High and increasing prevalence of SARS-CoV-2 swab positivity in England during end September beginning October 2020: REACT-1 round 5 updated report

  1. Steven Riley
  2. Kylie E. C. Ainslie
  3. Oliver Eales
  4. Caroline E. Walters
  5. Haowei Wang
  6. Christina Atchison
  7. Claudio Fronterre
  8. Peter J. Diggle
  9. Deborah Ashby
  10. Christl A. Donnelly
  11. Graham Cooke
  12. Wendy Barclay
  13. Helen Ward
  14. Ara Darzi
  15. Paul Elliott

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Abstract

Background

REACT-1 is quantifying prevalence of SARS-CoV-2 infection among random samples of the population in England based on PCR testing of self-administered nose and throat swabs. Here we report results from the fifth round of observations for swabs collected from the 18th September to 5th October 2020. This report updates and should be read alongside our round 5 interim report.

Methods

Representative samples of the population aged 5 years and over in England with sample size ranging from 120,000 to 175,000 people at each round. Prevalence of PCR-confirmed SARS-CoV-2 infection, estimation of reproduction number (R) and time trends between and within rounds using exponential growth or decay models.

Results

175,000 volunteers tested across England between 18th September and 5th October. Findings show a national prevalence of 0.60% (95% confidence interval 0.55%, 0.71%) and doubling of the virus every 29 (17, 84) days in England corresponding to an estimated national R of 1.16 (1.05, 1.27). These results correspond to 1 in 170 people currently swab-positive for the virus and approximately 45,000 new infections each day. At regional level, the highest prevalence is in the North West, Yorkshire and The Humber and the North East with strongest regional growth in North West, Yorkshire and The Humber and West Midlands.

Conclusion

Rapid growth has led to high prevalence of SARS-CoV-2 virus in England, with highest rates in the North of England. Prevalence has increased in all age groups, including those at highest risk. Improved compliance with existing policy and, as necessary, additional interventions are required to control the spread of SARS-CoV-2 in the community and limit the numbers of hospital admissions and deaths from COVID-19.

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  1. ScreenIT

    SciScore for 10.1101/2020.10.12.20211227: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: Research ethics approval was obtained from the South Central-Berkshire B Research Ethics Committee (IRAS ID: 283787).
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot 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: We detected the following sentences addressing limitations in the study:
    Our study has limitations. While we corrected for differences in population characteristics introduced by our sampling strategy and differential response rates, it is possible that our study is not fully representative of the population of England. At the time of sampling for round 5, difficulties were being experienced by symptomatic individuals in obtaining a test through the routine testing system in England. This suggests that a greater proportion of such individuals may have accessed testing through REACT-1 in round 5 than in previous rounds. Although the proportion of non-symptomatic people who tested positive was lower in the current round than previously [3], it was still 50%, and this did not vary between the first [5] and second halves of round 5 of REACT-1. Since the rapid increase in infection that we observed at the end of August and beginning of September, a number of measures have been put into place to attempt to curb the epidemic. These include the ‘rule of six’ limiting the number of contacts at a social event to no more than six people, closure of hospitality venues by 10 pm, and a series of local lockdown measures in areas of high apparent prevalence [9]. While the rapid rate of rise observed in the previous round has slowed, the national epidemic is still growing. In combination with the high prevalence, and evidence of faster growth in some regions, the country is now at a critical point in the second wave. Continued vigilance and adherence to the public...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    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. Version published to 10.1101/2020.10.12.20211227 on medRxiv