REACT-1: real-time assessment of community transmission of coronavirus (COVID-19) in January 2021
Updated 23 April 2021
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This publication is available at https://www.gov.uk/government/publications/react-1-study-of-coronavirus-transmission-january-2021-final-results/react-1-real-time-assessment-of-community-transmission-of-coronavirus-covid-19-in-january-2021
Methodology
A representative cross-section of volunteers tested themselves with swabs from 6 January to 22 January. Swabs were analysed using polymerase chain reaction (PCR).
Results
Over the 17 days of the completed round of testing, out of 167,642 swab results, 2,282 were positive, giving a weighted prevalence of 1.57% (95% CI, 1.49%, 1.66%) or 157 people per 10,000 infected. This is the highest prevalence recorded by REACT-1 since it started in May 2020. Within round 8, the estimated R was at 0.98 (95% CI, 0.92, 1.04).
Regional prevalence is now highest in London at 2.83%; East of England at 1.78%; West Midlands at 1.66%; South East at 1.61%; North West at 1.38%; North East at 1.22%; East Midlands at 1.16%; Yorkshire and The Humber 0.80%; South West at 0.87%.
Prevalence is now highest in 18 to 24 year olds with a weighted prevalence of 2.44%, and prevalence in those aged 65 and over is at 0.93%.
Age-prevalence patterns vary substantially by region. London has the highest weighted prevalence nationally at greater than 2% in those aged 55 to 64 and those 65 years and over; and 4% in those aged 13 to 17 and 18 to 24 years.
Large household size, living in a deprived neighbourhood, and black and Asian ethnicity were all associated with increased prevalence. People living in neighbourhoods in the 2 most deprived quintiles had prevalence of 1.79% and 1.95% compared with 1.22% for those in the least deprived.
Participants of black and Asian ethnicity had increased prevalence at 3.07% and 2.80% respectively compared with 1.41% among white participants.
Both healthcare and care home workers, and other key workers, had increased odds of swab-positivity compared to other workers at 1.48 and 1.35 respectively.
Conclusion
During the period 6 January to 22 January, infections remained high through the period with the SARS-CoV-2 virus circulating at a high prevalence with 157 in 10,000 infected.
Subsequent rounds of REACT-1 will allow further accurate assessment of trends in prevalence and transmission.