REACT-1 study is an ongoing COVID-19 prevalence study in England and round 8a suggests there was no evidence of a decline in the prevalence of COVID-19 during the third national lockdown.
The Real-time Assessment of Community Transmission (REACT-1) is a longitudinal study of the community prevalence of COVID-19, led by a team from Imperial College, London. The study regularly reports on the prevalence of COVID-19 collected from a random sample of more than 120,000 people in England, identified from national health service records linked to a patient’s GP. Invited participants, who vary in age from 5 years to over 65, are sent a nasopharyngeal swab kit for home testing and which is then collected and analysed for COVID-19. The study has been collecting data since June 2020 and provides an important snapshot of the prevalence of COVID-19 in the community.
The REACT-1 (8a) covers the period 6-15 January 2021. Researchers found a total of 1962 positive swabs from 142,909 individuals giving a weighted prevalence of 1.58% (95% CI 1.49-1.68%). Interestingly, they note that this represents the highest prevalence since the study began in May 2020, when the prevalence was 0.16%. Moreover, it is more than 50% higher than round 7 (the previous data collection period), between November to December 2020). However, using a growth model, the team could not find any evidence of either a growth or decay in prevalence and estimated the transmission rate, R to be 1.04. In analysing mobility data from the Facebook app, the team found a decreased activity at the end of December 2020 that began to rise again in January 2021. As a result, they speculated that this increased activity might have caused the rise in cases. Across the country, the prevalence more than doubled in the London area from last round 7 (1.21%-2.47%) and in the East of England (0.59%-1.74%). However, infection rates decreased in Yorkshire and The Humber and remained broadly similar to round 7 in the East Midlands. The age-related prevalence showed an increase among those aged 18 to 24 (0.99%-2.51%) and among those aged 65 years and over (0.41%-0.94%). In discussing their findings, the authors noted that there was no continued decline in prevalence during the third national lockdown but rather a slight initial decline followed by a plateau or possible increase. They also cautioned that if rates do not fall there will be an increase in hospitalisations, which will negatively impact on healthcare delivery.
REACT-1 round 8 interim report; SARS-CoV-2 prevalence during the initial stages of the third national lockdown in England.