Resuming professional football (soccer) during the COVID-19 pandemic in a country with high infection rates: a prospective cohort study

  1. Yorck Olaf Schumacher
  2. Montassar Tabben
  3. Khalid Hassoun
  4. Asmaa Al Marwani
  5. Ibrahim Al Hussein
  6. Peter Coyle
  7. Ahmed Khellil Abbassi
  8. Hani Taleb Ballan
  9. Abdulaziz Al-Kuwari
  10. Karim Chamari
  11. Roald Bahr

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Abstract

The risk of viral transmission associated with contact sports such as football (soccer) during the COVID-19 pandemic is unknown. The aim of this study was to describe the infective and immune status of professional football players, team staff and league officials over a truncated football season resumed at the height of the COVID-19 pandemic in a country with high infection rates and to investigate the clinical symptoms related to COVID-19 infection in professional football players.

Methods

Prospective cohort study of 1337 football players, staff and officials during a truncated football season (9 weeks) with a tailored infection control programme based on preventive measures and regular SARS-CoV-2 PCR swab testing (every 3–5 days) combined with serology testing for immunity (every 4 weeks). Clinical symptoms in positive participants were recorded using a 26-item, Likert-Scale-based scoring system.

Results

During the study period, 85 subjects returned positive (cycle threshold (cT) ≤30) or reactive (30<cT<40) PCR tests, of which 36 were players. The infection rate was consistent with that of the general population during the same time period. More than half of infected subjects were asymptomatic, and the remaining had only mild symptoms with no one requiring hospitalisation. Symptom severity was associated with lower cT values. Social contacts and family were the most common sources of infection, and no infection could be traced to training or matches. Of the 36 infected players, 15 presented positive serology during the study period.

Conclusion

Football played outdoors involving close contact between athletes represents a limited risk for SARS-CoV-2 infection and severe illness when preventive measures are in place.

Article activity feed

  1. Version published to 10.1136/bjsports-2020-103724
  2. Version published to 10.1101/2020.11.17.20233023v2 on medRxiv
  3. ScreenIT

    SciScore for 10.1101/2020.11.17.20233023: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: The study was approved by the Institutional Review Board of Aspire Zone Foundation (Application number E202009011).
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    SARS-CoV-2 antibody analyses: SARS-CoV-2-specific antibodies were measured in serum samples using an electrochemiluminescence immunoassay (Elecsys® Anti-SARS-CoV-2, Roche Diagnostics, Rotkreuz, Switzerland).
    Anti-SARS-CoV-2
    suggested: None

    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:
    Limitations: This study is limited in that all infections could not be traced to a source. Thus, player to player transmission could not be ruled out with certainty. Still, player transmission during football activities appears unlikely to play a major role in viral spread, given the pattern of infections among the different teams (Figure 2). Clearly, there were no mass outbreaks within teams. Conclusion: Our data suggest that professional football played outdoors involving close contact between athletes represents a limited risk for SARS-CoV-2 infection and severe illness when preventive measures are in place, even if the risk of viral transmission in the general population is high. These data may guide organizers of major sports events such as the Olympic Games or continental football championships in their decision-making.

    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.

  4. Version published to 10.1101/2020.11.17.20233023v1 on medRxiv