalarial treatment is assessed using serial microscopy. New techniques for accurate measurement of the Plasmodium falciparum histidine-rich protein 2 (HRP2) antigen have allowed for monitoring of the antigen concentration over time, offering a potential alternative for assessing treatment response. Methods Posttreatment HRP2 concentrations were measured in samples obtained longitudinally from 537 individuals with P. falciparum malaria who were participating in efficacy trials in Angola, Tanzania, and Senegal. The HRP2 half-life was estimated using a first-order kinetics clearance model. The association between the HRP2 concentration 3 days after treatment and recrudescence of infection was assessed. Results Despite substantial variation in HRP2 concentrations among participants at baseline, concentrations consistently showed a first-order exponential decline. The median half-life of HRP2 was estimated to be 4.5 days (interquartile range [IQR], 3.3-6.6 days) in Angola, 4.7 days (IQR, 4.0-5.9 days) in Tanzania, and 3.0 days (IQR, 2.1-4.5 days) in Senegal. The day 3 HRP2 concentration was predictive of eventual recrudescence, with an area under the receiver operating characteristic curve of 0.86 (95% confidence interval, .73-.99). Conclusions Consistent HRP2 clearance dynamics following successful antimalarial treatment imply a common underlying mechanism of biological clearance. Patients who ultimately did not respond to treatment did not exhibit this same pattern of clearance, even in the absence of other indications of inadequate response to treatment.
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Affiliation(s)
- Mateusz M Plucinski
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Filomeno Fortes
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Salim Abdulla
- Ifakara Health Institute, Ifakara Health Research and Development Center, Tanzania
| | - Saumu Ahmed
- Ifakara Health Institute, Ifakara Health Research and Development Center, Tanzania
| | - Julie Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - S Patrick Kachur
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Aida Badiane
- School of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University, Dakar, Senegal
| | - Daouda Ndiaye
- School of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University, Dakar, Senegal
| | - Eldin Talundzic
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Naomi Lucchi
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Aidoo
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Venkatachalam Udhayakumar
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Halsey
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Rogier
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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9
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Makuuchi R, Jere S, Hasejima N, Chigeda T, Gausi J. The correlation between malaria RDT (Paracheck pf.®) faint test bands and microscopy in the diagnosis of malaria in Malawi. BMC Infect Dis 2017; 17:317. [PMID: 28464837 PMCID: PMC5414284 DOI: 10.1186/s12879-017-2413-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 04/21/2017] [Indexed: 11/25/2022] Open
Abstract
Background Faint test bands of Paracheck Pf.® are interpreted as malaria positive according to world health organization (WHO) guideline. However if there are conspicuous number of faint test bands, a performance of Paracheck Pf.® could be influenced depending on whether interpreting faint test bands as malaria positive or negative. Finding out the frequency and accurate interpretation of faint test bands are important to prevent the overdiagnosis and drug resistance. Methods A cross-sectional, descriptive study was conducted to find out the frequency of faint test bands and evaluate the performance of Paracheck Pf.® by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosis of Paracheck Pf.® using microscopy as the gold standard. 388 suspected patients with malaria in Malawi were recruited in this study. Malaria rapid diagnostic tests (RDTs) and microscopy were used and patients’ information which includes age, sex, body temperature and signs or symptoms of malaria were recorded. Results Among all patients involved in the study, 29.1% (113/388) were found malaria positive by RDT. Overall 5.4% (21/388) of all Paracheck Pf.® tests resulted in a “faint test band” and 85.7% (18/21) corresponded with malaria negative by microscopy. Faint test bands which corresponded with malaria positive by microscopy were lower parasite density and there are no patients who showed definitive symptom of malaria, such as fever. When Paracheck Pf.® “faint test bands” were classified as positive, accuracy of diagnosis was 76.5% (95% CI 72%–80.7%) as compared to 80.4% (95% CI 76.1%–84.2%) when Paracheck Pf.® “faint test bands” were classified as negative. Conclusions This study shows that frequency of faint test bands is 5.4% in all malaria RDTs. The accuracy of diagnosis was improved when faint test bands were interpreted as malaria negative. However information and data obtained in this study may not be enough and more intensive research including a frequency and property of faint test bands is needed for significant interpretation of faint test bands.
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Affiliation(s)
- Ryoko Makuuchi
- Nippon International Cooperation for Community Development, 101 Nishi-rokkaku-cho, Nakagyo-ku, Kyoto, 604-8217, Japan.
| | - Sandy Jere
- Ministry of health, Community Health Science Unit, PO Box 30377, Lilongwe, Malawi
| | - Nobuchika Hasejima
- Nippon International Cooperation for Community Development, 101 Nishi-rokkaku-cho, Nakagyo-ku, Kyoto, 604-8217, Japan
| | - Thoms Chigeda
- Lilongwe District Health Office, PO Box 1274, Lilongwe, Malawi
| | - January Gausi
- Lilongwe District Health Office, PO Box 1274, Lilongwe, Malawi
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10
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Rogier E, Plucinski M, Lucchi N, Mace K, Chang M, Lemoine JF, Candrinho B, Colborn J, Dimbu R, Fortes F, Udhayakumar V, Barnwell J. Bead-based immunoassay allows sub-picogram detection of histidine-rich protein 2 from Plasmodium falciparum and estimates reliability of malaria rapid diagnostic tests. PLoS One 2017; 12:e0172139. [PMID: 28192523 PMCID: PMC5305216 DOI: 10.1371/journal.pone.0172139] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/31/2017] [Indexed: 11/18/2022] Open
Abstract
Detection of histidine-rich protein 2 (HRP2) from the malaria parasite Plasmodium falciparum provides evidence for active or recent infection, and is utilized for both diagnostic and surveillance purposes, but current laboratory immunoassays for HRP2 are hindered by low sensitivities and high costs. Here we present a new HRP2 immunoassay based on antigen capture through a bead-based system capable of detecting HRP2 at sub-picogram levels. The assay is highly specific and cost-effective, allowing fast processing and screening of large numbers of samples. We utilized the assay to assess results of HRP2-based rapid diagnostic tests (RDTs) in different P. falciparum transmission settings, generating estimates for true performance in the field. Through this method of external validation, HRP2 RDTs were found to perform well in the high-endemic areas of Mozambique and Angola with 86.4% and 73.9% of persons with HRP2 in their blood testing positive by RDTs, respectively, and false-positive rates of 4.3% and 0.5%. However, in the low-endemic setting of Haiti, only 14.5% of persons found to be HRP2 positive by the bead assay were RDT positive. Additionally, 62.5% of Haitians showing a positive RDT test had no detectable HRP2 by the bead assay, likely indicating that these were false positive tests. In addition to RDT validation, HRP2 biomass was assessed for the populations in these different settings, and may provide an additional metric by which to estimate P. falciparum transmission intensity and measure the impact of interventions.
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Affiliation(s)
- Eric Rogier
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
- * E-mail:
| | - Mateusz Plucinski
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
| | - Naomi Lucchi
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
| | - Kimberly Mace
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
| | - Michelle Chang
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
| | - Jean Frantz Lemoine
- Programme National de Contrôle de la Malaria, Ministère de la Santé Publique et de la Population (MSPP), Port-au-Prince, Haiti
| | | | - James Colborn
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| | - Rafael Dimbu
- National Malaria Control Program, Luanda, Angola
| | | | - Venkatachalam Udhayakumar
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
| | - John Barnwell
- The Centers for Disease Control and Prevention, Center for Global Health, Division of Parasitic Diseases and Malaria, Malaria Branch, Atlanta, GA, United States of America
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11
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Prevalence of pfhrp2 and/or pfhrp3 Gene Deletion in Plasmodium falciparum Population in Eight Highly Endemic States in India. PLoS One 2016; 11:e0157949. [PMID: 27518538 PMCID: PMC4982695 DOI: 10.1371/journal.pone.0157949] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 06/07/2016] [Indexed: 11/25/2022] Open
Abstract
Background Plasmodium falciparum encoded histidine rich protein (HRP2) based malaria rapid diagnostic tests (RDTs) are used in India. Deletion of pfhrp2 and pfhrp3 genes contributes to false negative test results, and large numbers of such deletions have been reported from South America, highlighting the importance of surveillance to detect such deletions. Methods This is the first prospective field study carried out at 16 sites located in eight endemic states of India to assess the performance of PfHRP2 based RDT kits used in the national malaria control programme. In this study, microscopically confirmed P. falciparum but RDT negative samples were assessed for presence of pfhrp2, pfhrp3, and their flanking genes using PCR. Results Among 1521 microscopically positive P. falciparum samples screened, 50 were negative by HRP2 based RDT test. Molecular testing was carried out using these 50 RDT negative samples by assuming that 1471 RDT positive samples carried pfhrp2 gene. It was found that 2.4% (36/1521) and 1.8% (27/1521) of samples were negative for pfhrp2 and pfhrp3 genes, respectively. However, the frequency of pfhrp2 deletions varied between the sites ranging from 0–25% (2.4, 95% CI; 1.6–3.3). The frequency of both pfhrp2 and pfhrp3 gene deletion varied from 0–8% (1.6, 95% CI; 1.0–2.4). Conclusion This study provides evidence for low level presence of pfhrp2 and pfhrp3 deleted P. falciparum parasites in different endemic regions of India, and periodic surveillance is warranted for reliable use of PfHRP2 based RDTs.
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