Thread by @DrKAinslie

Prevalence of #COVID19 in England is trending downward. Our new preprint on REACT 1 study found continued decline in prevalence and a shift in pattern of infection by age and occupation at end of initial lockdown in England. (1/n)
@SRileyIDD @DrCWalters
tinyurl.com/y6xzjppj

- Over both rounds combined, we estimate an
- average halving time of 38 (28, 58) days
- reproduction number (R) of 0.89.

- The proportion of asymptomatic swab-positive participants at the time of sampling increased from 69% (round 1) to 81% (round 2).

- Health care/care home workers were infected more frequently than other workers in round 1, but not in round 2
- Prevalence in 18-24 year olds reduced markedly between rounds
- Our data suggested increased risk of infection in Black and Asian (mainly South Asian) ethnicities

- Risk of infection was higher in London than in other areas.
- Our analyses suggest that working in London may be a risk factor for SARS-CoV-2 infection.
- We detected spatial clustering of positives in London

Conclusions:
- As the SARS-CoV-2 epidemic in England transitioned out of its initial lockdown phase, prevalence of swab-positivity continued to decrease.
- Community-based as well as symptomatic testing is essential to inform the current control strategies in the UK

Finally, a massive thank you to all the REACT study investigators (@profhelenward, et al.) and all of our collaborators!

I’d also like to thank the folks at @IpsosMORI @KellyIpsosMORI for all their help with data collection and processing. It has been amazing to get nice clean data to work with!