Determining the period of communicability of SARS-CoV-2: A rapid review of the literature

  1. Mina Park
  2. Colleen Pawliuk
  3. Tribesty Nguyen
  4. Amanda Griffitt
  5. Linda Dix-Cooper
  6. Nadia Fourik
  7. Martin Dawes

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Abstract

Introduction

How long individuals may transmit virus after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Understanding the communicability period of SARS-CoV-2 is important to inform the period of isolation required to prevent nosocomial and community spread. The objective of this study was to identify the reported communicable period of SARS-CoV-2, based on a rapid review of existing literature.

Methods

Studies reporting empirical data on the period of communicability of SARS-CoV-2 through investigations of duration of communicability based on in-person contact (“contact transmission”), isolation and culture of virus (“viral isolation”), and viral shedding by detection of nucleic acids by RT-PCR (“viral shedding”) were identified through searches of peer-reviewed and pre-print health sciences literature databases (Ovid MEDLINE, Embase, Google Scholar, medRxiv and arXiv) and the grey literature. Articles were screened for relevance, then data were extracted, analyzed, and synthesized.

Results

Out of the 165 studies included for qualitative analysis, one study investigated contact transmission, three investigated viral isolation, 144 investigated viral shedding, and 17 studies focused on both viral shedding and viral isolation. The median length of time until viral clearance across all viral isolation studies was nine days; however, the maximum identified duration was 32 days. Studies with data on both viral isolation and viral shedding showed a prolonged maximum time until viral clearance for viral shedding (9 days vs 24 days).

Discussion

Findings from this review support a minimum 10-day period of isolation; however, additional observation should be considered for individuals being released into high-risk settings.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2020.07.28.20163873: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Search strategy: We searched peer-reviewed and pre-print health sciences literature databases (Ovid MEDLINE, Embase, Google Scholar, medRxiv and arXiv) and the grey literature for reports or guidelines on discontinuation of isolation for SARS-CoV-2 from international and national public health organizations (World Health Organization, European Centre for Disease Prevention and Control, US Centre for Disease Control websites).
    Embase
    suggested: (EMBASE, RRID:SCR_001650)
    Google Scholar
    suggested: (Google Scholar, RRID:SCR_008878)
    arXiv
    suggested: (arXiv, RRID:SCR_006500)

    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:
    However, findings should be interpreted in light of significant limitations. There was a general paucity of high-quality evidence. Several of the included studies did not follow participants until viral clearance or collect samples at consistent intervals throughout the communicable period. We identified few studies that investigated viral isolation and many of the included studies had small sample sizes, making it difficult to draw robust findings from the n-of-1 studies. The included studies suffer from selection bias and non-representative populations, as case reports and case series often focus on highly specific clinical populations and may bias toward incidences of prolonged viral shedding. Findings from the available evidence support the general guidance of a minimum 10 day period of isolation [31]. Most studies showed an inability to isolate and culture virus beyond nine days. However, there should be additional precautions and longer observation considered for individuals being released into high-risk institutional settings such as long-term care facilities or those remaining in in-patient units, given that viable virus has been reported at 18 [30], 20 [21], 21 [15], and 32 days [28]. Notably, these positive findings were from individuals with mixed levels of underlying comorbidities, and who presented with heterogeneous disease profiles, from mild symptoms to severe complications and death associated with infection with SARS-CoV-2. An additional impetus for taking a...

    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.

    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. ScreenIT

    SciScore for 10.1101/2020.07.28.20163873: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board Statementnot detected.Randomizationnot detected.Blindingnot detected.Power Analysisnot detected.Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    (Ovid MEDLINE, Embase, Google Scholar, medRxiv and arXiv) and the grey literature for reports or guidelines on discontinuation of isolation for SARS-CoV-2 from international and national public health organizations (World Health Organization, European Centre for Disease Prevention and Control, US Centre for Disease Control websites).
    Embase
    suggested: (EMBASE, SCR_001650)
          <div style="margin-bottom:8px">
        <div><b>Google Scholar</b></div>
        <div>suggested: (Google Scholar, <a href="https://scicrunch.org/resources/Any/search?q=SCR_008878">SCR_008878</a>)</div>
      </div>
    
      <div style="margin-bottom:8px">
        <div><b>arXiv</b></div>
        <div>suggested: (arXiv, <a href="https://scicrunch.org/resources/Any/search?q=SCR_006500">SCR_006500</a>)</div>
      </div>
    </td></tr></table>

    Data from additional tools added to each annotation on a weekly basis.

    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 is not a substitute for expert review. SciScore checks for the presence and correctness of RRIDs (research resource identifiers) in the manuscript, and detects sentences that appear to be missing RRIDs. SciScore also checks to make sure that rigor criteria are addressed by authors. It does this by detecting sentences that discuss criteria such as blinding or power analysis. SciScore does not guarantee that the rigor criteria that it detects are appropriate for the particular study. Instead it assists authors, editors, and reviewers by drawing attention to sections of the manuscript that contain or should contain various rigor criteria and key resources. For details on the results shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2020.07.28.20163873v1 on medRxiv