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Lin EE, Razzaque UA, Burrows SA, Smoukov SK. End-to-end system for rapid and sensitive early-detection of SARS-CoV-2 for resource-poor and field-test environments using a $51 lab-in-a-backpack. PLoS One 2022; 17:e0259886. [PMID: 35081119 PMCID: PMC8791454 DOI: 10.1371/journal.pone.0259886] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/28/2021] [Indexed: 11/19/2022] Open
Abstract
COVID-19 has exposed stark inequalities between resource-rich and resource-poor countries. International UN- and WHO-led efforts, such as COVAX, have provided SARS-CoV-2 vaccines but half of African countries have less than 2% vaccinated in their population, and only 15 have reached 10% by October 2021, further disadvantaging local economic recovery. Key for this implementation and preventing further mutation and spread is the frequency of voluntary [asymptomatic] testing. It is limited by expensive PCR and LAMP tests, uncomfortable probes deep in the throat or nose, and the availability of hardware to administer in remote locations. There is an urgent need for an inexpensive "end-to-end" system to deliver sensitive and reliable, non-invasive tests in resource-poor and field-test conditions. We introduce a non-invasive saliva-based LAMP colorimetric test kit and a $51 lab-in-a-backpack system that detects as few as 4 viral RNA copies per μL. It consists of eight chemicals, a thermometer, a thermos bottle, two micropipettes and a 1000-4000 rcf electronically operated centrifuge made from recycled computer hard drives (CentriDrive). The centrifuge includes a 3D-printed rotor and a 12 V rechargeable Li-ion battery, and its 12 V standard also allows wiring directly to automobile batteries, to enable field-use of this and other tests in low infrastructure settings. The test takes 90 minutes to process 6 samples and has reagent costs of $3.5 per sample. The non-invasive nature of saliva testing would allow higher penetration of testing and wider adoption of the test across cultures and settings (including refugee camps and disaster zones). The attached graphical procedure would make the test suitable for self-testing at home, performing it in the field, or in mobile testing centers by minimally trained staff.
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Affiliation(s)
- E. Emily Lin
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - Umar A. Razzaque
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - Stephen A. Burrows
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - Stoyan K. Smoukov
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
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2
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Yokoyama T, Tasaki Y, Inoue N, Sugimoto N, Nariai E, Kuramoto S, Wada T. Rapid molecular diagnosis of Parechovirus infection using the reverse transcription loop-mediated isothermal amplification technique. PLoS One 2021; 16:e0260348. [PMID: 34843518 PMCID: PMC8629174 DOI: 10.1371/journal.pone.0260348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 11/08/2021] [Indexed: 11/18/2022] Open
Abstract
Objectives Human parechovirus (HPeV), especially HPeV A3 (HPeV3), causes sepsis-like diseases and sudden infant death syndrome in neonates and young infants. Development of rapid and easier diagnostic laboratory tests for HPeVs is desired. Methods Original inner primers, outer primers, and loop-primers were designed on the 5′ untranslated region of HPeV3. HPeV3 ribonucleic acids (RNAs), other viral RNAs, and clinical stool samples were used to confirm whether the designed primers would allow the detection of HPeV3 with the reverse transcription loop-mediated isothermal amplification (RT-LAMP) technique. Results Three combinations of primers were created and it was confirmed that all primer sets allowed the detection of HPeV3 RNAs. The primer sets had cross-reactivity with HPeV type 1 (HPeV1), but all sets showed negative results when applied to coxsackievirus, echovirus, enterovirus, norovirus, and adenovirus genomes. Four of six stool samples, obtained from newborn and infant patients with sepsis-like symptoms, showed positive results with our RT-LAMP technique. Conclusions This manuscript is the first description of an RT-LAMP for the diagnosis of HPeVs, allowing a faster, easier, and cheaper diagnosis. This technique is clinically useful for newborns and infants who have sepsis-like symptoms.
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Affiliation(s)
- Tadafumi Yokoyama
- Department of Pediatrics, Kanazawa University, Kanazawa, Ishikawa, Japan
- * E-mail:
| | - Yuko Tasaki
- Department of Pediatrics, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Natsumi Inoue
- Department of Pediatrics, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Naotoshi Sugimoto
- Department of Pediatrics, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Eri Nariai
- Health and Food Safety Department, Ishikawa Prefectural Institute of Public Health and Environmental Science, Kanazawa, Ishikawa, Japan
| | - Sanae Kuramoto
- Health and Food Safety Department, Ishikawa Prefectural Institute of Public Health and Environmental Science, Kanazawa, Ishikawa, Japan
| | - Taizo Wada
- Department of Pediatrics, Kanazawa University, Kanazawa, Ishikawa, Japan
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Chaouch M. Loop-mediated isothermal amplification (LAMP): An effective molecular point-of-care technique for the rapid diagnosis of coronavirus SARS-CoV-2. Rev Med Virol 2021; 31:e2215. [PMID: 33476080 PMCID: PMC7995099 DOI: 10.1002/rmv.2215] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/16/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022]
Abstract
The novel coronavirus disease-2019 (Covid-19) public health emergency has caused enormous loss around the world. This pandemic is a concrete example of the existing gap between availability of advanced diagnostics and current need for cost-effective methodology. The advent of the loop-mediated isothermal amplification (LAMP) assay provided an innovative tool for establishing a rapid diagnostic technique based on the molecular amplification of pathogen RNA or DNA. In this review, we explore the applications, diagnostic effectiveness of LAMP test for molecular diagnosis and surveillance of severe acute respiratory syndrome coronavirus 2. Our results show that LAMP can be considered as an effective point-of-care test for the diagnosis of Covid-19 in endemic areas, especially for low- and middle-income countries.
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Affiliation(s)
- Melek Chaouch
- Laboratory of Medical ParasitologyBiotechnology and Biomolecules LR 11 IPT 06Institut Pasteur de TunisTunisTunisia
- Laboratory of BioinformaticsBiomathematics and Biostatistics LR 16 IPT 09Institut Pasteur de TunisTunisTunisia
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Gotham D, McKenna L, Deborggraeve S, Madoori S, Branigan D. Public investments in the development of GeneXpert molecular diagnostic technology. PLoS One 2021; 16:e0256883. [PMID: 34464413 PMCID: PMC8407584 DOI: 10.1371/journal.pone.0256883] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 08/02/2021] [Indexed: 11/18/2022] Open
Abstract
Background The GeneXpert diagnostic platform from the US based company Cepheid is an automated molecular diagnostic device that performs sample preparation and pathogen detection within a single cartridge-based assay. GeneXpert devices can enable diagnosis at the district level without the need for fully equipped clinical laboratories, are simple to use, and offer rapid results. Due to these characteristics, the platform is now widely used in low- and middle-income countries for diagnosis of diseases such as TB and HIV. Assays for SARS-CoV-2 are also being rolled out. We aimed to quantify public sector investments in the development of the GeneXpert platform and Cepheid’s suite of cartridge-based assays. Methods Public funding data were collected from the proprietor company’s financial filings, grant databases, review of historical literature concerning key laboratories and researchers, and contacting key public sector entities involved in the technology’s development. The value of research and development (R&D) tax credits was estimated based on financial filings. Results Total public investments in the development of the GeneXpert technology were estimated to be $252 million, including >$11 million in funding for work in public laboratories leading to the first commercial product, $56 million in grants from the National Institutes of Health, $73 million from other U.S. government departments, $67 million in R&D tax credits, $38 million in funding from non-profit and philanthropic organizations, and $9.6 million in small business ‘springboard’ grants. Conclusion The public sector has invested over $250 million in the development of both the underlying technologies and the GeneXpert diagnostic platform and assays, and has made additional investments in rolling out the technology in countries with high burdens of TB. The key role played by the public sector in R&D and roll-out stands in contrast to the lack of public sector ability to secure affordable pricing and maintenance agreements.
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Affiliation(s)
| | - Lindsay McKenna
- Treatment Action Group, New York, NY, United States of America
| | | | - Suraj Madoori
- Treatment Action Group, New York, NY, United States of America
| | - David Branigan
- Treatment Action Group, New York, NY, United States of America
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Abstract
In settings with limited resources and a wide range of possible etiologies, molecular technologies offer an effective solution for infectious disease diagnostics, because they are agile, fast and flexible. Health systems that routinely use molecular diagnostics will achieve economies of scale, maximize limited expertize and rapidly respond to new threats.
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Affiliation(s)
- Iruka N Okeke
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Oyo State, Nigeria.
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de Biase D, Acquaviva G, Visani M, Marucci G, De Leo A, Maloberti T, Sanza V, Di Oto E, Franceschi E, Mura A, Ragazzi M, Serra S, Froio E, Bisagni A, Brandes AA, Pession A, Tallini G. Next-Generation Sequencing Panel for 1p/19q Codeletion and IDH1-IDH2 Mutational Analysis Uncovers Mistaken Overdiagnoses of 1p/19q Codeletion by FISH. J Mol Diagn 2021; 23:1185-1194. [PMID: 34186176 DOI: 10.1016/j.jmoldx.2021.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/15/2021] [Accepted: 06/08/2021] [Indexed: 02/08/2023] Open
Abstract
The 1p/19q codeletion is the result of a translocation between chromosome 1 (Chr1p) and chromosome 19 (Chr19q) with the loss of derivative (1;19)(p10;q10) chromosome. The 1p/19q codeletion has predictive and prognostic significance, and it is essential for the classification of gliomas. In routine practice, the fluorescence in situ hybridization (FISH) diagnosis of 1p/19q codeletion is sometimes unexpected. This study aimed to develop a next-generation sequencing panel for the concurrent definition of the 1p/19q codeletion and IDH1/IDH2 mutation status to resolve these equivocal cases. A total of 65 glioma samples were investigated using a 1p/19q-single-nucleotide polymorphism (SNP)-IDH panel. The panel consists of 192 amplicons, including SNPs mapping to Chr1 and Chr19 and amplicons for IDH1/IDH2 analysis. The 1p/19q SNP-IDH panel consistently identified IDH1/IDH2 mutations. In 49 of 60 cases (81.7%), it provided the same 1p/19q results obtained by FISH. In the remaining 11 cases, the 1p/19q SNP-IDH panel uncovered partial chromosome imbalances as a result of interstitial amplification or deletion of the regions where the FISH probes map, leading to a mistaken overdiagnosis of 1p/19q codeletion by FISH. The 1p/19q SNP-IDH next-generation sequencing panel allows reliable analysis of the 1p/19q codeletion and IDH1/IDH2 mutation at the same time. The panel not only allows resolution of difficult cases but also represents a cost-effective alternative to standard molecular diagnostics procedures.
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Affiliation(s)
- Dario de Biase
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy; Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Giorgia Acquaviva
- Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Michela Visani
- Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Gianluca Marucci
- Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Antonio De Leo
- Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Thais Maloberti
- Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Viviana Sanza
- Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Enrico Di Oto
- Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy
| | - Enrico Franceschi
- Department of Oncology, Azienda Unitá Sanitaria Locale (AUSL) Bologna, Bologna, Italy
| | - Antonella Mura
- Department of Oncology, Azienda Unitá Sanitaria Locale (AUSL) Bologna, Bologna, Italy
| | - Moira Ragazzi
- Anatomic Pathology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Silvia Serra
- Anatomic Pathology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Elisabetta Froio
- Anatomic Pathology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Alessandra Bisagni
- Anatomic Pathology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Alba A Brandes
- Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Annalisa Pession
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy; Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Giovanni Tallini
- Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Department of Medicine (Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale), University of Bologna, Bologna, Italy.
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Day AS, Ulep TH, Safavinia B, Hertenstein T, Budiman E, Dieckhaus L, Yoon JY. Emulsion-based isothermal nucleic acid amplification for rapid SARS-CoV-2 detection via angle-dependent light scatter analysis. Biosens Bioelectron 2021; 179:113099. [PMID: 33640656 PMCID: PMC7892303 DOI: 10.1016/j.bios.2021.113099] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/13/2021] [Accepted: 02/14/2021] [Indexed: 12/23/2022]
Abstract
The SARS-CoV-2 pandemic, an ongoing global health crisis, has revealed the need for new technologies that integrate the sensitivity and specificity of RT-PCR tests with a faster time-to-detection. Here, an emulsion loop-mediated isothermal amplification (eLAMP) platform was developed to allow for the compartmentalization of LAMP reactions, leading to faster changes in emulsion characteristics, and thus lowering time-to-detection. Within these droplets, ongoing LAMP reactions lead to adsorption of amplicons to the water-oil interface, causing a decrease in interfacial tension, resulting in smaller emulsion diameters. Changes in emulsion diameter allow for the monitoring of the reaction by use of angle-dependent light scatter (based off Mie scatter theory). Mie scatter simulations confirmed that light scatter intensity is diameter-dependent and smaller colloids have lower intensity values compared to larger colloids. Via spectrophotometers and fiber optic cables placed at 30° and 60°, light scatter intensity was monitored. Scatter intensities collected at 5 min, 30° could statistically differentiate 10, 103, and 105 copies/μL initial concentrations compared to NTC. Similarly, 5 min scatter intensities collected at 60° could statistically differentiate 105 copies/μL initial concentrations in comparison to NTC. The use of both angles during the eLAMP assay allows for distinction between high and low initial target concentrations. The efficacy of a smartphone-based platform was also tested and had a similar limit of detection and assay time of less than 10 min. Furthermore, fluorescence-labeled primers were used to validate target nucleic acid amplification. Compared to existing LAMP assays for SARS-CoV-2 detection, these times-to-detections are very rapid.
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Affiliation(s)
- Alexander S Day
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Tiffany-Heather Ulep
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Babak Safavinia
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Tyler Hertenstein
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Elizabeth Budiman
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Laurel Dieckhaus
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States
| | - Jeong-Yeol Yoon
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, United States.
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Joshi S, Dixit KK, Sharma V, Ramesh V, Singh R, Salotra P. Rapid Multiplex Loop-Mediated Isothermal Amplification (m-LAMP) Assay for Differential Diagnosis of Leprosy and Post-Kala-Azar Dermal Leishmaniasis. Am J Trop Med Hyg 2021; 104:2085-2090. [PMID: 33872215 PMCID: PMC8176499 DOI: 10.4269/ajtmh.19-0313] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/09/2019] [Indexed: 11/07/2022] Open
Abstract
Leprosy and post-kala-azar dermal leishmaniasis (PKDL) are co-endemic neglected tropical diseases often misdiagnosed because of close resemblance in their clinical manifestations. The test that aids in differential diagnosis of leprosy and PKDL would be useful in endemic areas. Here, we report development of a multiplex loop-mediated isothermal amplification (m-LAMP) assay for differential detection of Mycobacterium leprae and Leishmania donovani using a real-time fluorometer. The m-LAMP assay was rapid with a mean amplification time of 15 minutes, and analytical sensitivity of 1 fg for L. donovani and 100 fg for M. leprae. The distinct mean Tm values for M. leprae and L. donovani allowed differentiation of the two organisms in the m-LAMP assay. Diagnostic sensitivity of the assay was evaluated by using confirmed cases of leprosy (n = 40) and PKDL (n = 40) (tissue and slit aspirate samples). All the leprosy and PKDL samples used in this study were positive by organism-specific QPCR and loop-mediated isothermal amplification assays. The diagnostic sensitivity of the m-LAMP assay was 100% (95% CI: 91.2-100.0%) for detecting PKDL and 95% for leprosy (95% CI: 83.1-99.4%). Our m-LAMP assay was successfully used to detect both M. leprae and L. donovani in a patient coinfected with leprosy and macular PKDL. The m-LAMP assay is rapid, accurate, and applicable for differential diagnosis of leprosy versus PKDL, especially in endemic areas.
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Affiliation(s)
- Shweta Joshi
- Molecular Parasitology Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Keerti K. Dixit
- Molecular Parasitology Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Vanila Sharma
- Molecular Parasitology Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - V. Ramesh
- Department of Dermatology, Safdarjung Hospital, New Delhi, India
| | - Ruchi Singh
- Molecular Parasitology Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Poonam Salotra
- Molecular Parasitology Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
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Garneret P, Coz E, Martin E, Manuguerra JC, Brient-Litzler E, Enouf V, González Obando DF, Olivo-Marin JC, Monti F, van der Werf S, Vanhomwegen J, Tabeling P. Performing point-of-care molecular testing for SARS-CoV-2 with RNA extraction and isothermal amplification. PLoS One 2021; 16:e0243712. [PMID: 33428641 PMCID: PMC7799764 DOI: 10.1371/journal.pone.0243712] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 11/27/2020] [Indexed: 11/23/2022] Open
Abstract
To respond to the urgent need for COVID-19 testing, countries perform nucleic acid amplification tests (NAAT) for the detection of SARS-CoV-2 in centralized laboratories. Real-time RT-PCR (Reverse transcription-Polymerase Chain Reaction), used to amplify and detect the viral RNA., is considered, as the current gold standard for diagnostics. It is an efficient process, but the complex engineering required for automated RNA extraction and temperature cycling makes it incompatible for use in point of care settings [1]. In the present work, by harnessing progress made in the past two decades in isothermal amplification and paper microfluidics, we created a portable test, in which SARS-CoV-2 RNA is extracted, amplified isothermally by RT-LAMP (Loop-mediated Isothermal Amplification), and detected using intercalating dyes or fluorescent probes. Depending on the viral load in the tested samples, the detection takes between twenty minutes and one hour. Using a set of 16 pools of naso-pharyngal swab eluates, we estimated a limit of detection comparable to real-time RT-PCR (i.e. 1 genome copies per microliter of clinical sample) and no cross-reaction with eight major respiratory viruses currently circulating in Europe. We designed and fabricated an easy-to-use portable device called "COVIDISC" to carry out the test at the point of care. The low cost of the materials along with the absence of complex equipment will expedite the widespread dissemination of this device. What is proposed here is a new efficient tool to help managing the pandemics.
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Wang X, Shang X, Huang X. Next-generation pathogen diagnosis with CRISPR/Cas-based detection methods. Emerg Microbes Infect 2020; 9:1682-1691. [PMID: 32643563 PMCID: PMC7473117 DOI: 10.1080/22221751.2020.1793689] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023]
Abstract
Ideal methods for detecting pathogens should be sensitive, specific, rapid, cost-effective and instrument-free. Conventional nucleic acid pathogen detection strategies, mostly PCR-based techniques, have various limitations, such as expensive equipment, reagents and skilled performance. Recently, CRISPR/Cas-based methods have burst onto the scene, with the potential to power the pathogen detection field. Here we introduce these unique methods and discuss its hurdles and promises.
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Affiliation(s)
- Xinjie Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Xiaoyun Shang
- Suzhou Maximum Bio-tech Co., Ltd., Suzhou, People’s Republic of China
| | - Xingxu Huang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
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Cilloni L, Kranzer K, Stagg HR, Arinaminpathy N. Trade-offs between cost and accuracy in active case finding for tuberculosis: A dynamic modelling analysis. PLoS Med 2020; 17:e1003456. [PMID: 33264288 PMCID: PMC7710036 DOI: 10.1371/journal.pmed.1003456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/02/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Active case finding (ACF) may be valuable in tuberculosis (TB) control, but questions remain about its optimum implementation in different settings. For example, smear microscopy misses up to half of TB cases, yet is cheap and detects the most infectious TB cases. What, then, is the incremental value of using more sensitive and specific, yet more costly, tests such as Xpert MTB/RIF in ACF in a high-burden setting? METHODS AND FINDINGS We constructed a dynamic transmission model of TB, calibrated to be consistent with an urban slum population in India. We applied this model to compare the potential cost and impact of 2 hypothetical approaches following initial symptom screening: (i) 'moderate accuracy' testing employing a microscopy-like test (i.e., lower cost but also lower accuracy) for bacteriological confirmation and (ii) 'high accuracy' testing employing an Xpert-like test (higher cost but also higher accuracy, while also detecting rifampicin resistance). Results suggest that ACF using a moderate-accuracy test could in fact cost more overall than using a high-accuracy test. Under an illustrative budget of US$20 million in a slum population of 2 million, high-accuracy testing would avert 1.14 (95% credible interval 0.75-1.99, with p = 0.28) cases relative to each case averted by moderate-accuracy testing. Test specificity is a key driver: High-accuracy testing would be significantly more impactful at the 5% significance level, as long as the high-accuracy test has specificity at least 3 percentage points greater than the moderate-accuracy test. Additional factors promoting the impact of high-accuracy testing are that (i) its ability to detect rifampicin resistance can lead to long-term cost savings in second-line treatment and (ii) its higher sensitivity contributes to the overall cases averted by ACF. Amongst the limitations of this study, our cost model has a narrow focus on the commodity costs of testing and treatment; our estimates should not be taken as indicative of the overall cost of ACF. There remains uncertainty about the true specificity of tests such as smear and Xpert-like tests in ACF, relating to the accuracy of the reference standard under such conditions. CONCLUSIONS Our results suggest that cheaper diagnostics do not necessarily translate to less costly ACF, as any savings from the test cost can be strongly outweighed by factors including false-positive TB treatment, reduced sensitivity, and foregone savings in second-line treatment. In resource-limited settings, it is therefore important to take all of these factors into account when designing cost-effective strategies for ACF.
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Affiliation(s)
- Lucia Cilloni
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
- * E-mail:
| | - Katharina Kranzer
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Biomedical Research and Training Institute, Harare, Zimbabwe
- Research Centre Borstel, Sülfeld, Germany
| | - Helen R. Stagg
- Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Nimalan Arinaminpathy
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
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Samsom KG, Bosch LJW, Schipper LJ, Roepman P, de Bruijn E, Hoes LR, Riethorst I, Schoenmaker L, van der Kolk LE, Retèl VP, Frederix GWJ, Buffart TE, van der Hoeven JJM, Voest EE, Cuppen E, Monkhorst K, Meijer GA. Study protocol: Whole genome sequencing Implementation in standard Diagnostics for Every cancer patient (WIDE). BMC Med Genomics 2020; 13:169. [PMID: 33167975 PMCID: PMC7654005 DOI: 10.1186/s12920-020-00814-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/25/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND 'Precision oncology' can ensure the best suitable treatment at the right time by tailoring treatment towards individual patient and comprehensive tumour characteristics. In current molecular pathology, diagnostic tests which are part of the standard of care (SOC) only cover a limited part of the spectrum of genomic changes, and often are performed in an iterative way. This occurs at the expense of valuable patient time, available tissue sample, and interferes with 'first time right' treatment decisions. Whole Genome Sequencing (WGS) captures a near complete view of genomic characteristics of a tumour in a single test. Moreover, WGS facilitates faster implementation of new treatment relevant biomarkers. At present, WGS mainly has been applied in study settings, but its performance in a routine diagnostic setting remains to be evaluated. The WIDE study aims to investigate the feasibility and validity of WGS-based diagnostics in clinical practice. METHODS 1200 consecutive patients in a single comprehensive cancer centre with (suspicion of) a metastasized solid tumour will be enrolled with the intention to analyse tumour tissue with WGS, in parallel to SOC diagnostics. Primary endpoints are (1) feasibility of implementation of WGS-based diagnostics into routine clinical care and (2) clinical validation of WGS by comparing identification of treatment-relevant variants between WGS and SOC molecular diagnostics. Secondary endpoints entail (1) added clinical value in terms of additional treatment options and (2) cost-effectiveness of WGS compared to SOC diagnostics through a Health Technology Assessment (HTA) analysis. Furthermore, the (3) perceived impact of WGS-based diagnostics on clinical decision making will be evaluated through questionnaires. The number of patients included in (experimental) therapies initiated based on SOC or WGS diagnostics will be reported with at least 3 months follow-up. The clinical efficacy is beyond the scope of WIDE. Key performance indicators will be evaluated after every 200 patients enrolled, and procedures optimized accordingly, to continuously improve the diagnostic performance of WGS in a routine clinical setting. DISCUSSION WIDE will yield the optimal conditions under which WGS can be implemented in a routine molecular diagnostics setting and establish the position of WGS compared to SOC diagnostics in routine clinical care.
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Affiliation(s)
- Kris G Samsom
- Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Linda J W Bosch
- Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Luuk J Schipper
- Department of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Paul Roepman
- Hartwig Medical Foundation, Amsterdam, The Netherlands
| | | | - Louisa R Hoes
- Department of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | | | | | | | | | - Tineke E Buffart
- Department of Gastrointestinal Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | - Emile E Voest
- Department of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
- Center for Molecular Medicine and Oncode Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Edwin Cuppen
- Hartwig Medical Foundation, Amsterdam, The Netherlands
- Center for Molecular Medicine and Oncode Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kim Monkhorst
- Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands.
| | - Gerrit A Meijer
- Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands
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Proudman D, Miller A, Nellesen D, Gomes A, Mankoski R, Norregaard C, Sullivan E. Financial Implications of Avapritinib for Treatment of Unresectable Gastrointestinal Stromal Tumors in Patients With a PDGFRA Exon 18 Variant or After 3 Previous Therapies in a Hypothetical US Health Plan. JAMA Netw Open 2020; 3:e2025866. [PMID: 33201235 PMCID: PMC7672518 DOI: 10.1001/jamanetworkopen.2020.25866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
IMPORTANCE With the approval of avapritinib for adults with unresectable or metastatic gastrointestinal stromal tumors (GISTs) harboring a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 variant, including PDGFRA D842V variants, and National Comprehensive Cancer Network guideline recommendations as an option for patients with GIST after third-line treatment, it is important to estimate the potential financial implications of avapritinib on a payer's budget. OBJECTIVE To estimate the budget impact associated with the introduction of avapritinib to a formulary for metastatic or unresectable GISTs in patients with a PDGFRA exon 18 variant or after 3 or more previous treatments from the perspective of a US health plan. DESIGN, SETTING, AND PARTICIPANTS For this economic evaluation, a 3-year budget impact model was developed in March 2020, incorporating costs for drug acquisition, testing, monitoring, adverse events, and postprogression treatment. The model assumed that avapritinib introduction would be associated with increased PDGFRA testing rates from the current 49% to 69%. The health plan population was assumed to be mixed 69% commercial, 22% Medicare, and 9% Medicaid. Base case assumptions included a GIST incidence rate of 9.6 diagnoses per million people, a metastatic PDGFRA exon 18 mutation rate of 1.9%, and progression rate from first-line to fourth-line treatment of 17%. EXPOSURES The model compared scenarios with and without avapritinib in a formulary. MAIN OUTCOMES AND MEASURES Annual, total, and per member per month (PMPM) budget impact. RESULTS In a hypothetical 1-million member plan, fewer than 0.1 new patients with a PDGFRA exon 18 variant per year and 1.2 patients receiving fourth-line therapy per year were eligible for treatment. With avapritinib available, the total increase in costs in year 3 for all eligible adult patients with a PDGFRA exon 18 variant was $46 875, or $0.004 PMPM. For patients undergoing fourth-line treatment, the total increase in costs in year 3 was $69 182, or $0.006 PMPM. The combined total budget impact in year 3 was $115 604, or $0.010 PMPM, including an offset of $3607 in postprogression costs avoided or delayed. The higher rates of molecular testing resulted in a minimal incremental testing cost of $453 in year 3. CONCLUSIONS AND RELEVANCE These results suggest that adoption of avapritinib as a treatment option would have a minimal budget impact to a hypothetical US health plan. This would be primarily attributable to the small eligible patient population and cost offsets from reduced or delayed postprogression costs.
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Affiliation(s)
| | | | | | | | | | | | - Erin Sullivan
- Blueprint Medicines Corporation, Cambridge, Massachusetts
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Abstract
The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had an enormous impact on society worldwide, threatening the lives and livelihoods of many. The effects will continue to grow and worsen if economies begin to open without the proper precautions, including expanded diagnostic capabilities. To address this need for increased testing, we have developed a sensitive reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay compatible with current reagents, which utilizes a colorimetric readout in as little as 30 min. A rapid inactivation protocol capable of inactivating virions, as well as endogenous nucleases, was optimized to increase sensitivity and sample stability. This protocol, combined with the RT-LAMP assay, has a sensitivity of at least 50 viral RNA copies per microliter in a sample. To further increase the sensitivity, a purification protocol compatible with this inactivation method was developed. The inactivation and purification protocol, combined with the RT-LAMP assay, brings the sensitivity to at least 1 viral RNA copy per microliter in a sample. This simple inactivation and purification pipeline is inexpensive and compatible with other downstream RNA detection platforms and uses readily available reagents. It should increase the availability of SARS-CoV-2 testing as well as expand the settings in which this testing can be performed.
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Affiliation(s)
- Brian A Rabe
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Constance Cepko
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115;
- Howard Hughes Medical Institute, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
- Department of Ophthalmology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
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15
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Rabe BA, Cepko C. SARS-CoV-2 detection using isothermal amplification and a rapid, inexpensive protocol for sample inactivation and purification. Proc Natl Acad Sci U S A 2020; 117:24450-24458. [PMID: 32900935 DOI: 10.1101/2020.04.23.20076877] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023] Open
Abstract
The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had an enormous impact on society worldwide, threatening the lives and livelihoods of many. The effects will continue to grow and worsen if economies begin to open without the proper precautions, including expanded diagnostic capabilities. To address this need for increased testing, we have developed a sensitive reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay compatible with current reagents, which utilizes a colorimetric readout in as little as 30 min. A rapid inactivation protocol capable of inactivating virions, as well as endogenous nucleases, was optimized to increase sensitivity and sample stability. This protocol, combined with the RT-LAMP assay, has a sensitivity of at least 50 viral RNA copies per microliter in a sample. To further increase the sensitivity, a purification protocol compatible with this inactivation method was developed. The inactivation and purification protocol, combined with the RT-LAMP assay, brings the sensitivity to at least 1 viral RNA copy per microliter in a sample. This simple inactivation and purification pipeline is inexpensive and compatible with other downstream RNA detection platforms and uses readily available reagents. It should increase the availability of SARS-CoV-2 testing as well as expand the settings in which this testing can be performed.
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Affiliation(s)
- Brian A Rabe
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Constance Cepko
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115;
- Howard Hughes Medical Institute, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
- Department of Ophthalmology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
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16
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Hou T, Zeng W, Yang M, Chen W, Ren L, Ai J, Wu J, Liao Y, Gou X, Li Y, Wang X, Su H, Gu B, Wang J, Xu T. Development and evaluation of a rapid CRISPR-based diagnostic for COVID-19. PLoS Pathog 2020; 16:e1008705. [PMID: 32853291 PMCID: PMC7451577 DOI: 10.1371/journal.ppat.1008705] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/15/2020] [Indexed: 12/17/2022] Open
Abstract
The recent outbreak of human infections caused by SARS-CoV-2, the third zoonotic coronavirus has raised great public health concern globally. Rapid and accurate diagnosis of this novel pathogen posts great challenges not only clinically but also technologically. Metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) have been the most commonly used molecular methodologies. However, each has their own limitations. In this study, we developed an isothermal, CRISPR-based diagnostic for COVID-19 with near single-copy sensitivity. The diagnostic performances of all three technology platforms were also compared. Our study aimed to provide more insights into the molecular detection of SARS-CoV-2, and also to present a novel diagnostic option for this new emerging virus. The recently discovered betacoronavirus severe acute respiratory syndrome (SARS)-CoV-2 has caused an outbreak of Coronavirus Disease 2019 (COVID-19) that rapidly developed into a global pandemic. The surging demand for rapid screening and identification of COVID-19 posts great diagnostic challenges. A lack of rapid and accurate molecular tools has hampered efficient public health responses to the viral threat. Here, we harnessed the unique collateral activity of programmable CRISPR/Cas13a to develop CRISPR-COVID, a rapid and sensitive diagnostic for SARS-CoV-2 infection, and compared it to sequencing-based metagenomic and RT-PCR-based assays in a clinical cohort. CRISPR-COVID demonstrated a sensitivity level of near single copy and was highly specific without cross reacting to related pathogens. CRISPR-COVID takes only 40 mins and requires no sophiscated thermo-cyclers, providing a valuable alternative to the conventional RT–PCR assay to circumvent the bottlenecks in assay turnaround time, equipment and reagent supplies for COVID-19 testing.
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Affiliation(s)
- Tieying Hou
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Weiqi Zeng
- Vision Medicals Center for Infectious Diseases, Guangdong, China
- Key Laboratory of Animal Gene Editing and Animal Cloning in Yunnan Province and College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
| | - Minling Yang
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Wenjing Chen
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Lili Ren
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, IPB, CAMS-Fondation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, Beijing, China
| | - Jingwen Ai
- Department of Infectious Diseases, Huashan Hospital affiliated to Fudan University, Shanghai, China
| | - Ji Wu
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Yalong Liao
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Xuejing Gou
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Yongjun Li
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Xiaorui Wang
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Hang Su
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Bing Gu
- Medical Technology School of Xuzhou Medical University, Xuzhou, China
- Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
- * E-mail: (BG); (JW); (TX)
| | - Jianwei Wang
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, IPB, CAMS-Fondation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, Beijing, China
- * E-mail: (BG); (JW); (TX)
| | - Teng Xu
- Vision Medicals Center for Infectious Diseases, Guangdong, China
- Key Laboratory of Animal Gene Editing and Animal Cloning in Yunnan Province and College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
- * E-mail: (BG); (JW); (TX)
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Gummery L, Jallow S, Raftery AG, Bennet E, Rodgers J, Sutton DGM. Comparison of loop-mediated isothermal amplification (LAMP) and PCR for the diagnosis of infection with Trypanosoma brucei ssp. in equids in The Gambia. PLoS One 2020; 15:e0237187. [PMID: 32833981 PMCID: PMC7444819 DOI: 10.1371/journal.pone.0237187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 07/21/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction Infection of equids with Trypanosoma brucei (T. brucei) ssp. is of socioeconomic importance across sub-Saharan Africa as the disease often progresses to cause fatal meningoencephalitis. Loop-mediated isothermal amplification (LAMP) has been developed as a cost-effective molecular diagnostic test and is potentially applicable for use in field-based laboratories. Part I Threshold levels for T. brucei ssp. detection by LAMP were determined using whole equine blood specimens spiked with known concentrations of parasites. Results were compared to OIE antemortem gold standard of T. brucei-PCR (TBR-PCR). Results I Threshold for detection of T. brucei ssp. on extracted DNA from whole blood was 1 parasite/ml blood for LAMP and TBR-PCR, and there was excellent agreement (14/15) between tests at high (1 x 103/ml) concentrations of parasites. Detection threshold was 100 parasites/ml using LAMP on whole blood (LWB). Threshold for LWB improved to 10 parasites/ml with detergent included. Performance was excellent for LAMP at high (1 x 103/ml) concentrations of parasites (15/15, 100%) but was variable at lower concentrations. Agreement between tests was weak to moderate, with the highest for TBR-PCR and LAMP on DNA extracted from whole blood (Cohen’s kappa 0.95, 95% CI 0.64–1.00). Part II A prospective cross-sectional study of working equids meeting clinical criteria for trypanosomiasis was undertaken in The Gambia. LAMP was evaluated against subsequent TBR-PCR. Results II Whole blood samples from 321 equids in The Gambia were processed under field conditions. There was weak agreement between LWB and TBR-PCR (Cohen’s kappa 0.34, 95% CI 0.19–0.49) but excellent agreement when testing CSF (100% agreement on 6 samples). Conclusions Findings support that LAMP is comparable to PCR when used on CSF samples in the field, an important tool for clinical decision making. Results suggest repeatability is low in animals with low parasitaemia. Negative samples should be interpreted in the context of clinical presentation.
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Affiliation(s)
- Lauren Gummery
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
| | - Saloum Jallow
- Gambia Horse and Donkey Trust, Sambel Kunda, The Gambia
| | - Alexandra G. Raftery
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Euan Bennet
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jean Rodgers
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - David G. M. Sutton
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Hou T, Zeng W, Yang M, Chen W, Ren L, Ai J, Wu J, Liao Y, Gou X, Li Y, Wang X, Su H, Gu B, Wang J, Xu T. Development and evaluation of a rapid CRISPR-based diagnostic for COVID-19. PLoS Pathog 2020; 16:e1008705. [PMID: 32853291 DOI: 10.1101/2020.02.22.20025460] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/15/2020] [Indexed: 05/28/2023] Open
Abstract
The recent outbreak of human infections caused by SARS-CoV-2, the third zoonotic coronavirus has raised great public health concern globally. Rapid and accurate diagnosis of this novel pathogen posts great challenges not only clinically but also technologically. Metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) have been the most commonly used molecular methodologies. However, each has their own limitations. In this study, we developed an isothermal, CRISPR-based diagnostic for COVID-19 with near single-copy sensitivity. The diagnostic performances of all three technology platforms were also compared. Our study aimed to provide more insights into the molecular detection of SARS-CoV-2, and also to present a novel diagnostic option for this new emerging virus.
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Affiliation(s)
- Tieying Hou
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Weiqi Zeng
- Vision Medicals Center for Infectious Diseases, Guangdong, China
- Key Laboratory of Animal Gene Editing and Animal Cloning in Yunnan Province and College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
| | - Minling Yang
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Wenjing Chen
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Lili Ren
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, IPB, CAMS-Fondation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, Beijing, China
| | - Jingwen Ai
- Department of Infectious Diseases, Huashan Hospital affiliated to Fudan University, Shanghai, China
| | - Ji Wu
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Yalong Liao
- Laboratory Medicine, Provincial People's Hospital, Guangdong Academy of Medical Sciences Guangzhou, Guangdong, China
| | - Xuejing Gou
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Yongjun Li
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Xiaorui Wang
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Hang Su
- Vision Medicals Center for Infectious Diseases, Guangdong, China
| | - Bing Gu
- Medical Technology School of Xuzhou Medical University, Xuzhou, China
- Department of Laboratory Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Jianwei Wang
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, IPB, CAMS-Fondation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College, Beijing, China
| | - Teng Xu
- Vision Medicals Center for Infectious Diseases, Guangdong, China
- Key Laboratory of Animal Gene Editing and Animal Cloning in Yunnan Province and College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
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19
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Lamb LE, Bartolone SN, Ward E, Chancellor MB. Rapid detection of novel coronavirus/Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by reverse transcription-loop-mediated isothermal amplification. PLoS One 2020; 15:e0234682. [PMID: 32530929 PMCID: PMC7292379 DOI: 10.1371/journal.pone.0234682] [Citation(s) in RCA: 203] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/01/2020] [Indexed: 01/12/2023] Open
Abstract
Novel Corona virus/Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or 2019-nCoV), and the subsequent disease caused by the virus (coronavirus disease 2019 or COVID-19), is an emerging global health concern that requires a rapid diagnostic test. Quantitative reverse transcription PCR (qRT-PCR) is currently the standard for SARS-CoV-2 detection; however, Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) may allow for faster and cheaper field based testing at point-of-risk. The objective of this study was to develop a rapid screening diagnostic test that could be completed in 30-45 minutes. Simulated patient samples were generated by spiking serum, urine, saliva, oropharyngeal swabs, and nasopharyngeal swabs with a portion of the SARS-CoV-2 nucleic sequence. RNA isolated from nasopharyngeal swabs collected from actual COVID-19 patients was also tested. The samples were tested using RT-LAMP as well as by conventional qRT-PCR. Specificity of the RT-LAMP was evaluated by also testing against other related coronaviruses. RT-LAMP specifically detected SARS-CoV-2 in both simulated patient samples and clinical specimens. This test was performed in 30-45 minutes. This approach could be used for monitoring of exposed individuals or potentially aid with screening efforts in the field and potential ports of entry.
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Affiliation(s)
- Laura E. Lamb
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
- Oakland University William Beaumont School of Medicine, Rochester Hills, Michigan, United States of America
| | - Sarah N. Bartolone
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
| | - Elijah Ward
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
| | - Michael B. Chancellor
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
- Oakland University William Beaumont School of Medicine, Rochester Hills, Michigan, United States of America
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Fawsitt CG, Vickerman P, Cooke GS, Welton NJ. Cost-Effectiveness Analysis of Baseline Testing for Resistance-Associated Polymorphisms to Optimize Treatment Outcome in Genotype 1 Noncirrhotic Treatment-Naïve Patients With Chronic Hepatitis C Virus. Value Health 2020; 23:180-190. [PMID: 32113623 PMCID: PMC7057278 DOI: 10.1016/j.jval.2019.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 08/13/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES Direct-acting antivirals containing nonstructural protein 5A (NS5A) inhibitors administered over 8 to 12 weeks are effective in ∼95% of patients with hepatitis C virus. Nevertheless, patients resistant to NS5A inhibitors have lower cure rates over 8 weeks (<85%); for these patients, 12 weeks of treatment produces cure rates greater than 95%. We evaluated the lifetime cost-effectiveness of testing for NS5A resistance at baseline and optimizing treatment duration accordingly in genotype 1 noncirrhotic treatment-naïve patients from the perspective of the UK National Health Service. METHODS A decision-analytic model compared (1) standard 12-week treatment (no testing), (2) shortened 8-week treatment (no testing), and (3) baseline testing with 12-/8-week treatment for those with/without NS5A polymorphisms. Patients who failed first-line therapy were retreated for 12 weeks. Model inputs were derived from published studies. Costs, quality-adjusted life-years, and the probability of cost-effectiveness were calculated. RESULTS Baseline testing had an incremental net monetary benefit (INMB) of £11 838 versus standard 12 weeks of therapy (no testing) and low probability (31%) of being the most cost-effective, assuming £30 000 willingness to pay. Shortened 8 weeks of treatment (no testing) had an INMB of £12 294 and the highest probability (69%) of being most cost-effective. Scenario analyses showed baseline testing generally had the highest INMB and probability of being most cost-effective if first- and second-line drug prices were low (<£20k). CONCLUSIONS Optimizing treatment duration based on NS5A polymorphisms for genotype 1 noncirrhotic treatment-naive patients in the United Kingdom is not cost-effective if the drug costs are high; the strategy is generally most cost-effective when drug prices are low (<£20k).
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Affiliation(s)
- Christopher G Fawsitt
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, UK.
| | - Peter Vickerman
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, UK
| | - Graham S Cooke
- Department of Medicine, Imperial College London, London, England, UK
| | - Nicky J Welton
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, UK
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Yakhelef N, Audibert M, Ferlazzo G, Sitienei J, Wanjala S, Varaine F, Bonnet M, Huerga H. Cost-effectiveness of diagnostic algorithms including lateral-flow urine lipoarabinomannan for HIV-positive patients with symptoms of tuberculosis. PLoS One 2020; 15:e0227138. [PMID: 31999746 PMCID: PMC6992347 DOI: 10.1371/journal.pone.0227138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/12/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is the leading cause of death among HIV-positive patients. We assessed the cost-effectiveness of including lateral-flow urine lipoarabinomannan (LF-LAM) in TB diagnostic algorithms for severely ill or immunosuppressed HIV-positive patients with symptoms of TB in Kenya. METHODS From a decision-analysis tree, ten diagnostic algorithms were elaborated and compared. All algorithms included clinical exam. The costs of each algorithm were calculated using a 'micro-costing' method. The efficacy was estimated through a prospective study that included severely ill or immunosuppressed (CD4<200cells/μL) HIV-positive adults with symptoms of TB. The cost-effectiveness analysis was performed using the disability-adjusted life year (DALY) averted as effectiveness outcome. A 4% discount rate was applied. RESULTS The algorithm that added LF-LAM alone to the clinical exam lead to the least average cost per TB case detected (€47) and was the most cost-effective with a cost/DALY averted of €4.6. The algorithms including LF-LAM, microscopy and X-ray, and LF-LAM and Xpert in sputum, detected a high number of TB cases with a cost/DALY averted of €6.1 for each of them. In the comparisons of the algorithms two by two, using LF-LAM instead of microscopy (clinic&LAM vs clinicµscopy) and using LF-LAM along with GeneXpert in sputum instead of GeneXpert in urine along with GeneXpert in sputum, (clinic&LAM&Xpert_sputum vs clinic&Xpert_sputum&Xpert_urine) led to the highest increase in the cost-effectiveness ratios (ICERs): €-7.2 and €-12.6 respectively. In these two comparisons, using LF-LAM increased the number of TB patients detected while reducing costs. Adding LF-LAM to smear microscopy alone or to smear microscopy and Xray led to the highest increase in the additional number of TB cases detected (31 and 25 respectively) with an incremental efficiency estimated at 134 and 344 DALYs respectively. The ICERs were €22.0 and €8.6 respectively. CONCLUSION Including LF-LAM in TB diagnostic algorithms is cost-effective for severely ill or immunosuppressed HIV-positive patients.
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Affiliation(s)
| | - Martine Audibert
- Université Clermont Auvergne, CNRS, CERDI, Clermont-Ferrand, France
| | | | - Joseph Sitienei
- Division of National Strategic Health Programs, Ministry of Health, Nairobi, Kenya
- Médecins Sans Frontières, Nairobi, Kenya
| | - Steve Wanjala
- IRD UMI 233 TransVIHMI—UM–INSERM U1175, Montpellier, France
| | | | - Maryline Bonnet
- Epicentre, Paris, France
- IRD UMI 233 TransVIHMI—UM–INSERM U1175, Montpellier, France
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Lamb LE, Bartolone SN, Ward E, Chancellor MB. Rapid detection of novel coronavirus/Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by reverse transcription-loop-mediated isothermal amplification. PLoS One 2020; 15:e0234682. [PMID: 32530929 DOI: 10.1101/2020.02.19.20025155] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/01/2020] [Indexed: 05/18/2023] Open
Abstract
Novel Corona virus/Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or 2019-nCoV), and the subsequent disease caused by the virus (coronavirus disease 2019 or COVID-19), is an emerging global health concern that requires a rapid diagnostic test. Quantitative reverse transcription PCR (qRT-PCR) is currently the standard for SARS-CoV-2 detection; however, Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) may allow for faster and cheaper field based testing at point-of-risk. The objective of this study was to develop a rapid screening diagnostic test that could be completed in 30-45 minutes. Simulated patient samples were generated by spiking serum, urine, saliva, oropharyngeal swabs, and nasopharyngeal swabs with a portion of the SARS-CoV-2 nucleic sequence. RNA isolated from nasopharyngeal swabs collected from actual COVID-19 patients was also tested. The samples were tested using RT-LAMP as well as by conventional qRT-PCR. Specificity of the RT-LAMP was evaluated by also testing against other related coronaviruses. RT-LAMP specifically detected SARS-CoV-2 in both simulated patient samples and clinical specimens. This test was performed in 30-45 minutes. This approach could be used for monitoring of exposed individuals or potentially aid with screening efforts in the field and potential ports of entry.
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Affiliation(s)
- Laura E Lamb
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
- Oakland University William Beaumont School of Medicine, Rochester Hills, Michigan, United States of America
| | - Sarah N Bartolone
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
| | - Elijah Ward
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
| | - Michael B Chancellor
- Department of Urology, Beaumont Health System, Royal Oak, Michigan, United States of America
- Oakland University William Beaumont School of Medicine, Rochester Hills, Michigan, United States of America
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Briksí A, Hubáček P, Šumová J, Nováková V, Chramostová P, Hornychová R, Špatná B, Zajac M. [Comparing traditional and commercial molecular biology detection of gastrointestinal pathogens with AusDiagnostics panels in Motol University Hospital]. Klin Mikrobiol Infekc Lek 2019; 25:132-139. [PMID: 32311066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND The aim was to do an internal audit of gastrointestinal pathogen detection at the Department of Medical Microbiology, Motol University Hospital between the years 2014 and 2018 and to test two commercial multiplex molecular biology assays potentially improving the diagnostic process and reducing costs. MATERIAL AND METHODS Based on data from a laboratory information system (LIS), a total of 45,888 samples were identified which had been tested for the presence of gastrointestinal pathogens using culture, immunochromatographic, microscopic and molecular biology techniques between 2014-2018. Novel multiplex molecular biology detection was used to test 182 nucleic acid isolates obtained from stool samples with the Enteric Viruses (8-well) assay (Viral Panel, EVP) or Faecal Pathogens M (16-well) assay (Microbial Panel, FPM) manufactured by AusDiagnostics. RESULTS The LIS data showed 6.2 % of positive pathogens causing diarrhea from all tested samples (detection rates: 4.5 % for bacterial agents, 21.6 % for viral agents and 0.4 % for parasitic agents). Valid samples (98.9 % of all tested samples) tested by the molecular biology technique yielded, in descending order: C. difficile toxin B (19 %), norovirus (9 %), astrovirus (8 %), Campylobacter (7 %), sapovirus (6 %), Yersinia enterocolitica (6 %), rotavirus (4 %), enterovirus (3 %), Aeromonas (3 %), adenovirus (2 %) and Salmonella (1 %). There was found at least 1 additional new positive detection in 27 % of stools tested by the Viral Panel and in 40 % of stools tested by the Microbial Panel in comparison with the traditional approach. Introducing the panels into routine diagnostic practice will not reduce the costs. CONCLUSIONS The introduction of novel multiplex molecular biology assays for detecting gastrointestinal pathogens will considerably increase pathogen detection rates even though the costs will be higher for the Department of Medical Microbiology.
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Affiliation(s)
- Aleš Briksí
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Czech Republic, e-mail:
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Papaiakovou M, Wright J, Pilotte N, Chooneea D, Schär F, Truscott JE, Dunn JC, Gardiner I, Walson JL, Williams SA, Littlewood DTJ. Pooling as a strategy for the timely diagnosis of soil-transmitted helminths in stool: value and reproducibility. Parasit Vectors 2019; 12:443. [PMID: 31522691 PMCID: PMC6745781 DOI: 10.1186/s13071-019-3693-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The strategy of pooling stool specimens has been extensively used in the field of parasitology in order to facilitate the screening of large numbers of samples whilst minimizing the prohibitive cost of single sample analysis. The aim of this study was to develop a standardized reproducible pooling protocol for stool samples, validated between two different laboratories, without jeopardizing the sensitivity of the quantitative polymerase chain reaction (qPCR) assays employed for the detection of soil-transmitted helminths (STHs). Two distinct experimental phases were recruited. First, the sensitivity and specificity of the established protocol was assessed by real-time PCR for each one of the STHs. Secondly, agreement and reproducibility of the protocol between the two different laboratories were tested. The need for multiple stool sampling to avoid false negative results was also assessed. Finally, a cost exercise was conducted which included labour cost in low- and high-wage settings, consumable cost, prevalence of a single STH species, and a simple distribution pattern of the positive samples in pools to estimate time and money savings suggested by the strategy. RESULTS The sensitivity of the pooling method was variable among the STH species but consistent between the two laboratories. Estimates of specificity indicate a 'pooling approach' can yield a low frequency of 'missed' infections. There were no significant differences regarding the execution of the protocol and the subsequent STH detection between the two laboratories, which suggests in most cases the protocol is reproducible by adequately trained staff. Finally, given the high degree of agreement, there appears to be little or no need for multiple sampling of either individuals or pools. CONCLUSIONS Our results suggest that the pooling protocol developed herein is a robust and efficient strategy for the detection of STHs in 'pools-of-five'. There is notable complexity of the pool preparation to ensure even distribution of helminth DNA throughout. Therefore, at a given setting, cost of labour among other logistical and epidemiological factors, is the more concerning and determining factor when choosing pooling strategies, rather than losing sensitivity and/or specificity of the molecular assay or the method.
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Affiliation(s)
- Marina Papaiakovou
- Department of Life Sciences, Natural History Museum, London, UK.
- Department of Biological Sciences, Smith College, Northampton, MA, USA.
| | - James Wright
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
- The Hospital for Sick Children, Toronto, ON, Canada
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - Darren Chooneea
- Core Research Laboratories, Natural History Museum, London, UK
| | | | - James E Truscott
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Julia C Dunn
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | | | - Judd L Walson
- DeWorm3, Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, MA, USA
- Molecular and Cellular Biology Programme, University of Massachusetts, Amherst, MA, USA
| | - D Timothy J Littlewood
- Department of Life Sciences, Natural History Museum, London, UK
- DeWorm3, Natural History Museum, London, UK
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Abstract
Background: Molecular tests (MT) using gene expression and/or mutational analysis have been developed to reduce the need for diagnostic surgery for indeterminate (Bethesda III/IV) thyroid nodules. Prior cost-effectiveness studies have shown mixed results but none has included the recent and more comprehensive versions of the two commonly utilized MT. The aim of this study is to compare the cost-effectiveness of diagnostic lobectomy (DL), the Afirma Gene Sequencing Classifier (GSC), and ThyroSeq version 3 (TSv3). Methods: A decision tree from the payer perspective was created using a base case of a 40-year-old euthyroid woman with a solitary 2 cm Bethesda III or IV thyroid nodule. In this model, all patients in the DL arm had lobectomy, which was also performed for patients with positive MT, while those with negative MT underwent 20 years of surveillance. The outcome was a correct diagnosis, defined as malignant histology after DL or 20 years of nodule stability after negative MT. Costs were obtained from the Centers for Medicare & Medicaid Services (CMS) data and existing literature, and probabilities were obtained from the literature. Sensitivity analysis was performed for costs, pretest probability of malignancy, and performance parameters. Results: The cost per correct diagnosis was $14,277 for TSv3, $17,873 for GSC, and $38,408 for DL. TSv3 was preferred over both GSC and DL. One-way sensitivity analysis between TSv3 and GSC demonstrated that the results were robust to variations in cost, cancer prevalence, and length of surveillance. In the two-way sensitivity analysis, TSv3 was preferred over GSC at all considered test costs, and in probabilistic sensitivity analysis, TSv3 was the preferred management strategy in 68.5% of cases. Conclusions: In hypothetical modeling to determine whether surgery versus MT is optimal for indeterminate (Bethesda III/IV) nodules, either of the major MT was considerably more cost-effective than DL, although TSv3 was more likely to be cost-effective than GSC. Use of either MT adjunct should be strongly considered in the absence of other indications for thyroidectomy.
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Affiliation(s)
- Kristina J. Nicholson
- Division of Endocrine Surgery, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mark S. Roberts
- Division of General Internal Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Division of General Internal Medicine, Department of Health Policy and Management, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kelly L. McCoy
- Division of Endocrine Surgery, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sally E. Carty
- Division of Endocrine Surgery, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Linwah Yip
- Division of Endocrine Surgery, Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
- Address correspondence to: Linwah Yip, MD, Division of Endocrine Surgery, Department of Surgery, University of Pittsburgh, 3471 Fifth Avenue Ste 101, Pittsburgh, PA 15213
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Grädel C, Terrazos Miani MA, Barbani MT, Leib SL, Suter-Riniker F, Ramette A. Rapid and Cost-Efficient Enterovirus Genotyping from Clinical Samples Using Flongle Flow Cells. Genes (Basel) 2019; 10:genes10090659. [PMID: 31470607 PMCID: PMC6770998 DOI: 10.3390/genes10090659] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 01/22/2023] Open
Abstract
Enteroviruses affect millions of people worldwide and are of significant clinical importance. The standard method for enterovirus identification and genotyping still relies on Sanger sequencing of short diagnostic amplicons. In this study, we assessed the feasibility of nanopore sequencing using the new flow cell “Flongle” for fast, cost-effective, and accurate genotyping of human enteroviruses from clinical samples. PCR amplification of partial VP1 gene was performed from multiple patient samples, which were multiplexed together after barcoding PCR and sequenced multiple times on Flongle flow cells. The nanopore consensus sequences obtained from mapping reads to a reference database were compared to their Sanger sequence counterparts. Using clinical specimens sampled over different years, we were able to correctly identify enterovirus species and genotypes for all tested samples, even when doubling the number of barcoded samples on one flow cell. Average sequence identity across sequencing runs was >99.7%. Phylogenetic analysis showed that the consensus sequences achieved with Flongle delivered accurate genotyping. We conclude that the new Flongle-based assay with its fast turnover time, low cost investment, and low cost per sample represents an accurate, reproducible, and cost-effective platform for enterovirus identification and genotyping.
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Affiliation(s)
- Carole Grädel
- Institute for Infectious Diseases, University of Bern, CH-3012 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | | | - Maria Teresa Barbani
- Institute for Infectious Diseases, University of Bern, CH-3012 Bern, Switzerland
| | - Stephen L Leib
- Institute for Infectious Diseases, University of Bern, CH-3012 Bern, Switzerland
| | | | - Alban Ramette
- Institute for Infectious Diseases, University of Bern, CH-3012 Bern, Switzerland.
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Santaus TM, Li S, Saha L, Chen WH, Bhagat S, Stine OC, Geddes CD. A comparison of Lyse-It to other cellular sample preparation, bacterial lysing, and DNA fragmentation technologies. PLoS One 2019; 14:e0220102. [PMID: 31335892 PMCID: PMC6650070 DOI: 10.1371/journal.pone.0220102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/08/2019] [Indexed: 02/05/2023] Open
Abstract
The ability for safe and rapid pathogenic sample transportation and subsequent detection is an increasing challenge throughout the world. Herein, we describe and use bead-beating, vortex, sonication, 903 protein saver cards, and Lyse-It methods, aiming to inactivate Gram-positive and -negative bacteria with subsequent genome DNA (quantitative Polymerase Chain Reaction) qPCR detection. The basic concepts behind the four chosen technologies is their versatility, cost, and ease of use in developed and underdeveloped countries. The four methods target the testing of bacterial resilience, cellular extraction from general and complex media and subsequent DNA extraction for qPCR detection and amplification. These results demonstrate that conventional high temperature heating, 903 protein saver cards, and Lyse-It are all viable options for inactivating bacterial growth for safe shipping. Additionally, Lyse-It was found to be particularly useful as this technology can inactivate bacteria, extract cells from 903 protein saver cards, lyse bacterial cells, and additionally keep genomic DNA viable for qPCR detection.
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Affiliation(s)
- Tonya M. Santaus
- Chemistry and Biochemistry Department, University of Maryland, Baltimore County, Baltimore, MD, United States of America
- Institute of Fluorescence, University of Maryland, Baltimore County, Baltimore, MD, United States of America
| | - Shan Li
- Epidemiology and Public Health Department, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Lahari Saha
- Chemistry and Biochemistry Department, University of Maryland, Baltimore County, Baltimore, MD, United States of America
| | - Wilbur H. Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Siya Bhagat
- Chemistry and Biochemistry Department, University of Maryland, Baltimore County, Baltimore, MD, United States of America
| | - O. Colin Stine
- Epidemiology and Public Health Department, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Chris D. Geddes
- Chemistry and Biochemistry Department, University of Maryland, Baltimore County, Baltimore, MD, United States of America
- Institute of Fluorescence, University of Maryland, Baltimore County, Baltimore, MD, United States of America
- * E-mail:
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van Waalwijk van Doorn-Khosrovani SB, Pisters-van Roy A, van Saase L, van der Graaff M, Gijzen J, Sleijfer S, Hoes LR, van Berge Henegouwen JM, van der Wijngaart H, van der Velden DL, van Werkhoven E, Retel VP, van Harten WH, Huitema ADR, Timmers L, Gelderblom H, Verheul HMW, Voest EE. Personalised reimbursement: a risk-sharing model for biomarker-driven treatment of rare subgroups of cancer patients. Ann Oncol 2019; 30:663-665. [PMID: 31038154 DOI: 10.1093/annonc/mdz119] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | - L van Saase
- National Health Care Institute (Zorginstituut Nederland), Diemen
| | - M van der Graaff
- National Health Care Institute (Zorginstituut Nederland), Diemen
| | | | - S Sleijfer
- Department of Medical Oncology, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam; Center for Personalised Cancer Treatment (CPCT)
| | - L R Hoes
- Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam
| | | | - H van der Wijngaart
- Division of Medical Oncology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam
| | - D L van der Velden
- Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam
| | - E van Werkhoven
- Department of Biometrics, Netherlands Cancer Institute, Amsterdam
| | - V P Retel
- Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Amsterdam; Department of Health Technology and Services Research, University of Twente, Enschede
| | - W H van Harten
- Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Amsterdam; Department of Health Technology and Services Research, University of Twente, Enschede; Rijnstate Hospital, Arnhem
| | - A D R Huitema
- Department of Pharmacy & Pharmacology, Netherlands Cancer Institute, Amsterdam; Department of Clinical Pharmacy, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - L Timmers
- National Health Care Institute (Zorginstituut Nederland), Diemen
| | - H Gelderblom
- Division of Medical Oncology, Leiden University Medical Center, Leiden
| | - H M W Verheul
- Division of Medical Oncology, Leiden University Medical Center, Leiden
| | - E E Voest
- Center for Personalised Cancer Treatment (CPCT); Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam.
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Sarin S, Huddart S, Raizada N, Parija D, Kalra A, Rao R, Salhotra VS, Khaparde SD, Boehme C, Denkinger CM, Sohn H. Cost and operational impact of promoting upfront GeneXpert MTB/RIF test referrals for presumptive pediatric tuberculosis patients in India. PLoS One 2019; 14:e0214675. [PMID: 30933997 PMCID: PMC6443160 DOI: 10.1371/journal.pone.0214675] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/18/2019] [Indexed: 12/03/2022] Open
Abstract
Background Outreach and promotion programs are essential to ensuring uptake of new public health interventions and guidelines. We assessed the costs and operation dynamics of outreach and promotion efforts for up front Xpert MTB/RIF (Xpert) testing for pediatric presumptive tuberculosis (TB) patients in four major Indian cities. Methods Xpert test costs were assessed as weighted average per-test costs based on the daily workload dynamics matched by test volume specific Xpert unit cost at each study site. Costs of outreach programs to recruit health providers to refer pediatric patients for Xpert testing were assessed as cost per referral for each quarter based on total program costs and referral data. All costs were assessed in the health service provider’s perspective and expressed in 2015 USD. Results Weighted average per-test costs ranged from $14.71 to $17.81 at the four laboratories assessed. Differences between laboratories were associated with unused testing capacity and/or frequencies of overtime work to cope with increasing demand and same-day testing requirements. Outreach activities generated between 825 and 2,065 Xpert testing referrals on average each quarter across the four study sites, translating into $0.63 to $2.55 per patient referred. Overall outreach costs per referral decreased with time, stabilizing at an average cost of $1.10, and demonstrated a clear association with increased referrals. Conclusions Xpert test and outreach program costs within and across study sites were mainly driven by the dynamics of Xpert testing demand resulting from the combined outreach activities. However, these increases in demand required considerable overtime work resulting in additional costs and operational challenges at the study laboratories. Therefore, careful laboratory operational adjustment should be evaluated at target areas in parallel to the anticipated demand from the Xpert referral outreach program scale-up in other Indian regions.
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Affiliation(s)
- Sanjay Sarin
- Foundation for Innovative New Diagnostics, New Delhi, India
| | - Sophie Huddart
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- McGill International TB Centre, Montreal, Quebec, Canada
| | - Neeraj Raizada
- Foundation for Innovative New Diagnostics, New Delhi, India
| | | | - Aakshi Kalra
- Foundation for Innovative New Diagnostics, New Delhi, India
| | - Raghuram Rao
- Central TB Division, Government of India, New Delhi, India
| | | | | | | | | | - Hojoon Sohn
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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Samwel K, Kahesa C, Mwaiselage J, Gonzalez D, West JT, Wood C, Palefsky J, Angeletti PC. Analytical performance of a low-cost multiplex polymerase chain reaction human papillomavirus genotyping assay for use in Sub-Saharan Africa. J Med Virol 2019; 91:308-316. [PMID: 30281790 PMCID: PMC6519259 DOI: 10.1002/jmv.25329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/25/2018] [Indexed: 12/12/2022]
Abstract
We have tested a multiplex polymerase chain reaction (PCR) human papillomavirus (HPV) genotyping assay to fill the need for rapid and low-cost HPV detection in Sub-Saharan Africa. This method allows high throughput genotyping and simultaneous detection of 14 high-risk and two low-risk HPV types, by PCR amplification of HPV DNAs in a single reaction tube. In this study, we describe stepwise experiments to validate the multiplex HPV PCR assay for determination of HPV genotypes from 104 cervical brush samples from Tanzanian women. Assay performance was evaluated by determination of intra-laboratory reproducibility, sensitivity, and specificity. Further performance was assessed by comparison with the widely accepted and validated HPV My09/My11 amplification and hybridization assay. Statistics; the Cohen kappa (κ) and McNemar P values were used to analyze interobserver and intermethod agreement. Overall concordance between the multiplex and line blot hybridization assays was 99% (per sample) with a κ value equal to 0.95; and 96.49% (per detection event) with a κ value of 0.92. Interobserver reproducibility of the assay per sample was 95.76% with κ of 0.91. These results demonstrate that the multiplex HPV PCR assay has high analytical sensitivity and specificity in detecting as many as 16 different HPV genotypes and that its simplicity and low cost makes it well suited for sub-Saharan Africa.
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Affiliation(s)
- Kandali Samwel
- Nebraska Center for Virology, School of Biological Sciences, University of NebraskaLincolnNebraska
| | | | | | - Daniela Gonzalez
- Nebraska Center for Virology, School of Biological Sciences, University of NebraskaLincolnNebraska
| | - John T. West
- Nebraska Center for Virology, School of Biological Sciences, University of NebraskaLincolnNebraska
| | - Charles Wood
- Nebraska Center for Virology, School of Biological Sciences, University of NebraskaLincolnNebraska
| | - Joel Palefsky
- University of California San FranciscoSan FranciscoCalifornia
| | - Peter C. Angeletti
- Nebraska Center for Virology, School of Biological Sciences, University of NebraskaLincolnNebraska
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Abstract
AIMS Broad molecular profiling of patients with advanced non-small cell lung cancer (NSCLC) is strongly advised to optimize genomic matching with available targeted treatment options or investigational agents. Unlike conventional molecular diagnostic testing, or smaller hotspot panels, comprehensive genomic profiling (CGP) identifies genomic alterations across hundreds of clinically relevant cancer genes from a single tissue specimen. The present study sought to estimate the budget impact of increased use of CGP using a 324-gene panel (FoundationOne) vs non-CGP (represented by a mix of conventional molecular diagnostic testing and smaller NGS hotspot panels) and the number needed to test with CGP to gain 1 life year. MATERIALS AND METHODS A decision analytic model was developed to assess the budget impact of increased CGP in advanced NSCLC from a US private payer perspective. Model inputs were based on published literature (epidemiology and treatment outcomes), real-world data (testing and rates, medical service costs), list prices for CGP and anti-cancer drugs, and assumptions for clinical trial participation. RESULTS Among 2 million covered lives, 532 had advanced NSCLC; 266 underwent molecular diagnostic testing. An increase in CGP among those tested, from 2% to 10%, was associated with $0.02 per member per month budget impact, of which $0.013 was attributable to costs of prolonged drug treatment and survival and $0.005 to testing cost. Approximately 12 patients would need to be tested with CGP to add 1 life year. LIMITATIONS The model incorporated certain assumptions to account for inputs with a limited evidence profile and simplify the possible post-CGP treatments. CONCLUSIONS An increase in CGP utilization from 2% to 10% among patients with advanced NSCLC undergoing molecular diagnostic testing was associated with a modest budget impact, most of which was attributable to increased use of more effective treatments and prolonged survival.
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Affiliation(s)
| | - Zhou Zhou
- a Analysis Group, Inc. , Boston , MA , USA
| | - Jason Ryan
- b Foundation Medicine, Inc. , Cambridge , MA , USA
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Brachmann M, Kikull K, Kill C, Betz S. Economic and operational impact of an improved pathway using rapid molecular diagnostic testing for patients with influenza-like illness in a German emergency department. J Clin Monit Comput 2019; 33:1129-1138. [PMID: 30610515 PMCID: PMC6823314 DOI: 10.1007/s10877-018-00243-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/22/2018] [Indexed: 11/27/2022]
Abstract
To evaluate the economic and operational effects of implementing a shorted diagnostic pathway during influenza epidemics. This retrospective study used emergency department (ED) data from the 2014/2015 influenza season. Alere i influenza A & B rapid molecular diagnostic test (RDT) was compared with the polymerase chain reaction (PCR) pathway. Differences in room occupancy time in the ED and inpatient ward and cost differences were calculated for the 14-week influenza season. The process flow was more streamlined with the RDT pathway, and the necessary isolation time in the ED was 9 h lower than for PCR. The difference in the ED examination room occupancy time was 2.9 h per patient on a weekday and 4 h per patient on a weekend day, and the difference in the inpatient room occupancy time was 2 h per patient on a weekday and 3 h per patient on a weekend day. Extrapolated time differences across the influenza season were projected to be 2733 h in the ED examination room occupancy and 1440 h in inpatient room occupancy. In patients with a negative diagnosis, the RDT was also estimated to reduce the total diagnostic costs by 41.52 € per patient compared with PCR. The total cost difference was projected to be 31,892 € across a 14-week influenza season. The improved process and earlier diagnosis with the RDT pathway compared with conventional PCR resulted in considerable savings in ED, inpatient room occupancy time and cost across the influenza season.
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Affiliation(s)
- Matthias Brachmann
- bcmed GmbH, Neue Strasse 76, 89073, Ulm, Germany
- Witten/Herdecke University, 58448, Witten, Germany
| | - Katja Kikull
- Ategris hospitals, CEO's Office, 45468, Muelheim, Germany
| | - Clemens Kill
- Center for Emergency Medicine, Essen University Hospital, 45147, Essen, Germany.
| | - Susanne Betz
- Department of Emergency Medicine, University Hospital Marburg, 35033, Marburg, Germany
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Chawla A, Peeples M, Li N, Anhorn R, Ryan J, Signorovitch J. Real-world utilization of molecular diagnostic testing and matched drug therapies in the treatment of metastatic cancers. J Med Econ 2018; 21:543-552. [PMID: 29295635 DOI: 10.1080/13696998.2017.1423488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
AIMS To assess the frequency of biopsies and molecular diagnostic testing (human DNA/RNA analysis), anti-cancer drug use (genomically-matched targeted therapy [GMTT], unmatched targeted therapy [UTT], endocrine therapy [ET], and chemotherapy [CT]), and medical service costs among adults with metastatic cancer. METHODS Adults diagnosed with metastatic breast, non-small cell lung (NSCLC), colorectal, head and neck, ovarian, and uterine cancer (2010Q1-2015Q1) were identified in the OptumHealth Care Solutions claims database and followed from first metastatic diagnosis for ≥1 month and until the end of data availability. Utilization was assessed for each cancer cohort (all and patients aged ≥65 years); per-patient-per-month (PPPM) medical service costs were assessed for all patients. Testing frequency estimates were applied to Surveillance, Epidemiology, and End Results Program data to estimate the number of untested patients (2010-2014). RESULTS Patients with metastatic cancer (n = 8,193; breast [n = 3,414], NSCLC [n = 2,231], colorectal [n = 1,611], head and neck [n = 511], ovarian [n = 275], and uterine [n = 151]) were 63 years old (mean), with 11.1-22.2 months of observation. Biopsy and molecular diagnostic testing frequencies ranged from 7% (uterine) to 73% (ovarian), and from 34% (head and neck) to 52% (breast), respectively. Few were treated with GMTT (breast, 11%; NSCLC, 9%; colorectal, 6%). Treatment with UTT ranged from 0.7% (uterine) to 21% (colorectal). Biopsy, diagnostic testing, and anti-cancer drug therapy were less frequent for those ≥65 years. Medical service costs (PPPM, mean) ranged from $6,618 (head and neck) to $9,940 (ovarian). The estimated number of untested new patients with metastatic cancer was 636,369 (all) and 341,397 (≥65). LIMITATIONS In addition to the limitations of claims analyses, diagnostic testing frequency may be under-estimated if patients underwent testing prior to study inclusion. CONCLUSIONS The low frequency of molecular diagnostic testing suggests there are opportunities to better inform management of patients with advanced cancer, particularly decisions to treat with GMTT.
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Affiliation(s)
| | | | - Nanxin Li
- b Analysis Group, Inc. , Boston , MA , USA
| | | | - Jason Ryan
- c Foundation Medicine, Inc. , Cambridge , MA , USA
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Nellesen D, Dea K, Guerin A, Culver KW, Mutebi A, Dalal A. Reimbursement landscape for molecular testing in non-small cell lung cancer (NSCLC). Am J Manag Care 2018; 24:SP37-SP42. [PMID: 29689141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Abstract
Malaria continues to be one of the most devastating diseases impacting global health. Although there have been significant reductions in global malaria incidence and mortality rates over the past 17 years, the disease remains endemic throughout the world, especially in low- and middle-income countries. The World Health Organization has put forth ambitious milestones moving toward a world free of malaria as part of the United Nations Millennium Goals. Mass screening and treatment of symptomatic and asymptomatic malaria infections in endemic regions is integral to these goals and requires diagnostics that are both sensitive and affordable. Lab-on-a-chip technologies provide a path toward sensitive, portable, and affordable diagnostic platforms. Here, we review and compare currently-available and emerging lab-on-a-chip diagnostic approaches in three categories: (1) protein-based tests, (2) nucleic acid tests, and (3) cell-based detection. For each category, we highlight the opportunities and challenges in diagnostics development for malaria elimination, and comment on their applicability to different phases of elimination strategies.
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Affiliation(s)
- N Kolluri
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
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Bonney LC, Watson RJ, Afrough B, Mullojonova M, Dzhuraeva V, Tishkova F, Hewson R. A recombinase polymerase amplification assay for rapid detection of Crimean-Congo Haemorrhagic fever Virus infection. PLoS Negl Trop Dis 2017; 11:e0006013. [PMID: 29028804 PMCID: PMC5656326 DOI: 10.1371/journal.pntd.0006013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/25/2017] [Accepted: 10/04/2017] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Crimean-Congo Haemorrhagic fever Virus (CCHFV) is a rapidly emerging vector-borne pathogen and the cause of a virulent haemorrhagic fever affecting large parts of Europe, Africa, the Middle East and Asia. METHODOLOGY/PRINCIPLE FINDINGS An isothermal recombinase polymerase amplification (RPA) assay was successfully developed for molecular detection of CCHFV. The assay showed rapid (under 10 minutes) detection of viral extracts/synthetic virus RNA of all 7 S-segment clades of CCHFV, with high target specificity. The assay was shown to tolerate the presence of inhibitors in crude preparations of mock field samples, indicating that this assay may be suitable for use in the field with minimal sample preparation. The CCHFV RPA was successfully used to screen and detect CCHFV positives from a panel of clinical samples from Tajikistan. CONCLUSIONS/SIGNIFICANCE The assay is a rapid, isothermal, simple-to-perform molecular diagnostic, which can be performed on a light, portable real-time detection device. It is ideally placed therefore for use as a field-diagnostic or in-low resource laboratories, for monitoring of CCHF outbreaks at the point-of-need, such as in remote rural regions in affected countries.
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Affiliation(s)
- Laura C. Bonney
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
- * E-mail:
| | - Robert J. Watson
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
| | - Babak Afrough
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
| | - Manija Mullojonova
- Department of Virology, Tajik Research Institute of Preventive Medicine of the Ministry of Health of the Republic of Tajikistan, Dushanbe, Republic of Tajikistan
| | - Viktoriya Dzhuraeva
- Department of Virology, Tajik Research Institute of Preventive Medicine of the Ministry of Health of the Republic of Tajikistan, Dushanbe, Republic of Tajikistan
| | - Farida Tishkova
- Department of Virology, Tajik Research Institute of Preventive Medicine of the Ministry of Health of the Republic of Tajikistan, Dushanbe, Republic of Tajikistan
| | - Roger Hewson
- National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom
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Taslimi Y, Sadeghipour P, Habibzadeh S, Mashayekhi V, Mortazavi H, Müller I, Lane ME, Kropf P, Rafati S. A novel non-invasive diagnostic sampling technique for cutaneous leishmaniasis. PLoS Negl Trop Dis 2017; 11:e0005750. [PMID: 28704463 PMCID: PMC5526608 DOI: 10.1371/journal.pntd.0005750] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/25/2017] [Accepted: 06/26/2017] [Indexed: 11/18/2022] Open
Abstract
Accurate diagnosis of cutaneous leishmaniasis (CL) is important for chemotherapy and epidemiological studies. Common approaches for Leishmania detection involve the invasive collection of specimens for direct identification of amastigotes by microscopy and the culturing of promastigotes from infected tissues. Although these techniques are highly specific, they require highly skilled health workers and have the inherent risks of all invasive procedures, such as pain and risk of bacterial and fungal super-infection. Therefore, it is essential to reduce discomfort, potential infection and scarring caused by invasive diagnostic approaches especially for children. In this report, we present a novel non-invasive method, that is painless, rapid and user-friendly, using sequential tape strips for sampling and isolation of DNA from the surface of active and healed skin lesions of CL patients. A total of 119 patients suspected of suffering from cutaneous leishmaniasis with different clinical manifestations were recruited and samples were collected both from their lesions and from uninfected areas. In addition, 15 fungal-infected lesions and 54 areas of healthy skin were examined. The duration of sampling is short (less than one minute) and species identification by PCR is highly specific and sensitive. The sequential tape stripping sampling method is a sensitive, non-invasive and cost-effective alternative to traditional diagnostic assays and it is suitable for field studies as well as for use in health care centers.
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Affiliation(s)
- Yasaman Taslimi
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
| | - Pardis Sadeghipour
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
| | - Sima Habibzadeh
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
| | - Vahid Mashayekhi
- Emam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossien Mortazavi
- Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ingrid Müller
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Majella E. Lane
- University College London, School of Pharmacy, London, United Kingdom
| | - Pascale Kropf
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Sima Rafati
- Department of Immunotherapy and Leishmania Vaccine Research, Pasteur Institute of Iran, Tehran, Iran
- * E-mail:
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Sharma M, Seoud M, Kim JJ. Cost-effectiveness of increasing cervical cancer screening coverage in the Middle East: An example from Lebanon. Vaccine 2016; 35:564-569. [PMID: 28017434 DOI: 10.1016/j.vaccine.2016.12.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/12/2016] [Accepted: 12/09/2016] [Indexed: 01/23/2023]
Abstract
BACKGROUND Most cervical cancer (CC) cases in Lebanon are detected at later stages and associated with high mortality. There is no national organized CC screening program so screening is opportunistic and limited to women who can pay out-of-pocket. Therefore, a small percentage of women receive repeated screenings while most are under-or never screened. We evaluated the cost-effectiveness of increasing screening coverage and extending intervals. METHODS We used an individual-based Monte Carlo model simulating HPV and CC natural history and screening. We calibrated the model to epidemiological data from Lebanon, including CC incidence and HPV type distribution. We evaluated cytology and HPV DNA screening for women aged 25-65years, varying coverage from 20 to 70% and frequency from 1 to 5years. RESULTS At 20% coverage, annual cytologic screening reduced lifetime CC risk by 14% and had an incremental cost-effectiveness ratio of I$80,670/year of life saved (YLS), far exceeding Lebanon's gross domestic product (GDP) per capita (I$17,460), a commonly cited cost-effectiveness threshold. By comparison, increasing cytologic screening coverage to 50% and extending screening intervals to 3 and 5years provided greater CC reduction (26.1% and 21.4, respectively) at lower costs compared to 20% coverage with annual screening. Screening every 5years with HPV DNA testing at 50% coverage provided greater CC reductions than cytology at the same frequency (23.4%) and was cost-effective assuming a cost of I$18 per HPV test administered (I$12,210/YLS); HPV DNA testing every 4years at 50% coverage was also cost-effective at the same cost per test (I$16,340). Increasing coverage of annual cytology was not found to be cost-effective. CONCLUSION Current practice of repeated cytology in a small percentage of women is inefficient. Increasing coverage to 50% with extended screening intervals provides greater health benefits at a reasonable cost and can more equitably distribute health gains. Novel HPV DNA strategies offer greater CC reductions and may be more cost-effective than cytology.
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Affiliation(s)
- Monisha Sharma
- University of Washington, Department of Epidemiology, 1959 NE Pacific Street, Seattle, WA 98195, USA.
| | - Muhieddine Seoud
- Department of Obstetrics and Gynecology, Gynecologic Oncology, American University of Beirut, Beirut, Lebanon
| | - Jane J Kim
- Harvard T. H. Chan School of Public Health, Center for Health Decision Science, Boston, MA 02115, USA
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Puri L, Oghor C, Denkinger CM, Pai M. Xpert MTB/RIF for tuberculosis testing: access and price in highly privatised health markets. Lancet Glob Health 2016; 4:e94-5. [PMID: 26823226 DOI: 10.1016/s2214-109x(15)00269-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/03/2015] [Indexed: 11/18/2022]
Affiliation(s)
- Lekha Puri
- McGill International Tuberculosis Center, McGill University, Montreal, Canada
| | - Collins Oghor
- McGill International Tuberculosis Center, McGill University, Montreal, Canada
| | | | - Madhukar Pai
- McGill International Tuberculosis Center, McGill University, Montreal, Canada; Department of Epidemiology and Biostatistics, 1020 Pine Avenue West, Montreal QC H3A 1A2, Canada.
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Dittrich S, Tadesse BT, Moussy F, Chua A, Zorzet A, Tängdén T, Dolinger DL, Page AL, Crump JA, D’Acremont V, Bassat Q, Lubell Y, Newton PN, Heinrich N, Rodwell TJ, González IJ. Target Product Profile for a Diagnostic Assay to Differentiate between Bacterial and Non-Bacterial Infections and Reduce Antimicrobial Overuse in Resource-Limited Settings: An Expert Consensus. PLoS One 2016; 11:e0161721. [PMID: 27559728 PMCID: PMC4999186 DOI: 10.1371/journal.pone.0161721] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/09/2016] [Indexed: 11/30/2022] Open
Abstract
Acute fever is one of the most common presenting symptoms globally. In order to reduce the empiric use of antimicrobial drugs and improve outcomes, it is essential to improve diagnostic capabilities. In the absence of microbiology facilities in low-income settings, an assay to distinguish bacterial from non-bacterial causes would be a critical first step. To ensure that patient and market needs are met, the requirements of such a test should be specified in a target product profile (TPP). To identify minimal/optimal characteristics for a bacterial vs. non-bacterial fever test, experts from academia and international organizations with expertise in infectious diseases, diagnostic test development, laboratory medicine, global health, and health economics were convened. Proposed TPPs were reviewed by this working group, and consensus characteristics were defined. The working group defined non-severely ill, non-malaria infected children as the target population for the desired assay. To provide access to the most patients, the test should be deployable to community health centers and informal health settings, and staff should require <2 days of training to perform the assay. Further, given that the aim is to reduce inappropriate antimicrobial use as well as to deliver appropriate treatment for patients with bacterial infections, the group agreed on minimal diagnostic performance requirements of >90% and >80% for sensitivity and specificity, respectively. Other key characteristics, to account for the challenging environment at which the test is targeted, included: i) time-to-result <10 min (but maximally <2 hrs); ii) storage conditions at 0–40°C, ≤90% non-condensing humidity with a minimal shelf life of 12 months; iii) operational conditions of 5–40°C, ≤90% non-condensing humidity; and iv) minimal sample collection needs (50–100μL, capillary blood). This expert approach to define assay requirements for a bacterial vs. non-bacterial assay should guide product development, and enable targeted and timely efforts by industry partners and academic institutions.
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Affiliation(s)
- Sabine Dittrich
- Foundation for Innovative New Diagnostics (FIND), 9 Chemin des Mines, 1202 Geneva, Switzerland
- * E-mail:
| | - Birkneh Tilahun Tadesse
- Foundation for Innovative New Diagnostics (FIND), 9 Chemin des Mines, 1202 Geneva, Switzerland
- Special Programme for Research & Training in Tropical Diseases (TDR), World Health Organization, Avenue Appia 20, 1211, Geneva 27, Switzerland
- Hawassa University, College of Medicine and Health Sciences, Department of Pediatrics, Hawassa, Ethiopia
| | - Francis Moussy
- World Health Organization, 20 Avenue Appia, 1211, Geneva 27, Switzerland
| | - Arlene Chua
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Anna Zorzet
- ReAct Europe, Uppsala University, Box 256, 751 05, Uppsala, Sweden
| | - Thomas Tängdén
- ReAct Europe, Uppsala University, Box 256, 751 05, Uppsala, Sweden
| | - David L. Dolinger
- Foundation for Innovative New Diagnostics (FIND), 9 Chemin des Mines, 1202 Geneva, Switzerland
- World Health Organization, 20 Avenue Appia, 1211, Geneva 27, Switzerland
- Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Anne-Laure Page
- Epidemiology and Population Health, Epicentre, Paris, France
| | - John A. Crump
- Centre for International Health, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Duke Global Health Institute, Box 90519, Duke University, Durham, NC, 27708, United States of America
- Division of Infectious Diseases and International Health, Box 102359, Duke University Medical Center, Durham, NC, 27710, United States of America
| | - Valerie D’Acremont
- Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland
- Department of Ambulatory Care and Community Medicine, University of Lausanne, Bugnon 44, 1011, Lausanne, Switzerland
| | - Quique Bassat
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Yoel Lubell
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Paul N. Newton
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Lao PDR
| | - Norbert Heinrich
- Division for Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany; German Center for Infection Research, Munich partner site, Leopoldstr 5, D-80802, Munich, Germany
| | - Timothy J. Rodwell
- Foundation for Innovative New Diagnostics (FIND), 9 Chemin des Mines, 1202 Geneva, Switzerland
| | - Iveth J. González
- Foundation for Innovative New Diagnostics (FIND), 9 Chemin des Mines, 1202 Geneva, Switzerland
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Roth VR, Longpre T, Coyle D, Suh KN, Taljaard M, Muldoon KA, Ramotar K, Forster A. Cost Analysis of Universal Screening vs. Risk Factor-Based Screening for Methicillin-Resistant Staphylococcus aureus (MRSA). PLoS One 2016; 11:e0159667. [PMID: 27462905 PMCID: PMC4963093 DOI: 10.1371/journal.pone.0159667] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/05/2016] [Indexed: 12/03/2022] Open
Abstract
Background The literature remains conflicted regarding the most effective way to screen for MRSA. This study was designed to assess costs associated with universal versus risk factor-based screening for the reduction of nosocomial MRSA transmission. Methods The study was conducted at The Ottawa Hospital, a large multi-centre tertiary care facility with approximately 47,000 admissions annually. From January 2006-December 2007, patients underwent risk factor-based screening for MRSA on admission. From January 2008 to August 2009 universal MRSA screening was implemented. A comparison of costs incurred during risk factor-based screening and universal screening was conducted. The model incorporated probabilities relating to the likelihood of being tested and the results of polymerase chain reaction (PCR) testing with associated effects in terms of MRSA bacteremia and true positive and negative test results. Inputted costs included laboratory testing, contact precautions and infection control, private room costs, housekeeping, and length of hospital stay. Deterministic sensitivity analyses were conducted. Results The risk factor-based MRSA screening program screened approximately 30% of admitted patients and cost the hospital over $780 000 annually. The universal screening program screened approximately 83% of admitted patients and cost over $1.94 million dollars, representing an excess cost of $1.16 million per year. The estimated additional cost per patient screened was $17.76. Conclusion This analysis demonstrated that a universal MRSA screening program was costly from a hospital perspective and was previously known to not be clinically effective at reducing MRSA transmission. These results may be useful to inform future model-based economic analyses of MRSA interventions.
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Affiliation(s)
- Virginia R. Roth
- Department of Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
| | - Tara Longpre
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Doug Coyle
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Health Economics Research Group, Brunel University, Uxbridge, Middlesex, United Kingdom
| | - Kathryn N. Suh
- Department of Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Monica Taljaard
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Katherine A. Muldoon
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Karamchand Ramotar
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, Ontario, Canada
| | - Alan Forster
- Department of Medicine, The Ottawa Hospital and University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Brunstein J. Is MDx cost-effective for infectious disease applications? MLO Med Lab Obs 2016; 48:50-52. [PMID: 27551715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Beal SG, Assarzadegan N, Rand KH. Sample-to-result molecular infectious disease assays: clinical implications, limitations and potential. Expert Rev Mol Diagn 2016; 16:323-41. [PMID: 26689497 PMCID: PMC7103687 DOI: 10.1586/14737159.2016.1134325] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/17/2015] [Indexed: 01/01/2023]
Abstract
Molecular infectious disease diagnostic tests have undergone major advances in the past decade and will continue to rapidly evolve. Assays have become extraordinarily simple to perform, eliminating the need for pre-analytic sample preparation and post-amplification analysis. This allows these tests to be performed in settings without sophisticated expertise in molecular biology, including locations with limited resources. Additionally, the sensitivity and specificity of these assays is superb and many offer extremely fast turn-around times. These tests have major impacts on patient care, but also have some limitations.
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Affiliation(s)
- Stacy G. Beal
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
| | - Naziheh Assarzadegan
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
| | - Kenneth H. Rand
- Department of Pathology, Immunology and Laboratory Medicine,
University of Florida College of Medicine, Gainesville, FL,
USA
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Berry SM, Pezzi HM, Williams ED, Loeb JM, Guckenberger DJ, Lavanway AJ, Puchalski AA, Kityo CM, Mugyenyi PN, Graziano FM, Beebe DJ. Using Exclusion-Based Sample Preparation (ESP) to Reduce Viral Load Assay Cost. PLoS One 2015; 10:e0143631. [PMID: 26630135 PMCID: PMC4667969 DOI: 10.1371/journal.pone.0143631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/06/2015] [Indexed: 01/20/2023] Open
Abstract
Viral load (VL) measurements are critical to the proper management of HIV in developing countries. However, access to VL assays is limited by the high cost and complexity of existing assays. While there is a need for low cost VL assays, performance must not be compromised. Thus, new assays must be validated on metrics of limit of detection (LOD), accuracy, and dynamic range. Patient plasma samples from the Joint Clinical Research Centre in Uganda were de-identified and measured using both an existing VL assay (Abbott RealTime HIV-1) and our assay, which combines low cost reagents with a simplified method of RNA isolation termed Exclusion-Based Sample Preparation (ESP).71 patient samples with VLs ranging from <40 to >3,000,000 copies/mL were used to compare the two methods. We demonstrated equivalent LOD (~50 copies/mL) and high accuracy (average difference between methods of 0.08 log, R2 = 0.97). Using expenditures from this trial, we estimate that the cost of the reagents and consumables for this assay to be approximately $5 USD. As cost is a significant barrier to implementation of VL testing, we anticipate that our assay will enhance access to this critical monitoring test in developing countries.
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Affiliation(s)
- Scott M. Berry
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Hannah M. Pezzi
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | | | - Jennifer M. Loeb
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - David J. Guckenberger
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Alex J. Lavanway
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Alice A. Puchalski
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | | | - Peter N. Mugyenyi
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | | | - David J. Beebe
- Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
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45
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Burns J. Growing testiness: Disagreements between insurers, labs about new molecular tests. Manag Care 2015; 24:47. [PMID: 26807475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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46
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Zhang C, Niu P, Hong Y, Wang J, Zhang J, Ma X. A probe-free four-tube real-time PCR assay for simultaneous detection of twelve enteric viruses and bacteria. J Microbiol Methods 2015; 118:93-8. [PMID: 26342434 DOI: 10.1016/j.mimet.2015.08.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 08/27/2015] [Accepted: 08/27/2015] [Indexed: 12/30/2022]
Abstract
OBJECTIVES We aim to develop a multiplex real-time PCR assay to detect the most common pathogens causing community outbreaks of diarrhea. METHODS Four reaction systems of fluorescence dye-based real-time PCR assay were performed to amplify genes of norovirus, sapovirus, rotavirus, astrovirus, adenovirus, Campylobacter jejuni, Yersinia enterocolitica, Vibrio parahaemolyticus, Salmonella spp., Escherichia coli, and Shigella spp. PCR products of each pathogen were identified by characteristic peaks in melting curves. RESULTS The assay was able to achieve detection limit of 50 copies/reaction for each individual virus target, and 140-500CFU/mL for each individual bacterium target. A total of 122 clinical specimens from hospitalized children with acute diarrhea were used to evaluate the assay. The clinical sensitivity was very similar to that of reference methods. Norovirus genogroup II revealed the highest detectable rate (45/122, 36.9%). Coinfection was found in 28 out of 122 (23%) clinical specimens. CONCLUSION This assay proved to be a cost-effective, sensitive and reliable method for simultaneous detection of enteric viruses and bacteria.
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Affiliation(s)
- Chen Zhang
- Key Laboratory for Medical Virology, Ministry of Health, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Peihua Niu
- Key Laboratory for Medical Virology, Ministry of Health, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Yanying Hong
- Beijing Traditional Chinese Medicine Hospital, Capital Medical University Medical Laboratory, Beijing, China
| | - Ji Wang
- Key Laboratory for Medical Virology, Ministry of Health, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Jingyun Zhang
- National Institute for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Xuejun Ma
- Key Laboratory for Medical Virology, Ministry of Health, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
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Ragavendar MS, Jayaraman S, Ramya VM, Roy R, Manwani H. Performance evaluation of low cost microfluidic chips made using a digital craft cutter for point of care applications in nucleic acid tests. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:6609-12. [PMID: 25571511 DOI: 10.1109/embc.2014.6945143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A point of care (POC) diagnostic system development for nucleic acid testing (NAT) for developing countries faces several challenges and barriers among which affordability is a very critical one [1,4]. Hence a study was made to evaluate the effectiveness of microfluidic chips made from a digital craft cutter to be used as a disposable cartridge. Low cost materials like double sided tapes, transparent sheets and connectors were used to realize the microfluidic chip [2]. An in-house IVD sample preparation kit for nucleic acid extraction was used as a representative assay. Modifications were made to the assay workflow considering the feature sizes, design and volume of the microfluidic chip made from the paper cutter and other POC system requirements like turnaround time (TAT). The workflow was optimized by reducing overall TAT from 50min to 15min, sample volume from 150 μL to 12.5 μL and reduced reagent volumes. The method was also optimized to work at an isothermal condition. The results showed good correlation and yield in terms of both quality and quantity when compared to results obtained from the established baseline protocol. Thus microfluidic chips made using a digital craft cutter can very well be a low cost alternative to manufacture disposable chips for POC applications in nucleic acid tests.
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Kadiyska T, Nossikoff A. Stool DNA methylation assays in colorectal cancer screening. World J Gastroenterol 2015; 21:10057-10061. [PMID: 26401070 PMCID: PMC4572786 DOI: 10.3748/wjg.v21.i35.10057] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 06/18/2015] [Accepted: 08/25/2015] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) is fourth most common cancer in men and third in women worldwide. Developing a diagnostic panel of sensitive and specific biomarkers for the early detection of CRC is recognised as to be crucial for early initial diagnosis, which in turn leads to better long term survival. Most of the research on novel potential CRC biomarkers in the last 2 decades has been focussed on stool DNA analysis. In this paper, we describe the recent advances in non-invasive CRC screening and more specifically in molecular assays for aberrantly methylated BMP3 and NDRG4 promoter regions. In several research papers these markers showed superior rates for sensitivity and specificity in comparison to previously described assays. These tests detected the majority of adenomas ≥ 1 cm in size and the detection rates progressively increased with larger adenomas. The methylation status of the BMP3 and NDRG4 promoters demonstrated effective detection of neoplasms at all sites throughout the colon and was not affected by common clinical variables. Recently, a multitarget stool DNA test consisting of molecular assays for aberrantly methylated BMP3 and NDRG4 promoter regions, mutant KRAS and immunochemical assay for human haemoglobin has been made commercially available and is currently reimbursed in the United States. Although this is the most sensitive non-invasive CRC screening test, there is the need for further research in several areas - establishment of the best timeframe for repeated DNA stool testing; validation of the results in populations outside of North America; usefulness for surveillance and prognosis of patients; cost-effectiveness of DNA stool testing in real-life populations.
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Hillery N, Groessl EJ, Trollip A, Catanzaro D, Jackson L, Rodwell TC, Garfein RS, Lin SYG, Eisenach K, Ganiats TG, Park D, Valafar F, Rodrigues C, Crudu V, Victor TC, Catanzaro A. The Global Consortium for Drug-resistant Tuberculosis Diagnostics (GCDD): design of a multi-site, head-to-head study of three rapid tests to detect extensively drug-resistant tuberculosis. Trials 2014; 15:434. [PMID: 25377177 PMCID: PMC4232628 DOI: 10.1186/1745-6215-15-434] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 10/24/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Drug-resistant tuberculosis (DR-TB) remains a threat to global public health, owing to the complexity and delay of diagnosis and treatment. The Global Consortium for Drug-resistant Tuberculosis Diagnostics (GCDD) was formed to develop and evaluate assays designed to rapidly detect DR-TB, so that appropriate treatment might begin more quickly. This paper describes the methodology employed in a prospective cohort study for head-to-head assessment of three different rapid diagnostic tools. METHODS Subjects at risk of DR-TB were enrolled from three countries. Data were gathered from a combination of patient interviews, chart reviews, and laboratory testing from each site's reference laboratory. The primary outcome of interest was reduction in time from specimen arrival in the laboratory to results of rapid drug susceptibility tests, as compared with current standard mycobacterial growth indicator tube (MGIT) drug susceptibility tests. RESULTS Successful implementation of the trial in diverse multinational populations is explained, in addition to challenges encountered and recommendations for future studies with similar aims or populations. CONCLUSIONS The GCDD study was a head-to-head study of multiple rapid diagnostic assays aimed at improving accuracy and precision of diagnostics and reducing overall time to detection of DR-TB. By conducting a large prospective study, which captured epidemiological, clinical, and biological data, we have produced a high-quality unique dataset, which will be beneficial for analyzing study aims as well as answering future DR-TB research questions. Reduction in detection time for XDR-TB would be a major public health success as it would allow for improved treatment and more successful patient outcomes. Executing successful trials is critical in assessment of these reductions in highly variable populations. TRIAL REGISTRATION ClinicalTrials.gov NCT02170441.
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Affiliation(s)
- Naomi Hillery
- />Department of Family & Preventive Medicine, University of California, San Diego, CA USA
| | - Erik J Groessl
- />Department of Family & Preventive Medicine, University of California, San Diego, CA USA
| | - Andre Trollip
- />Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa
| | - Donald Catanzaro
- />Division of Bioinformatics and Medical Informatics, San Diego State University, San Diego, CA USA
| | - Lynn Jackson
- />Department of Medicine, University of California, San Diego, CA USA
| | - Timothy C Rodwell
- />Department of Medicine, University of California, San Diego, CA USA
| | - Richard S Garfein
- />Department of Medicine, University of California, San Diego, CA USA
| | - S-Y Grace Lin
- />California Department of Public Health, Richmond, CA USA
| | - Kathleen Eisenach
- />Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR USA
| | - Theodore G Ganiats
- />Department of Family & Preventive Medicine, University of California, San Diego, CA USA
| | - Daniel Park
- />Department of Medicine, University of California, San Diego, CA USA
| | - Faramarz Valafar
- />Division of Bioinformatics and Medical Informatics, San Diego State University, San Diego, CA USA
| | | | - Valeriu Crudu
- />Microbiology and Morphology Laboratory, Institute of Phthisiopneumology, Chisinau, Moldova
| | - Thomas C Victor
- />Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa
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50
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Peabody JW, Shimkhada R, Tong KB, Zubiller MB. New thinking on clinical utility: hard lessons for molecular diagnostics. Am J Manag Care 2014; 20:750-756. [PMID: 25365750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVES To describe 5 basic requirements for planning, implementing, and proving clinical utility for diagnostic tests, drawing on recent reimbursement decisions. STUDY DESIGN Review of recent reimbursement decisions by Palmetto GBA's MolDx program, and summary of lessons learned. METHODS Qualitative review of publicly available coverage and reimbursement decisions, plus our industry experience. RESULTS Lack of clinical utility data is the most commonly cited reason for why companies fail to receive favorable coverage and reimbursement decisions in this rapidly growing industry. We summarize 5 strategies to establish clinical utility and secure coverage with reimbursement: 1) understanding that outcomes are hard to capture, but that clinical behavior change is always proximate to outcomes change, 2) starting clinical utility studies early, 3) learning from successes and failures, 4) determining clinical utility with rigorous science, and 5) understanding that clinical utility studies may need to involve private payers and providers from the start. CONCLUSIONS Coverage and reimbursement are shifting from relatively low entry barriers to higher, evidence-based barriers that will require test developers to generate evidence of the net clinical benefits before widespread clinical use will occur. Concerted, early investment in rigorously designed clinical utility studies is necessary.
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Affiliation(s)
- John W Peabody
- QURE Healthcare, 1000 Fourth St, Suite 300, San Rafael, CA 94901. E-mail:
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