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Benié EMA, Silué KD, Ding XC, Yeo I, Assamoi JB, Tuo K, Gnagne AP, Esso LJCE, Coulibaly JT, Assi SB, Bonfoh B, Yavo W, N’Goran EK. Accuracy of a rapid diagnosis test, microscopy and loop-mediated isothermal amplification in the detection of asymptomatic Plasmodium infections in Korhogo, Northern Côte d’Ivoire. Malar J 2022; 21:111. [PMID: 35366883 PMCID: PMC8976314 DOI: 10.1186/s12936-022-04133-6] [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: 07/09/2021] [Accepted: 03/21/2022] [Indexed: 11/26/2022] Open
Abstract
Background Highly sensitive and accurate malaria diagnostic tools are essential to identify asymptomatic low parasitaemia infections. This study evaluated the performance of histidine-rich protein 2 (HRP-2) based rapid diagnostic tests (RDTs), microscopy and loop-mediated isothermal amplification (LAMP) for the detection of asymptomatic Plasmodium spp. infections in Northern Côte d’Ivoire, using nested polymerase chain reaction (nPCR) as reference. Methods A household-based survey was carried out in July 2016, in the health district of Korhogo, involving 1011 adults without malaria symptom nor history of fever during the week before recruitment. The fresh capillary blood samples were collected to detect Plasmodium infections using on HRP-2-based RDTs, microscopy and LAMP and stored as dried blood spots (DBS). A subset of the DBS (247/1011, 24.4%) was randomly selected for nPCR analyses. Additionally, venous blood samples, according to LAMP result (45 LAMP positive and 65 LAMP negative) were collected among the included participants to perform the nested PCR used as the reference. Results The prevalence of asymptomatic Plasmodium spp. infections determined by RDT, microscopy, and LAMP were 4% (95% confidence interval (CI) 2.8–5.3), 5.2% (95% CI 3.9–6.6) and 18.8% (95% CI 16.4–21.2), respectively. Considering PCR on venous blood as reference, performed on 110 samples, the sensibility and specificity were, respectively, 17.8% (95% CI 6.1–29.4) and 100% for RDT, 20.0% (95% CI 7.8–32) and 100% for microscopy, and 93.3% (95% CI 85.7–100) and 95.4% (95% CI 92.2–100) for LAMP. Conclusion In Northern Côte d’Ivoire, asymptomatic Plasmodium infection was found to be widely distributed as approximately one out of five study participants was found to be Plasmodium infected. LAMP appears currently to be the only available diagnostic method that can identify in the field this reservoir of infections and should be the method to consider for potential future active case detection interventions targeting elimination of these infections.
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Lee JE, Kim SA, Mun H, Kim SR, Ha KS, Shim WB. A rapid and colorimetric loop-mediated isothermal amplification (LAMP) based on HRP-mimicking molecular beacon for the detection of major 6 Listeria species in enoki mushroom. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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3
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Erber AC, Sandler PJ, de Avelar DM, Swoboda I, Cota G, Walochnik J. Diagnosis of visceral and cutaneous leishmaniasis using loop-mediated isothermal amplification (LAMP) protocols: a systematic review and meta-analysis. Parasit Vectors 2022; 15:34. [PMID: 35073980 PMCID: PMC8785018 DOI: 10.1186/s13071-021-05133-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/16/2021] [Indexed: 12/13/2022] Open
Abstract
Sensitive, reliable and fast diagnostic tools that are applicable in low-resource settings, at the point of care (PoC), are seen as crucial in the fight against visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Addressing the need for a PoC test, several diagnostic tests, including serological and molecular methods, have been developed and evaluated in the past. One promising molecular method, already implemented for diagnosis of a range of diseases, is the loop-mediated isothermal amplification (LAMP) protocol. In this systematic review and meta-analysis, using a comprehensive search strategy, we focus on studies evaluating the performance of LAMP for the diagnosis of leishmaniasis in humans and other mammals such as dogs, compared with microscopy and/or any other molecular diagnostic method. A meta-analysis, pooling sensitivity and specificity rates and calculating areas under the curve (AUCs) in summary receiver operating characteristic (SROC) plots, was conducted on datasets extracted from studies, grouped by clinical condition and sample type. We found high sensitivity and specificity for LAMP when compared with microscopy and PCR using blood samples, with pooled estimate values of > 90% for all subgroups, corresponding to calculated AUC values > 0.96, except for LAMP compared to microscopy for diagnosis of CL. However, only a limited number of studies were truly comparable. Most of the observed heterogeneity is likely based on true differences between the studies rather than sampling error only. Due to simple readout methods and low laboratory equipment requirements for sample preparation compared to other molecular methods, LAMP is a promising candidate for a molecular (near-)PoC diagnostic method for VL and CL.
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Affiliation(s)
- Astrid Christine Erber
- Department of Epidemiology, Center for Public Health, Medical University of Vienna, Kinderspitalgasse 15, 1st floor, 1090, Vienna, Austria. .,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG, UK.
| | - Peter Julian Sandler
- Department of Applied Life Sciences, FH Campus Wien University of Applied Sciences, Helmut-Qualtinger Gasse 2, 1030, Vienna, Austria
| | - Daniel Moreira de Avelar
- Pesquisa Clínica e Políticas Públicas em Doenças Infecciosas e Parasitárias, Instituto René Rachou-Fundação Oswaldo Cruz, Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Ines Swoboda
- Department of Applied Life Sciences, FH Campus Wien University of Applied Sciences, Helmut-Qualtinger Gasse 2, 1030, Vienna, Austria
| | - Gláucia Cota
- Pesquisa Clínica e Políticas Públicas em Doenças Infecciosas e Parasitárias, Instituto René Rachou-Fundação Oswaldo Cruz, Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria
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Choi G, Guan W. Sample-to-Answer Microfluidic Nucleic Acid Testing (NAT) on Lab-on-a-Disc for Malaria Detection at Point of Need. Methods Mol Biol 2022; 2393:297-313. [PMID: 34837186 PMCID: PMC9191616 DOI: 10.1007/978-1-0716-1803-5_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
One of the grand challenges for field-deployable NATs is related to the front end of the assays-nucleic acid extraction from raw samples. The ideal nucleic acid sample preparation should be simple, scalable, and easy-to-operate. In this chapter, we present a lab-on-a-disc NAT device for sample-to-answer malaria diagnosis. The parasite DNA sample preparation and subsequent real-time LAMP detection are seamlessly integrated on a disposable single microfluidic compact disc, driven by energy-efficient, non-centrifuge-based magnetic field interactions. Each disc contains four parallel testing units, which could be configured either as four identical tests or as four species-specific tests. When configured as species-specific tests, it could identify two of the most life-threatening malaria species (P. falciparum and P. vivax). The reagent disc with a 4-plex analyzer (discussed in Chapter 1 ) is capable of processing four samples simultaneously with 40 min turnaround time. It achieves a detection limit of ~0.5 parasites/μl for whole blood, sufficient for detecting asymptomatic parasite carriers. The assay is performed with an automated device described in Chapter 14 . The combination of sensitivity, specificity, cost, and scalable sample preparation suggests the real-time fluorescence LAMP device could be particularly useful for malaria screening in field settings.
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Affiliation(s)
- Gihoon Choi
- Department of Electrical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Weihua Guan
- Department of Electrical Engineering, Pennsylvania State University, University Park, PA, USA.
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.
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5
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The mechanism and improvements to the isothermal amplification of nucleic acids, at a glance. Anal Biochem 2021; 631:114260. [PMID: 34023274 DOI: 10.1016/j.ab.2021.114260] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 01/08/2023]
Abstract
A comparative review of the most common isothermal methods is provided. In the last two decades, the challenge of using isothermal amplification systems as an alternate to the most extensive and long-standing nucleic acids-amplifying method-the polymerase chain reaction-has arisen. The main advantage of isothermal amplification is no requirement for expensive laboratory equipment for thermal cycling. Considerable efforts have been made to improve the current techniques of nucleic acid amplification and the development of new approaches based on the main drawbacks of each method. The most important and challenging goal was to achieve a low-cost, straightforward system that is rapid, specific, accurate, and sensitive.
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6
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Performance and Application of Commercially Available Loop-Mediated Isothermal Amplification (LAMP) Kits in Malaria Endemic and Non-Endemic Settings. Diagnostics (Basel) 2021; 11:diagnostics11020336. [PMID: 33670618 PMCID: PMC7922894 DOI: 10.3390/diagnostics11020336] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 01/04/2023] Open
Abstract
Loop-mediated isothermal amplification (LAMP) is a sensitive molecular tool suitable for use as a near point-of-care test for the diagnosis of malaria. Recent meta-analyses have detailed high sensitivity and specificity of malaria LAMP when compared to microscopy, rapid diagnostic tests, and polymerase chain reaction in both endemic and non-endemic settings. Despite this, the use of malaria LAMP has primarily been limited to research settings to date. In this review, we aim to assess to what extent commercially available malaria LAMP kits have been applied in different settings, and to identify possible obstacles that may have hindered their use from being adopted further. In order to address this, we conducted a literature search in PubMed.gov using the search terms (((LAMP) OR (Loop-mediated isothermal amplification)) AND ((Malaria) OR (Plasmodium))). Focusing primarily on studies employing one of the commercially available kits, we then selected three key areas of LAMP application for further review: the performance and application of LAMP in malaria endemic settings including low transmission areas; LAMP for malaria screening during pregnancy; and malaria LAMP in returning travelers in non-endemic settings.
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7
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Hsiang MS, Ntshalintshali N, Kang Dufour MS, Dlamini N, Nhlabathi N, Vilakati S, Malambe C, Zulu Z, Maphalala G, Novotny J, Murphy M, Schwartz A, Sturrock H, Gosling R, Dorsey G, Kunene S, Greenhouse B. Active Case Finding for Malaria: A 3-Year National Evaluation of Optimal Approaches to Detect Infections and Hotspots Through Reactive Case Detection in the Low-transmission Setting of Eswatini. Clin Infect Dis 2021; 70:1316-1325. [PMID: 31095677 PMCID: PMC7318780 DOI: 10.1093/cid/ciz403] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 05/15/2019] [Indexed: 11/15/2022] Open
Abstract
Background Reactive case detection (RACD) is a widely practiced malaria elimination intervention whereby close contacts of index cases receive malaria testing to inform treatment and other interventions. However, the optimal diagnostic and operational approaches for this resource-intensive strategy are not clear. Methods We conducted a 3-year prospective national evaluation of RACD in Eswatini, a malaria elimination setting. Loop-mediated isothermal amplification (LAMP) was compared to traditional rapid diagnostic testing (RDT) for the improved detection of infections and for hotspots (RACD events yielding ≥1 additional infection). The potential for index case–, RACD-, and individual-level factors to improve efficiencies was also evaluated. Results Among 377 RACD events, 10 890 participants residing within 500 m of index cases were tested. Compared to RDT, LAMP provided a 3-fold and 2.3-fold higher yield to detect infections (1.7% vs 0.6%) and hotspots (29.7% vs 12.7%), respectively. Hotspot detection improved with ≥80% target population coverage and response times within 7 days. Proximity to the index case was associated with a dose-dependent increased infection risk (up to 4-fold). Individual-, index case–, and other RACD-level factors were considered but the simple approach of restricting RACD to a 200-m radius maximized yield and efficiency. Conclusions We present the first large-scale national evaluation of optimal RACD approaches from a malaria elimination setting. To inform delivery of antimalarial drugs or other interventions, RACD, when conducted, should utilize more sensitive diagnostics and clear context-specific operational parameters. Future studies of RACD’s impact on transmission may still be needed.
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Affiliation(s)
- Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas.,Malaria Elimination Initiative, Global Health Group.,Department of Pediatrics, University of California, San Francisco (UCSF)
| | | | | | | | | | | | | | | | | | - Joseph Novotny
- Clinton Health Access Initiative, Eswatini Office, Mbabane
| | - Maxwell Murphy
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, UCSF
| | - Alanna Schwartz
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, UCSF
| | | | - Roly Gosling
- Malaria Elimination Initiative, Global Health Group
| | - Grant Dorsey
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, UCSF
| | | | - Bryan Greenhouse
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, UCSF
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8
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Optimization of Lyophilized LAMP and RT-PCR Reaction Mixes for Detection of Tuberculosis. THE EUROBIOTECH JOURNAL 2020. [DOI: 10.2478/ebtj-2020-0027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Undoubtedly, one of the most infectious diseases in the world is tuberculosis. Key factor for tuberculosis control is to prevent possible contagion with rapid diagnosis and effective treatment. The culture method, which it takes several weeks to obtain results, is the gold standard method for laboratory diagnosis of tuberculosis. In order to prevent possible contagion of tuberculosis, diagnosis must be made in short time and treatment should be started as soon as possible. Normally, clinical samples are studied in advanced laboratories designed for this purpose. However, especially after the screening in rural areas, the transmission of the samples to the centers has many negative effects on the clinical material. Therefore, the latest trend molecular techniques in microbiological diagnosis are developing into point of care systems that can be applied in the field without laboratory infrastructure. The major challenge for molecular-based point-of-care tests is the need to store polymerase enzymes and some of the ingredients used in the cold chain. The aim of this study is to increase the resistance of the amplification reaction mixtures by lyophilizing the tuberculosis diagnosis. Lyophilization was performed on Loop-mediated isothermal amplification (LAMP) and Real-time PCR mixtures. For the lyophilization of LAMP and RT-PCR mixtures, two different experimental setups were tried from the literature except for the developed content. Chemicals such as stachyose, trehalose, glycerol and PEG 8000 are widely using as cryoprotectants. As a result, the developed content (0.5% PEG 8000, 2.0 % Stachyose) was determined the best cryoprotectant mixture. Accordingly, amplification mixtures can be produced with the developed lyophilization method and point of care kits can be developed.
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9
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Lee JE, Mun H, Kim SR, Kim MG, Chang JY, Shim WB. A colorimetric Loop-mediated isothermal amplification (LAMP) assay based on HRP-mimicking molecular beacon for the rapid detection of Vibrio parahaemolyticus. Biosens Bioelectron 2020; 151:111968. [DOI: 10.1016/j.bios.2019.111968] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/21/2019] [Accepted: 12/14/2019] [Indexed: 12/20/2022]
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10
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Das D, Panigrahi P. CFD simulations for paper-based DNA amplification reaction (LAMP) of Mycobacterium tuberculosis—point-of-care diagnostic perspective. Med Biol Eng Comput 2019; 58:271-289. [DOI: 10.1007/s11517-019-02082-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/12/2019] [Indexed: 12/29/2022]
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11
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Tedla M. A focus on improving molecular diagnostic approaches to malaria control and elimination in low transmission settings: Review. Parasite Epidemiol Control 2019; 6:e00107. [PMID: 31193331 PMCID: PMC6525315 DOI: 10.1016/j.parepi.2019.e00107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/19/2019] [Accepted: 04/19/2019] [Indexed: 11/18/2022] Open
Abstract
The malaria elimination goal is back to the global agenda. Understanding its epidemiology in low transmission settings is crucial to design reliable strategies to detect a large reservoir of individuals infected with sub-microscopic (and often asymptomatic) infections characterized by low-parasite densities and gametocyte carriage. Traditional diagnostic methods such a light microscopy is widely used mainly in developing countries and as a result, the true picture of malaria epidemiology is misrepresented. In the last few decades, the advancement of molecular diagnostic tools significantly improved our understanding of the epidemiology of the diseases. However, the detection capacity of different molecular assays is determined by different factors such as the sensitivity of the assay and the transmission and infection dynamics of the disease particularly when there is low parasitic density in reservoir hosts. Hence, in this review, the epidemiology of malaria in low transmission settings and the priority in addressing the malaria control and elimination goals are highlighted.
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12
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Loop-mediated isothermal amplification (LAMP) and Polymerase Chain Reaction (PCR) as quality assurance tools for Rapid Diagnostic Test (RDT) malaria diagnosis in Northern Namibia. PLoS One 2018; 13:e0206848. [PMID: 30540744 PMCID: PMC6291133 DOI: 10.1371/journal.pone.0206848] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 10/19/2018] [Indexed: 11/19/2022] Open
Abstract
Malaria cases sometimes go undetected using RDTs due to their inaccurate use, poor storage conditions and failure to detect low parasitaemia (<50parasites/μL). This could result in continuous transmission of malaria and sustenance of parasite reservoirs. Molecular diagnostic tools are more sensitive and specific than RDTs in the detection of plasmodium parasites. However, the Polymerase Chain Reaction (PCR) is not routinely used because equipment and reagents are expensive and requires highly skilled personnel. Loop-mediated isothermal amplification (LAMP) is a relatively new molecular diagnostic tool for malaria with all the advantages of PCR (sensitive and specific) without the mentioned disadvantages. However, it has not been evaluated extensively as a point of care diagnostic in the field. One hundred and fifteen used RDTs were collected from health facilities in Northern Namibia in a blind study and PCR and LAMP were used to determine the presence of Plasmodium DNA. The sensitivities and PPV were 40.91% and 90% respectively for RDTs, 72.73% and 100% respectively for PCR with LAMP as the golden standard. In low malaria transmission settings, LAMP can be also be considered for use as a surveillance tool to detect all sources of malaria and determine proportion of low parasitaemia infections in order to eliminate them.
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13
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The application of loop-mediated isothermal amplification (LAMP) assays for the rapid diagnosis of food-borne mycotoxigenic fungi. Curr Opin Food Sci 2018. [DOI: 10.1016/j.cofs.2018.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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14
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Kollenda H, Hagen RM, Hanke M, Rojak S, Hinz R, Wassill L, Poppert S, Tannich E, Frickmann H. Poor Diagnostic Performance of a Species-Specific Loop-Mediated Isothermal Amplification (LAMP) Platform for Malaria. Eur J Microbiol Immunol (Bp) 2018; 8:112-118. [PMID: 30719327 PMCID: PMC6348705 DOI: 10.1556/1886.2018.00020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 08/19/2018] [Indexed: 12/31/2022] Open
Abstract
Background The objective of this study was to assess an in-house loop-mediated isothermal amplification (LAMP) platform for malaria parasite detection and identification on species level. Methods LAMP primers specific for the human Plasmodium spp., namely, P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, as well as genus-specific primers, were tested against a composite gold standard comprising microscopy from thick and thin blood films, commercial genus-specific Meridian illumigene Malaria LAMP, in-house real-time polymerase chain reaction (PCR), and commercial fast-track diagnostics (FTD) Malaria differentiation PCR. Results Of the 523 blood samples analyzed, the composite gold standard indicated 243 Plasmodium-species-DNA-containing samples (46.5%). Sensitivity and specificity of the analyzed genus- and species-specific LAMP primers were 71.0%–100.0% and 90.8%–100.0%, respectively. The influence of parasitemia was best documented for P. falciparum-specific LAMP with sensitivity values of 35.5% (22/62) for microscopically negative samples containing P. falciparum DNA, 50% (19/38) for parasitemia ≤50/μL, 84% (21/25) for parasitemia ≤500/μL, and 100% (92/92) for parasitemia >500/μL. Conclusions In our hands, performance characteristics of species-specific in-house LAMP for malaria lack reliability required for diagnostic laboratories. The use of the easy-to-apply technique for surveillance purposes may be considered.
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Affiliation(s)
- Hans Kollenda
- Department of Microbiology and Hospital Hygiene, Tropical Microbiology and Entomology Unit, Bundeswehr Hospital Hamburg, Hamburg, Germany
| | - Ralf Matthias Hagen
- Department of Preventive Medicine, Bundeswehr Medical Academy, Munich, Germany
| | - Miriam Hanke
- Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Sandra Rojak
- Department of Microbiology and Hospital Hygiene, Tropical Microbiology and Entomology Unit, Bundeswehr Hospital Hamburg, Hamburg, Germany.,Department of Infectious Diseases and Tropical Medicine, Bundeswehr Hospital Hamburg, Hamburg, Germany
| | - Rebecca Hinz
- Department of Microbiology and Hospital Hygiene, Tropical Microbiology and Entomology Unit, Bundeswehr Hospital Hamburg, Hamburg, Germany
| | | | - Sven Poppert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,Faculty of Medicine, University Basel, Basel, Switzerland
| | - Egbert Tannich
- National Reference Centre for Tropical Pathogens, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Hagen Frickmann
- Department of Microbiology and Hospital Hygiene, Tropical Microbiology and Entomology Unit, Bundeswehr Hospital Hamburg, Hamburg, Germany.,Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
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15
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Tambo M, Auala JR, Sturrock HJ, Kleinschmidt I, Bock R, Smith JL, Gosling R, Mumbengegwi DR. Evaluation of loop-mediated isothermal amplification as a surveillance tool for malaria in reactive case detection moving towards elimination. Malar J 2018; 17:255. [PMID: 29986717 PMCID: PMC6038281 DOI: 10.1186/s12936-018-2399-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/25/2018] [Indexed: 11/11/2022] Open
Abstract
Background As malaria transmission decreases, the proportion of infections that are asymptomatic at any given time increases. This poses a challenge for diagnosis as routinely used rapid diagnostic tests (RDTs) miss asymptomatic malaria cases with low parasite densities due to poor sensitivity. Yet, asymptomatic infections can contribute to onward transmission of malaria and therefore act as infectious reservoirs and perpetuate malaria transmission. This study compared the performance of RDTs to loop-mediated isothermal amplification (LAMP) in the diagnosis of malaria during reactive active case detection surveillance. Methods All reported malaria cases in the Engela Health District of Namibia were traced back to their place of residence and persons living within the four closest neighbouring houses to the index case (neighbourhood) were tested for malaria infection with RDTs and dried blood spots (DBS) were collected. LAMP and nested PCR (nPCR) were carried out on all RDTs and DBS. The same procedure was followed in randomly selected control neighbourhoods. Results Some 3151 individuals were tested by RDT, LAMP and nPCR. Sensitivity of RDTs and LAMP were 9.30 and 95.50%, respectively, and specificities were 99.27 and 99.92%, respectively, compared to nPCR. LAMP carried out on collected RDTs showed a sensitivity and specificity of 95.35 and 99.85% compared to nPCR carried out on DBS. There were 2 RDT samples that were negative by LAMP but the corresponding DBS samples were positive by PCR. Conclusion The study showed that LAMP had the equivalent performance as nPCR for the identification of Plasmodium falciparum infection. Given its relative simplicity to implement over more complex and time-consuming methods, such as PCR, LAMP is particularly useful in elimination settings where high sensitivity and ease of operation are important.
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Affiliation(s)
- Munyaradzi Tambo
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Joyce R Auala
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Hugh J Sturrock
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Immo Kleinschmidt
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Ronnie Bock
- Department of Biological Sciences, University of Namibia, Windhoek, Namibia
| | - Jennifer L Smith
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Roland Gosling
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Davis R Mumbengegwi
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia.
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16
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Choi G, Prince T, Miao J, Cui L, Guan W. Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening. Biosens Bioelectron 2018; 115:83-90. [PMID: 29803865 DOI: 10.1016/j.bios.2018.05.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 04/29/2018] [Accepted: 05/10/2018] [Indexed: 12/22/2022]
Abstract
The effectiveness of malaria screening and treatment highly depends on the low-cost access to the highly sensitive and specific malaria test. We report a real-time fluorescence nucleic acid testing device for malaria field detection with automated and scalable sample preparation capability. The device consists a compact analyzer and a disposable microfluidic reagent compact disc. The parasite DNA sample preparation and subsequent real-time LAMP detection were seamlessly integrated on a single microfluidic compact disc, driven by energy efficient non-centrifuge based magnetic field interactions. Each disc contains four parallel testing units which could be configured either as four identical tests or as four species-specific tests. When configured as species-specific tests, it could identify two of the most life-threatening malaria species (P. falciparum and P. vivax). The NAT device is capable of processing four samples simultaneously within 50 min turnaround time. It achieves a detection limit of ~0.5 parasites/µl for whole blood, sufficient for detecting asymptomatic parasite carriers. The combination of the sensitivity, specificity, cost, and scalable sample preparation suggests the real-time fluorescence LAMP device could be particularly useful for malaria screening in the field settings.
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Affiliation(s)
- Gihoon Choi
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA
| | - Theodore Prince
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA
| | - Jun Miao
- Department of Entomology, Pennsylvania State University, University Park 16802, USA
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park 16802, USA
| | - Weihua Guan
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA; Department of Biomedical Engineering, Pennsylvania State University, University Park 16802, USA.
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Horton S, Sullivan R, Flanigan J, Fleming KA, Kuti MA, Looi LM, Pai SA, Lawler M. Delivering modern, high-quality, affordable pathology and laboratory medicine to low-income and middle-income countries: a call to action. Lancet 2018; 391:1953-1964. [PMID: 29550030 DOI: 10.1016/s0140-6736(18)30460-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/28/2017] [Accepted: 12/08/2017] [Indexed: 11/17/2022]
Abstract
Modern, affordable pathology and laboratory medicine (PALM) systems are essential to achieve the 2030 Sustainable Development Goals for health in low-income and middle-income countries (LMICs). In this last in a Series of three papers about PALM in LMICs, we discuss the policy environment and emphasise three crucial high-level actions that are needed to deliver universal health coverage. First, nations need national strategic laboratory plans; second, these plans require adequate financing for implementation; and last, pathologists themselves need to take on leadership roles to advocate for the centrality of PALM to achieve the Sustainable Development Goals for health. The national strategic laboratory plan should deliver a tiered, networked laboratory system as a central element. Appropriate financing should be provided, at a level of at least 4% of health expenditure. Financing of new technologies such as molecular diagnostics is challenging for LMICs, even though many of these tests are cost-effective. Point-of-care testing can substantially reduce test-reporting time, but this benefit must be balanced with higher costs. Our research analysis highlights a considerable deficiency in advocacy for PALM; pathologists have been invisible in national and international health discourse and leadership. Embedding PALM in LMICs can only be achieved if pathologists advocate for these services, and undertake leadership roles, both nationally and internationally. We articulate eight key recommendations to address the current barriers identified in this Series and issue a call to action for all stakeholders to come together in a global alliance to ensure the effective provision of PALM services in resource-limited settings.
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Affiliation(s)
- Susan Horton
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada.
| | | | - John Flanigan
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kenneth A Fleming
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Green Templeton College, University of Oxford, Oxford, UK
| | - Modupe A Kuti
- Department of Chemical Pathology, College of Medicine, University of Ibadan, and University Hospital, Ibadan, Nigeria
| | - Lai Meng Looi
- Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sanjay A Pai
- Columbia Asia Referral Hospital, Bangalore, India
| | - Mark Lawler
- Faculty of Medicine, Health and Life Sciences and Centre for Cancer Research and Cell Biology, Queens University, Belfast, UK
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18
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Sayed S, Cherniak W, Lawler M, Tan SY, El Sadr W, Wolf N, Silkensen S, Brand N, Looi LM, Pai SA, Wilson ML, Milner D, Flanigan J, Fleming KA. Improving pathology and laboratory medicine in low-income and middle-income countries: roadmap to solutions. Lancet 2018; 391:1939-1952. [PMID: 29550027 DOI: 10.1016/s0140-6736(18)30459-8] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/11/2022]
Abstract
Insufficient awareness of the centrality of pathology and laboratory medicine (PALM) to a functioning health-care system at policy and governmental level, with the resultant inadequate investment, has meant that efforts to enhance PALM in low-income and middle-income countries have been local, fragmented, and mostly unsustainable. Responding to the four major barriers in PALM service delivery that were identified in the first paper of this Series (workforce, infrastructure, education and training, and quality assurance), this second paper identifies potential solutions that can be applied in low-income and middle-income countries (LMICs). Increasing and retaining a quality PALM workforce requires access to mentorship and continuing professional development, task sharing, and the development of short-term visitor programmes. Opportunities to enhance the training of pathologists and allied PALM personnel by increasing and improving education provision must be explored and implemented. PALM infrastructure must be strengthened by addressing supply chain barriers, and ensuring laboratory information systems are in place. New technologies, including telepathology and point-of-care testing, can have a substantial role in PALM service delivery, if used appropriately. We emphasise the crucial importance of maintaining PALM quality and posit that all laboratories in LMICs should participate in quality assurance and accreditation programmes. A potential role for public-private partnerships in filling PALM services gaps should also be investigated. Finally, to deliver these solutions and ensure equitable access to essential services in LMICs, we propose a PALM package focused on these countries, integrated within a nationally tiered laboratory system, as part of an overarching national laboratory strategic plan.
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Affiliation(s)
- Shahin Sayed
- Department of Pathology, Aga Khan University Hospital Nairobi, Nairobi, Kenya.
| | - William Cherniak
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Mark Lawler
- Faculty of Medicine, Health, and Life Sciences and Centre for Cancer Research and Cell Biology, Queens University, Belfast, UK
| | - Soo Yong Tan
- Department of Pathology, National University of Singapore, National University Hospital, Singapore
| | - Wafaa El Sadr
- ICAP at Columbia University, Mailman School of Public Health, New York, NY, USA
| | - Nicholas Wolf
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shannon Silkensen
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nathan Brand
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Lai Meng Looi
- Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sanjay A Pai
- Columbia Asia Referral Hospital, Bangalore, Karnataka, India
| | - Michael L Wilson
- Department of Pathology and Laboratory Services, Denver Health, Denver, CO, USA; Department of Pathology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Danny Milner
- American Society for Clinical Pathology, Chicago, IL, USA
| | - John Flanigan
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kenneth A Fleming
- Center for Global Health, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Green Templeton College, University of Oxford, Oxford, UK
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Frith KA, Fogel R, Goldring JPD, Krause RGE, Khati M, Hoppe H, Cromhout ME, Jiwaji M, Limson JL. Towards development of aptamers that specifically bind to lactate dehydrogenase of Plasmodium falciparum through epitopic targeting. Malar J 2018; 17:191. [PMID: 29724225 PMCID: PMC5934816 DOI: 10.1186/s12936-018-2336-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/26/2018] [Indexed: 11/19/2022] Open
Abstract
Background Early detection is crucial for the effective treatment of malaria, particularly in those cases infected with Plasmodium falciparum. There is a need for diagnostic devices with the capacity to distinguish P. falciparum from other strains of malaria. Here, aptamers generated against targeted species-specific epitopes of P. falciparum lactate dehydrogenase (rPfLDH) are described. Results Two classes of aptamers bearing high binding affinity and specificity for recombinant P. falciparum lactate dehydrogenase (rPfLDH) and P. falciparum-specific lactate dehydrogenase epitopic oligopeptide (LDHp) were separately generated. Structurally-relevant moieties with particular consensus sequences (GGTAG and GGCG) were found in aptamers reported here and previously published, confirming their importance in recognition of the target, while novel moieties particular to this work (ATTAT and poly-A stretches) were identified. Aptamers with diagnostically-supportive functions were synthesized, prime examples of which are the aptamers designated as LDHp 1, LDHp 11 and rLDH 4 and rLDH 15 in work presented herein. Of the sampled aptamers raised against the recombinant protein, rLDH 4 showed the highest binding to the target rPfLDH in the ELONA assay, with both rLDH 4 and rLDH 15 indicating an ability to discriminate between rPfLDH and rPvLDH. LDHp 11 was generated against a peptide selected as a unique P. falciparum LDH peptide. The aptamer, LDHp 11, like antibodies against the same peptide, only detected rPfLDH and discriminated between rPfLDH and rPvLDH. This was supported by affinity binding experiments where only aptamers generated against a unique species-specific epitope showed an ability to preferentially bind to rPfLDH relative to rPvLDH rather than those generated against the whole recombinant protein. In addition, rLDH 4 and LDHp 11 demonstrated in situ binding to P. falciparum cells during confocal microscopy. Conclusions The utilization and application of LDHp 11, an aptamer generated against a unique species-specific epitope of P. falciparum LDH indicated the ability to discriminate between recombinant P. falciparum and Plasmodium vivax LDH. This aptamer holds promise as a biorecognition element in malaria diagnostic devices for the detection, and differentiation, of P. falciparum and P. vivax malaria infections. This study paves the way to explore aptamer generation against targeted species-specific epitopes of other Plasmodium species.
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Affiliation(s)
- Kelly-Anne Frith
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Ronen Fogel
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - J P Dean Goldring
- Department of Biochemistry, Genetics and Microbiology, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, KwaZulu-Natal, South Africa
| | - Robert G E Krause
- Department of Biochemistry, Genetics and Microbiology, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, KwaZulu-Natal, South Africa
| | - Makobetsa Khati
- Emerging Health Technologies Platform, Biosciences Division, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, Gauteng, South Africa
| | - Heinrich Hoppe
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Mary E Cromhout
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Meesbah Jiwaji
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Janice L Limson
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa.
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Björkman A, Cook J, Sturrock H, Msellem M, Ali A, Xu W, Molteni F, Gosling R, Drakeley C, Mårtensson A. Spatial Distribution of Falciparum Malaria Infections in Zanzibar: Implications for Focal Drug Administration Strategies Targeting Asymptomatic Parasite Carriers. Clin Infect Dis 2018; 64:1236-1243. [PMID: 28431115 PMCID: PMC5399945 DOI: 10.1093/cid/cix136] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 12/30/2022] Open
Abstract
Background. Optimal use of mass/targeted screen-and-treat or mass or focal drug administration as malaria elimination strategies remains unclear. We therefore studied spatial distribution of Plasmodium falciparum infections to compare simulated effects of these strategies on reducing the parasite reservoir in a pre-elimination setting. Methods. P. falciparum rapid diagnostic tests (RDTs) and molecular (polymerase chain reaction [PCR]) and serological (enzyme-linked immunosorbent assay) analyses were performed on finger-prick blood samples from a population-based survey in 3 adjacent communities. Results. Among 5278 persons screened, 13 (0.2%) were positive by RDT and 123 (2.3%) by PCR. PCR-positive individuals were scattered over the study area, but logistic regression analysis suggested a propensity of these infections to cluster around RDT-positive individuals. The odds ratios for being PCR positive was 7.4 (95% confidence interval, 2.8–19.9) for those living in the household of an RDT-positive individual and 1.64 (1.0–2.8; P = .06) for those living within <300 m, compared with >1000 m. Treating everyone within households of RDT-positive individuals (1% population) would target 13% of those who are PCR positive. Treating all living within a radius of <300 or <1000 m (14% or 58% population) would target 30% or 66% of infections, respectively. Among 4431 serologically screened individuals, 26% were seropositive. Treating everyone within seropositive households (63% population) would target 77% of PCR-positive individuals. Conclusions. Presumptive malaria treatment seemed justified within RDT-positive households and potentially worth considering within, for example, a radius of <300 m. Serology was not discriminative enough in identifying ongoing infections for improving focal interventions in this setting but may rather be useful to detect larger transmission foci.
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Affiliation(s)
- Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jackie Cook
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,MRC Tropical Epidemiology Group, Faculty of Epidemiology and Population Health
| | - Hugh Sturrock
- Global Health Group, University of California, San Francisco, CA, USA
| | - Mwinyi Msellem
- Zanzibar Malaria Elimination Programme, Zanzibar Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Weiping Xu
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Dar es Salaam, Tanzania
| | - Roly Gosling
- Global Health Group, University of California, San Francisco, CA, USA
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Sweden
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21
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Grimberg BT, Grimberg KO. Hemozoin detection may provide an inexpensive, sensitive, 1-minute malaria test that could revolutionize malaria screening. Expert Rev Anti Infect Ther 2016; 14:879-83. [PMID: 27530228 PMCID: PMC5224914 DOI: 10.1080/14787210.2016.1222900] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 08/08/2016] [Indexed: 12/25/2022]
Abstract
Malaria remains widespread throughout the tropics and is a burden to the estimated 3.5 billion people who are exposed annually. The lack of a fast and accurate diagnostic method contributes to preventable malaria deaths and its continued transmission. In many areas diagnosis is made solely based on clinical presentation. Current methods for malaria diagnosis take more than 20 minutes from the time blood is drawn and are frequently inaccurate. The introduction of an accurate malaria diagnostic that can provide a result in less than 1 minute would allow for widespread screening and treatment of endemic populations, and enable regions that have gained a foothold against malaria to prevent its return. Using malaria parasites' waste product, hemozoin, as a biomarker for the presence of malaria could be the tool needed to develop this rapid test.
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Affiliation(s)
- Brian T Grimberg
- a School of Medicine - Center for Global Health and Diseases , Case Western Reserve University , Cleveland , OH , USA
| | - Kerry O Grimberg
- b School of Medicine, Department of Radiology , Case Western Reserve University , Cleveland , OH , USA
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22
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Britton S, Cheng Q, McCarthy JS. Novel molecular diagnostic tools for malaria elimination: a review of options from the point of view of high-throughput and applicability in resource limited settings. Malar J 2016; 15:88. [PMID: 26879936 PMCID: PMC4754967 DOI: 10.1186/s12936-016-1158-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 02/09/2016] [Indexed: 02/08/2023] Open
Abstract
As malaria transmission continues to decrease, an increasing number of countries will enter pre-elimination and elimination. To interrupt transmission, changes in control strategies are likely to require more accurate identification of all carriers of Plasmodium parasites, both symptomatic and asymptomatic, using diagnostic tools that are highly sensitive, high throughput and with fast turnaround times preferably performed in local health service settings. Currently available immunochromatographic lateral flow rapid diagnostic tests and field microscopy are unlikely to consistently detect infections at parasite densities less than 100 parasites/µL making them insufficiently sensitive for detecting all carriers. Molecular diagnostic platforms, such as PCR and LAMP, are currently available in reference laboratories, but at a cost both financially and in turnaround time. This review describes the recent progress in developing molecular diagnostic tools in terms of their capacity for high throughput and potential for performance in non-reference laboratories for malaria elimination.
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Affiliation(s)
- Sumudu Britton
- University of Queensland, Brisbane, Australia. .,QIMR Berghofer Medical Research Institute, Brisbane, Australia.
| | - Qin Cheng
- Australian Army Malaria Institute, Brisbane, Australia.
| | - James S McCarthy
- University of Queensland, Brisbane, Australia. .,QIMR Berghofer Medical Research Institute, Brisbane, Australia.
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23
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Towards ultrasensitive malaria diagnosis using surface enhanced Raman spectroscopy. Sci Rep 2016; 6:20177. [PMID: 26858127 PMCID: PMC4746575 DOI: 10.1038/srep20177] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/23/2015] [Indexed: 01/03/2023] Open
Abstract
We report two methods of surface enhanced Raman spectroscopy (SERS) for hemozoin detection in malaria infected human blood. In the first method, silver nanoparticles were synthesized separately and then mixed with lysed blood; while in the second method, silver nanoparticles were synthesized directly inside the parasites of Plasmodium falciparum. It was observed that the first method yields a smaller variation in SERS measurements and stronger correlation between the estimated contribution of hemozoin and the parasitemia level, which is preferred for the quantification of the parasitemia level. In contrast, the second method yields a higher sensitivity to a low parasitemia level thus could be more effective in the early malaria diagnosis to determine whether a given blood sample is positive.
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Cordray MS, Richards-Kortum RR. A paper and plastic device for the combined isothermal amplification and lateral flow detection of Plasmodium DNA. Malar J 2015; 14:472. [PMID: 26611141 PMCID: PMC4661981 DOI: 10.1186/s12936-015-0995-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 11/18/2015] [Indexed: 12/16/2022] Open
Abstract
Background Isothermal amplification techniques are emerging as a promising method for malaria diagnosis since they are capable of detecting extremely low concentrations of parasite target while mitigating the need for infrastructure and training required by other nucleic acid based tests. Recombinase polymerase amplification (RPA) is promising for further development since it operates in a short time frame (<30 min) and produces a product that can be visually detected on a lateral flow dipstick. A self-sealing paper and plastic system that performs both the amplification and detection of a malaria DNA sequence is presented. Methods Primers were designed using the NCBI nBLAST tools and screened using gel electrophoresis. Paper and plastic devices were prototyped using commercial design software and parts were cut using a laser cutter and assembled by hand. Synthetic copies of the Plasmodium 18S gene were spiked into solution and used as targets for the RPA reaction. To test the performance of the device the same samples spiked with synthetic target were run in parallel both in the paper and plastic devices and using conventional bench top methods. Results Novel RPA primers were developed that bind to sequences present in the four species of Plasmodium which infect humans. The paper and plastic devices were found to be capable of detecting as few as 5 copies/µL of synthetic Plasmodium DNA (50 copies total), comparable to the same reaction run on the bench top. The devices produce visual results in an hour, cost approximately $1, and are self-contained once the device is sealed. Conclusions The device was capable of carrying out the RPA reaction and detecting meaningful amounts of synthetic Plasmodium DNA in a self-sealing and self-contained device. This device may be a step towards making nucleic acid tests more accessible for malaria detection.
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Affiliation(s)
- Michael S Cordray
- Rice University Department of Bioengineering, 6100 Main St., Houston, TX, 77005, USA.
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25
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Field Evaluation of Malaria Microscopy, Rapid Malaria Tests and Loop-Mediated Isothermal Amplification in a Rural Hospital in South Western Ethiopia. PLoS One 2015; 10:e0142842. [PMID: 26555068 PMCID: PMC4640523 DOI: 10.1371/journal.pone.0142842] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/27/2015] [Indexed: 11/22/2022] Open
Abstract
Background In up to one third of the hospitals in some rural areas of Africa, laboratory services in malaria diagnosis are limited to microscopy by thin film, as no capability to perform thick film exists (gold standard in terms of sensitivity for malaria diagnosis). A new rapid molecular malaria diagnostic test called Loop-mediated isothermal DNA amplification (LAMP) has been recently validated in clinical trials showing exceptional sensitivity and specificity features. It could be a reliable diagnostic tool to be implemented without special equipment or training. Objective The objective of this proof of concept study was to confirm the feasibility of using LAMP technique for diagnosis of malaria in a rural Ethiopian hospital with limited resources. Methodology/Principal Findings This study was carried out in Gambo General Hospital, West Arsi Province (Ethiopia), from November 1st to December 31st 2013. A total of 162 patients with a non-focal febrile syndrome were investigated. The diagnostic capability (sensitivity, specificity, positive predictive and negative predictive values) of rapid malaria tests and microscopy by thin film was evaluated in comparison with LAMP. Eleven (6.79%) out of the 162 patients with fever and suspected malaria, tested positive for LAMP, 3 (1.85%) for rapid malaria tests and none of the eleven cases was detected by thin film microscopy. Conclusions/Significance LAMP can be performed in basic rural laboratories without the need for specialized infrastructure and it may set a reliable tool for malaria control to detect a low level parasitemia.
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26
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Cheng N, Xu Y, Yan X, Shang Y, Zhu P, Tian W, Liang Z, Xu W. An Advanced Visual Qualitative and EVA Green-Based Quantitative Isothermal Amplification Method to Detect L
isteria Monocytogenes. J Food Saf 2015. [DOI: 10.1111/jfs.12236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Nan Cheng
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Yuancong Xu
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Xinghua Yan
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Ying Shang
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Pengyu Zhu
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Wenying Tian
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Zhihong Liang
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
| | - Wentao Xu
- Laboratory of Food Safety; College of Food Science and Nutritional Engineering; China Agricultural University; Beijing 100083 China
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27
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Britton S, Cheng Q, Sutherland CJ, McCarthy JS. A simple, high-throughput, colourimetric, field applicable loop-mediated isothermal amplification (HtLAMP) assay for malaria elimination. Malar J 2015; 14:335. [PMID: 26315027 PMCID: PMC4552465 DOI: 10.1186/s12936-015-0848-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 08/11/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND To detect all malaria infections in elimination settings sensitive, high throughput and field deployable diagnostic tools are required. Loop-mediated isothermal amplification (LAMP) represents a possible field-applicable molecular diagnostic tool. However, current LAMP platforms are limited by their capacity for high throughput. METHODS A high-throughput LAMP (HtLAMP) platform amplifying mitochondrial targets using a 96-well microtitre plate platform, processing 85 samples and 11 controls, using hydroxynaphtholblue as a colourimetric indicator was optimized for the detection of malaria parasites. Objective confirmation of visually detectable colour change results was made using a spectrophotometer. A dilution series of laboratory-cultured 3D7 Plasmodium falciparum parasites was used to determine the limit of detection of the HtLAMP assay, using P. falciparum (HtLAMP-Pf) and Plasmodium genus (HtLAMP-Pg) primers, on whole blood and filter paper, and using different DNA extraction protocols. The diagnostic accuracy of HtLAMP was validated using clinical samples from Papua New Guinea, Malaysia, Ghana and The Gambia and its field applicability was evaluated in Kota Marudu district hospital, Sabah, Malaysia. RESULTS The HtLAMP assay proved to be a simple method generating a visually-detectable blue and purple colour change that could be objectively confirmed in a spectrophotometer at a wavelength of 600 nm. When compared with PCR, overall HtLAMP-Pg had a sensitivity of 98 % (n = 260/266, 95 % CI 95-99) and specificity 83 % (n = 15/18, 95 % CI 59-96). HtLAMP-Pf had a sensitivity of 97 % (n = 124/128, 95 % CI 92-99) and specificity of 96 % (n = 151/157, 95 % CI 92-99). A validation study in a regional hospital laboratory demonstrated ease of performance and interpretation of the HtLAMP assay. HtLAMP-Pf performed in this field setting had a sensitivity of 100 % (n = 17/17, 95 % CI 80-100) and specificity of 95 % (n = 123/128, 95 % CI 90-98) compared with multiplex PCR. HtLAMP-Pf also performed well on filter paper samples from asymptomatic Ghanaian children with a sensitivity of 88 % (n = 23/25, 95 % CI 69-97). CONCLUSION This colourimetric HtLAMP assay holds much promise as a field applicable molecular diagnostic tool for the purpose of malaria elimination.
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Affiliation(s)
- Sumudu Britton
- University of Queensland, Brisbane, Australia. .,QIMR Berghofer Medical Research Institute, Brisbane, Australia.
| | - Qin Cheng
- Australian Army Malaria Institute, Brisbane, Australia.
| | | | - James S McCarthy
- University of Queensland, Brisbane, Australia. .,QIMR Berghofer Medical Research Institute, Brisbane, Australia.
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28
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Tanner M, Greenwood B, Whitty CJM, Ansah EK, Price RN, Dondorp AM, von Seidlein L, Baird JK, Beeson JG, Fowkes FJI, Hemingway J, Marsh K, Osier F. Malaria eradication and elimination: views on how to translate a vision into reality. BMC Med 2015; 13:167. [PMID: 26208740 PMCID: PMC4514994 DOI: 10.1186/s12916-015-0384-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although global efforts in the past decade have halved the number of deaths due to malaria, there are still an estimated 219 million cases of malaria a year, causing more than half a million deaths. In this forum article, we asked experts working in malaria research and control to discuss the ways in which malaria might eventually be eradicated. Their collective views highlight the challenges and opportunities, and explain how multi-factorial and integrated processes could eventually make malaria eradication a reality.
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Affiliation(s)
- Marcel Tanner
- Swiss Tropical & Public Health Institute, 4002, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Christopher J M Whitty
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Evelyn K Ansah
- Research and Development Division, Ghana Health Service, Accra, Ghana.
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Arjen M Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Lorenz von Seidlein
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - J Kevin Baird
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No.69, Jakarta, 10430, Indonesia.
| | - James G Beeson
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. .,Department of Microbiology, Monash University, 19 Innovation Walk, Victoria, 3800, Australia.
| | - Freya J I Fowkes
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. .,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia. .,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia. .,Department of Infectious Diseases, Monash University, Melbourne, Australia.
| | - Janet Hemingway
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Kevin Marsh
- African Academy of Sciences, Miotoni Road, Miotoni Lane, House No. 8 Karen, P.O. Box 24916-00502, Nairobi, Kenya.
| | - Faith Osier
- KEMRI Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.
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Morris U, Khamis M, Aydin-Schmidt B, Abass AK, Msellem MI, Nassor MH, González IJ, Mårtensson A, Ali AS, Björkman A, Cook J. Field deployment of loop-mediated isothermal amplification for centralized mass-screening of asymptomatic malaria in Zanzibar: a pre-elimination setting. Malar J 2015; 14:205. [PMID: 25982190 PMCID: PMC4440539 DOI: 10.1186/s12936-015-0731-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/08/2015] [Indexed: 12/14/2022] Open
Abstract
Background Molecular tools for detection of low-density asymptomatic Plasmodium infections are needed in malaria elimination efforts. This study reports results from the hitherto largest implementation of loop-mediated isothermal amplification (LAMP) for centralized mass screening of asymptomatic malaria in Zanzibar. Methods Healthy individuals present and willing to participate in randomly selected households in 60 villages throughout Zanzibar were screened for malaria by rapid diagnostic tests (RDT). In 50 % of the study households, participants were asked to provide 60 μL of finger-prick blood for additional LAMP screening. LAMP was conducted in two centralized laboratories in Zanzibar, by trained technicians with limited or no previous experience of molecular methods. The LAMP assay was performed with LoopampTM MALARIA Pan/Pf Detection Kit (Eiken Chemical Company, Japan). Samples positive for Plasmodium genus (Pan)-LAMP were re-tested using Plasmodium falciparum-specific LAMP kits. Results Paired RDT and LAMP samples were available from 3983 individuals. The prevalence of asymptomatic malaria was 0.5 % (CI 95 % 0.1-0.8) and 1.6 % (CI 95 % 1.1-2.2) by RDT and Pan-LAMP, respectively. LAMP detected 3.4 (CI 95 % 2.2-5.2) times more Plasmodium positive samples than RDT. DNA contamination was experienced, but solved by repetitive decontamination of all equipment and reagents. Conclusions LAMP is a simple and sensitive molecular tool, and has potential in active surveillance and mass-screening programmes for detection of low-density asymptomatic malaria in pre-elimination settings. However, in order to deploy LAMP more effectively in field settings, protocols may need to be adapted for processing larger numbers of samples. A higher throughput, affordable closed system would be ideal to avoid contamination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0731-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ulrika Morris
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Mwinyi Khamis
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Berit Aydin-Schmidt
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Ali K Abass
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Mwinyi I Msellem
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Majda H Nassor
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Iveth J González
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland.
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden. .,Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. .,Centre for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden.
| | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Jackie Cook
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden. .,London School of Hygiene and Tropical Medicine, London, UK.
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30
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Hsiang MS, Greenhouse B, Rosenthal PJ. Reply to Goyal et al. J Infect Dis 2014; 211:1687. [PMID: 25512627 PMCID: PMC4407763 DOI: 10.1093/infdis/jiu811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 11/12/2022] Open
Affiliation(s)
- Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas Malaria Elimination Initiative, Global Health Group Department of Pediatrics, UCSF Benioff Children's Hospital
| | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco
| | - Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco
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31
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Goyal K, Kaur H, Sehgal A, Sehgal R. RealAmp Loop-Mediated Isothermal Amplification as a Point-of-Care Test for Diagnosis of Malaria: Neither Too Close nor Too Far. J Infect Dis 2014; 211:1686. [PMID: 25512623 DOI: 10.1093/infdis/jiu810] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/09/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Kapil Goyal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research
| | - Hargobinder Kaur
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research
| | - Alka Sehgal
- Department of Obstetrics and Gynaecology, Government Medical College and Hospital, Chandigarh, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research
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