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Murphy C, Mak L, Cheng SMS, Liu GYZ, Chun AMC, Leung KKY, Sum NYW, Poukka E, Peiris M, Cowling BJ. Diagnostic performance of multiplex lateral flow tests in ambulatory patients with acute respiratory illness. Diagn Microbiol Infect Dis 2024; 110:116421. [PMID: 38972132 DOI: 10.1016/j.diagmicrobio.2024.116421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/20/2024] [Accepted: 07/03/2024] [Indexed: 07/09/2024]
Abstract
We assessed the performance of three different multiplex lateral flow assays manufactured by SureScreen, Microprofit and Goldsite which provide results for influenza, respiratory syncytial virus (RSV) and SARS-CoV-2. Between 4 April and 20 October 2023, 1646 patients 6 months and older presenting to an outpatient department of a hospital in Hong Kong with ≥2 symptoms or signs of an acute respiratory illness were enrolled. The point estimates for all three multiplex tests had sensitivity >80% for influenza A and SARS-CoV-2 compared to PCR, and the tests manufactured by Microprofit and Goldsite had sensitivity >84% to detect RSV. Specificity was >97% for all three tests except for the SureScreen test which had specificity 86.2% (95% CI: 83.9% to 88.3%) for influenza A. Sensitivity was lower than reported by the manufacturers, resulting in a higher risk of false negatives. The three multiplex tests performed better in patients with high viral loads.
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Affiliation(s)
- Caitriona Murphy
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Loretta Mak
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Samuel M S Cheng
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Gigi Y Z Liu
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Alan M C Chun
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Katy K Y Leung
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Natalie Y W Sum
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eero Poukka
- Infectious Disease Control and Vaccinations Unit, Department of Health Security, Finnish Institute for Health and Welfare, Mannerheimintie 166, 00300 Helsinki, Finland; Department of Public Health, Faculty of Medicine, University of Helsinki, Yliopistonkatu 4, 00100 Helsinki, Finland
| | - Malik Peiris
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Centre for Immunology & Infection, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China
| | - Benjamin J Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China.
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2
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Futschik ME, Tunkel SA, Turek E, Chapman D, Thorlu-Bangura Z, Kulasegaran-Shylini R, Blandford E, Dodgson A, Klapper PE, Sudhanva M, Crook D, Bell J, Hopkins S, Peto T, Fowler T. Double testing with lateral flow antigen test devices for COVID-19: does a second test in quick succession add value? J Virol Methods 2024; 329:115000. [PMID: 39038659 DOI: 10.1016/j.jviromet.2024.115000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/24/2024]
Abstract
BACKGROUND/OBJECTIVES We investigated if performing two lateral flow device (LFD) tests, LFD2 immediately after LFD1, could improve diagnostic sensitivity or specificity for detecting severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) antigen. STUDY DESIGN Individuals aged ≥16 years attending UK community testing sites (February-May 2021) performed two successive LFD tests and provided a nose-and-throat sample for a polymerase chain reaction (PCR) test. Using the PCR result as the reference diagnosis, we assessed whether improvements could be achieved in sensitivity (by counting a positive result in either LFD as a positive overall test result) or specificity (by using LFD2 as confirmatory test). RESULTS Overall, 2231 participants were included with 159 (7 %) having a positive PCR test. Of 2223 participants who completed both LFD tests, LFD results were highly concordant both with each other and with PCR tests (>97 %). The proportion of discord LFD results decreased significantly over the study period. Combined LFD usage achieved a sensitivity of 68.6 %, versus 67.1 % for either LFD individually. The specificity increased from 99.5 % to 99.8 % when using LFD2 as confirmatory test. Observed increases in sensitivity and specificity were not statistically significant. Void results were recorded for 31 (1.4 %) LFD1s, 19 (0.9 %) LFD2s and 6 (0.3 %) combined LFD tests. CONCLUSIONS LFD tests were highly reproducible even when they were performed by untrained users following only written instructions and without supervision. While performing two LFD tests of the same type in quick succession marginally increased sensitivity or specificity, statistically significant improvements were not detected in our study.
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Affiliation(s)
- Matthias E Futschik
- UK Health Security Agency, London, UK; School of Biomedical Sciences, Faculty of Health, University of Plymouth, Plymouth, UK
| | | | | | | | | | | | | | | | - Paul E Klapper
- UK Health Security Agency, London, UK; School of Biological Sciences, University of Manchester, Manchester, UK
| | - Malur Sudhanva
- UK Health Security Agency, London, UK; South London Specialist Virology Centre, Infection Sciences, King's College Hospital NHS Foundation Trust, London, UK
| | - Derrick Crook
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - John Bell
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Tim Peto
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tom Fowler
- UK Health Security Agency, London, UK; William Harvey Research Institute, Queen Mary University of London, London, UK.
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Edwards N, Reboud J, Yan X, Guo X, Cooper JM, Wadsworth J, Waters R, Mioulet V, King DP, Shaw AE. Detection of foot-and-mouth disease virus RNA using a closed loop-mediated isothermal amplification system. Front Microbiol 2024; 15:1429288. [PMID: 39188314 PMCID: PMC11346313 DOI: 10.3389/fmicb.2024.1429288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/18/2024] [Indexed: 08/28/2024] Open
Abstract
Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals responsible for economic losses that amount to >$20 billion annually. Rapid recognition of FMD cases provides vital information to guide control programmes. A range of point-of-need amplification technologies have been developed which allow sensitive detection of the causative virus (FMDV) in the field at locations remote from laboratories. Here we describe a novel system to detect FMDV RNA using loop-mediated isothermal amplification (LAMP). This test was evaluated using a panel of FMDV isolates (n = 79) and RNA standards demonstrating capability to amplify viral genome directly from clinical material in the absence of nucleic acid extraction. This extraction-free RT-LAMP assay was transferred to a bespoke closed-system lateral flow test (LFT) that was used in combination with a low-cost hand-held heater. Our results show that the RT-LAMP-LFT assay retains a high level of diagnostic and analytical sensitivity when using direct clinical material, with a limit of detection under 80 copies per reaction. Together, our data support the potential for the use of this assay at the point-of-need to facilitate rapid feedback on the status of suspect cases.
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Affiliation(s)
| | - Julien Reboud
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Xiaoxiang Yan
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Xin Guo
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Jonathan M. Cooper
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | | | - Ryan Waters
- The Pirbright Institute, Woking, United Kingdom
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Loy JK, Kimmig C, Klos S, Wunram HL, Langer T, Breitinger E, Bender S. Influence parental- and child-related factors on the acceptance of SARS-CoV-2 test methods in schools and daycare facilities. Front Public Health 2024; 12:1264019. [PMID: 39091535 PMCID: PMC11291219 DOI: 10.3389/fpubh.2024.1264019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 06/26/2024] [Indexed: 08/04/2024] Open
Abstract
Introduction Rapid testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections was an essential step in reducing the spread of the virus and monitoring pandemic development. Most mandatory standard pandemic testing in Germany has been performed in schools and daycare facilities. We investigated the influence of behavioral and attitudinal characteristics of children and caregivers on their acceptance of (i) antigen-based nasal swab rapid and (ii) oral saliva-based pooled Polymerase Chain Reaction (PCR) tests. Methods Conducted through a cross-sectional survey between November and December 2021, with 1962 caregivers and 581 children/adolescents participating, the study evaluated the acceptability of each testing method on a six-point scale. Participants scored one test method conducted on their child at one of six levels with 1 and 6 denoting "excellent" (1) and "inadequate" (6), respectively. We considered demographic variables, vaccination status, child mental health (measured by the SDQ-questionnaire), and facility type (kindergarten, primary school, secondary school) as covariates. Results Results reveal a preference for saliva-based PCR tests over nasal swabs by about one grade, particularly among parents of unvaccinated children, especially if their child expressed future vaccination reluctance. Testing acceptance was lower among children with mental health issues, primary school-aged, and those with less-educated parents. Perception of test accuracy and convenience influenced attitudes, favoring saliva-based PCR tests. Moreover, children with mental health issues felt less secure during testing. Discussion To our knowledge, this is the first study to investigate the influence of different testing methods on testing acceptance for SARS-CoV-2 in children and caregivers. Our study identifies predictors of lower acceptance of public health surveillance measures and enables the development of educational programs on testing and vaccination tailored to the needs of specific target groups. Moreover, we demonstrate that test acceptance in vulnerable groups can be enhanced by careful choice of an appropriate testing method.
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Affiliation(s)
- Johanna K. Loy
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Cologne, Germany
| | - Christian Kimmig
- Department of Pediatrics, University of Freiburg, Freiburg, Germany
| | - Simon Klos
- Faculty of Medicine, School of Child and Adolescent Cognitive Behavior Therapy (AKiP), University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Heidrun Lioba Wunram
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Cologne, Germany
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, Köln, Germany
| | - Thorsten Langer
- Department of Pediatrics, University of Freiburg, Freiburg, Germany
| | - Eva Breitinger
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Cologne, Germany
| | - Stephan Bender
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Cologne, Germany
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Theel ES, Kirby JE, Pollock NR. Testing for SARS-CoV-2: lessons learned and current use cases. Clin Microbiol Rev 2024; 37:e0007223. [PMID: 38488364 PMCID: PMC11237512 DOI: 10.1128/cmr.00072-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024] Open
Abstract
SUMMARYThe emergence and worldwide dissemination of SARS-CoV-2 required both urgent development of new diagnostic tests and expansion of diagnostic testing capacity on an unprecedented scale. The rapid evolution of technologies that allowed testing to move out of traditional laboratories and into point-of-care testing centers and the home transformed the diagnostic landscape. Four years later, with the end of the formal public health emergency but continued global circulation of the virus, it is important to take a fresh look at available SARS-CoV-2 testing technologies and consider how they should be used going forward. This review considers current use case scenarios for SARS-CoV-2 antigen, nucleic acid amplification, and immunologic tests, incorporating the latest evidence for analytical/clinical performance characteristics and advantages/limitations for each test type to inform current debates about how tests should or should not be used.
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Affiliation(s)
- Elitza S. Theel
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - James E. Kirby
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Nira R. Pollock
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Laboratory Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
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Tan CY, Zeng K, Cui L, Lin RTP, Chen M. Diagnostic performance of rapid antigen tests (RAT) for COVID-19 and factors associated with RAT-negative results among RT-PCR-positive individuals during Omicron BA.2, BA.5 and XBB.1 predominance. BMC Infect Dis 2024; 24:504. [PMID: 38769524 PMCID: PMC11107039 DOI: 10.1186/s12879-024-09408-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/15/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND While numerous studies have evaluated the real-world performance of rapid antigen tests (RATs), data on the effect of Omicron sublineages such as XBB and reinfections on RAT performance is limited. We assessed the performance of RATs and factors associated with RAT-negative results among individuals who tested SARS-CoV-2-positive by reverse transcription-polymerase chain reaction (RT-PCR). METHODS We conducted a retrospective study among Singapore residents who underwent testing for SARS-CoV-2 with RAT (Acon Flowflex or SD Biosensor) and RT-PCR in the same clinical encounter between 9 May 2022 and 21 November 2022. RT-PCR served as a reference standard for RAT performance. Logistic regression was used to estimate the odds ratios (OR) of factors associated with negative RAT results among RT-PCR-positive cases. RESULTS Of 8,620 clinical encounters analysed, 3,519 (40.8%) were SARS-CoV-2-positive on RT-PCR. Overall sensitivity and specificity of RAT was 84.6% (95% CI 83.3-85.7%) and 99.4% (95% CI 99.1-99.6%) respectively. Acon Flowflex consistently achieved higher sensitivity and specificity than SD Biosensor test kit. Among RT-PCR-positive cases, individuals who had a previous documented SARS-CoV-2 infection, coinfection with another respiratory pathogen or tested ≥ 6 days from symptom onset had higher odds of testing RAT-negative, but the associations were attenuated after adjustment for cycle threshold values (proxy for viral load). There was no significant difference in RAT performance between Omicron sublineages BA.2, BA.5 and XBB.1. CONCLUSION Diagnostic performance of RAT was not affected by changes in predominant circulating Omicron sublineages. However, reinfection cases may be under ascertained by RAT. In individuals with a previous SARS-CoV-2 infection episode or symptom onset ≥ 6 days prior to testing, a confirmatory RT-PCR may be considered if there is high clinical suspicion.
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Affiliation(s)
- Celine Y Tan
- National Preventive Medicine Residency Programme, National University Health System, Singapore, Singapore.
- National Centre for Infectious Diseases, Singapore, Singapore.
| | - Kangwei Zeng
- National Centre for Infectious Diseases, Singapore, Singapore
- Ministry of Health, Singapore, Singapore
| | - Lin Cui
- National Centre for Infectious Diseases, Singapore, Singapore
| | - Raymond T P Lin
- National Centre for Infectious Diseases, Singapore, Singapore
| | - Mark Chen
- National Centre for Infectious Diseases, Singapore, Singapore
- Ministry of Health, Singapore, Singapore
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7
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Ehrenzeller S, Zaffini R, Pecora ND, Kanjilal S, Rhee C, Klompas M. Cycle threshold dynamics of non-severe acute respiratory coronavirus virus 2 (SARS-CoV-2) respiratory viruses. Infect Control Hosp Epidemiol 2024; 45:630-634. [PMID: 38234188 DOI: 10.1017/ice.2023.286] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
OBJECTIVE Many providers use severe acute respiratory coronavirus virus 2 (SARS-CoV-2) cycle thresholds (Ct values) as approximate measures of viral burden in association with other clinical data to inform decisions about treatment and isolation. We characterized temporal changes in Ct values for non-SARS-CoV-2 respiratory viruses as a first step to determine whether cycle thresholds could play a similar role in the management of non-SARS-CoV-2 respiratory viruses. DESIGN Retrospective cohort study. SETTING Brigham and Women's Hospital, Boston. METHODS We retrospectively identified all adult patients with positive nasopharyngeal PCRs for influenza, respiratory syncytial virus (RSV), parainfluenza, human metapneumovirus (HMPV), rhinovirus, or adenovirus between January 2022 and March 2023. We plotted Ct distributions relative to days since symptom onset, and we assessed whether distributions varied by immunosuppression and other comorbidities. RESULTS We analyzed 1,863 positive samples: 506 influenza, 502 rhinovirus, 430 RSV, 219 HMPV, 180 parainfluenza, 26 adenovirus. Ct values were generally 25-30 on the day of symptom onset, lower over the ensuing 1-3 days, and progressively higher thereafter with Ct values ≥30 after 1 week for most viruses. Ct values were generally higher and more stable over time for rhinovirus. There was no association between immunocompromised status and median intervals from symptom onset until Ct values were ≥30. CONCLUSIONS Ct values relative to symptom onset for influenza, RSV, and other non-SARS-CoV-2 respiratory viruses generally mirror patterns seen with SARS-CoV-2. Further data on associations between Ct values and viral viability, transmissibility, host characteristics, and response to treatment for non-SARS-CoV-2 respiratory viruses are needed to determine how clinicians and infection preventionists might integrate Ct values into treatment and isolation decisions.
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Affiliation(s)
- Selina Ehrenzeller
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, United States
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, University of Basel, Basel, Switzerland
- Department of Medicine, Limmattal Hospital Zurich, Schlieren, Switzerland
| | - Rebecca Zaffini
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Nicole D Pecora
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Sanjat Kanjilal
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, United States
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Chanu Rhee
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, United States
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Michael Klompas
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, United States
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
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8
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Futschik ME, Johnson S, Turek E, Chapman D, Carr S, Thorlu-Bangura Z, Klapper PE, Sudhanva M, Dodgson A, Cole-Hamilton JR, Germanacos N, Kulasegaran-Shylini R, Blandford E, Tunkel S, Peto T, Hopkins S, Fowler T. Rapid antigen testing for SARS-CoV-2 by lateral flow assay: A field evaluation of self- and professional testing at UK community testing sites. J Clin Virol 2024; 171:105654. [PMID: 38387136 DOI: 10.1016/j.jcv.2024.105654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/06/2024] [Accepted: 02/11/2024] [Indexed: 02/24/2024]
Abstract
BACKGROUND The advent of lateral flow devices (LFDs) for SARS-CoV-2 detection enabled widespread use of rapid self-tests during the pandemic. While self-testing using LFDs is now common, whether self-testing provides comparable performance to professional testing was a key question that remained important for pandemic planning. METHODS Three prospective multi-centre studies were conducted to compare the performance of self- and professional testing using LFDs. Participants tested themselves or were tested by trained (professional) testers at community testing sites in the UK. Corresponding qRT-PCR test results served as reference standard. The performance of Innova, Orient Gene and SureScreen LFDs by users (self) and professional testers was assessed in terms of sensitivity, specificity, and kit failure (void) rates. Impact of age, sex and symptom status was analysed using logistic regression modelling. RESULTS 16,617 participants provided paired tests, of which 15,418 were included in the analysis. Self-testing with Innova, Orient Gene or SureScreen LFDs achieved sensitivities of 50 %, 53 % or 72 %, respectively, compared to qRT-PCR. Self and professional LFD testing showed no statistically different sensitivity with respect to corresponding qRT-PCR testing. Specificity was consistently equal to or higher than 99 %. Sex and age had no or only marginal impact on LFD performance while sensitivity was significantly higher for symptomatic individuals. Sensitivity of LFDs increased strongly to up to 90 % with higher levels of viral RNA measured by qRT-PCR. CONCLUSIONS Our results support SARS-CoV-2 self-testing with LFDs, especially for the detection of individuals whose qRT-PCR tests showed high viral concentrations.
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Affiliation(s)
- Matthias E Futschik
- UK Health Security Agency, London, United Kingdom; University of Plymouth, School of Biomedical Sciences, Faculty of Health, Plymouth, United Kingdom
| | | | - Elena Turek
- Deloitte, London, United Kingdom, Deloitte MCS Ltd, London, United Kingdom
| | - David Chapman
- Deloitte, London, United Kingdom, Deloitte MCS Ltd, London, United Kingdom
| | - Simon Carr
- Deloitte, London, United Kingdom, Deloitte MCS Ltd, London, United Kingdom
| | | | - Paul E Klapper
- UK Health Security Agency, London, United Kingdom; University of Manchester, Manchester, United Kingdom
| | - Malur Sudhanva
- UK Health Security Agency, London, United Kingdom; King's College Hospital NHS Foundation Trust, London, UK
| | - Andrew Dodgson
- UK Health Security Agency, London, United Kingdom; University of Manchester, Manchester, United Kingdom
| | | | | | | | | | - Sarah Tunkel
- UK Health Security Agency, London, United Kingdom
| | | | | | - Tom Fowler
- UK Health Security Agency, London, United Kingdom; Queen Mary University of London, William Harvey Research Institute, London, United Kingdom.
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9
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Ryan F, Cole-Hamilton J, Dandamudi N, Futschik ME, Needham A, Saquib R, Kulasegaran-Shylini R, Blandford E, Kidd M, O'Moore É, Hall I, Sudhanva M, Klapper P, Dodgson A, Moore A, Duke M, Tunkel S, Kenny C, Fowler T. Faster detection of asymptomatic COVID-19 cases among care home staff in England through the combination of SARS-CoV-2 testing technologies. Sci Rep 2024; 14:7475. [PMID: 38553484 PMCID: PMC10980794 DOI: 10.1038/s41598-024-57817-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 03/21/2024] [Indexed: 04/02/2024] Open
Abstract
To detect SARS-CoV-2 amongst asymptomatic care home staff in England, a dual-technology weekly testing regime was introduced on 23 December 2020. A lateral flow device (LFD) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) test were taken on the same day (day 0) and a midweek LFD test was taken three to four days later. We evaluated the effectiveness of using dual-technology to detect SARS-CoV-2 between December 2020 to April 2021. Viral concentrations derived from qRT-PCR were used to determine the probable stage of infection and likely level of infectiousness. Day 0 PCR detected 1,493 cases of COVID-19, of which 53% were in the early stages of infection with little to no risk of transmission. Day 0 LFD detected 83% of cases that were highly likely to be infectious. On average, LFD results were received 46.3 h earlier than PCR, enabling removal of likely infectious staff from the workplace quicker than by weekly PCR alone. Demonstrating the rapidity of LFDs to detect highly infectious cases could be combined with the ability of PCR to detect cases in the very early stages of infection. In practice, asymptomatic care home staff were removed from the workplace earlier, breaking potential chains of transmission.
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Affiliation(s)
- Finola Ryan
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
- King's College Hospital NHS Foundation Trust, London, UK
- Division of Surgery & Interventional Science, University College London, London, UK
| | - Joanna Cole-Hamilton
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Niharika Dandamudi
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Matthias E Futschik
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
- School of Biomedical Sciences, Faculty of Health, University of Plymouth, Plymouth, UK
| | - Alexander Needham
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Rida Saquib
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Raghavendran Kulasegaran-Shylini
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Edward Blandford
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | | | - Éamonn O'Moore
- National Health Protection Office, HSE, Dublin, D01 A4A3, Ireland
| | - Ian Hall
- Department of Mathematics, The University of Manchester, Manchester, UK
- Advanced Analytics, Analytics & Data Science, UK Health Security Agency, London, UK
| | - Malur Sudhanva
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
- King's College Hospital NHS Foundation Trust, London, UK
| | - Paul Klapper
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
- Clinical Virology, Division of Evolution, Infections and Genomics, University of Manchester, Manchester, UK
| | - Andrew Dodgson
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Adam Moore
- Operational Policy, UK Health Security Agency, London, UK
| | - Madeleine Duke
- Operational Policy, UK Health Security Agency, London, UK
| | - Sarah Tunkel
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Chris Kenny
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK
| | - Tom Fowler
- Public Health and Clinical Oversight (PHCO), Clinical and Public Health Group, UK Health Security Agency, 10 South Colonade, Canary Wharf, London, E14 4PU, UK.
- Queen Mary University of London William Harvey Research Institute, London, UK.
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Bown A, Sweed A, Catton M, Nelthorpe-Cowne J, Conti-Frith H, Elderfield R, Terrey J, Abib H, Lui C, Fisher E, Bewley KR, Coombes NS, Robinson D, Agrawal S, Hallis B, Blandford E, Fowler T, Williamson DA, Vipond R. Detection of SARS-CoV-2 BA.2.86 by lateral flow devices. Int J Infect Dis 2024; 139:168-170. [PMID: 38151115 DOI: 10.1016/j.ijid.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 12/29/2023] Open
Abstract
We evaluated the performance of 12 lateral flow devices by assessing their analytical sensitivity for SARS-CoV-2 variant BA.2.86. Kits from ACON, Orient Gene, Xiamen Biotime, Getein, and SureScreen detected variant BA.2.86 to sufficient sensitivity levels, comparable to those observed with previous Omicron variants. The stocks of lateral flow devices currently held by the UK government do not currently need changing for deployment for this variant.
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Affiliation(s)
- Abbie Bown
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK.
| | - Angela Sweed
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Matthew Catton
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Joshua Nelthorpe-Cowne
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Hermione Conti-Frith
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Ruth Elderfield
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Jacob Terrey
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Hamsa Abib
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Caleb Lui
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Ella Fisher
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
| | - Kevin R Bewley
- Vaccine Development and Evaluation Preparedness Division, UK Health Security Agency, Porton Down, UK
| | - Naomi S Coombes
- Vaccine Development and Evaluation Preparedness Division, UK Health Security Agency, Porton Down, UK
| | | | | | - Bassam Hallis
- Vaccine Development and Evaluation Preparedness Division, UK Health Security Agency, Porton Down, UK
| | - Edward Blandford
- Public Health and Clinical Oversight, Clinical and Public Health Division, UK Health Security Agency, UK
| | - Tom Fowler
- Public Health and Clinical Oversight, Clinical and Public Health Division, UK Health Security Agency, UK
| | | | - Richard Vipond
- Diagnostic Evaluation and Innovation Group, Diagnostics and Pathogen Characterisation Division, UK Health Security Agency, Porton Down, UK
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11
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Heath B, Evans S, Robertson DS, Robotham JV, Villar SS, Presanis AM. Evaluating pooled testing for asymptomatic screening of healthcare workers in hospitals. BMC Infect Dis 2023; 23:900. [PMID: 38129789 PMCID: PMC10740241 DOI: 10.1186/s12879-023-08881-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND There is evidence that during the COVID pandemic, a number of patient and HCW infections were nosocomial. Various measures were put in place to try to reduce these infections including developing asymptomatic PCR (polymerase chain reaction) testing schemes for healthcare workers. Regularly testing all healthcare workers requires many tests while reducing this number by only testing some healthcare workers can result in undetected cases. An efficient way to test as many individuals as possible with a limited testing capacity is to consider pooling multiple samples to be analysed with a single test (known as pooled testing). METHODS Two different pooled testing schemes for the asymptomatic testing are evaluated using an individual-based model representing the transmission of SARS-CoV-2 in a 'typical' English hospital. We adapt the modelling to reflect two scenarios: a) a retrospective look at earlier SARS-CoV-2 variants under lockdown or social restrictions, and b) transitioning back to 'normal life' without lockdown and with the omicron variant. The two pooled testing schemes analysed differ in the population that is eligible for testing. In the 'ward' testing scheme only healthcare workers who work on a single ward are eligible and in the 'full' testing scheme all healthcare workers are eligible including those that move across wards. Both pooled schemes are compared against the baseline scheme which tests only symptomatic healthcare workers. RESULTS Including a pooled asymptomatic testing scheme is found to have a modest (albeit statistically significant) effect, reducing the total number of nosocomial healthcare worker infections by about 2[Formula: see text] in both the lockdown and non-lockdown setting. However, this reduction must be balanced with the increase in cost and healthcare worker isolations. Both ward and full testing reduce HCW infections similarly but the cost for ward testing is much less. We also consider the use of lateral flow devices (LFDs) for follow-up testing. Considering LFDs reduces cost and time but LFDs have a different error profile to PCR tests. CONCLUSIONS Whether a PCR-only or PCR and LFD ward testing scheme is chosen depends on the metrics of most interest to policy makers, the virus prevalence and whether there is a lockdown.
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Affiliation(s)
- Bethany Heath
- MRC Biostatistics Unit, Univeristy of Cambridge, Robinson Way, Cambridge, CB2 0SR, Cambridgeshire, United Kingdom.
| | - Stephanie Evans
- HCAI, Fungal, AMR, AMU and Sepsis Division, UK Health Security Agency, London, United Kingdom
- Statistics, Modelling and Economics Division, UK Health Security Agency, London, United Kingdom
| | - David S Robertson
- MRC Biostatistics Unit, Univeristy of Cambridge, Robinson Way, Cambridge, CB2 0SR, Cambridgeshire, United Kingdom
| | - Julie V Robotham
- HCAI, Fungal, AMR, AMU and Sepsis Division, UK Health Security Agency, London, United Kingdom
- Statistics, Modelling and Economics Division, UK Health Security Agency, London, United Kingdom
- NIHR Health Protection Research Unit in Modelling and Health Economics at Imperial College London in partnership with the UK Health Security Agency and London School of Hygiene and Tropical Medicine, London, United Kingdom
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with the UK Health Security Agency, Oxford, United Kingdom
| | - Sofía S Villar
- MRC Biostatistics Unit, Univeristy of Cambridge, Robinson Way, Cambridge, CB2 0SR, Cambridgeshire, United Kingdom
| | - Anne M Presanis
- MRC Biostatistics Unit, Univeristy of Cambridge, Robinson Way, Cambridge, CB2 0SR, Cambridgeshire, United Kingdom
- NIHR Health Protection Research Unit in Behavioural Science and Evaluation at University of Bristol in partnership with the UK Health Security Agency and MRC Biostatistics Unit, University of Cambridge, Bristol, United Kingdom
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12
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Kyo H, Patel SA, Yamamoto M, Matsumura Y, Ikeda T, Nagao M. A population-based study of the trend in SARS-CoV-2 diagnostic modalities from the beginning of the pandemic to the Omicron surge in Kyoto City, Kyoto, Japan. BMC Public Health 2023; 23:2551. [PMID: 38129830 PMCID: PMC10734122 DOI: 10.1186/s12889-023-17498-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND The coronavirus disease 2019 (COVID-19) presents critical diagnostic challenges for managing the pandemic. We investigated the 30-month changes in COVID-19 testing modalities and functional testing sites from the early period of the pandemic to the most recent Omicron surge in 2022 in Kyoto City, Japan. METHODS This is a retrospective-observational study using a local anonymized population database that included patients' demographic and clinical information, testing methods and facilities from January 2020 to June 2022, a total of 30 months. We computed the distribution of symptomatic presentation, testing methods, and testing facilities among cases. Differences over time were tested using chi-square tests of independence. RESULTS During the study period, 133,115 confirmed COVID-19 cases were reported, of which 90.9% were symptomatic. Although nucleic acid amplification testing occupied 68.9% of all testing, the ratio of lateral flow devices (LFDs) rapidly increased in 2022. As the pandemic continued, the testing capability was shifted from COVID-19 designated facilities to general practitioners, who became the leading testing providers (57.3% of 99,945 tests in 2022). CONCLUSIONS There was a dynamic shift in testing modality during the first 30 months of the pandemic in Kyoto City. General practitioners increased their role substantially as the use of LFDs spread dramatically in 2022. By comprehending and documenting the evolution of testing methods and testing locations, it is anticipated that this will contribute to the establishment of an even more efficient testing infrastructure for the next pandemic.
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Affiliation(s)
- Hiroki Kyo
- MetroAtlanta Ambulance Service, Emory Healthcare Network, Atlanta, GA, USA
| | - Shivani A Patel
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Masaki Yamamoto
- Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Clinical Laboratory, Kyoto University Hospital, Kyoto, Japan
| | - Yasufumi Matsumura
- Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Clinical Laboratory, Kyoto University Hospital, Kyoto, Japan
| | - Takeshi Ikeda
- Public Health and Welfare Bureau of Kyoto City, Kyoto, Japan
| | - Miki Nagao
- Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
- Department of Clinical Laboratory, Kyoto University Hospital, Kyoto, Japan.
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13
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Galipeau Y, Xavier A, Dyks A, Cooper C, Langlois MA. Continuous false positive results by SARS-CoV-2 rapid antigen testing: a case report. Front Public Health 2023; 11:1240308. [PMID: 38026284 PMCID: PMC10657208 DOI: 10.3389/fpubh.2023.1240308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/29/2023] [Indexed: 12/01/2023] Open
Abstract
Efficient and rapid identification of active SARS-CoV-2 infections has been key to monitoring and mitigating the spread of the virus. The implementation of nucleic acid testing (e.g., RT-PCR) was broadly adopted by most public health organizations at the national and community levels across the globe, which was followed by more accessible means of home testing including lateral flow immunochromatographic assay (LFA), also known as a rapid antigen test. Here we report the case of an adult female who repeatedly and consecutively tested positive by RAT (BTNX inc). This sustained false positive was not linked with an active SARS-CoV-2 infection, which was ruled out by RT-PCR and serological analyses. SARS-CoV-2 serology revealed no detectable levels of antibodies against the nucleocapsid suggesting no recent prior infection by SARS-CoV-2. This continuous false positive was limited to BTNX testing devices. This case report aims to describe that such continuous false positives can occur and describes alternative testing approaches that can be performed to confirm RAT results. In addition, broader awareness of such occurrences is warranted in the healthcare and public health community to avoid unnecessary negative impacts on individual's day to day life.
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Affiliation(s)
- Yannick Galipeau
- Department of Biochemistry, Microbiology & Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Abishek Xavier
- Department of Biochemistry, Microbiology & Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Aaron Dyks
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Curtis Cooper
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Marc-André Langlois
- Department of Biochemistry, Microbiology & Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Centre for Infection, Immunity and Inflammation (CI3), Ottawa, ON, Canada
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14
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Nonnenmacher T, Dandamudi N, Futschik ME, Tunkel SA, Kulasegaran-Shylini R, Germanacos N, Cole-Hamilton J, Blandford E, Goddard A, Hillier J, Finer S, Hopkins S, Fowler T. PCR testing of traced contacts for SARS-CoV-2 in England, January to July 2021. Euro Surveill 2023; 28:2300019. [PMID: 37917031 PMCID: PMC10623643 DOI: 10.2807/1560-7917.es.2023.28.44.2300019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/16/2023] [Indexed: 11/03/2023] Open
Abstract
BackgroundThe NHS Test and Trace (NHSTT) programme was established in May 2020 in England to deliver SARS-CoV-2 testing and contact tracing in order to identify infected individuals and reduce COVID-19 spread. To further control transmission, people identified as contacts were asked to self-isolate for 10 days and test only if they became symptomatic. From March 2021, eligibility criteria for PCR testing expanded to include asymptomatic contacts of confirmed cases.AimTo analyse testing patterns of contacts before and after the change in testing guidance in England to assess the impact on PCR testing behaviour with respect to symptom status and contact type.MethodsTesting and contact tracing data were extracted from the national data systems and linked. Subsequently, descriptive statistical analysis was applied to identify trends in testing behaviour.ResultsBetween 1 January and 31 July 2021, over 5 million contacts were identified and reached by contact tracers; 42.3% took a PCR test around the time they were traced. Overall positivity rate was 44.3% and consistently higher in symptomatic (60-70%) than asymptomatic (around 20%, March-June) contacts. The proportion of tests taken by asymptomatic contacts increased over time, especially after the change in testing guidance. No link was observed between uptake of PCR tests and vaccination coverage. Fully vaccinated contacts showed lower positivity (23.8%) than those with one dose (37.2%) or unvaccinated (51.0%).ConclusionAlmost 1 million asymptomatic contacts were tested for SARS-CoV-2, identifying 214,056 positive cases, demonstrating the value of offering PCR testing to this group.
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Affiliation(s)
| | | | - Matthias Erwin Futschik
- Faculty of Health, School of Biomedical Sciences, University of Plymouth, Plymouth, United Kingdom
- United Kingdom Health Security Agency, London, United Kingdom
| | - Sarah A Tunkel
- United Kingdom Health Security Agency, London, United Kingdom
| | | | - Nick Germanacos
- United Kingdom Health Security Agency, London, United Kingdom
| | | | | | - Ashley Goddard
- United Kingdom Health Security Agency, London, United Kingdom
| | - Joe Hillier
- United Kingdom Health Security Agency, London, United Kingdom
| | - Stephen Finer
- United Kingdom Health Security Agency, London, United Kingdom
| | - Susan Hopkins
- United Kingdom Health Security Agency, London, United Kingdom
| | - Tom Fowler
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
- United Kingdom Health Security Agency, London, United Kingdom
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15
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Rao A, Westbrook A, Bassit L, Parsons R, Fitts E, Greenleaf M, McLendon K, Sullivan JA, O’Sick W, Baugh T, Bowers HB, Frank F, Wang E, Le M, Frediani J, Roychoudhury P, Greninger AL, Jerris R, Pollock NR, Ortlund EA, Roback JD, Lam WA, Piantadosi A. Sensitivity of rapid antigen tests against SARS-CoV-2 Omicron and Delta variants. J Clin Microbiol 2023; 61:e0013823. [PMID: 37728336 PMCID: PMC10654096 DOI: 10.1128/jcm.00138-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 07/22/2023] [Indexed: 09/21/2023] Open
Abstract
Rapid antigen tests (RATs) have become an invaluable tool for combating the COVID-19 pandemic. However, concerns have been raised regarding the ability of existing RATs to effectively detect emerging SARS-CoV-2 variants. We compared the performance of 10 commercially available, emergency use authorized RATs against the Delta and Omicron SARS-CoV-2 variants using both individual patient and serially diluted pooled clinical samples. The RATs exhibited lower sensitivity for Omicron samples when using PCR cycle threshold (CT) value (a rough proxy for RNA concentration) as the comparator. Interestingly, however, they exhibited similar sensitivity for Omicron and Delta samples when using quantitative antigen concentration as the comparator. We further found that the Omicron samples had lower ratios of antigen to RNA, which offers a potential explanation for the apparent lower sensitivity of RATs for that variant when using C T value as a reference. Our findings underscore the complexity in assessing RAT performance against emerging variants and highlight the need for ongoing evaluation in the face of changing population immunity and virus evolution.
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Affiliation(s)
- Anuradha Rao
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Adrianna Westbrook
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Leda Bassit
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Laboratory of Biochemical Pharmacology, Emory University, Atlanta, Georgia, USA
| | - Richard Parsons
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia, USA
| | - Eric Fitts
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Morgan Greenleaf
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Emory University School of Medicine, Atlanta, Georgia, USA
| | - Kaleb McLendon
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory/Children’s Laboratory for Innovative Assay Development, Atlanta, Georgia, USA
| | - Julie A. Sullivan
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - William O’Sick
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory/Children’s Laboratory for Innovative Assay Development, Atlanta, Georgia, USA
| | - Tyler Baugh
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory/Children’s Laboratory for Innovative Assay Development, Atlanta, Georgia, USA
| | - Heather B. Bowers
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Laboratory of Biochemical Pharmacology, Emory University, Atlanta, Georgia, USA
| | - Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ethan Wang
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Mimi Le
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jennifer Frediani
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia, USA
| | - Pavitra Roychoudhury
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
| | | | - Robert Jerris
- Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Nira R. Pollock
- Department of Laboratory Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Eric A. Ortlund
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - John D. Roback
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory/Children’s Laboratory for Innovative Assay Development, Atlanta, Georgia, USA
| | - Wilbur A. Lam
- The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Aflac Cancer and Blood Disorders Center at Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Anne Piantadosi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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16
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Wertenauer C, Pfeifer C, Roskos M, März W. Rapid antigen tests for SARS-CoV-2-a synopsis of the medical evidence. Diagn Microbiol Infect Dis 2023; 107:116027. [PMID: 37516068 DOI: 10.1016/j.diagmicrobio.2023.116027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/31/2023]
Abstract
SARS-CoV-2, the causative agent of the COVID-19 pandemic, continues to influence health, economy, and stability worldwide. Diagnostic testing for SARS-CoV-2 is important to contain the COVID-19 pandemic. With the commercial availability of certified antigen (Ag) rapid diagnostic tests (RDTs), which can be used to identify an infection with SARS-CoV-2 an easy-to-use tool was introduced. Self-tests can offer advantages to complement professionally administered rapid antigen detection or nucleic acid amplification testing (NAAT). Compared to real-time polymerase chain reaction (RT-PCR), Ag-RDTs are cost inexpensive, do not need specialized laboratory equipment, facilitating high-throughput testing. However, Ag-RDT sensitivities are strongly dependent on the viral load within the specimen, which has limited their application in clinical settings so far. The methodical limitations of Ag-RDTs may produce false negative test results, particularly when specimens with low viral loads are examined. This may facilitate viral transmissions if protective measurements are lifted mistakenly.
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Affiliation(s)
- Christoph Wertenauer
- Medical Clinic V, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
| | | | | | - Winfried März
- Medical Clinic V, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; SYNLAB Academy, SYNLAB Holding Deutschland GmbH, Mannheim, Germany; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
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