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Wiriyachaiporn N, Kongrueng J, Sukkuea K, Tanrattanawong R, Vanichtanankul J, Saeyang T, Jantra T, Japrung D, Maneeprakorn W, Bamrungsap S, Janchompoo P, Pasomsub E. Characterizing a visual lateral flow device for rapid SARS-CoV-2 virus protein detection: pre-clinical and system assessment. Anal Methods 2024; 16:2740-2750. [PMID: 38634326 DOI: 10.1039/d3ay02075d] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections have affected more than 769 million individuals worldwide over the last few years. Although the pandemic is transitioning into an endemic, the COVID-19 outbreak is still a global concern. A rapid screening platform is needed for effective preventive and control measures. Herein, a visual rapid lateral flow platform for SARS-CoV-2 nucleocapsid protein detection is developed. Under optimal conditions, the system demonstrated good detection sensitivity and selectivity against tested respiratory viruses. The system provides direct visual detection with a limit of 0.7 ng of the nucleocapsid protein per mL of a sample (0.7 ng mL-1) within 15 minutes. Further, a correlation between direct visual detection and semi-quantitative analysis using a reader showed a similar detection limit (R2 = 0.9571). The repeatability and reproducibility studies highlighted the potential of the system for the rapid screening of SARS-CoV-2 infection, with variations within 5% and 10% at high and low protein concentrations, respectively. Subsequent pre-clinical validation to correlate the performance with the standard molecular approach (RT-PCR) using 170 nasopharyngeal swabs demonstrated 98% estimated sensitivity (95% CI, 89.35-99.95%) and 100% specificity (95% CI, 96.38-100%). The positive and negative predictive values were reported to be 100% and 99%, respectively, with an accuracy of 99.3%. With high viral load samples (Ct value ≤25, n = 47), the system demonstrated 100% detection sensitivity and specificity. The proposed technique provides a valuable platform for potential use in rapid screening, particularly during pandemics, where diagnostic capacity and mass screening are crucial.
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Affiliation(s)
- Natpapas Wiriyachaiporn
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Jetnapang Kongrueng
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Kannika Sukkuea
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Rattana Tanrattanawong
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Jarunee Vanichtanankul
- National Center of Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| | - Thanaya Saeyang
- National Center of Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| | - Tararat Jantra
- National Center of Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| | - Deanpen Japrung
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Weerakanya Maneeprakorn
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Suwussa Bamrungsap
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Pareena Janchompoo
- Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Ekawat Pasomsub
- Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Hampel KJ, Gerrard DL, Francis D, Armstrong J, Cameron M, Ostafin A, Mahoney B, Malik M, Sidiropoulos N. When False-Positives Arise: Troubleshooting a SARS-Coronavirus-2 (SARS-CoV-2) Detection Assay on a Semi-Automated Platform. J Appl Lab Med 2024:jfae016. [PMID: 38507614 DOI: 10.1093/jalm/jfae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/29/2023] [Indexed: 03/22/2024]
Abstract
BACKGROUND During the COVID-19 pandemic, many molecular diagnostic laboratories performed high-throughput SARS-CoV-2 testing often with implementation of automated workflows. In parallel, vaccination campaigns resulted increasingly in specimens from fully vaccinated patients, with resultant clinical inquiries regarding positive results in this patient population. This prompted a quality improvement initiative to investigate the semi-automated testing workflow for false-positive results. The troubleshooting workflow is described and procedural improvements are outlined that serve as a resource for other molecular diagnostic laboratories that need to overcome testing anomalies in a semi-automated environment. METHODS This workflow utilized the MagMax-96 Viral RNA kit and the CDC 2019-nCoV RT-qPCR Panel on the Agilent Bravo Liquid-Handler (Bravo). Screening of the environment, personnel, and the mechanical performance of instrumentation using low Ct checkerboard challenges was executed to identify sources of cross-contamination. Evaluation of the assay and reporting design was conducted. RESULTS Specimen contamination was observed during the viral extraction process on the Bravo. Changes to the program reduced plate contamination by 50% and importantly revealed consistent hallmarks of contaminated samples. We adjusted the reporting algorithm using these indicators of false positives. False positives that were identified made up 0.11% of the 45 000+ tests conducted over the following 8 months. CONCLUSIONS These adjustments provided confident and quality results while maintaining turnaround time for patients and pandemic-related public health initiatives. This corrected false-positive rate is concordant with previously published studies from diagnostic laboratories utilizing automated systems and may be considered a laboratory performance standard for this type of testing.
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Affiliation(s)
- Kenneth J Hampel
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Diana L Gerrard
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Denise Francis
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Jordan Armstrong
- Technical Assistance Center for Biotek Products, Agilent Technologies Inc., Winooski, VT, United States
| | - Margaret Cameron
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Alexa Ostafin
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Briege Mahoney
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Miles Malik
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
| | - Nikoletta Sidiropoulos
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT, United States
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de Souza LR, da Silva IEP, Celis-Silva G, Raddatz BW, Imamura LM, Kim EYS, Valderrama GV, Riedi HDP, Rogal SR, de Almeida BMM, Figueredo MVM, Bengtson MH, Massirer KB. Improved protocol for Bst polymerase and reverse transcriptase production and application to a point-of-care diagnostics system. Exp Biol Med (Maywood) 2023; 248:1671-1683. [PMID: 38088106 PMCID: PMC10723028 DOI: 10.1177/15353702231215815] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023] Open
Abstract
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised awareness in the scientific community about the importance of being prepared for sanitary emergencies. Many measures implemented during the COVID pandemic are now being expanded to other applications. In the field of molecular and immunological diagnostics, the need to massively test the population worldwide resulted in the application of a variety of methods to detect viral infection. Besides gold standard reverse transcription quantitative polymerase chain reaction (RT-qPCR), the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) arose as an alternative and sensitive method to amplify and detect viral genetic material. We have used openly available protocols and have improved the protein production of RT-LAMP enzymes Bst polymerase and HIV-reverse transcriptase. To optimize enzyme production, we tested different protein tags, and we shortened the protein purification protocol, resulting in reduced processing time and handling of the enzymes and, thus, preserved the protein activity with high purity. The enzymes showed significant stability at 4 °C and 25 °C, over 60 days, and were highly reliable when used as a one-step RT-LAMP reaction in a portable point-of-care device with clinical samples. The enzymes and the reaction setup can be further expanded to detect other infectious diseases agents.
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Affiliation(s)
- Lucas Rodrigo de Souza
- Center for Molecular Biology and Genetic Engineering (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-875, Brazil
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
| | - Italo Esposti Poly da Silva
- Center for Molecular Biology and Genetic Engineering (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-875, Brazil
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
- Department of Biochemistry and Tissue Biology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-862, Brazil
| | - Gabriele Celis-Silva
- Center for Molecular Biology and Genetic Engineering (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-875, Brazil
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
| | | | | | | | - Gabriel Vieira Valderrama
- Center for Molecular Biology and Genetic Engineering (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-875, Brazil
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
| | | | | | | | | | - Mario Henrique Bengtson
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
- Department of Biochemistry and Tissue Biology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-862, Brazil
| | - Katlin Brauer Massirer
- Center for Molecular Biology and Genetic Engineering (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-875, Brazil
- Center for Medicinal Chemistry (CQMED), Universidade Estadual de Campinas (UNICAMP), Campinas/SP 13083-886, Brazil
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Cui X, Ngang S, Liu DD, Cheow LF. Rapid Single-Round Pool Testing of Infectious Disease Enabled by Multicolor Digital Melting PCR. Small 2023; 19:e2205636. [PMID: 37209020 DOI: 10.1002/smll.202205636] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 04/27/2023] [Indexed: 05/21/2023]
Abstract
Pooled nucleic acid amplification test is a promising strategy to reduce cost and resources for screening large populations for infectious disease. However, the benefit of pooled testing is reversed when disease prevalence is high, because of the need to retest each sample to identify infected individual when a pool is positive. Split, Amplify, and Melt analysis of Pooled Assay (SAMPA) is presented, a multicolor digital melting PCR assay in nanoliter chambers that simultaneously identify infected individuals and quantify their viral loads in a single round of pooled testing. This is achieved by early sample tagging with unique barcodes and pooling, followed by single molecule barcode identification in a digital PCR platform using a highly multiplexed melt curve analysis strategy. The feasibility is demonstrated of SAMPA for quantitative unmixing and variant identification from pools of eight synthetic DNA and RNA samples corresponding to the N1 gene, as well as from heat-inactivated SARS-CoV-2 virus. Single round pooled testing of barcoded samples with SAMPA can be a valuable tool for rapid and scalable population testing of infectious disease.
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Affiliation(s)
- Xu Cui
- Department of Biomedical Engineering & Institute for Health Innovation and Technology, National University of Singapore, Singapore, 119077, Singapore
| | - Shaun Ngang
- Department of Biomedical Engineering & Institute for Health Innovation and Technology, National University of Singapore, Singapore, 119077, Singapore
| | - Dong Dong Liu
- Department of Biomedical Engineering & Institute for Health Innovation and Technology, National University of Singapore, Singapore, 119077, Singapore
| | - Lih Feng Cheow
- Department of Biomedical Engineering & Institute for Health Innovation and Technology, National University of Singapore, Singapore, 119077, Singapore
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Nairz M, Todorovic T, Gehrer CM, Grubwieser P, Burkert F, Zimmermann M, Trattnig K, Klotz W, Theurl I, Bellmann-Weiler R, Weiss G. Single-Center Experience in Detecting Influenza Virus, RSV and SARS-CoV-2 at the Emergency Department. Viruses 2023; 15:v15020470. [PMID: 36851685 PMCID: PMC9958692 DOI: 10.3390/v15020470] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 02/10/2023] Open
Abstract
Reverse transcription polymerase chain reaction (RT-PCR) on respiratory tract swabs has become the gold standard for sensitive and specific detection of influenza virus, respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this retrospective analysis, we report on the successive implementation and routine use of multiplex RT-PCR testing for patients admitted to the Internal Medicine Emergency Department (ED) at a tertiary care center in Western Austria, one of the hotspots in the early coronavirus disease 2019 (COVID-19) pandemic in Europe. Our description focuses on the use of the Cepheid® Xpert® Xpress closed RT-PCR system in point-of-care testing (POCT). Our indications for RT-PCR testing changed during the observation period: From the cold season 2016/2017 until the cold season 2019/2020, we used RT-PCR to diagnose influenza or RSV infection in patients with fever and/or respiratory symptoms. Starting in March 2020, we used the RT-PCR for SARS-CoV-2 and a multiplex version for the combined detection of all these three respiratory viruses to also screen subjects who did not present with symptoms of infection but needed in-hospital medical treatment for other reasons. Expectedly, the switch to a more liberal RT-PCR test strategy resulted in a substantial increase in the number of tests. Nevertheless, we observed an immediate decline in influenza virus and RSV detections in early 2020 that coincided with public SARS-CoV-2 containment measures. In contrast, the extensive use of the combined RT-PCR test enabled us to monitor the re-emergence of influenza and RSV detections, including asymptomatic cases, at the end of 2022 when COVID-19 containment measures were no longer in place. Our analysis of PCR results for respiratory viruses from a real-life setting at an ED provides valuable information on the epidemiology of those infections over several years, their contribution to morbidity and need for hospital admission, the risk for nosocomial introduction of such infection into hospitals from asymptomatic carriers, and guidance as to how general precautions and prophylactic strategies affect the dynamics of those infections.
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Lübke N, Repges K, Menne C, Walker A, Jensen BO, Freise NF, Gliga S, Eickhoff SB, Bosse HM, Adams O, Timm J. Quantitative analysis of different respiratory specimens on two automated test systems for detection of SARS-CoV-2 RNA. Diagn Microbiol Infect Dis 2023; 105:115800. [PMID: 36252283 DOI: 10.1016/j.diagmicrobio.2022.115800] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 08/12/2022] [Accepted: 08/20/2022] [Indexed: 12/04/2022]
Abstract
Molecular testing of SARS-CoV-2 RNA is essential during the pandemic. Here, we compared the results of different respiratory specimens including anterior nasal swabs, pharyngeal swabs, saliva swabs, and gargle lavage samples to nasopharyngeal swabs on two automated SARS-CoV-2 test systems. Samples were collected and tested simultaneously from a total of 36 hospitalized symptomatic COVID-19 patients. Detection and quantification of SARS-CoV-2 was performed on cobas®6800 (Roche) and NeuMoDx™ (Qiagen) systems. Both assays showed reliable detection and quantification of SARS-CoV-2 RNA, with nasopharyngeal swabs showing the highest sensitivity. SARS-CoV-2 RNA concentrations in other respiratory specimens were lower (mean 2.5 log10 copies/ml) or even undetectable in up to 20%. These data clearly indicate that not all respiratory materials are equally suitable for the management of hospitalized patients, especially, in the late phase of COVID-19, when the viral phase subsides and inflammation becomes the predominant factor, making detection of even lower viral loads increasingly important.
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Irungu JK, Munyua P, Ochieng C, Juma B, Amoth P, Kuria F, Kiiru J, Makayotto L, Abade A, Bulterys M, Hunsperger E, Emukule GO, Onyango C, Samandari T, Barr BAT, Akelo V, Weyenga H, Munywoki PK, Bigogo G, Otieno NA, Kisivuli JA, Ochieng E, Nyaga R, Hull N, Herman-Roloff A, Aman R. Diagnostic accuracy of the Panbio COVID-19 antigen rapid test device for SARS-CoV-2 detection in Kenya, 2021: A field evaluation. PLoS One 2023; 18:e0277657. [PMID: 36696882 PMCID: PMC9876661 DOI: 10.1371/journal.pone.0277657] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/01/2022] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Accurate and timely diagnosis is essential in limiting the spread of SARS-CoV-2 infection. The reference standard, rRT-PCR, requires specialized laboratories, costly reagents, and a long turnaround time. Antigen RDTs provide a feasible alternative to rRT-PCR since they are quick, relatively inexpensive, and do not require a laboratory. The WHO requires that Ag RDTs have a sensitivity ≥80% and specificity ≥97%. METHODS This evaluation was conducted at 11 health facilities in Kenya between March and July 2021. We enrolled persons of any age with respiratory symptoms and asymptomatic contacts of confirmed COVID-19 cases. We collected demographic and clinical information and two nasopharyngeal specimens from each participant for Ag RDT testing and rRT-PCR. We calculated the diagnostic performance of the Panbio™ Ag RDT against the US Centers for Disease Control and Prevention's (CDC) rRT-PCR test. RESULTS We evaluated the Ag RDT in 2,245 individuals where 551 (24.5%, 95% CI: 22.8-26.3%) tested positive by rRT-PCR. Overall sensitivity of the Ag RDT was 46.6% (95% CI: 42.4-50.9%), specificity 98.5% (95% CI: 97.8-99.0%), PPV 90.8% (95% CI: 86.8-93.9%) and NPV 85.0% (95% CI: 83.4-86.6%). Among symptomatic individuals, sensitivity was 60.6% (95% CI: 54.3-66.7%) and specificity was 98.1% (95% CI: 96.7-99.0%). Among asymptomatic individuals, sensitivity was 34.7% (95% CI 29.3-40.4%) and specificity was 98.7% (95% CI: 97.8-99.3%). In persons with onset of symptoms <5 days (594/876, 67.8%), sensitivity was 67.1% (95% CI: 59.2-74.3%), and 53.3% (95% CI: 40.0-66.3%) among those with onset of symptoms >7 days (157/876, 17.9%). The highest sensitivity was 87.0% (95% CI: 80.9-91.8%) in symptomatic individuals with cycle threshold (Ct) values ≤30. CONCLUSION The overall sensitivity and NPV of the Panbio™ Ag RDT were much lower than expected. The specificity of the Ag RDT was high and satisfactory; therefore, a positive result may not require confirmation by rRT-PCR. The kit may be useful as a rapid screening tool only for symptomatic patients in high-risk settings with limited access to rRT-PCR. A negative result should be interpreted based on clinical and epidemiological information and may require retesting by rRT-PCR.
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Affiliation(s)
- Jack Karuga Irungu
- Field Epidemiology and Laboratory Training Program, Ministry of Health, Nairobi, Kenya
- * E-mail:
| | - Peninah Munyua
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Caroline Ochieng
- Kenya Medical Research Institute (KEMRI), Center for Global Health Research, Nairobi, Kenya
| | - Bonventure Juma
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | | | | | | | | | - Ahmed Abade
- Field Epidemiology and Laboratory Training Program, Ministry of Health, Nairobi, Kenya
| | - Marc Bulterys
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | | | | | - Clayton Onyango
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Taraz Samandari
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | | | - Victor Akelo
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Herman Weyenga
- U.S. Centers for Disease Control and Prevention, Nairobi, Kenya
| | | | - Godfrey Bigogo
- Kenya Medical Research Institute (KEMRI), Center for Global Health Research, Nairobi, Kenya
| | - Nancy A. Otieno
- Kenya Medical Research Institute (KEMRI), Center for Global Health Research, Nairobi, Kenya
| | | | - Edwin Ochieng
- Association of Public Health Laboratories (APHL), Nairobi, Kenya
| | - Rufus Nyaga
- Association of Public Health Laboratories (APHL), Nairobi, Kenya
| | - Noah Hull
- Association of Public Health Laboratories (APHL), Nairobi, Kenya
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Bustin S, Bustin C, Kirvell S, Nolan T, Mueller R, Shipley G. Maximising the Use of Scarce qPCR Master Mixes. Int J Mol Sci 2022; 23:8486. [PMID: 35955620 PMCID: PMC9368830 DOI: 10.3390/ijms23158486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/24/2022] [Accepted: 07/28/2022] [Indexed: 02/01/2023] Open
Abstract
The COVID-19 pandemic resulted in a universal, immediate, and vast demand for comprehensive molecular diagnostic testing, especially real-time quantitative (qPCR)-based methods. This rapidly triggered a global shortage of testing capacity, equipment, and reagents. Even today, supply times for chemicals from date of order to delivery are often much longer than pre-pandemic. Furthermore, many companies have ratcheted up the price for minimum volumes of reaction master mixes essential for qPCR assays, causing additional problems for academic laboratories often operating on a shoestring. We have validated two strategies that stretch reagent supplies and, whilst particularly applicable in case of scarcity, can readily be incorporated into standard qPCR protocols, with appropriate validation. The first strategy demonstrates equivalent performance of a selection of “past expiry date” and newly purchased master mixes. This approach is valid for both standard and fast qPCR protocols. The second validates the use of these master mixes at less than 1x final concentration without loss of qPCR efficiency or sensitivity.
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Tobik ER, Kitfield-Vernon LB, Thomas RJ, Steel SA, Tan SH, Allicock OM, Choate BL, Akbarzada S, Wyllie AL. Saliva as a sample type for SARS-CoV-2 detection: implementation successes and opportunities around the globe. Expert Rev Mol Diagn 2022; 22:519-535. [PMID: 35763281 DOI: 10.1080/14737159.2022.2094250] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Symptomatic testing and asymptomatic screening for SARS-CoV-2 continue to be essential tools for mitigating virus transmission. Though COVID-19 diagnostics initially defaulted to oropharyngeal or nasopharyngeal sampling, the worldwide urgency to expand testing efforts spurred innovative approaches and increased diversity of detection methods. Strengthening innovation and facilitating widespread testing remains critical for global health, especially as additional variants emerge and other mitigation strategies are recalibrated. AREAS COVERED A growing body of evidence reflects the need to expand testing efforts and further investigate the efficiency, sensitivity, and acceptability of saliva samples for SARS-CoV-2 detection. Countries have made pandemic response decisions based on resources, costs, procedures, and regional acceptability - the adoption and integration of saliva-based testing among them. Saliva has demonstrated high sensitivity and specificity while being less invasive relative to nasopharyngeal swabs, securing saliva's position as a more acceptable sample type. EXPERT OPINION Despite the accessibility and utility of saliva sampling, global implementation remains low compared to swab-based approaches. In some cases, countries have validated saliva-based methods but face challenges with testing implementation or expansion. Here, we review the localities that have demonstrated success with saliva-based SARS-CoV-2 testing approaches and can serve as models for transforming concepts into globally-implemented best practices.
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Affiliation(s)
- Emily R Tobik
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Lily B Kitfield-Vernon
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Russell J Thomas
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Sydney A Steel
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Steph H Tan
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA.,Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut, USA
| | - Orchid M Allicock
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Brittany L Choate
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Sumaira Akbarzada
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anne L Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
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Delgado-Diaz DJ, Sakthivel D, Nguyen HHT, Farrokzhad K, Hopper W, Narh CA, Richards JS. Strategies That Facilitate Extraction-Free SARS-CoV-2 Nucleic Acid Amplification Tests. Viruses 2022; 14:v14061311. [PMID: 35746782 PMCID: PMC9230587 DOI: 10.3390/v14061311] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 05/23/2022] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 02/01/2023] Open
Abstract
The COVID-19 pandemic has resulted in an unprecedented global demand for in vitro diagnostic reagents. Supply shortages and hoarding have impacted testing capacity which has led to inefficient COVID-19 case identification and transmission control, predominantly in developing countries. Traditionally, RNA extraction is a prerequisite for conducting SARS-CoV-2 nucleic acid amplification tests (NAAT); however, simplified methods of sample processing have been successful at bypassing typical nucleic acid extraction steps, enabling extraction-free SARS-CoV-2 NAAT workflows. These methods involve chemical and physical approaches that are inexpensive and easily accessible alternatives to overcome extraction kit supply shortages, while offering acceptable test performance. Here we provide an overview of three main sample preparation strategies that have been shown to facilitate extraction-free SARS-CoV-2 NAATs.
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Affiliation(s)
- David J. Delgado-Diaz
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
- Correspondence:
| | - Dhanasekaran Sakthivel
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
| | - Hanh H. T. Nguyen
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
| | - Khashayar Farrokzhad
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
| | - William Hopper
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
| | - Charles A. Narh
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
- Department of Medicine, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Infectious Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Jack S. Richards
- ZIP Diagnostics Pty Ltd., Collingwood, VIC 3066, Australia; (D.S.); (H.H.T.N.); (K.F.); (W.H.); (C.A.N.); (J.S.R.)
- Department of Medicine, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Infectious Diseases, Monash University, Melbourne, VIC 3004, Australia
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11
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Wang Y, Upadhyay A, Pillai S, Khayambashi P, Tran SD. Saliva as a diagnostic specimen for SARS-CoV-2 detection: a scoping review. Oral Dis 2022; 28 Suppl 2:2362-2390. [PMID: 35445491 PMCID: PMC9115496 DOI: 10.1111/odi.14216] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 03/22/2022] [Accepted: 04/12/2022] [Indexed: 12/03/2022]
Abstract
Objectives This scoping review aims to summarize the diagnostic value of saliva assessed from current studies that (1) compare its performance in reverse transcriptase‐polymerase chain reaction testing to nasopharyngeal swabs, (2) evaluate its performance in rapid and point‐of‐care COVID‐19 diagnostic tests, and (3) explore its use as a specimen for detecting anti‐SARS‐CoV‐2 antibodies. Materials and Methods A systematic search was performed on the following databases: Medline and Embase (Ovid), World Health Organization, Centers for Disease Control and Prevention, and Global Health (Ovid) from January 2019 to September 2021. Of the 657 publications identified from the searches, n = 146 articles were included in the final scoping review. Results Our findings showcase that salivary samples exceed nasopharyngeal swabs in detecting SARS‐CoV‐2 using reverse transcriptase‐polymerase chain reaction testing in several studies. A select number of rapid antigen and point‐of‐care tests from the literature were also identified capable of high detection rates using saliva. Moreover, anti‐SARS‐CoV‐2 antibodies have been shown to be detectable in saliva through biochemical assays. Conclusion We highlight the potential of saliva as an all‐rounded specimen in detecting SARS‐CoV‐2. However, future large‐scale clinical studies will be needed to support its widespread use as a non‐invasive clinical specimen for COVID‐19 testing.
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12
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May L, Tran N, Ledeboer NA. Point-of-care COVID-19 testing in the emergency department: current status and future prospects. Expert Rev Mol Diagn 2021; 21:1333-1340. [PMID: 34758686 PMCID: PMC8631689 DOI: 10.1080/14737159.2021.2005582] [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] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 11/09/2021] [Indexed: 01/08/2023]
Abstract
INTRODUCTION This expert review outlines current and future point-of-care technologies for the diagnosis of the SARS-CoV-2 virus, which is responsible for causing coronavirus disease COVID-19 in the emergency department. COVID-19 first emerged in late 2019 and is responsible for a range of presentations from minor upper respiratory tract symptoms to severe pneumonia and multisystem organ failure. Among the technologies available include the gold standard of molecular point-of-care tests as well as antigen detection tests. AREAS COVERED We discuss point-of-care molecular tests including multiplex, targeted, and single plex panels as well as various antigen testing methodologies in terms of availability and performance characteristics. In addition, we focus on current testing best practices and considerations for point-of-care testing in the emergency department based on a search of the literature available in PubMed to date and a review of FDA and CDC guidance. EXPERT OPINION While there have been many advances in SARS-CoV-2 point-of-care testing, there remain challenges to implementation in the emergency department setting. A paradigm shift is needed to improve diagnosis and clinical outcomes.
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Affiliation(s)
- Larissa May
- Davis Department of Emergency Medicine, University of California, Sacramento, CA, USA
| | - Nam Tran
- Davis Department of Pathology and Laboratory Medicine, University of California, USA
| | - Nathan A. Ledeboer
- Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, USA
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13
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Chappleboim A, Joseph-Strauss D, Rahat A, Sharkia I, Adam M, Kitsberg D, Fialkoff G, Lotem M, Gershon O, Schmidtner AK, Oiknine-Djian E, Klochendler A, Sadeh R, Dor Y, Wolf D, Habib N, Friedman N. Early sample tagging and pooling enables simultaneous SARS-CoV-2 detection and variant sequencing. Sci Transl Med 2021; 13:eabj2266. [PMID: 34591660 PMCID: PMC9928115 DOI: 10.1126/scitranslmed.abj2266] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Most severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic tests have relied on RNA extraction followed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays. Whereas automation improved logistics and different pooling strategies increased testing capacity, highly multiplexed next-generation sequencing (NGS) diagnostics remain a largely untapped resource. NGS tests have the potential to markedly increase throughput while providing crucial SARS-CoV-2 variant information. Current NGS-based detection and genotyping assays for SARS-CoV-2 are costly, mostly due to parallel sample processing through multiple steps. Here, we have established ApharSeq, in which samples are barcoded in the lysis buffer and pooled before reverse transcription. We validated this assay by applying ApharSeq to more than 500 clinical samples from the Clinical Virology Laboratory at Hadassah hospital in a robotic workflow. The assay was linear across five orders of magnitude, and the limit of detection was Ct 33 (~1000 copies/ml, 95% sensitivity) with >99.5% specificity. ApharSeq provided targeted high-confidence genotype information due to unique molecular identifiers incorporated into this method. Because of early pooling, we were able to estimate a 10- to 100-fold reduction in labor, automated liquid handling, and reagent requirements in high-throughput settings compared to current testing methods. The protocol can be tailored to assay other host or pathogen RNA targets simultaneously. These results suggest that ApharSeq can be a promising tool for current and future mass diagnostic challenges.
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Affiliation(s)
- Alon Chappleboim
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Daphna Joseph-Strauss
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Ayelet Rahat
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Israa Sharkia
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Miriam Adam
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Daniel Kitsberg
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Gavriel Fialkoff
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Matan Lotem
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Omer Gershon
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Anna-Kristina Schmidtner
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Esther Oiknine-Djian
- Hadassah Hebrew University Medical Center, Jerusalem 9112001, Israel.,Lautenberg Centre for Immunology and Cancer Research, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Ronen Sadeh
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Dana Wolf
- Hadassah Hebrew University Medical Center, Jerusalem 9112001, Israel.,Lautenberg Centre for Immunology and Cancer Research, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Naomi Habib
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nir Friedman
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel.,Rachel and Selim Benin School of Computer Science, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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14
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Morecchiato F, Coppi M, Baccani I, Maggini N, Ciccone N, Antonelli A, Rossolini GM. Evaluation of extraction-free RT-PCR methods for faster and cheaper detection of SARS-CoV-2 using two commercial systems. Int J Infect Dis 2021; 112:264-268. [PMID: 34563710 PMCID: PMC8458106 DOI: 10.1016/j.ijid.2021.09.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 12/19/2022] Open
Abstract
Objective When using high-throughput batched diagnostic platforms based on RT-PCR for SARS-CoV-2 detection, avoidance of the conventional nucleic acid extraction step can help to reduce the turnaround time and increase processivity. This approach can also spare reagents and plasticware, which have experienced a shortage during the initial waves of the pandemic, reducing the overall testing costs. Methods This study evaluated the performance of extraction-free protocols based on simple dilution of the specimen in sterile RNAse free water (with or without a heating step) in comparison to standard RNA extraction protocols, using two commercial kits for molecular detection of SARS-CoV-2 (Allplex™ SARS-CoV-2 assay and Allplex™ SARS-CoV-2/FluA/FluB/RSV assay) in nasopharyngeal swabs (NPS). Results Compared with conventional protocols, extraction-free protocols based on sample dilution without a heating step exhibited a lower analytical sensitivity: 74.0% and 82.1% with the Allplex™ SARS-CoV-2 assay (tested with 139 NPS samples) and the Allplex™ SARS-CoV-2/FluA/FluB/RSV assay (tested with 69 NPS samples), with a mean increase of Ct values of +2.04 and +1.32, respectively. Most false negative results were observed with sampled low viral load. Including a step of heat exposure did not improve but actually decreased the analytical sensitivity of the assay. Conclusions Results confirmed that extraction-free protocols could be a faster and cheaper approach to SARS-CoV-2 detection in NPS samples, which could improve processivity of diagnostic platforms.
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Affiliation(s)
- Fabio Morecchiato
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Marco Coppi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Ilaria Baccani
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Niccolò Maggini
- Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Nunziata Ciccone
- Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Alberto Antonelli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Gian Maria Rossolini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy.
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15
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Banik S, Saibire K, Suryavanshi S, Johns G, Chakravorty S, Kwiatkowski R, Alland D, Banada PP. Inactivation of SARS-CoV-2 virus in saliva using a guanidium based transport medium suitable for RT-PCR diagnostic assays. PLoS One 2021; 16:e0252687. [PMID: 34115762 PMCID: PMC8195355 DOI: 10.1371/journal.pone.0252687] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/20/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Upper respiratory samples used to test for SARS-CoV-2 virus may be infectious and present a hazard during transport and testing. A buffer with the ability to inactivate SARS-CoV-2 at the time of sample collection could simplify and expand testing for COVID-19 to non-conventional settings. METHODS We evaluated a guanidium thiocyanate-based buffer, eNAT™ (Copan) as a possible transport and inactivation medium for downstream Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) testing to detect SARS-CoV-2. Inactivation of SARS-CoV-2 USA-WA1/2020 in eNAT and in diluted saliva was studied at different incubation times. The stability of viral RNA in eNAT was also evaluated for up to 7 days at room temperature (28°C), refrigerated conditions (4°C) and at 35°C. RESULTS SARS-COV-2 virus spiked directly in eNAT could be inactivated at >5.6 log10 PFU/ml within a minute of incubation. When saliva was diluted 1:1 in eNAT, no cytopathic effect (CPE) on VeroE6 cells was observed, although SARS-CoV-2 RNA could be detected even after 30 min incubation and after two cell culture passages. A 1:2 (saliva:eNAT) dilution abrogated both CPE and detectable viral RNA after as little as 5 min incubation in eNAT. SARS-CoV-2 RNA from virus spiked at 5X the limit of detection remained positive up to 7 days of incubation in all tested conditions. CONCLUSION eNAT and similar guanidinium thiocyanate-based media may be of value for transport, stabilization, and processing of clinical samples for RT-PCR based SARS-CoV-2 detection.
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Affiliation(s)
- Sukalyani Banik
- Department of Medicine, Center for Emerging Pathogens, Rutgers-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Kaheerman Saibire
- Department of Medicine, Center for Emerging Pathogens, Rutgers-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Shraddha Suryavanshi
- Department of Medicine, Center for Emerging Pathogens, Rutgers-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Glenn Johns
- Cepheid, Sunnyvale, California, United States of America
| | | | | | - David Alland
- Department of Medicine, Center for Emerging Pathogens, Rutgers-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Padmapriya P. Banada
- Department of Medicine, Center for Emerging Pathogens, Rutgers-New Jersey Medical School, Newark, New Jersey, United States of America
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