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McNitt SA, Dick JK, Hernandez Castaneda M, Sangala JA, Pierson M, Macchietto M, Burrack KS, Crompton PD, Seydel KB, Hamilton SE, Hart GT. Phenotype and function of IL-10 producing NK cells in individuals with malaria experience. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.11.593687. [PMID: 38798324 PMCID: PMC11118352 DOI: 10.1101/2024.05.11.593687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Plasmodium falciparum infection can trigger high levels of inflammation that lead to fever and sometimes severe disease. People living in malaria-endemic areas gradually develop resistance to symptomatic malaria and control both parasite numbers and the inflammatory response. We previously found that adaptive natural killer (NK) cells correlate with reduced parasite load and protection from symptoms. We also previously found that murine NK cell production of IL-10 can protect mice from experimental cerebral malaria. Human NK cells can also secrete IL-10, but it was unknown what NK cell subsets produce IL-10 and if this is affected by malaria experience. We hypothesize that NK cell immunoregulation may lower inflammation and reduce fever induction. Here, we show that NK cells from subjects with malaria experience make significantly more IL-10 than subjects with no malaria experience. We then determined the proportions of NK cells that are cytotoxic and produce interferon gamma and/or IL-10 and identified a signature of adaptive and checkpoint molecules on IL-10-producing NK cells. Lastly, we find that co-culture with primary monocytes, Plasmodium -infected RBCs, and antibody induces IL-10 production by NK cells. These data suggest that NK cells may contribute to protection from malaria symptoms via IL-10 production.
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2
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Li J, Saidi AM, Seydel K, Lillehoj PB. Rapid diagnosis and prognosis of malaria infection using a microfluidic point-of-care immunoassay. Biosens Bioelectron 2024; 250:116091. [PMID: 38325074 DOI: 10.1016/j.bios.2024.116091] [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: 11/15/2023] [Revised: 01/23/2024] [Accepted: 01/28/2024] [Indexed: 02/09/2024]
Abstract
Malaria is a major cause of illness and death worldwide. Rapid diagnostic tests are the most widely used tool for detecting malaria infection, however, they only provide binary results and lack the sensitivity needed to detect many asymptomatic infections. Molecular assays for quantifying malaria biomarkers offer higher detection sensitivity, however, they are time-consuming, and require expert training and expensive equipment, making them unsuitable for use in most of Africa. To address the need for simple, accurate and field-deployable malaria diagnostic tests, we have developed a microfluidic point-of-care (mPOC) immunoassay for rapid quantification of Plasmodium falciparum histidine-rich protein 2 (PfHRP2), a malaria parasite biomarker, in whole blood. This device features two diagnostic modes for detecting PfHRP2 at low (100's pg/mL) and high (1,000's ng/mL) concentrations, making it useful for multiple diagnostic applications, including the detection of asymptomatic infection, prediction of disease outcomes and diagnosis of cerebral malaria. Measurements of PfHRP2 in blood samples from malaria patients demonstrates that this platform offers similar accuracy as an ultra-sensitive PfHRP2 enzyme-linked immunosorbent assay (ELISA) test, while being 12× faster and simpler to use. This mPOC immunoassay can be deployed in rural health centers to assist clinicians in diagnosing and triaging malaria patients, ultimately improving patient outcomes.
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Affiliation(s)
- Jiran Li
- Department of Mechanical Engineering, Rice University, Houston, TX 77005, USA
| | - Alexuse M Saidi
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Karl Seydel
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi; Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48864, USA
| | - Peter B Lillehoj
- Department of Mechanical Engineering, Rice University, Houston, TX 77005, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA.
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3
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Nguyen ST, Du D, Wychrij D, Cain MD, Wu Q, Klein RS, Russo I, Goldberg DE. Histidine-rich protein II nanoparticle delivery of heme iron load drives endothelial inflammation in cerebral malaria. Proc Natl Acad Sci U S A 2023; 120:e2306318120. [PMID: 37307435 PMCID: PMC10293821 DOI: 10.1073/pnas.2306318120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/19/2023] [Indexed: 06/14/2023] Open
Abstract
Histidine-rich protein II (HRPII) is secreted by Plasmodium falciparum during the blood stage of malaria infection. High plasma levels of HRPII are associated with cerebral malaria, a severe and highly fatal complication of malaria. HRPII has been shown to induce vascular leakage, the hallmark of cerebral malaria, in blood-brain barrier (BBB) and animal models. We have discovered an important mechanism for BBB disruption that is driven by unique features of HRPII. By characterizing serum from infected patients and HRPII produced by P. falciparum parasites in culture, we found that HRPII exists in large multimeric particles of 14 polypeptides that are richly laden with up to 700 hemes per particle. Heme loading of HRPII is required for efficient binding and internalization via caveolin-mediated endocytosis in hCMEC/D3 cerebral microvascular endothelial cells. Upon acidification of endolysosomes, two-thirds of the hemes are released from acid-labile binding sites and metabolized by heme oxygenase 1, generating ferric iron and reactive oxygen species. Subsequent activation of the NLRP3 inflammasome and IL-1β secretion resulted in endothelial leakage. Inhibition of these pathways with heme sequestration, iron chelation, or anti-inflammatory drugs protected the integrity of the BBB culture model from HRPII:heme. Increased cerebral vascular permeability was seen after injection of young mice with heme-loaded HRPII (HRPII:heme) but not with heme-depleted HRPII. We propose that during severe malaria infection, HRPII:heme nanoparticles in the bloodstream deliver an overwhelming iron load to endothelial cells to cause vascular inflammation and edema. Disrupting this process is an opportunity for targeted adjunctive therapies to reduce the morbidity and mortality of cerebral malaria.
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Affiliation(s)
- Suong T. Nguyen
- Division of Infectious Diseases, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO63110
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Daniel Du
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Daniel Wychrij
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Matthew D. Cain
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Qingping Wu
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Robyn S. Klein
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Ilaria Russo
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
| | - Daniel E. Goldberg
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO63110
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO63110
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4
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Lin Y, Tebulo A, Small D, Seydel K, Taylor T, Zhang B. Using Malarial Retinopathy to Improve the Diagnosis of Pediatric Cerebral Malaria. Am J Trop Med Hyg 2023; 108:69-75. [PMID: 36509055 PMCID: PMC9833082 DOI: 10.4269/ajtmh.22-0547] [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: 08/24/2022] [Accepted: 10/03/2022] [Indexed: 12/14/2022] Open
Abstract
In malaria endemic areas, a high proportion of children have detectable parasitemia but show no clinical symptoms. When comatose from a cause other than malaria, this group confounds the cerebral malaria (CM) definition, making accurate diagnosis challenging. One important biomarker of CM is malarial retinopathy, a set of specific features visible in the ocular fundus. In this study, we quantified the contribution of malarial retinopathy in discriminating malaria-caused coma from non-malaria-caused coma. We estimated that 10% of our study cohort of N = 1,192 patients who met the WHO clinical definition of CM in Malawi had non-malarial coma based on a Gaussian mixture model using the parasite protein Plasmodium falciparum histidine-rich protein-2. A classification based on platelets, white blood cells, and retinopathy significantly improved the discriminative power of a previously established model including only platelets plus white blood cells (area under the receiver operating characteristic curve: 0.89 versus 0.75, P value < 0.001). We conclude that malarial retinopathy is highly predictive of malaria-caused versus non-malaria-caused coma and recommend that an ocular funduscopic examination to determine malarial retinopathy status be included in the assessment of parasitemic comatose African children.
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Affiliation(s)
- Yuzhou Lin
- Department of Statistics, Harvard University, Cambridge, Massachusetts
| | - Andrew Tebulo
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Dylan Small
- Department of Statistics and Data Science, The Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Karl Seydel
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, Michigan
| | - Terrie Taylor
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, Michigan
| | - Bo Zhang
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, Washington
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5
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Application of egg yolk IgY on carboxylated polypyrrole films for impedimetric detection of PfHRP2 antigen. Bioelectrochemistry 2022; 148:108273. [DOI: 10.1016/j.bioelechem.2022.108273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022]
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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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Uyoga S, Olupot-Olupot P, Connon R, Kiguli S, Opoka RO, Alaroker F, Muhindo R, Macharia AW, Dondorp AM, Gibb DM, Walker AS, George EC, Maitland K, Williams TN. Sickle cell anaemia and severe Plasmodium falciparum malaria: a secondary analysis of the Transfusion and Treatment of African Children Trial (TRACT). THE LANCET. CHILD & ADOLESCENT HEALTH 2022; 6:606-613. [PMID: 35785794 PMCID: PMC7613576 DOI: 10.1016/s2352-4642(22)00153-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND Sickle cell anaemia (SCA) has historically been associated with high levels of childhood mortality in Africa. Although malaria has a major contribution to this mortality, to date, the clinical pathology of malaria among children with SCA has been poorly described. We aimed to explore the relationship between SCA and Plasmodium falciparum malaria in further detail by investigating the burden and severity of malaria infections among children recruited with severe anaemia to the TRACT trial of blood transfusion in Africa. METHODS This study is a post-hoc secondary analysis of the TRACT trial data, conducted after trial completion. TRACT was an open-label, multicentre, factorial, randomised controlled trial enrolling children aged 2 months to 12 years who presented with severe anaemia (haemoglobin <6·0 g/dL) to four hospitals in Africa. This secondary analysis is restricted to Uganda, where the birth prevalence of SCA is approximately 1% and malaria transmission is high. Children were classified as normal (HbAA), heterozygous (HbAS), or homozygous (HbSS; SCA) for the rs334 A→T sickle mutation in HBB following batch-genotyping by PCR at the end of the trial. To avoid confounding from SCA-specific medical interventions, we considered children with an existing diagnosis of SCA (known SCA) separately from those diagnosed at the end of the trial (unknown SCA). The outcomes considered in this secondary analysis were measures of P falciparum parasite burden, features of severe malaria, and mortality at day 28 in malaria-positive children. FINDINGS Between Sept 17, 2014, and May 15, 2017, 3944 children with severe anaemia were enrolled into the TRACT trial. 3483 children from Uganda were considered in this secondary analysis. Overall, 1038 (30%) of 3483 Ugandan children had SCA. 1815 (78%) of 2321 children without SCA (HbAA) tested positive for P falciparum malaria, whereas the prevalence was significantly lower in children with SCA (347 [33%] of 1038; p<0·0001). Concentrations of plasma P falciparum histidine-rich protein 2 (PfHRP2), a marker of the total burden of malaria parasites within an individual, were significantly lower in children with either known SCA (median 8 ng/mL; IQR 0-57) or unknown SCA (7 ng/mL; 0-50) than in HbAA children (346 ng/mL; 21-2121; p<0·0001). In contrast to HbAA children, few HbSS children presented with classic features of severe and complicated malaria, but both the frequency and severity of anaemia were higher in HbSS children. We found no evidence for increased mortality at day 28 in those with SCA compared with those without SCA overall (hazard ratios 1·07 [95% CI 0·31-3·76] for known SCA and 0·67 [0·15-2·90] for unknown SCA). INTERPRETATION The current study suggests that children with SCA are innately protected against classic severe malaria. However, it also shows that even low-level infections can precipitate severe anaemic crises that would likely prove fatal without rapid access to blood transfusion services. FUNDING UK Medical Research Council, Wellcome, and UK National Institute for Health and Care Research.
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Affiliation(s)
- Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Peter Olupot-Olupot
- Busitema University Faculty of Health Sciences, Mbale Regional Referral Hospital, Mbale, Uganda; Mbale Clinical Research Institute, Mbale, Uganda
| | - Roisin Connon
- Medical Research Council Clinical Trials Unit (MRC CTU) at University College London, London, UK
| | - Sarah Kiguli
- Department of Paediatrics and Child Health, School of Medicine, Makerere University, Kampala, Uganda
| | - Robert O Opoka
- Department of Paediatrics and Child Health, School of Medicine, Makerere University, Kampala, Uganda
| | | | - Rita Muhindo
- Mbale Clinical Research Institute, Mbale, Uganda
| | | | - Arjen M Dondorp
- Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Diana M Gibb
- Medical Research Council Clinical Trials Unit (MRC CTU) at University College London, London, UK
| | - A Sarah Walker
- Medical Research Council Clinical Trials Unit (MRC CTU) at University College London, London, UK
| | - Elizabeth C George
- Medical Research Council Clinical Trials Unit (MRC CTU) at University College London, London, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Department of Infectious Disease and Institute of Global Health Innovation, Division of Medicine, Imperial College London, London, UK
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Department of Infectious Disease and Institute of Global Health Innovation, Division of Medicine, Imperial College London, London, UK.
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8
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Dao F, Djonor SK, Ayin CTM, Adu GA, Sarfo B, Nortey P, Akuffo KO, Danso-Appiah A. Burden of malaria in children under five and caregivers' health-seeking behaviour for malaria-related symptoms in artisanal mining communities in Ghana. Parasit Vectors 2021; 14:418. [PMID: 34419123 PMCID: PMC8380373 DOI: 10.1186/s13071-021-04919-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/02/2021] [Indexed: 01/21/2023] Open
Abstract
Background Artisanal mining creates enabling breeding ground for the vector of malaria parasites. There is paucity of data on the effects of artisanal mining on malaria. This study assessed burden of malaria and caregivers’ health-seeking behaviour for children under five in artisanal mining communities in East Akim District in Ghana. Methods A cross-sectional study involving caregivers and their children under five was conducted in three artisanal mining communities in the East Akim District in Ghana. Caregivers were interviewed using a structured questionnaire. Finger prick blood samples were collected and analysed for haemoglobin concentration using a rapid diagnostic test, and thick and thin blood smears were analysed to confirm the presence of malaria parasites. Results Of the 372 children under 5 years included in the study, 197 (53.1%) were male, with a mean age (± SD) of 23.0 ± 12.7 months. The proportion of children with malaria (Plasmodium falciparum and P. malariae) was 98.1% and 1.9%, respectively, whilst the proportion with anaemia (Hb < 11.0 g/dl) was 39.5% (n = 147). Almost all caregivers were female (98.9%), and 28.6% (n = 106) did not have access to any malaria control information. Caregivers associated malaria infection with mosquito bites (68.3%, n = 254) and poor sanitation (21.2%, n = 79). Malaria in children under five was significantly associated with anaemia (OR 11.07, 95% CI 6.59–18.68, n = 111/160, 69.4%; P < 0.0001), residing close to stagnant water (≤ 25 m) from an artisanal mining site (AOR 2.91, 95% CI 1.47–5.76, P = 0.002) and caregiver age younger than 30 years (OR 0.44, 95% CI 0.208–0.917, n = 162, 43.55%, P = 0.001). Conclusions There is a high burden of malaria and anaemia among children under five in artisanal mining communities of the East Akim District, and far higher than in non-artisanal mining sites. Interventions are needed to effectively regulate mining activities in these communities, and strengthen malaria control and health education campaigns to curtail the high malaria burden and improve health-seeking behaviour. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04919-8.
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Affiliation(s)
- Francois Dao
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana.,Malaria Research and Training Center, Department of Epidemiology and Infectious Diseases, University of Science Techniques and Technologies of Bamako, Bamako, Mali
| | - Sampson Kafui Djonor
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Christian Teye-Muno Ayin
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | | | - Bismark Sarfo
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Pricillia Nortey
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana
| | - Kwadwo Owusu Akuffo
- Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Anthony Danso-Appiah
- Department of Epidemiology and Disease Control, School of Public Health, University of Ghana, Legon, Ghana. .,University of Ghana Centre for Evidence Synthesis and Policy, School of Public Health, University of Ghana, Legon, Ghana.
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9
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Considerations for quality assurance of multiplex malaria antigen detection assays with large sample sets. Sci Rep 2021; 11:13248. [PMID: 34168264 PMCID: PMC8225651 DOI: 10.1038/s41598-021-92723-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/15/2021] [Indexed: 11/24/2022] Open
Abstract
Multiplex assays for malaria antigen detection can gather data from large sample sets, but considerations for the consistency and quality assurance (QA) of mass testing lack evaluation. We present a QA framework for a study occurring November 2019 to March 2020 involving 504 assay plates detecting four Plasmodium antigens: pan-Plasmodium aldolase and lactate dehydrogenase (LDH), histidine-rich protein 2 (HRP2), P. vivax LDH (PvLDH). Controls on each plate included buffer blank, antigen negative blood, and 4-point positive dilution curve. The blank and negative blood provided consistently low signal for all targets except for pAldolase, which showed variability. Positive curve signals decreased throughout the 5-month study duration but retained a coefficient of variation (CV) of < 5%, with the exception of HRP2 in month 5 (CV of 11%). Regression fittings for inter-plate control signals provided mean and standard deviations (SDs), and of 504 assay plates, 6 (1.2%) violated the acceptable deviation limits and were repeated. For the 40,272 human blood samples assayed in this study, of 161,088 potential data points (each sample × 4 antigens), 160,641 (99.7%) successfully passed quality checks. The QA framework presented here can be utilized to ensure quality of laboratory antigen detection for large sample sets.
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10
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Kingston HWF, Ghose A, Rungpradubvong V, Satitthummanid S, Herdman MT, Plewes K, Leopold SJ, Ishioka H, Mohanty S, Maude RJ, Schultz MJ, Lagrand WK, Hossain MA, Day NPJ, White NJ, Anstey NM, Dondorp AM. Reduced Cardiac Index Reserve and Hypovolemia in Severe Falciparum Malaria. J Infect Dis 2021; 221:1518-1527. [PMID: 31693130 PMCID: PMC7137886 DOI: 10.1093/infdis/jiz568] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 11/05/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Impaired microvascular perfusion is central to the development of coma and lactic acidosis in severe falciparum malaria. Refractory hypotension is rare on admission but develops frequently in fatal cases. We assessed cardiac function and volume status in severe falciparum malaria and its prognostic significance. METHODS Patients with severe (N = 101) or acute uncomplicated falciparum malaria (N = 83) were recruited from 2 hospitals in India and Bangladesh, and healthy participants (N = 44) underwent echocardiography. RESULTS Patients with severe malaria had 38% shorter left ventricular (LV) filling times and 25% shorter LV ejection times than healthy participants because of tachycardia; however, stroke volume, LV internal diameter in diastole (LVIDd), and LV internal diameter in systole (LVIDs) indices were similar. A low endocardial fraction shortening (eFS) was present in 17% (9 of 52) of severe malaria patients. Adjusting for preload and afterload, eFS was similar in health and severe malaria. Fatal cases had smaller baseline LVIDd and LVIDs indices, more collapsible inferior vena cavae (IVC), and higher heart rates than survivors. The LVIDs and IVC collapsibility were independent predictors for mortality, together with base excess and Glasgow Coma Scale. CONCLUSIONS Patients with severe malaria have rapid ejection of a normal stroke volume. Fatal cases had features of relative hypovolemia and reduced cardiac index reserve.
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Affiliation(s)
- Hugh W F Kingston
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia.,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | | | - Voravut Rungpradubvong
- Division of Cardiology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Cardiac Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - Sudarat Satitthummanid
- Division of Cardiology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Cardiac Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - M Trent Herdman
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Katherine Plewes
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Stije J Leopold
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Haruhiko Ishioka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Richard J Maude
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Marcus J Schultz
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Wim K Lagrand
- Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
| | | | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
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11
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Dip Gandarilla AM, Regiart M, Bertotti M, Correa Glória J, Morais Mariuba LA, Ricardo Brito W. One-step enzyme-free dual electrochemical immunosensor for histidine-rich protein 2 determination. RSC Adv 2020; 11:408-415. [PMID: 35423017 PMCID: PMC8691096 DOI: 10.1039/d0ra08729g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/09/2020] [Indexed: 11/21/2022] Open
Abstract
In the present work, we describe a novel one-step enzyme-free dual electrochemical immunosensor for the determination of histidine-rich protein 2 (Ag-PfHRP2), a specific malaria biomarker. A gold electrode (GE) was functionalized with the PfHRP2 antibody (Ab-PfHRP2) using dihexadecyl phosphate (DHP) polymer as an immobilization platform. The Ab-PfHRP2/DHP/GE sensor was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The developed immunosensor was employed for indirect Ag-PfHRP2 determination by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The linear range was 10-400 ng mL-1 and 10-500 ng mL-1 for EIS and DPV, while the limit of detection was 3.3 ng mL-1 and 2.8 ng mL-1, respectively. The electrochemical immunosensor was successfully applied for Ag-PfHRP2 determination in human serum samples. Its performance was compared with an ELISA test, and good correspondence was achieved. The coefficients of intra- and inter-assay variations were less than 5%. The electrochemical immunosensor is a useful and straightforward tool for in situ malaria biomarker determination.
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Affiliation(s)
| | - Matias Regiart
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo São Paulo 05508-000 Brazil +55 11 982885489
| | - Mauro Bertotti
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo São Paulo 05508-000 Brazil +55 11 982885489
| | - Juliane Correa Glória
- Leônidas and Maria Deane Institute, Oswaldo Cruz Foundation Manaus Amazonas 69057-070 Brazil
| | | | - Walter Ricardo Brito
- Department of Chemistry, Federal University of Amazonas Manaus Amazonas 69067-005 Brazil +55 92 981379920
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12
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Jiang X, Lillehoj PB. Lateral flow immunochromatographic assay on a single piece of paper. Analyst 2020; 146:1084-1090. [PMID: 33347520 DOI: 10.1039/d0an02073g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Lateral flow immunochromatographic assays (LFIAs) are analytical devices used to detect the presence of one or more target analytes in a liquid sample. While LFIAs are one of the simplest and inexpensive types of immunoassays, they consist of multiple components (sample pad, conjugate pad, membrane, absorbent pad, backing card) and materials, requiring time-consuming device assembly. Here, we report a unique lateral flow immunochromatographic assay constructed from a single piece of cellulose paper, which is fabricated via laser cutting. Compared with conventional lateral flow immunochromatographic devices, this single-layer immunoassay enables simpler and faster fabrication, while minimizing material consumption and overall device costs. For proof-of-concept, this device was used to detect Plasmodium falciparum histidine-rich protein 2 (PfHRP2), a biomarker for malaria infection, which could be detected at concentrations as low as 4 ng mL-1 by the naked eye with no cross reactivity with other common Plasmodium protein biomarkers. While offering similar speed and ease-of-use as conventional LFIAs with a higher detection sensitivity than existing LFIAs for PfHRP2 detection, this single-layer lateral flow immunoassay has the potential to improve malaria testing, as well as the detection of other important protein biomarkers for point-of-care testing.
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Affiliation(s)
- Xue Jiang
- Department of Mechanical Engineering, Rice University, Houston, TX 77005, USA.
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13
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Patel H, Dunican C, Cunnington AJ. Predictors of outcome in childhood Plasmodium falciparum malaria. Virulence 2020; 11:199-221. [PMID: 32063099 PMCID: PMC7051137 DOI: 10.1080/21505594.2020.1726570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 12/16/2022] Open
Abstract
Plasmodium falciparum malaria is classified as either uncomplicated or severe, determining clinical management and providing a framework for understanding pathogenesis. Severe malaria in children is defined by the presence of one or more features associated with adverse outcome, but there is wide variation in the predictive value of these features. Here we review the evidence for the usefulness of these features, alone and in combination, to predict death and other adverse outcomes, and we consider the role that molecular biomarkers may play in augmenting this prediction. We also examine whether a more personalized approach to predicting outcome for specific presenting syndromes of severe malaria, particularly cerebral malaria, has the potential to be more accurate. We note a general need for better external validation in studies of outcome predictors and for the demonstration that predictors can be used to guide clinical management in a way that improves survival and long-term health.
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Affiliation(s)
- Harsita Patel
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
| | - Claire Dunican
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
| | - Aubrey J. Cunnington
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
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14
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Salminen T, Mehdi F, Rohila D, Kumar M, Talha SM, Prakash JAJ, Khanna N, Pettersson K, Batra G. Ultrasensitive and Robust Point-of-Care Immunoassay for the Detection of Plasmodium falciparum Malaria. Anal Chem 2020; 92:15766-15772. [PMID: 33228352 DOI: 10.1021/acs.analchem.0c02748] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Plasmodium falciparum malaria is widespread in the tropical and subtropical regions of the world. There is ongoing effort to eliminate malaria from endemic regions, and sensitive point-of-care (POC) diagnostic tests are required to support this effort. However, current POC tests are not sufficiently sensitive to detect P. falciparum in asymptomatic individuals. After extensive optimization, we have developed a highly sensitive and robust POC test for the detection of P. falciparum infection. The test is based on upconverting nanophosphor-based lateral flow (UCNP-LF) immunoassay. The developed UCNP-LF test was validated using whole blood reference panels containing samples at different parasite densities covering eight strains of P. falciparum from different geographical areas. The limit of detection was compared to a WHO-prequalified rapid diagnostic test (RDT). The UCNP-LF achieved a detection limit of 0.2-2 parasites/μL, depending on the strain, which is 50- to 250-fold improvement in analytical sensitivity over the conventional RDTs. The developed UCNP-LF is highly stable even at 40 °C for at least 5 months. The extensively optimized UCNP-LF assay is as simple as the conventional malaria RDTs and requires 5 μL of whole blood as sample. Results can be read after 20 min from sample addition, with a simple photoluminescence reader. In the absence of a reader device at the testing site, the strips after running the test can be transported and read at a central location with access to a reader. We have found that the test and control line signals are stable for at least 10 months after running the test. The UCNP-LF has potential for diagnostic testing of both symptomatic and asymptomatic individuals.
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Affiliation(s)
- Teppo Salminen
- Department of Biotechnology, University of Turku, Kiinamyllynkatu 10, Turku 20520, Finland
| | - Farha Mehdi
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
| | - Deepak Rohila
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
| | - Manjit Kumar
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
| | - Sheikh M Talha
- Department of Biotechnology, University of Turku, Kiinamyllynkatu 10, Turku 20520, Finland
| | - John Antony Jude Prakash
- Department of Clinical Microbiology, Christian Medical College, Vellore 632004, Tamil Nadu, India
| | - Navin Khanna
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Kim Pettersson
- Department of Biotechnology, University of Turku, Kiinamyllynkatu 10, Turku 20520, Finland
| | - Gaurav Batra
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
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15
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Jiang X, Lillehoj PB. Microneedle-based skin patch for blood-free rapid diagnostic testing. MICROSYSTEMS & NANOENGINEERING 2020; 6:96. [PMID: 33194222 PMCID: PMC7605440 DOI: 10.1038/s41378-020-00206-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 07/24/2020] [Accepted: 08/15/2020] [Indexed: 06/02/2023]
Abstract
Rapid diagnostic tests are one of the most commonly used tests to detect and screen for infectious diseases in the developing world. While these tests are simple, inexpensive, and readily available, they rely on finger-prick blood sampling, which requires trained medical personnel, poses risks of infection, and can complicate cooperation in young children, asymptomatic individuals, and communities with blood taboos. Here, we report a novel microneedle-based skin patch for the rapid detection of protein biomarkers in dermal interstitial fluid. Sample collection is facilitated by a hydrophilic hollow microneedle array that autonomously extracts and transports interstitial fluid to an antibody-based lateral flow test strip via surface tension for colorimetric antigen detection. We employ a simple gold enhancement treatment to enhance the detection sensitivity of this colloidal gold-based lateral flow assay and elucidate the underlying mechanism of this enhancement mechanism through experimental investigation. For proof-of-concept, this device was used to detect Plasmodium falciparum histidine-rich protein 2, a biomarker for malaria infection, which could be detected at concentrations as low as 8 ng/mL. Each test can be completed in <20 min and requires no equipment. To the best of our knowledge, this work is the first demonstration of a microneedle-based lateral flow assay for rapid protein detection in dermal interstitial fluid. In addition to its simplicity, minimally invasive nature, and low cost, this diagnostic device can be readily adapted to detect other protein biomarkers in interstitial fluid, making it a promising tool for point-of-care testing.
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Affiliation(s)
- Xue Jiang
- Department of Mechanical Engineering, Rice University, Houston, TX 77005 USA
| | - Peter B. Lillehoj
- Department of Mechanical Engineering, Rice University, Houston, TX 77005 USA
- Department of Bioengineering, Rice University, Houston, TX 77030 USA
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16
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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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17
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Varo R, Erice C, Johnson S, Bassat Q, Kain KC. Clinical trials to assess adjuvant therapeutics for severe malaria. Malar J 2020; 19:268. [PMID: 32709257 PMCID: PMC7382078 DOI: 10.1186/s12936-020-03340-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/17/2020] [Indexed: 01/07/2023] Open
Abstract
Despite potent anti-malarial treatment, mortality rates associated with severe falciparum malaria remain high. To attempt to improve outcome, several trials have assessed a variety of potential adjunctive therapeutics, however none to date has been shown to be beneficial. This may be due, at least partly, to the therapeutics chosen and clinical trial design used. Here, we highlight three themes that could facilitate the choice and evaluation of putative adjuvant interventions for severe malaria, paving the way for their assessment in randomized controlled trials. Most clinical trials of adjunctive therapeutics to date have been underpowered due to the large number of participants required to reach mortality endpoints, rendering these study designs challenging and expensive to conduct. These limitations may be mitigated by the use of risk-stratification of participants and application of surrogate endpoints. Appropriate surrogate endpoints include direct measures of pathways causally involved in the pathobiology of severe and fatal malaria, including markers of host immune and endothelial activation and microcirculatory dysfunction. We propose using circulating markers of these pathways to identify high-risk participants that would be most likely to benefit from adjunctive therapy, and further by adopting these biomarkers as surrogate endpoints; moreover, choosing interventions that target deleterious host immune responses that directly contribute to microcirculatory dysfunction, multi-organ dysfunction and death; and, finally, prioritizing where possible, drugs that act on these pathways that are already approved by the FDA, or other regulators, for other indications, and are known to be safe in target populations, including children. An emerging understanding of the critical role of the host response in severe malaria pathogenesis may facilitate both clinical trial design and the search of effective adjunctive therapeutics.
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Affiliation(s)
- Rosauro Varo
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Manhiça, Mozambique
| | - Clara Erice
- Sandra-Rotman Centre for Global Health, Toronto General Research Institute, University Health Network-Toronto General Hospital, Toronto, ON, Canada
| | | | - Quique Bassat
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Manhiça, Mozambique.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Kevin C Kain
- Sandra-Rotman Centre for Global Health, Toronto General Research Institute, University Health Network-Toronto General Hospital, Toronto, ON, Canada. .,Department of Medicine, Division of Infectious Diseases, Tropical Disease Unit, University of Toronto, Toronto, Canada.
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18
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Akech S, Chepkirui M, Ogero M, Agweyu A, Irimu G, English M, Snow RW. The Clinical Profile of Severe Pediatric Malaria in an Area Targeted for Routine RTS,S/AS01 Malaria Vaccination in Western Kenya. Clin Infect Dis 2020; 71:372-380. [PMID: 31504308 PMCID: PMC7353324 DOI: 10.1093/cid/ciz844] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 08/23/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The malaria prevalence has declined in western Kenya, resulting in the risk of neurological phenotypes in older children. This study investigates the clinical profile of pediatric malaria admissions ahead of the introduction of the RTS,S/AS01 vaccine. METHODS Malaria admissions in children aged 1 month to 15 years were identified from routine, standardized, inpatient clinical surveillance data collected between 2015 and 2018 from 4 hospitals in western Kenya. Malaria phenotypes were defined based on available data. RESULTS There were 5766 malaria admissions documented. The median age was 36 months (interquartile range, 18-60): 15% were aged between 1-11 months of age, 33% were aged 1-23 months of age, and 70% were aged 1 month to 5 years. At admission, 2340 (40.6%) children had severe malaria: 421/2208 (19.1%) had impaired consciousness, 665/2240 (29.7%) had an inability to drink or breastfeed, 317/2340 (13.6%) had experienced 2 or more convulsions, 1057/2340 (45.2%) had severe anemia, and 441/2239 (19.7%) had severe respiratory distress. Overall, 211 (3.7%) children admitted with malaria died; 163/211 (77% deaths, case fatality rate 7.0%) and 48/211 (23% deaths, case fatality rate 1.4%) met the criteria for severe malaria and nonsevere malaria at admission, respectively. The median age for fatal cases was 33 months (interquartile range, 12-72) and the case fatality rate was highest in those unconscious (44.4%). CONCLUSIONS Severe malaria in western Kenya is still predominantly seen among the younger pediatric age group and current interventions targeted for those <5 years are appropriate. However, there are increasing numbers of children older than 5 years admitted with malaria, and ongoing hospital surveillance would identify when interventions should target older children.
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Affiliation(s)
- Samuel Akech
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Mercy Chepkirui
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Morris Ogero
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Ambrose Agweyu
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
| | - Grace Irimu
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
- Department of Paediatrics and Child Health, University of Nairobi, Nairobi, Kenya
| | - Mike English
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert W Snow
- Kenya Medical Research Institute/Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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19
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Fredenburgh JC. His-rich materials: Elucidating the role of histidine-rich protein II in inflammation in malaria. J Thromb Haemost 2020; 18:1271-1273. [PMID: 32496019 DOI: 10.1111/jth.14780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 02/19/2020] [Indexed: 08/31/2023]
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20
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Berg A, Patel S, Tellevik MG, Haanshuus CG, Dalen I, Otterdal K, Ueland T, Moyo SJ, Aukrust P, Langeland N. Plasma parasitemia as assessed by quantitative PCR in relation to clinical disease severity in African adults with falciparum malaria with and without HIV co-infection. Infection 2020; 48:367-373. [PMID: 32077073 PMCID: PMC7256066 DOI: 10.1007/s15010-020-01399-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 02/04/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE When considering malaria disease severity, estimation of parasitemia in erythrocytes is important, but sometimes misleading, since the infected erythrocytes may be sequestered in peripheral capillaries. In African children and Asian adults with falciparum malaria, parasitemia as assessed by quantitative PCR (qPCR) in plasma seems to be a valuable indicator of disease severity, but data on African adults as well as the impact of co-infection with HIV is lacking. METHODS In 131 patients with falciparum malaria in a public tertiary teaching hospital in Mozambique, plasma malaria parasitemia as assessed by qPCR, compared to qualitative malaria PCR in blood cell fraction, was related to malaria disease severity and HIV co-infection. RESULTS Of the 131 patients with falciparum malaria, based on positive qualitative PCR in the blood cell fraction, 93 patients (72%) had positive malaria qPCR in plasma. Patients with severe malaria as defined by the WHO criteria had higher malaria quantitative plasma parasitemia (median 143 genomes/µL) compared to those with uncomplicated malaria (median 55 genomes/µL, p = 0.037) in univariate analysis, but this difference was attenuated after adjusting for age, sex and HIV co-infection (p = 0.055). A quarter of the patients with severe malaria had negative qPCR in plasma. CONCLUSIONS This study of adult African in-patients with falciparum malaria with and without HIV co-infection, neither confirms nor rejects previous studies of malaria qPCR in plasma as an indicator of disease severity in patients with falciparum malaria. There is a need for further and larger studies to clarify if parasitemia as assessed malaria qPCR in plasma could be a surrogate marker of disease severity in falciparum malaria.
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Affiliation(s)
- Aase Berg
- Department of Medicine, Stavanger University Hospital, PO Box 8100, 4068 Stavanger, Norway
| | - Sam Patel
- Department of Medicine, Central Hospital of Maputo, Maputo, Mozambique
| | - Marit G. Tellevik
- Norwegian National Advisory Unit On Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Christel G. Haanshuus
- Norwegian National Advisory Unit On Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Ingvild Dalen
- Department of Research, Stavanger University Hospital, 4011 Stavanger, Norway
| | - Kari Otterdal
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Thor Ueland
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
- K. G. Jepsen Inflammatory Research Centre, University of Oslo, 0424 Oslo, Norway
- Faculty of Medicine, University of Oslo, 0316 Oslo, Norway
- Faculty of Health Sciences, University of Tromsø, 9037 Tromsø, Norway
| | - Sabrina J. Moyo
- Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Pål Aukrust
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
- K. G. Jepsen Inflammatory Research Centre, University of Oslo, 0424 Oslo, Norway
- Faculty of Medicine, University of Oslo, 0316 Oslo, Norway
- Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital Rikshospitalet, 0372 Oslo, Norway
| | - Nina Langeland
- Norwegian National Advisory Unit On Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Haraldsplass Deaconess Hospital, Bergen, Norway
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21
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Dinarvand P, Yang L, Biswas I, Giri H, Rezaie AR. Plasmodium falciparum histidine rich protein HRPII inhibits the anti-inflammatory function of antithrombin. J Thromb Haemost 2020; 18:1473-1483. [PMID: 31858717 PMCID: PMC7274886 DOI: 10.1111/jth.14713] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/14/2019] [Accepted: 12/06/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND It has been reported that histidine-rich protein II (HRPII), secreted by the malaria parasite, Plasmodium falciparum (Pf), inhibits the heparin-dependent anticoagulant activity of antithrombin (AT) in vitro and in plasma-based assay systems. OBJECTIVE The objective of this study was to test the hypothesis that HRPII may also interact with the AT-binding vascular glycosaminoglycans (GAGs), thereby inhibiting the anti-inflammatory signaling function of the serpin. METHODS We expressed HRPII in bacteria, purified it to homogeneity and studied its effect on endothelial cell signaling in the absence and presence of AT employing established signaling assays. RESULTS We demonstrate that a low concentration of HRPII potently disrupts the barrier permeability function of endothelial cells. Moreover, HRPII competitively inhibits the protective effect of AT by a concentration-dependent manner. Similarly, AT inhibits the pro-inflammatory activity of HRPII by a concentration-dependent manner. The siRNA knockdown of 3-O-sulfotransferase 1 (3-OST-1), the enzyme responsible for the essential 3-O-sulfation of the AT-binding GAGs, downregulates the pro-inflammatory function of HRPII in endothelial cells, supporting the hypothesis that HRPII competitively inhibits the interaction of AT with 3-OS containing vascular GAGs. Histidine-rich protein II elicits its barrier-disruptive effect by the Src-dependent phosphorylation of vascular endothelial (VE)-cadherin and AT counteracts this effect. We further demonstrate that inorganic polyphosphates bind HRPII with a high affinity to amplify the pro-inflammatory signaling function of HRPII in both cellular and in vivo permeability models. CONCLUSION We postulate that Pf-derived HRPII and polyphosphate can contribute to the pathogenesis of malaria infection by downregulating the AT-dependent anti-inflammatory and anticoagulant pathways.
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Affiliation(s)
- Peyman Dinarvand
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis
| | - Likui Yang
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation
| | - Indranil Biswas
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation
| | - Hemant Giri
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation
| | - Alireza R. Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
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22
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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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23
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Fan J, Zhang S, Li F, Yang Y, Du M. Recent advances in cellulose-based membranes for their sensing applications. CELLULOSE (LONDON, ENGLAND) 2020; 27:9157-9179. [PMID: 32934443 PMCID: PMC7483080 DOI: 10.1007/s10570-020-03445-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/07/2020] [Indexed: 05/13/2023]
Abstract
ABSTRACT In recent years, sensing applications have played a very important role in various fields. As a novel natural material, cellulose-based membranes with many merits can be served as all kinds of sensors. This review summarizes the recent progress of cellulose membranes as sensors, mainly focusing on their preparation processes and sensing properties. In addition, the opportunities and challenges of cellulose membrane-based sensors are also prospected. This review provides some references for the design of cellulose membrane materials for sensing applications in the future.
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Affiliation(s)
- Jiang Fan
- Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Key Laboratory of Paper Based Functional Materials of China National Light Industry, Shaanxi University of Science and Technology, Xi’an, 710021 People’s Republic of China
| | - Sufeng Zhang
- Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Key Laboratory of Paper Based Functional Materials of China National Light Industry, Shaanxi University of Science and Technology, Xi’an, 710021 People’s Republic of China
| | - Fei Li
- The Second Kindergarten, Economic and Technological Development Zone, Xi’an, 710021 People’s Republic of China
| | - Yonglin Yang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi’an, 710021 People’s Republic of China
| | - Min Du
- Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Key Laboratory of Paper Based Functional Materials of China National Light Industry, Shaanxi University of Science and Technology, Xi’an, 710021 People’s Republic of China
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24
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Modelling pathogen load dynamics to elucidate mechanistic determinants of host-Plasmodium falciparum interactions. Nat Microbiol 2019; 4:1592-1602. [PMID: 31209307 PMCID: PMC6708439 DOI: 10.1038/s41564-019-0474-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/30/2019] [Indexed: 12/21/2022]
Abstract
During infection, increasing pathogen load stimulates both protective and
harmful aspects of the host response. The dynamics of this interaction are hard
to quantify in humans, but doing so could improve understanding of mechanisms of
disease and protection. We sought to model the contributions of parasite
multiplication rate and host response to observed parasite load in individual
subjects with Plasmodium falciparum malaria, using only data
obtained at the time of clinical presentation, and then to identify their
mechanistic correlates. We predicted higher parasite multiplication rates and
lower host responsiveness in severe malaria cases, with severe anemia being more
insidious than cerebral malaria. We predicted that parasite growth-inhibition
was associated with platelet consumption, lower expression of
CXCL10 and type-1 interferon-associated genes, but
increased cathepsin G and matrix metallopeptidase 9 expression. We found that
cathepsin G and matrix metallopeptidase 9 directly inhibit parasite invasion
into erythrocytes. Parasite multiplication rate was associated with host iron
availability and higher complement factor H levels, lower expression of
gametocyte-associated genes but higher expression of translation-associated
genes in the parasite. Our findings demonstrate the potential of using explicit
modelling of pathogen load dynamics to deepen understanding of host-pathogen
interactions and identify mechanistic correlates of protection.
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25
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Geostatistical analysis and mapping of malaria risk in children under 5 using point-referenced prevalence data in Ghana. Malar J 2019; 18:67. [PMID: 30871551 PMCID: PMC6419518 DOI: 10.1186/s12936-019-2709-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/06/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria remains a major challenge in sub-Saharan Africa and Ghana is not an exception. Effective malaria transmission control requires evidence-based targeting and utilization of resources. Disease risk mapping provides an effective and efficient tool for monitoring transmission and control efforts. The aim of this study is to analyse and map malaria risk in children under 5 years old, with the ultimate goal of identifying areas where control efforts can be targeted. METHODS Data collected from the 2016 Ghana demographic and health survey was analyzed. Binomial logistic regression was applied to examine the determinants of malaria risk among children. Model-based geostatistical methods were applied to analyze, predict and map malaria prevalence. RESULTS There is a significant association of malaria prevalence with area of residence (rural/urban), age, indoor residual spray use, social economic status and mother's education level. Overall, parasitaemia prevalence among children under 5 years old for the year 2016 is low albeit characterized by "hotspots" in specific areas. CONCLUSION The risk maps indicate the spatial heterogeneity of malaria prevalence. The high resolution maps can serve as an effective tool in the identification of locations that require targeted interventions by programme implementers; this is key and relevant for reducing malaria burden in Ghana.
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26
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Plucinski MM, Herman C, Jones S, Dimbu R, Fortes F, Ljolje D, Lucchi N, Murphy SC, Smith NT, Cruz KR, Seilie AM, Halsey ES, Udhayakumar V, Aidoo M, Rogier E. Screening for Pfhrp2/3-Deleted Plasmodium falciparum, Non-falciparum, and Low-Density Malaria Infections by a Multiplex Antigen Assay. J Infect Dis 2019; 219:437-447. [PMID: 30202972 PMCID: PMC6325347 DOI: 10.1093/infdis/jiy525] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/30/2018] [Indexed: 11/13/2022] Open
Abstract
Background Detection of Plasmodium antigens provides evidence of malaria infection status and is the basis for most malaria diagnosis. Methods We developed a sensitive bead-based multiplex assay for laboratory use, which simultaneously detects pan-Plasmodium aldolase (pAldo), pan-Plasmodium lactate dehydrogenase (pLDH), and P. falciparum histidine-rich protein 2 (PfHRP2) antigens. The assay was validated against purified recombinant antigens, monospecies malaria infections, and noninfected blood samples. To test against samples collected in an endemic setting, Angolan outpatient samples (n = 1267) were assayed. Results Of 466 Angolan samples positive for at least 1 antigen, the most common antigen profiles were PfHRP2+/pAldo+/pLDH+ (167, 36%), PfHRP2+/pAldo-/pLDH- (163, 35%), and PfHRP2+/pAldo+/pLDH- (129, 28%). Antigen profile was predictive of polymerase chain reaction (PCR) positivity and parasite density. Eight Angolan samples (1.7%) had no or very low PfHRP2 but were positive for 1 or both of the other antigens. PCR analysis confirmed 3 (0.6%) were P. ovale infections and 2 (0.4%) represented P. falciparum parasites lacking Pfhrp2 and/or Pfhrp3. Conclusions These are the first reports of Pfhrp2/3 deletion mutants in Angola. High-throughput multiplex antigen detection can inexpensively screen for low-density P. falciparum, non-falciparum, and Pfhrp2/3-deleted parasites to provide population-level antigen estimates and identify specimens requiring further molecular characterization.
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Affiliation(s)
- Mateusz M Plucinski
- Malaria Branch, 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
| | - Camelia Herman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- CDC Foundation, Atlanta, Georgia
| | - Sophie Jones
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- Atlanta Research and Education Foundation, Georgia
| | - Rafael Dimbu
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Filomeno Fortes
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Dragan Ljolje
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- Atlanta Research and Education Foundation, Georgia
| | - Naomi Lucchi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Sean C Murphy
- Department of Laboratory Medicine, University of Washington, Seattle
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle
| | - Nahum T Smith
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Kurtis R Cruz
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Annette M Seilie
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Eric S Halsey
- Malaria Branch, 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
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Aidoo
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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27
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Dutta G, Lillehoj PB. Wash-free, label-free immunoassay for rapid electrochemical detection of PfHRP2 in whole blood samples. Sci Rep 2018; 8:17129. [PMID: 30459336 PMCID: PMC6244414 DOI: 10.1038/s41598-018-35471-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 11/05/2018] [Indexed: 02/06/2023] Open
Abstract
Currently, the diagnosis of many diseases relies on laboratory-based immunoassays (ELISA, Western Blot), which are laborious, time-consuming and expensive. To address these limitations, we report a wash-free and label-free electrochemical immunoassay for rapid measurements of protein biomarkers in blood samples. This immunosensor employs a unique detection scheme based on electrochemical-chemical (EC) redox cycling for signal amplification combined with an affinity-based protein quantification strategy. All of the reagents required for this assay are dried and stored on a stacked membrane assembly, consisting of a Vivid Plasma Separation membrane and two cellulose membranes situated above the sensor, enabling excellent stability at room temperature for up to 2 months. Proof of concept was carried out by performing measurements of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) in whole blood samples, which could be detected from 100 ng/mL to 100 µg/mL with excellent specificity and reproducibility. Each measurement requires only two liquid dispensing steps and can completed in 5 min, making this diagnostic platform promising for point-of-care testing in resource-limited settings.
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Affiliation(s)
- Gorachand Dutta
- Department of Electronic and Electrical Engineering, University of Bath, Claverton Down, Bath, BA2 7AY, UK.,Centre for Biosensors, Bioelectronics and Biodevices, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Peter B Lillehoj
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Biomedical Engineering, Michigan State University, East Lansing, MI, 48824, USA.
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28
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Oldenburg CE, Guerin PJ, Berthé F, Grais RF, Isanaka S. Malaria and Nutritional Status Among Children With Severe Acute Malnutrition in Niger: A Prospective Cohort Study. Clin Infect Dis 2018; 67:1027-1034. [PMID: 29522089 PMCID: PMC6137121 DOI: 10.1093/cid/ciy207] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/06/2018] [Indexed: 11/14/2022] Open
Abstract
Background The relationship between malaria infection and nutritional status is complex. Previous studies suggest malaria may increase the incidence and severity of malnutrition, while malnutrition may increase the risk of malaria infection. Here, we report bidirectional associations between malaria and nutritional status among children with uncomplicated severe acute malnutrition (SAM). Methods This study is a secondary analysis of a randomized, controlled trial for the treatment of uncomplicated SAM in Niger. Children aged 6-59 months were enrolled and followed for 12 weeks. Malaria infection was assessed using an histidine-rich protein 2 (HRP2) rapid diagnostic test at admission and at any follow-up visit with fever. We assessed the association of nutritional status at admission on malaria incidence using Cox proportional hazards regression and malaria infection at admission on nutritional recovery and weight and height gain using linear regression. Results Of 2399 children included in the analysis, 1327 (55.3%) were infected with malaria at admission. Malaria incidence was 12.1 cases/100 person-months among those without malaria infection at admission. Nutritional status at admission was not associated with malaria incidence. Children with malaria infection at admission and subsequently treated with an artemisinin-based combination therapy had increased weight gain (0.38 g/kg/day; 95% confidence interval [CI], 0.07 to 0.69) and reduced height gain (-0.002 mm/day; 95% CI, -0.004 to -0.0008). Conclusions Malaria infection was common among children treated for uncomplicated SAM. Malaria infection may impair height gain. Proper medical and nutritional management should be ensured to prevent adverse effects of malaria infection. Clinical Trials Registration NCT01613547.
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Affiliation(s)
- Catherine E Oldenburg
- Francis I. Proctor Foundation, University of California, San Francisco
- Department of Ophthalmology, University of California, San Francisco
| | - Philippe J Guerin
- WorldWide Antimalarial Resistance Network, University of Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | | | | | - Sheila Isanaka
- Department of Research, Epicentre, Paris, France
- Departments of Nutrition and Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
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29
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Aung NM, Nyein PP, Htut TY, Htet ZW, Kyi TT, Anstey NM, Kyi MM, Hanson J. Antibiotic Therapy in Adults with Malaria (ANTHEM): High Rate of Clinically Significant Bacteremia in Hospitalized Adults Diagnosed with Falciparum Malaria. Am J Trop Med Hyg 2018; 99:688-696. [PMID: 30014826 DOI: 10.4269/ajtmh.18-0378] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
It has been believed that concomitant bacteremia is uncommon in adults hospitalized with falciparum malaria. Accordingly, the World Health Organization treatment guidelines presently only recommended additional antibacterial therapy in these patients if they have a clinical syndrome compatible with serious bacterial infection. Admission blood cultures were collected from 20 consecutive adults in Myanmar, hospitalized with a positive immunochromatographic test and blood film, suggesting a diagnosis of falciparum malaria; four (20%) had bacteremia with a clinically significant pathogen. These case series' data were pooled with a previously published multicenter study from Myanmar which had also collected blood cultures in adults hospitalized with a diagnosis of falciparum malaria. Among 87 patients in the two studies, 13 (15%) had clinically significant bacteremia on admission, with Gram-negative organisms in 10 (77%) and Staphylococcus aureus in the remaining three (23%). Bacteremic patients had more severe disease than non-bacteremic patients (median [interquartile range] respiratory coma acidosis malaria score 2 [1-4] versus 1 [1-2], P = 0.02) and were more likely to die (2/13 [15%] versus 1/74 [1%], P = 0.01). However, bacterial coinfection was suspected clinically in a minority of bacteremic patients (5/13 [38%] compared with 13/70 [19%] of non-bacteremic patients, P = 0.11). Concomitant bacteremia in adults diagnosed with falciparum malaria may be more common than previously believed and is difficult to identify clinically in resource-poor settings. Death is more common in these patients, suggesting that clinicians should have a lower threshold for commencing empirical antibacterial therapy in adults diagnosed with falciparum malaria in these locations than is presently recommended.
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Affiliation(s)
- Ne Myo Aung
- University of Medicine 2, Yangon, Myanmar.,Insein General Hospital, Yangon, Myanmar
| | | | | | | | - Tint Tint Kyi
- Department of Medical Care, Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Nicholas M Anstey
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Mar Mar Kyi
- University of Medicine 2, Yangon, Myanmar.,Insein General Hospital, Yangon, Myanmar
| | - Josh Hanson
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Kirby Institute, University of New South Wales, Sydney, Australia.,University of Medicine 2, Yangon, Myanmar
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30
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Lee HJ, Georgiadou A, Walther M, Nwakanma D, Stewart LB, Levin M, Otto TD, Conway DJ, Coin LJ, Cunnington AJ. Integrated pathogen load and dual transcriptome analysis of systemic host-pathogen interactions in severe malaria. Sci Transl Med 2018; 10:eaar3619. [PMID: 29950443 PMCID: PMC6326353 DOI: 10.1126/scitranslmed.aar3619] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 01/31/2018] [Accepted: 06/08/2018] [Indexed: 12/13/2022]
Abstract
The pathogenesis of infectious diseases depends on the interaction of host and pathogen. In Plasmodium falciparum malaria, host and parasite processes can be assessed by dual RNA sequencing of blood from infected patients. We performed dual transcriptome analyses on samples from 46 malaria-infected Gambian children to reveal mechanisms driving the systemic pathophysiology of severe malaria. Integrating these transcriptomic data with estimates of parasite load and detailed clinical information allowed consideration of potentially confounding effects due to differing leukocyte proportions in blood, parasite developmental stage, and whole-body pathogen load. We report hundreds of human and parasite genes differentially expressed between severe and uncomplicated malaria, with distinct profiles associated with coma, hyperlactatemia, and thrombocytopenia. High expression of neutrophil granule-related genes was consistently associated with all severe malaria phenotypes. We observed severity-associated variation in the expression of parasite genes, which determine cytoadhesion to vascular endothelium, rigidity of infected erythrocytes, and parasite growth rate. Up to 99% of human differential gene expression in severe malaria was driven by differences in parasite load, whereas parasite gene expression showed little association with parasite load. Coexpression analyses revealed interactions between human and P. falciparum, with prominent co-regulation of translation genes in severe malaria between host and parasite. Multivariate analyses suggested that increased expression of granulopoiesis and interferon-γ-related genes, together with inadequate suppression of type 1 interferon signaling, best explained severity of infection. These findings provide a framework for understanding the contributions of host and parasite to the pathogenesis of severe malaria and identifying new treatments.
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Affiliation(s)
- Hyun Jae Lee
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
| | | | - Michael Walther
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Fajara, The Gambia
| | - Davis Nwakanma
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Fajara, The Gambia
| | - Lindsay B Stewart
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Michael Levin
- Section of Paediatrics, Imperial College, London W2 1PG, UK
| | - Thomas D Otto
- Wellcome Trust Sanger Centre, Hinxton, Cambridge CB10 1SA, UK
| | - David J Conway
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Lachlan J Coin
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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31
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Abstract
PURPOSE OF REVIEW Advances in diagnostic methods mean that co-infections are increasingly being detected in clinical practice, yet their significance is not always obvious. In parallel, basic science studies are increasingly investigating interactions between pathogens to try to explain real-life observations and elucidate biological mechanisms. RECENT FINDINGS Co-infections may be insignificant, detrimental, or even beneficial, and these outcomes can occur through multiple levels of interactions which include modulation of the host response, altering the performance of diagnostic tests, and drug-drug interactions during treatment. The harmful effects of chronic co-infections such as tuberculosis or Hepatitis B and C in association with HIV are well established, and recent studies have focussed on strategies to mitigate these effects. However, consequences of many acute co-infections are much less certain, and recent conflicting findings simply highlight many of the challenges of studying naturally acquired infections in humans. SUMMARY Tackling these challenges, using animal models, or careful prospective studies in humans may prove to be worthwhile. There are already tantalizing examples where identification and treatment of relevant co-infections seems to hold promise for improved health outcomes.
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Affiliation(s)
| | - Anna Turkova
- MRC Clinical Trials Unit, Institute of Clinical Trials and Methodology, University College London
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32
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Lee HJ, Georgiadou A, Otto TD, Levin M, Coin LJ, Conway DJ, Cunnington AJ. Transcriptomic Studies of Malaria: a Paradigm for Investigation of Systemic Host-Pathogen Interactions. Microbiol Mol Biol Rev 2018; 82:e00071-17. [PMID: 29695497 PMCID: PMC5968457 DOI: 10.1128/mmbr.00071-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transcriptomics, the analysis of genome-wide RNA expression, is a common approach to investigate host and pathogen processes in infectious diseases. Technical and bioinformatic advances have permitted increasingly thorough analyses of the association of RNA expression with fundamental biology, immunity, pathogenesis, diagnosis, and prognosis. Transcriptomic approaches can now be used to realize a previously unattainable goal, the simultaneous study of RNA expression in host and pathogen, in order to better understand their interactions. This exciting prospect is not without challenges, especially as focus moves from interactions in vitro under tightly controlled conditions to tissue- and systems-level interactions in animal models and natural and experimental infections in humans. Here we review the contribution of transcriptomic studies to the understanding of malaria, a parasitic disease which has exerted a major influence on human evolution and continues to cause a huge global burden of disease. We consider malaria a paradigm for the transcriptomic assessment of systemic host-pathogen interactions in humans, because much of the direct host-pathogen interaction occurs within the blood, a readily sampled compartment of the body. We illustrate lessons learned from transcriptomic studies of malaria and how these lessons may guide studies of host-pathogen interactions in other infectious diseases. We propose that the potential of transcriptomic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in study design rather than as a consequence of technological constraints. Further advances will require the integration of transcriptomic data with analytical approaches from other scientific disciplines, including epidemiology and mathematical modeling.
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Affiliation(s)
- Hyun Jae Lee
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | | | - Thomas D Otto
- Centre of Immunobiology, University of Glasgow, Glasgow, United Kingdom
| | - Michael Levin
- Section of Paediatrics, Imperial College, London, United Kingdom
| | - Lachlan J Coin
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - David J Conway
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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33
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Thakur KT, Vareta J, Carson KA, Kampondeni S, Potchen MJ, Birbeck GL, MacCormick I, Taylor T, Sullivan DJ, Seydel KB. Cerebrospinal fluid Plasmodium falciparum histidine-rich protein-2 in pediatric cerebral malaria. Malar J 2018; 17:125. [PMID: 29566695 PMCID: PMC5865338 DOI: 10.1186/s12936-018-2272-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 03/14/2018] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Cerebral malaria (CM) causes a rapidly developing coma, and remains a major contributor to morbidity and mortality in malaria-endemic regions. This study sought to determine the relationship between cerebrospinal fluid (CSF) Plasmodium falciparum histidine rich protein-2 (PfHRP-2) and clinical, laboratory and radiographic features in a cohort of children with retinopathy-positive CM. METHODS Patients included in the study were admitted (2009-2013) to the Pediatric Research Ward (Queen Elizabeth Central Hospital, Blantyre, Malawi) meeting World Health Organization criteria for CM with findings of malarial retinopathy. Enzyme-linked immunosorbent assay was used to determine plasma and CSF PfHRP-2 levels. Wilcoxon rank-sum tests and multivariable logistic regression analysis assessed the association of clinical and radiographic characteristics with the primary outcome of death during hospitalization. RESULTS In this cohort of 94 patients, median age was 44 (interquartile range 29-62) months, 53 (56.4%) patients were male, 6 (7%) were HIV-infected, and 10 (11%) died during hospitalization. Elevated concentrations of plasma lactate (p = 0.005) and CSF PfHRP-2 (p = 0.04) were significantly associated with death. On multivariable analysis, higher PfHRP-2 in the CSF was associated with death (odds ratio 9.00, 95% confidence interval 1.44-56.42) while plasma PfHRP-2 was not (odds ratio 2.05, 95% confidence interval 0.45-9.35). CONCLUSIONS Elevation of CSF, but not plasma PfHRP-2, is associated with death in this paediatric CM cohort. PfHRP-2 egress into the CSF may represent alteration of blood brain barrier permeability related to the sequestration of parasitized erythrocytes in the cerebral microvasculature.
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Affiliation(s)
- Kiran T Thakur
- Division of Critical Care and Hospitalist Neurology, Department of Neurology, Columbia University Medical Center, 177 Fort Washington Avenue, Milstein Hospital, 8GS-300, New York, NY, 10032, USA.
| | - Jimmy Vareta
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Kathryn A Carson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Samuel Kampondeni
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Neuroradiology Division, Department of Imaging Sciences, University of Rochester, Rochester, NY, USA
- Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Michael J Potchen
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Neuroradiology Division, Department of Imaging Sciences, University of Rochester, Rochester, NY, USA
| | - Gretchen L Birbeck
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Epilepsy Division, Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Ian MacCormick
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Eye and Vision Science, University of Liverpool, Liverpool, UK
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Terrie Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - David J Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Karl B Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
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34
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Fitzgerald E, Mlotha-Mitole R, Ciccone EJ, Tilly AE, Montijo JM, Lang HJ, Eckerle M. A pediatric death audit in a large referral hospital in Malawi. BMC Pediatr 2018; 18:75. [PMID: 29466967 PMCID: PMC5822526 DOI: 10.1186/s12887-018-1051-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 02/06/2018] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND Death audits have been used to describe pediatric mortality in under-resourced settings, where record keeping is often a challenge. This information provides the cornerstone for the foundation of quality improvement initiatives. Malawi, located in sub-Saharan Africa, currently has an Under-5 mortality rate of 64/1000. Kamuzu Central Hospital, in the capital city Lilongwe, is a busy government referral hospital, which admits up to 3000 children per month. A study published in 2013 reported mortality rates as high as 9%. This is the first known audit of pediatric death files conducted at this hospital. METHODS A retrospective chart review on all pediatric deaths that occurred at Kamuzu Central Hospital (excluding deaths in the neonatal nursery) during a 13-month period was done using a standardized death audit form. A descriptive analysis was completed, including patient demographics, HIV and nutritional status, and cause of death. Modifiable factors were identified that may have contributed to mortality, including a lack of vital sign collection, poor documentation, and delays in the procurement or results of tests, studies, and specialist review. RESULTS Seven hundred forty three total pediatric deaths were recorded and 700 deceased patient files were reviewed. The mortality rate by month ranged from a low of 2.2% to a high of 4.4%. Forty-four percent of deaths occurred within the first 24 h of admission, and 59% occurred within the first 48 h. The most common causes of death were malaria, malnutrition, HIV-related illnesses, and sepsis. CONCLUSIONS The mortality rate for this pediatric referral center has dramatically decreased in the 6 years since the last published mortality data, but remains high. Areas identified for continued development include improved record keeping, improved patient assessment and monitoring, and more timely and reliable provision of testing and treatment. This study demonstrates that in low-resource settings, where reliable record keeping is often difficult, death audits are useful tools to describe the sickest patient population and determine factors possibly contributing to mortality that may be amenable to quality improvement interventions.
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Affiliation(s)
- Elizabeth Fitzgerald
- Assistant Professor of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, USA.
| | | | - Emily J Ciccone
- University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Alyssa E Tilly
- University of North Carolina at Chapel Hill, Chapel Hill, USA
| | | | - Hans-Joerg Lang
- Médecins sans Frontières - Belgium, Paediatric Referent, Brussels, Belgium
| | - Michelle Eckerle
- Assistant Professor of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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35
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Kingston HW, Ghose A, Plewes K, Ishioka H, Leopold SJ, Maude RJ, Paul S, Intharabut B, Silamut K, Woodrow C, Day NPJ, Chotivanich K, Anstey NM, Hossain A, White NJ, Dondorp AM. Disease Severity and Effective Parasite Multiplication Rate in Falciparum Malaria. Open Forum Infect Dis 2017; 4:ofx169. [PMID: 29302604 PMCID: PMC5739038 DOI: 10.1093/ofid/ofx169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 11/18/2017] [Indexed: 11/13/2022] Open
Abstract
Patients presenting with severe falciparum malaria in a Bangladeshi tertiary hospital had higher total parasite burden, estimated by parasitemia and plasma PfHRP2, than uncomplicated malaria patients despite shorter fever duration. This suggests that higher parasite multiplication rates (PMR) contribute to causing the higher biomass found in severe disease. Compared with patients without a history of previous malaria, patients with previous malaria carried a lower parasite biomass with similar fever duration at presentation, suggesting that host immunity reduces the PMR.
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Affiliation(s)
- Hugh W Kingston
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | | | - Katherine Plewes
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Haruhiko Ishioka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stije J Leopold
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Richard J Maude
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Sanjib Paul
- Chittagong Medical College, Chittagong, Bangladesh
| | - Benjamas Intharabut
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kamorat Silamut
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles 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 Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Kesinee Chotivanich
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Amir Hossain
- Chittagong Medical College, Chittagong, Bangladesh
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, United Kingdom
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36
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Fanello C, Onyamboko M, Lee SJ, Woodrow C, Setaphan S, Chotivanich K, Buffet P, Jauréguiberry S, Rockett K, Stepniewska K, Day NPJ, White NJ, Dondorp AM. Post-treatment haemolysis in African children with hyperparasitaemic falciparum malaria; a randomized comparison of artesunate and quinine. BMC Infect Dis 2017; 17:575. [PMID: 28818049 PMCID: PMC5561573 DOI: 10.1186/s12879-017-2678-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 08/09/2017] [Indexed: 11/10/2022] Open
Abstract
Background Parenteral artesunate is the treatment of choice for severe malaria. Recently, haemolytic anaemia occurring 1 to 3 weeks after artesunate treatment of falciparum malaria has been reported in returning travellers in temperate countries. Methods To assess these potential safety concerns in African children, in whom most deaths from malaria occur, an open-labelled, randomized controlled trial was conducted in Kinshasa, Democratic Republic of Congo. 217 children aged between 6 months and 14 years with acute uncomplicated falciparum malaria and parasite densities over 100,000/μL were randomly allocated to intravenous artesunate or quinine, hospitalized for 3 days and then followed for 42 days. Results The immediate reduction in haemoglobin was less with artesunate than with quinine: median (IQR) fall at 72 h 1.4 g/dL (0.90–1.95) vs. 1.7 g/dL (1.10–2.40) (p = 0.009). This was explained by greater pitting then recirculation of once infected erythrocytes. Only 5% of patients (in both groups) had a ≥ 10% reduction in haemoglobin after day 7 (p = 0.1). One artesunate treated patient with suspected concomitant sepsis had a protracted clinical course and required a blood transfusion on day 14. Conclusions Clinically significant delayed haemolysis following parenteral artesunate is uncommon in African children hospitalised with acute falciparum malaria and high parasitaemias. Trial registration ClinicalTrials.gov; Identifier: NCT02092766 (18/03/2014) Electronic supplementary material The online version of this article (doi:10.1186/s12879-017-2678-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- C Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - M Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - S J Lee
- 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
| | - C 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
| | - S Setaphan
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - K Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - P Buffet
- Institut National de la Transfusion Sanguine, Université Paris Descartes/INSERM UMR_S 1134, Paris, France.,Laboratoire d'Excellence GR-Ex, Paris, France.,Assistance Publique-Hôpitaux de Paris, Centre National de Référence du Paludisme, Paris, France
| | - S Jauréguiberry
- Assistance Publique-Hôpitaux de Paris, Centre National de Référence du Paludisme, Paris, France
| | - K Rockett
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - K Stepniewska
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,WorldWide Antimalarial Resistance Network, Oxford, UK
| | - N 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
| | - N 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
| | - A M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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37
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Park GS, Opoka RO, Shabani E, Wypyszynski A, Hanisch B, John CC. Plasmodium falciparum Histidine-Rich Protein-2 Plasma Concentrations Are Higher in Retinopathy-Negative Cerebral Malaria Than in Severe Malarial Anemia. Open Forum Infect Dis 2017; 4:ofx151. [PMID: 28948179 PMCID: PMC5597884 DOI: 10.1093/ofid/ofx151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/14/2017] [Indexed: 11/14/2022] Open
Abstract
Background Malaria retinopathy has been proposed as marker of “true” cerebral malaria (CM), ie, coma due to Plasmodium falciparum vs coma due to other causes, with incidental P falciparum parasitemia. Plasma P falciparum histidine-rich protein-2 (PfHRP2) concentrations distinguish retinopathy-positive (RP) from retinopathy-negative (RN) CM but have not been compared between RN CM and other forms of severe malaria or asymptomatic parasitemia (AP). Methods We compared plasma PfHRP2 concentrations in 260 children with CM (247 examined for retinopathy), 228 children with severe malarial anemia (SMA), and 30 community children with AP. Results Plasmodium falciparum HRP2 concentrations were higher in children with RP CM than RN CM (P = .006), with an area under the receiver operating characteristic curve of 0.61 (95% confidence interval, 0.53–0.68). Plasmodium falciparum HRP2 concentrations and sequestered parasite biomass were higher in RN CM than SMA (both P < .03) or AP (both P < .001). Conclusions Plasmodium falciparum HRP2 concentrations are higher in children with RN CM than in children with SMA or AP, suggesting that P falciparum is involved in disease pathogenesis in children with CM. Plasmodium falciparum HRP2 concentrations may provide a more feasible and consistent assessment of the contribution of P falciparum to severe disease than malaria retinopathy.
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Affiliation(s)
- Gregory S Park
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis
| | - Robert O Opoka
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Estela Shabani
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis.,Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University School of Medicine, Indianapolis
| | - Alexis Wypyszynski
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis
| | - Benjamin Hanisch
- Division of Pediatric Infectious Diseases, Children's National Medical Center, Washington, District of Columbia
| | - Chandy C John
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis.,Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University School of Medicine, Indianapolis
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38
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Ndour PA, Larréché S, Mouri O, Argy N, Gay F, Roussel C, Jauréguiberry S, Perillaud C, Langui D, Biligui S, Chartrel N, Mérens A, Kendjo E, Ghose A, Hassan MMU, Hossain MA, Kingston HWF, Plewes K, Dondorp AM, Danis M, Houzé S, Bonnefoy S, Thellier M, Woodrow CJ, Buffet PA. Measuring thePlasmodium falciparumHRP2 protein in blood from artesunate-treated malaria patients predicts post-artesunate delayed hemolysis. Sci Transl Med 2017; 9:9/397/eaaf9377. [DOI: 10.1126/scitranslmed.aaf9377] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 11/02/2016] [Accepted: 03/28/2017] [Indexed: 01/09/2023]
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39
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Ssempiira J, Nambuusi B, Kissa J, Agaba B, Makumbi F, Kasasa S, Vounatsou P. Geostatistical modelling of malaria indicator survey data to assess the effects of interventions on the geographical distribution of malaria prevalence in children less than 5 years in Uganda. PLoS One 2017; 12:e0174948. [PMID: 28376112 PMCID: PMC5380319 DOI: 10.1371/journal.pone.0174948] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/19/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malaria burden in Uganda has declined disproportionately among regions despite overall high intervention coverage across all regions. The Uganda Malaria Indicator Survey (MIS) 2014-15 was the second nationally representative survey conducted to provide estimates of malaria prevalence among children less than 5 years, and to track the progress of control interventions in the country. In this present study, 2014-15 MIS data were analysed to assess intervention effects on malaria prevalence in Uganda among children less than 5 years, assess intervention effects at regional level, and estimate geographical distribution of malaria prevalence in the country. METHODS Bayesian geostatistical models with spatially varying coefficients were used to determine the effect of interventions on malaria prevalence at national and regional levels. Spike-and-slab variable selection was used to identify the most important predictors and forms. Bayesian kriging was used to predict malaria prevalence at unsampled locations. RESULTS Indoor Residual Spraying (IRS) and Insecticide Treated Nets (ITN) ownership had a significant but varying protective effect on malaria prevalence. However, no effect was observed for Artemisinin Combination-based Therapies (ACTs). Environmental factors, namely, land cover, rainfall, day and night land surface temperature, and area type were significantly associated with malaria prevalence. Malaria prevalence was higher in rural areas, increased with the child's age, and decreased with higher household socioeconomic status and higher level of mother's education. The highest prevalence of malaria in children less than 5 years was predicted for regions of East Central, North East and West Nile, whereas the lowest was predicted in Kampala and South Western regions, and in the mountainous areas in Mid-Western and Mid-Eastern regions. CONCLUSIONS IRS and ITN ownership are important interventions against malaria prevalence in children less than 5 years in Uganda. The varying effects of the interventions calls for selective implementation of control tools suitable to regional ecological settings. To further reduce malaria burden and sustain malaria control in Uganda, current tools should be supplemented by health system strengthening, and socio-economic development.
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Affiliation(s)
- Julius Ssempiira
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- School of Public Health, Makerere University, Kampala, Uganda
| | - Betty Nambuusi
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- School of Public Health, Makerere University, Kampala, Uganda
| | | | | | | | - Simon Kasasa
- School of Public Health, Makerere University, Kampala, Uganda
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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40
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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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41
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Malaria: Biology and Disease. Cell 2016; 167:610-624. [PMID: 27768886 DOI: 10.1016/j.cell.2016.07.055] [Citation(s) in RCA: 449] [Impact Index Per Article: 56.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/17/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.
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42
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Plasmodium falciparum Histidine-Rich Protein II Compromises Brain Endothelial Barriers and May Promote Cerebral Malaria Pathogenesis. mBio 2016; 7:mBio.00617-16. [PMID: 27273825 PMCID: PMC4959673 DOI: 10.1128/mbio.00617-16] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cerebral malaria (CM) is a disease of the vascular endothelium caused by Plasmodium falciparum. It is characterized by parasite sequestration, inflammatory cytokine production, and vascular leakage. A distinguishing feature of P. falciparum infection is parasite production and secretion of histidine-rich protein II (HRPII). Plasma HRPII is a diagnostic and prognostic marker for falciparum malaria. We demonstrate that disruption of a human cerebral microvascular endothelial barrier by P. falciparum-infected erythrocytes depends on expression of HRPII. Purified recombinant or native HRPII can recapitulate these effects. HRPII action occurs via activation of the inflammasome, resulting in decreased integrity of tight junctions and increased endothelial permeability. We propose that HRPII is a virulence factor that may contribute to cerebral malaria by compromising endothelial barrier integrity within the central nervous system. Cerebral malaria is a devastating disease. Patients have high levels of the protein HRPII in their blood. We have found that endothelial cell barriers become leaky when treated with concentrations of HRPII similar to those found in patients. This result suggests that HRPII may be important in cerebral malaria. Our finding that HRPII functions by causing inflammation suggests points of intervention for therapy or vaccination against this disease.
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43
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The endothelial protein C receptor rs867186-GG genotype is associated with increased soluble EPCR and could mediate protection against severe malaria. Sci Rep 2016; 6:27084. [PMID: 27255786 PMCID: PMC4891778 DOI: 10.1038/srep27084] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/29/2016] [Indexed: 11/23/2022] Open
Abstract
The endothelial protein C receptor (EPCR) appears to play an important role in Plasmodium falciparum endothelial cell binding in severe malaria (SM). Despite consistent findings of elevated soluble EPCR (sEPCR) in other infectious diseases, field studies to date have provided conflicting data about the role of EPCR in SM. To better define this role, we performed genotyping for the rs867186-G variant, associated with increased sEPCR levels, and measured sEPCR levels in two prospective studies of Ugandan children designed to understand immunologic and genetic factors associated with neurocognitive deficits in SM including 551 SM children, 71 uncomplicated malaria (UM) and 172 healthy community children (CC). The rs867186-GG genotype was more frequent in CC (4.1%) than SM (0.6%, P = 0.002). The rs867186-G variant was associated with increased sEPCR levels and sEPCR was lower in children with SM than CC (P < 0.001). Among SM children, those who had a second SM episode showed a trend toward lower plasma sEPCR both at initial admission and at 6-month follow-up compared to those without repeated SM (P = 0.06 for both). The study findings support a role for sEPCR in severe malaria pathogenesis and emphasize a distinct role of sEPCR in malaria as compared to other infectious diseases.
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44
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Castro-Sesquen YE, Kim C, Gilman RH, Sullivan DJ, Searson PC. Nanoparticle-Based Histidine-Rich Protein-2 Assay for the Detection of the Malaria Parasite Plasmodium falciparum. Am J Trop Med Hyg 2016; 95:354-7. [PMID: 27185769 DOI: 10.4269/ajtmh.15-0772] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 03/28/2016] [Indexed: 11/07/2022] Open
Abstract
A nanoparticle-based assay for detection and quantification of Plasmodium falciparum histidine-rich protein 2 (HRP2) in urine and serum is reported. The assay uses magnetic beads conjugated with anti-HRP2 antibody for protein capture and concentration, and antibody-conjugated quantum dots for optical detection. Western blot analysis demonstrated that magnetic beads allow the concentration of HRP2 protein in urine by 20-fold. The concentration effect was achieved because large volume of urine can be incubated with beads, and magnetic separation can be easily performed in minutes to isolate beads containing HRP2 protein. Magnetic beads and quantum dots conjugated to anti-HRP2 antibodies allows the detection of low concentrations of HRP2 protein (0.5 ng/mL), and quantification in the range of 33-2,000 ng/mL corresponding to the range associated with non-severe to severe malaria. This assay can be easily adapted to a noninvasive point-of-care test for classification of severe malaria.
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Affiliation(s)
- Yagahira E Castro-Sesquen
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Chloe Kim
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland. Institute for Nanobiotechnology Johns Hopkins University, Baltimore, Maryland
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - David J Sullivan
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Peter C Searson
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland. Institute for Nanobiotechnology Johns Hopkins University, Baltimore, Maryland.
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45
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Severe adult malaria is associated with specific PfEMP1 adhesion types and high parasite biomass. Proc Natl Acad Sci U S A 2016; 113:E3270-9. [PMID: 27185931 DOI: 10.1073/pnas.1524294113] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The interplay between cellular and molecular determinants that lead to severe malaria in adults is unexplored. Here, we analyzed parasite virulence factors in an infected adult population in India and investigated whether severe malaria isolates impair endothelial protein C receptor (EPCR), a protein involved in coagulation and endothelial barrier permeability. Severe malaria isolates overexpressed specific members of the Plasmodium falciparum var gene/PfEMP1 (P. falciparum erythrocyte membrane protein 1) family that bind EPCR, including DC8 var genes that have previously been linked to severe pediatric malaria. Machine learning analysis revealed that DC6- and DC8-encoding var transcripts in combination with high parasite biomass were the strongest indicators of patient hospitalization and disease severity. We found that DC8 CIDRα1 domains from severe malaria isolates had substantial differences in EPCR binding affinity and blockade activity for its ligand activated protein C. Additionally, even a low level of inhibition exhibited by domains from two cerebral malaria isolates was sufficient to interfere with activated protein C-barrier protective activities in human brain endothelial cells. Our findings demonstrate an interplay between parasite biomass and specific PfEMP1 adhesion types in the development of adult severe malaria, and indicate that low impairment of EPCR function may contribute to parasite virulence.
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46
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Wihokhoen B, Dondorp AM, Turner P, Woodrow CJ, Imwong M. Use of Blood Smears and Dried Blood Spots for Polymerase Chain Reaction-Based Detection and Quantification of Bacterial Infection and Plasmodium falciparum in Severely Ill Febrile African Children. Am J Trop Med Hyg 2016; 94:322-326. [PMID: 26711525 PMCID: PMC4751960 DOI: 10.4269/ajtmh.15-0532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/31/2015] [Indexed: 11/07/2022] Open
Abstract
Molecular approaches offer a means of testing archived samples stored as dried blood spots in settings where standard blood cultures are not possible. Peripheral blood films are one suggested source of material, although the sensitivity of this approach has not been well defined. Thin blood smears and dried blood spots from a severe pediatric malaria study were assessed using specific polymerase chain reaction (PCR) primers to detect non-typhoidal Salmonella (NTS; MisL gene), Streptococcus pneumoniae (lytA), and Plasmodium falciparum (18S rRNA). Of 16 cases of NTS and S. pneumoniae confirmed on blood culture, none were positive by PCR using DNA extracts from blood films or dried blood spots. In contrast, four of 36 dried blood spots and two of 178 plasma samples were PCR positive for S. pneumoniae, despite negative bacterial blood cultures, suggesting false positives. Quantitative assessment revealed that the effective concentration of P. falciparum DNA in blood films was three log orders of magnitude lower than for dried blood spots. The P. falciparum kelch13 gene could not be amplified from blood films. These findings question the value of blood PCR-based approaches for detection of NTS and S. pneumoniae, and show that stored blood films are an inefficient method of studying P. falciparum.
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Affiliation(s)
| | | | | | | | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom; Cambodia-Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia
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47
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de Haan F, Onyamboko MA, Fanello CI, Woodrow CJ, Lubell Y, Boon WPC, Dondorp AM. Exploring health practitioners' acceptability of a prospective semi-quantitative pfHRP2 device to define severe malaria in the Democratic Republic of Congo. Malar J 2015; 14:503. [PMID: 26670489 PMCID: PMC4681050 DOI: 10.1186/s12936-015-0963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 10/24/2015] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A rapid diagnostic tool is being developed to discern severely ill children with severe malaria from children who are ill with alternative febrile diseases but have coincidental peripheral blood parasitaemia. The device semi-quantitatively measures plasma pfHRP2 and has the potential to reduce mortality in children with severe febrile illnesses by improving diagnosis. The aim of this study is to identify contributing and inhibiting factors that affect healthcare practitioners' acceptability of this prospective diagnostic device in a high malaria transmission setting in the Democratic Republic of Congo. METHODS Data were collected qualitatively by conducting semi-structured interviews with a purposeful sample of health professionals in Kinshasa, capital of Democratic Republic of Congo. In total, 11 interviews were held with professionals at four different institutes. RESULTS Four key findings emerged: (1) Congolese practitioners perceive the semi-quantitative pfHRP2 device as a welcome intervention as they recognize the limited reliability of their current diagnostic and therapeutic approaches to severe febrile illnesses; (2) compatibility of the semi-quantitative pfHRP2 device with clinical equipment and competences of Congolese health practitioners is considered to be limited, especially in rural settings; (3) a formal training programme is crucial for correct understanding and application of the semi-quantitative pfHRP2 device; and, (4) provision of evidence to practitioners, and support from health authorities would be important to establish confidence in the semi-quantitative pfHRP2 device. CONCLUSIONS Congolese practitioners perceive the prospective semi-quantitative pfHRP2 device as a welcome addition to their clinical equipment. The device could improve current diagnostic work-up of severe febrile illness, which might consequently improve treatment choices. However, despite this recognized potential, several hurdles and drivers need to be taken into account when implementing this device in DR Congo.
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Affiliation(s)
- Freek de Haan
- Innovation Studies Group, Copernicus Institute, Utrecht University, Utrecht, The Netherlands.
| | - Marie A Onyamboko
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo.
| | - Caterina I Fanello
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Charles J Woodrow
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Yoel Lubell
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Wouter P C Boon
- Innovation Studies Group, Copernicus Institute, Utrecht University, Utrecht, The Netherlands.
| | - Arjen M Dondorp
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Lubell Y, Blacksell SD, Dunachie S, Tanganuchitcharnchai A, Althaus T, Watthanaworawit W, Paris DH, Mayxay M, Peto TJ, Dondorp AM, White NJ, Day NPJ, Nosten F, Newton PN, Turner P. Performance of C-reactive protein and procalcitonin to distinguish viral from bacterial and malarial causes of fever in Southeast Asia. BMC Infect Dis 2015; 15:511. [PMID: 26558692 PMCID: PMC4642613 DOI: 10.1186/s12879-015-1272-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/05/2015] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Poor targeting of antimicrobial drugs contributes to the millions of deaths each year from malaria, pneumonia, and other tropical infectious diseases. While malaria rapid diagnostic tests have improved use of antimalarial drugs, there are no similar tests to guide the use of antibiotics in undifferentiated fevers. In this study we estimate the diagnostic accuracy of two well established biomarkers of bacterial infection, procalcitonin and C-reactive protein (CRP) in discriminating between common viral and bacterial infections in malaria endemic settings of Southeast Asia. METHODS Serum procalcitonin and CRP levels were measured in stored serum samples from febrile patients enrolled in three prospective studies conducted in Cambodia, Laos and, Thailand. Of the 1372 patients with a microbiologically confirmed diagnosis, 1105 had a single viral, bacterial or malarial infection. Procalcitonin and CRP levels were compared amongst these aetiological groups and their sensitivity and specificity in distinguishing bacterial infections and bacteraemias from viral infections were estimated using standard thresholds. RESULTS Serum concentrations of both biomarkers were significantly higher in bacterial infections and malaria than in viral infections. The AUROC for CRP in discriminating between bacterial and viral infections was 0.83 (0.81-0.86) compared with 0.74 (0.71-0.77) for procalcitonin (p < 0.0001). This relative advantage was evident in all sites and when stratifying patients by age and admission status. For CRP at a threshold of 10 mg/L, the sensitivity of detecting bacterial infections was 95% with a specificity of 49%. At a threshold of 20 mg/L sensitivity was 86% with a specificity of 67%. For procalcitonin at a low threshold of 0.1 ng/mL the sensitivity was 90% with a specificity of 39%. At a higher threshold of 0.5 ng/ul sensitivity was 60% with a specificity of 76%. CONCLUSION In samples from febrile patients with mono-infections from rural settings in Southeast Asia, CRP was a highly sensitive and moderately specific biomarker for discriminating between viral and bacterial infections. Use of a CRP rapid test in peripheral health settings could potentially be a simple and affordable measure to better identify patients in need of antibacterial treatment and part of a global strategy to combat the emergence of antibiotic resistance.
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Affiliation(s)
- Yoel Lubell
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Stuart D Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Susanna Dunachie
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Ampai Tanganuchitcharnchai
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Thomas Althaus
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Wanitda Watthanaworawit
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.
| | - Daniel H Paris
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos. .,Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Laos.
| | - Thomas J Peto
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - François Nosten
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.
| | - Paul N Newton
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Mahosot Hospital, Vientiane, Laos.
| | - Paul Turner
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Cambodia Oxford Medical Research Unit, Angkor Hospital for Children, Siem Reap, Cambodia.
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49
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Use of a rapid test to assess plasma Plasmodium falciparum HRP2 and guide management of severe febrile illness. Malar J 2015; 14:362. [PMID: 26391009 PMCID: PMC4578847 DOI: 10.1186/s12936-015-0900-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 09/12/2015] [Indexed: 11/24/2022] Open
Abstract
Background Plasma Plasmodium falciparum histidine-rich protein-2 (PfHRP2) is the most accurate biomarker for severe malaria, but its measurement by ELISA has been considered too unwieldy to incorporate into clinical management. Methods Plasma samples covering a wide range of PfHRP2 concentrations were applied to rapid diagnostic tests (RDTs). RDTs were read by eye and digital capture, and PfHRP2 concentrations were measured via serial dilution with results compared to ELISA readings. Results The Paracheck® brand showed the strongest correlation (r2 = 0.963) as well as the lowest inter-observer variability (combined kappa across band intensities for three observers = 0.938). Plasma PfHRP2 measurement via serial dilution showed minimal bias compared to ELISA and acceptable limits of agreement. Three different dilutions of a well characterized set of admission samples from uncomplicated and severe malaria patients studied in a low transmission setting gave an area under the receiver operator characteristic curve of 0.844 in terms of identifying severe malaria. Conclusions These studies show that plasma PfHRP2 can be assessed via a single RDT, with application of a plasma dilution of 1:5 or 1:10 providing useful diagnostic information to assist in patient management or clinical trial inclusion.
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50
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Silal SP, Little F, Barnes KI, White LJ. Predicting the impact of border control on malaria transmission: a simulated focal screen and treat campaign. Malar J 2015; 14:268. [PMID: 26164675 PMCID: PMC4499227 DOI: 10.1186/s12936-015-0776-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 06/28/2015] [Indexed: 12/31/2022] Open
Abstract
Background South Africa is one of many countries committed to malaria elimination with a target of 2018 and all malaria-endemic provinces, including Mpumalanga, are increasing efforts towards this ambitious goal. The reduction of imported infections is a vital element of an elimination strategy, particularly if a country is already experiencing high levels of imported infections. Border control of malaria is one tool that may be considered. Methods A metapopulation, non-linear stochastic ordinary differential equation model is used to simulate malaria transmission in Mpumalanga and Maputo province, Mozambique (the source of the majority of imported infections) to predict the impact of a focal screen and treat campaign at the Mpumalanga–Maputo border. This campaign is simulated by nesting an individual-based model for the focal screen and treat campaign within the metapopulation transmission model. Results The model predicts that such a campaign, simulated for different levels of resources, coverage and take-up rates with a variety of screening tools, will not eliminate malaria on its own, but will reduce transmission substantially. Making the campaign mandatory decreases transmission further though sub-patent infections are likely to remain undetected if the diagnostic tool is not adequately sensitive. Replacing screening and treating with mass drug administration results in substantially larger decreases as all (including sub-patent) infections are treated before movement into Mpumalanga. Conclusions The reduction of imported cases will be vital to any future malaria control or elimination strategy. This simulation predicts that FSAT at the Mpumalanga–Maputo border will be unable to eliminate local malaria on its own, but may still play a key role in detecting and treating imported infections before they enter the country. Thus FSAT may form part of an integrated elimination strategy where a variety of interventions are employed together to achieve malaria elimination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0776-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sheetal P Silal
- Department of Statistical Sciences, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.
| | - Francesca Little
- Department of Statistical Sciences, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.
| | - Karen I Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Lisa J White
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, UK.
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