REACT-1 round 6 updated report: high prevalence of SARS-CoV-2 swab positivity with reduced rate of growth in England at the start of November 2020

Abstract

BackgroundEngland is now in the midst of its second wave of the COVID-19 pandemic. Multiple regions of the country are at high infection prevalence and all areas experienced rapid recent growth of the epidemic during October 2020.MethodsREACT-1 is a series of community surveys of SARS-CoV-2 RT-PCR swab-positivity in England designed to monitor the spread of the epidemic and thus increase situational awareness. Round 6 of REACT-1 commenced swab-collection on 16th October. A prior interim report included data from 16th to 25th October for 85,971 participants. Here, we report data for the entire round on 160,175 participants with swab results obtained up to 2nd November 2020.ResultsOverall weighted prevalence of infection in the community in England was 1.3% or 130 people per 10,000 infected, up from 60 people per 10,000 in the round 5 report (18th September to 5th October 2020), doubling every 24 days on average since the prior round. The corresponding R number was estimated to be 1.2. Prevalence of infection was highest in North West (2.4%, up from 1.2%), followed by Yorkshire and The Humber (2.3% up from 0.84%), West Midlands (1.6% up from 0.60%), North East (1.5% up from 1.1%), East Midlands (1.3% up from 0.56%), London (0.97%, up from 0.54%), South West (0.80% up from 0.33%), South East (0.69% up from 0.29%), and East of England (0.69% up from 0.30%). Rapid growth in the South observed in the first half of round 6 was no longer apparent in the second half of round 6. We also observed a decline in prevalence in Yorkshire and The Humber during this period. Comparing the first and second halves of round 6, there was a suggestion of decline in weighted prevalence in participants aged 5 to 12 years and in those aged 25 to 44 years. While prevalence remained high, in the second half of round 6 there was suggestion of a slight fall then rise that was seen nationally and also separately in both the North and the South.ConclusionThe impact of the second national lockdown in England is not yet known. We provide here a detailed description of swab-positivity patterns at national, regional and local scales for the period immediately preceding lockdown, against which future trends in prevalence can be evaluated.

REACT-1 round 7 updated report: regional heterogeneity in changes in prevalence of SARS-CoV-2 infection during the second national COVID-19 lockdown in England

“…Nonetheless we have no reason to believe that any such biases have been operating differently over the period of the REACT-1 surveys, so time trends and estimates of R are likely to be less affected than absolute measures of prevalence. We have evidence to suggest that prevalence rates may change rapidly in response to behavioural or other changes, but with associated uncertainty [12]. Although we use statistical approaches to smooth rates over time (splines), we also display the calculated daily rates and confidence intervals, allowing the variability in the underlying data to be assessed.…”

REACT-1 round 7 interim report: fall in prevalence of swab-positivity in England during national lockdown

“…Participants are also invited to complete a brief questionnaire. Achieved sample sizes have ranged from 120,000 to 175,000 across the six rounds of data collection from May to beginning of November 2020 [1,2].…”

“…England entered a second national lockdown in response to the COVID-19 pandemic on 5th November 2020. This followed rises in prevalence across the country, and high prevalence of people testing positive for SARS-CoV-2 virus especially in the North [1]. The REal-time Assessment of Community Transmission-1 (REACT-1) study has been undertaking surveillance of the epidemic in England since May 2020 [2] using self-administered throat and nose swabs approximately monthly among random samples of the general population.…”

“…We recently reported results from the sixth round of data collection, which was undertaken in two halves, from 16th to 25th October [3] and from 26th October to 2nd November 2020 [1].…”

“…The REal-time Assessment of Community Transmission-1 (REACT-1) study has been undertaking surveillance of the epidemic in England since May 2020 [2] using self-administered throat and nose swabs approximately monthly among random samples of the general population. We recently reported results from the sixth round of data collection, which was undertaken in two halves, from 16th to 25th October [3] and from 26th October to 2nd November 2020 [1]. In the most recent round 6 data (second half) we found evidence for a fall then rise in prevalence.…”