Clinical validation of 3D-printed nasopharyngeal and oropharyngeal swabs for SARS-CoV-2 RT-PCR

  1. Åse Garløv Riis
  2. Tonje Merethe Røssland
  3. Iren Høyland Löhr
  4. Ingvild Dalen
  5. Lars Kåre Kleppe
  6. Jon Sundal
  7. Åse Berg
  8. May Sissel Vadla
  9. Ole Bernt Lenning
  10. Heidi Syre

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Abstract

Due to limited access to commercially available flocked nasopharyngeal (NP) and oropharyngeal (OP) swabs during the SARS-COV-2 pandemic, we have evaluated the sensitivity of 3D-printed swabs compared to commercial swabs in a clinical setting. We included 35 subjects with known exposure to SARS-CoV-2. Participants were tested with commercial and prototype NP/OP swab pairs 8 and 22 days after exposure. At day 8, the sensitivity of the prototype was 96% for NP-samples (CI 81-99%) and 91% for OP-samples (CI 72-97%). The sensitivity of the commercial swab was 92% for NP-samples (CI 76-98%) and 91% for OP-samples (CI 72-97%). At day 22, the sensitivities of the commercial swab were 100% for NP-samples (CI 82-100%) and OP-samples (CI 77-100%), whereas sensitivity of the prototype was 61% for NP-samples (CI 39-80%) and 54% for OP-samples (CI 29-77%). In conclusion, the prototype might be an alternative to commercial swabs when used early in the course of infection.

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  1. ScreenIT

    SciScore for 10.1101/2022.05.16.22274315: (What is this?)

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

    Table 1: Rigor

    EthicsConsent: Participants gave informed consent.
    Sex as a biological variablenot detected.
    RandomizationCommercial (FLOQSwabs, Copan, Italy) and prototype (3D-printed; HP inc, Norway) NP and OP swab pairs were collected from each participant in a random order.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Experimental Models: Organisms/Strains
    SentencesResources
    QuantStudio Real-Time PCR Software (AB) was used for the presentation of the RT-PCR results.
    AB
    suggested: RRID:BDSC_203)
    Software and Algorithms
    SentencesResources
    16.1; descriptive statistics and plots were created in SPSS v. 26. P-values <0.05 were considered statistically significant.
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    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: We detected the following sentences addressing limitations in the study:
    This study has some limitations. Testing was conducted on a low number of participants, and almost all the participants were SARS-CoV-2 positive, thus the study was not suitable for evaluating the specificity of the prototype. Furthermore, the usability of the prototype was not assessed. Thus, further testing is needed to determine the test-accuracy of 3D-printed swabs. One strength of the study is that we repeated testing with both swab types shortly after exposure and later in the course of infection; this enabled us to evaluate the performance of the prototype on samples with different viral loads. Because our study population consisted of a defined group with known exposure to SARS-CoV-2, we were able to include both symptomatic and asymptomatic individuals. Finally, sample collection techniques can affect the clinical sensitivity of the test. In our study, experienced personnel performed sampling, which reduced the risk of false negative results. To prevent swab shortages during future pandemics, or seasonal epidemics, caused by influenza or other viruses, 3D printing of swabs might help to maintain rapid, large scale diagnostic testing.

    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.

  2. Version published to 10.1101/2022.05.16.22274315v1 on medRxiv