Interim results from the Coronavirus (COVID-19) Infection Survey, UK: 24 December 2021

Today, we have published new interim data that show between 13 December 2021 and 19 December 2021:

• In England, the percentage of people testing positive for coronavirus (COVID-19) was 2.83%; we estimate that 1,544,600 people in England had COVID-19 (95% credible interval: 1,477,900 to 1,615,800), equating to around 1 in 35 people.

• In Wales, the percentage of people testing positive was 2.30%; we estimate that 70,000 people in Wales had COVID-19 (95% credible interval: 57,100 to 83,800), equating to around 1 in 45 people.

• In Northern Ireland, the percentage of people testing positive was 2.45%; we estimate that 44,900 people in Northern Ireland had COVID-19 (95% credible interval: 34,900 to 56,100), equating to around 1 in 40 people.

• In Scotland, the percentage of people testing positive was 1.50%; we estimate that 79,200 people in Scotland had COVID-19 (95% credible interval: 65,600 to 94,000), equating to around 1 in 65 people.

• In England, COVID-19 infections have increased in all age groups.

• In England, COVID-19 infections have increased in all regions except the South West in the latest week; the highest rates are in London where around 1 in 20 people had COVID-19 and lowest in the North East where around 1 in 55 people had COVID-19.

• COVID-19 infections compatible with the Omicron variant have increased in all regions in England with substantial regional variation; the highest rates are in London and the lowest in the North East.

Credible interval

A credible interval gives an indication of the uncertainty of an estimate from data analysis. The 95% credible intervals are calculated so that there is a 95% probability of the true value lying in the interval.

Reference dates

This week, the reference week for positivity is 13 to 19 December 2021 and the reference day for positivity is Thursday 16 December 2021. More information on reference weeks and days can be found in our previous release.

Survey fieldwork

Survey fieldwork for the pilot study began in England on 26 April 2020. In Wales, fieldwork began on 29 June 2020, in Northern Ireland fieldwork began on 26 July 2020 and in Scotland fieldwork began on 21 September 2020. 

Other Coronavirus Infection Survey (CIS) analysis and studies

This study is one of a number of studies that look to provide information around the coronavirus pandemic within the UK. For information on other studies see Section 11: Measuring the data in our previous bulletin dated 30 April 2021. 

Quality

More quality and methodology information on strengths, limitations, appropriate uses, and how the data were created is available in our methods article and the Coronavirus (COVID-19) Infection Survey QMI.