FOI Reference: FOI/2021/3771
You asked
How many people have tested positive for Omicron?
If it's not possible to distinguish between the variants, how many people have tested positive for COVID-19 since 1 December 2021?
We said
Thank you for your request.
The Office for National Statistics COVID-19 Infection Survey (CIS) is a household survey that estimates the number of people testing positive for infection and for antibodies in the UK. Our statistics refer to the number of current COVID-19 infections within the population living in private residential households.
We exclude those in hospitals, care homes and/or other communal establishments. In communal establishments, rates of COVID-19 infection are likely to be different.
The CIS tests nose and throat swabs for SARS-CoV-2 using reverse transcriptase polymerase chain reaction (RT-PCR). The RT-PCR test looks for three genes present in coronavirus: N protein, S protein and ORF1ab. Each swab can have one, two or all three genes detected. The Omicron variant currently dominant in the UK (BA.1) has changes in one of the three genes that COVID-19 swab tests detect, known as the S-gene. This means that the S-gene is not detected, and Omicron BA.1 has the gene pattern ORF1ab+N (S-gene negative). Other variants, including Delta and Omicron subvariant BA.2 are positive on all three genes, with the pattern ORF1ab+S+N. For more information, please see section 6 (analysis of viral load and variants of COVID-19) in our latest Coronavirus (COVID-19) Infection Survey, UK bulletin. You can find modelled daily rates of the percentage of the population testing positive for COVID-19 by ORF1ab+N (Omicron BA.1 compatible) and other variants in tab 1c of the technical dataset accompanying our latest bulletin.
Our Coronavirus (COVID-19) Infection Survey: technical dataset also contains several other tables relating to analysis on variants, including the genetic lineages of the virus seen in the samples we sequence. Our COVID-19 Infection Survey methods article gives more detail about how we sequence the virus' genetic material. Additionally, you can find our latest estimates of the total number of people testing positive for COVID-19 in our Coronavirus (COVID-19) Infection Survey, UK weekly bulletin.
Please note that the UK Health Security Agency (UKHSA, formerly Public Health England) are responsible for NHS Test and Trace. For more information on the government testing programme, you can visit the gov.uk coronavirus dashboard or contact UKHSA via email at informationrights@ukhsa.gov.uk.
Further information and an overview of data about the coronavirus (COVID-19) pandemic from the Office for National Statistics (ONS) and other sources can be found in our Coronavirus (COVID-19) latest insights tool.