SARS-CoV-2 infection in London, England: Impact of lockdown on community point-prevalence, March-May 2020

COVID-19 point prevalence PCR community testing allows disease burden estimation. In a sample of London residents, point prevalence decreased from 2.2% (95%CI 1.4;3.5) in early April (reflecting infection around lockdown implementation) to 0.2% (95%CI 0.03-1.6) in early May (reflecting infection 3-5 weeks into lockdown). Extrapolation from reports of confirmed cases suggest that 5-7.6% of total infections were confirmed by testing during this period. These data complement seroprevalence surveys improving the understanding of transmission in London.