REACT-1: real-time assessment of community transmission of coronavirus (COVID-19) in October 2020
Published 29 October 2020
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This publication is available at https://www.gov.uk/government/publications/react-1-study-of-coronavirus-transmission-october-2020-interim-results/react-1-real-time-assessment-of-community-transmission-of-coronavirus-covid-19-in-october-2020
Methodology
A representative cross-section of volunteers tested themselves with swabs from 16 to 25 October 2020, inclusive. Swabs were analysed using polymerase chain reaction (PCR).
Results
These results represent an interim report for round 6 of REACT-1. The overall weighted national prevalence of infection in the community was 1.28% (1.15%, 1.41%). This was significantly higher than a prevalence of 0.60% (0.55%, 0.71%) as measured in September to early October, and the highest observed prevalence of any round of this study since this study started reporting in May.
Data collected between 16 and 25 October suggests the national reproduction number, R, is 1.56 (1.27, 1.88) in comparison with the estimate for Round 5 in September, of 1.16 (1.05, 1.27).
An increase in prevalence has been observed in all age groups between rounds 5 and 6, with the highest relative increase in the 55 to 64 year old age group. Infection rates in people aged 65 years and over more than doubled with an unweighted prevalence of 0.75% (0.65%, 0.86%) from 16 to 25 October, compared with 0.33% (0.28%, 0.38%) from 18 September to 5 October. The highest unweighted prevalence was still seen in 18 to 24 year olds at 1.71% (1.31%, 2.24%) which has increased from 1.21% (0.98%, 1.50%) in September to early October. A substantial increase was noted in the prevalence of swab positivity in both primary and secondary aged children.
The prevalence of infection has increased in all regions since September and early October 2020. Unweighted prevalence of infection was highest in the North West at 1.91% (1.66%, 2.20%) and Yorkshire and The Humber at 1.83% (1.52%, 2.19%) and in the North East at 1.35% (1.01%, 1.81%). However based on estimates of regional R from data obtained between 16 and 25 October alone, epidemic growth is no longer fastest in the North.
Patterns of swab positivity by age between September and October were different across regions. In the highest prevalence regions of North West, Yorkshire and The Humber there has been a slowing in 18 to 24 year olds, but there is evidence of a more rapid growth in older people and school aged children.
Asian and Black ethnicity was associated with higher unweighted prevalence of infection at 1.22% (0.88%, 1.70%) and 1.16% (0.56%, 2.38%) respectively. Prevalence has increased across all ethnic groups since September.
Conclusion
During the period 16 October to 25 October 2020, SARS-CoV-2 virus was circulating with significantly higher prevalence than between 18 September to 5 October. Subsequent data collected from Round 6 of REACT-1 will allow further accurate assessment of trends in prevalence and transmission.
Background
Read the press notice accompanying these findings
Read the report published for pre-print.
This report is the latest from the REACT-1 studies.