Accuracy of 2 Rapid Antigen Tests During 3 Phases of SARS-CoV-2 Variants

This article has been Reviewed by the following groups

Read the full article See related articles

Abstract

Variants of SARS-CoV-2 have sequence variations in the viral genome that may alter the accuracy of rapid diagnostic tests.

Objective

To assess the analytical and clinical accuracy of 2 rapid diagnostic tests for detecting SARS-CoV-2 during 3 phases of variants.

Design, Setting, and Participants

This diagnostic study included participants aged 18 years or older who reported onset of COVID-19–like symptoms within the prior 5 days and were tested at multiple COVID-19 testing locations in King County, Washington, from February 17, 2021, to January 11, 2022, during 3 distinct phases of SARS-CoV-2 infection (pre-Delta, Delta, and Omicron).

Interventions

Two anterior nasal swab specimens were collected from each participant—1 for onsite testing by the SCoV-2 Ag Detect Rapid Self-Test and 1 for reverse transcriptase–polymerase chain reaction (RT-PCR) testing.

Main Outcomes and Measures

The analytical limit of detection of the 2 rapid diagnostic tests (SCoV-2 Ag Detect Rapid Self-Test and BinaxNOW COVID-19 Ag Card) was assessed using Omicron (B.1.1.529/BA.1), Delta (B.1.617.2), and a wild-type (USA-WA1/2020) variant. Diagnostic sensitivity and specificity of clinical testing for the rapid antigen tests were compared with that of RT-PCR testing.

Results

A total of 802 participants were enrolled (mean [SD] age, 37.3 [13.3] years; 467 [58.2%] female), 424 (52.9%) of whom had not received COVID-19 vaccination and presented a median of 2 days (IQR, 1-3 days) from symptom onset. Overall, no significant differences were found in the analytical limit of detection or clinical diagnostic accuracy of rapid antigen testing across SARS-CoV-2 variants. The estimated limit of detection for both rapid nucleocapsid antigen tests was at or below a 50% tissue culture infectious dose of 62.5, and the positive percent agreement of the SCoV-2 Ag Detect Rapid Self-Test ranged from 81.2% (95% CI, 69.5%-89.9%) to 90.7% (95% CI, 77.9%-97.4%) across the 3 phases of variants. The diagnostic sensitivity increased for nasal swabs with a lower cycle threshold by RT-PCR, which correlates with a higher viral load.

Conclusions and Relevance

In this diagnostic study, analytical and clinical performance data demonstrated accuracy of 2 rapid antigen tests among adults with COVID-19 symptoms across 3 phases of SARS-CoV-2 variants. The findings suggest that home-based rapid antigen testing programs may be an important intervention to reduce global SARS-CoV-2 transmission.

Article activity feed

  1. SciScore for 10.1101/2022.03.21.22272279: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    No key resources detected.


    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.


    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.