Occupation, work-related contact and SARS-CoV-2 anti-nucleocapsid serological status: findings from the Virus Watch prospective cohort study

  1. Sarah Beale
  2. Parth Patel
  3. Alison Rodger
  4. Isobel Braithwaite
  5. Thomas Byrne
  6. Wing Lam Erica Fong
  7. Ellen Fragaszy
  8. Cyril Geismar
  9. Jana Kovar
  10. Annalan Navaratnam
  11. Vincent Nguyen
  12. Madhumita Shrotri
  13. Anna Aryee
  14. Robert Aldridge
  15. Andrew Hayward

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Abstract

Risk of SARS-CoV-2 infection varies across occupations; however, investigation into factors underlying differential risk is limited. We aimed to estimate the total effect of occupation on SARS-CoV-2 serological status, whether this is mediated by workplace close contact, and how exposure to poorly ventilated workplaces varied across occupations.

Methods

We used data from a subcohort (n=3775) of adults in the UK-based Virus Watch cohort study who were tested for SARS-CoV-2 anti-nucleocapsid antibodies (indicating natural infection). We used logistic decomposition to investigate the relationship between occupation, contact and seropositivity, and logistic regression to investigate exposure to poorly ventilated workplaces.

Results

Seropositivity was 17.1% among workers with daily close contact vs 10.0% for those with no work-related close contact. Compared with other professional occupations, healthcare, indoor trade/process/plant, leisure/personal service, and transport/mobile machine workers had elevated adjusted total odds of seropositivity (1.80 (1.03 to 3.14) − 2.46 (1.82 to 3.33)). Work-related contact accounted for a variable part of increased odds across occupations (1.04 (1.01 to 1.08) − 1.23 (1.09 to 1.40)). Occupations with raised odds of infection after accounting for work-related contact also had greater exposure to poorly ventilated workplaces.

Conclusions

Work-related close contact appears to contribute to occupational variation in seropositivity. Reducing contact in workplaces is an important COVID-19 control measure.

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  1. Version published to 10.1136/oemed-2021-107920
  2. ScreenIT

    SciScore for 10.1101/2021.05.13.21257161: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: Ethics and Consent: The Virus Watch study was approved by the Hampstead NHS Health Research Authority Ethics Committee: 20/HRA/2320, and conformed to the ethical standards set out in the Declaration of Helsinki.
    Consent: All participants provided informed consent for all aspects of the study.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Outcome: The primary outcome of interest was binary-coded serological status (positive versus negative) for SARS-CoV-2 anti-nucleocapsid antibodies acquired through natural infection.
    SARS-CoV-2
    suggested: None
    anti-nucleocapsid
    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:
    Strengths and Limitations: Key strengths of the work include objective measurement of prior infection status through anti-nucleocapsid antibody testing which should not be affected by vaccination status. This in effect provides a cumulative measure of the infection risk through the first and second waves of the pandemic in England and Wales. Combining this data on occupational status and potential socio-demographic confounders allowed us to assess the independent effect of occupation on odds of SARS-CoV-2 infection, with adjustment informed by our directed acyclic graph. Furthermore, through use of a mediation model we were able to investigate a putative mechanism for increased occupational risk - work related close contact. Finally, we were able to investigate variations in exposure to poorly-ventilated workplace settings across occupational groups. Key limitations include that the timing of infection cannot be assessed from the serological tests, and consequently that we cannot determine which infections occurred in the first and second wave. Antibody waning may also lead to false negative results11, particularly for infections acquired early in the pandemic. Frequency of work-related contact was also measured during the second pandemic wave and may have changed compared to during the first wave. For many occupational groups - with the notable exception of primary and secondary teaching and education - legislation and guidance around workplace closures was broadly similar 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.
    • No funding statement was detected.
    • No protocol registration statement was detected.

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

    About SciScore

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  3. Version published to 10.1101/2021.05.13.21257161v1 on medRxiv