FOI/2021/2843
You asked
Please supply the evidence the government holds of the isolation (purification) of the COVID-19 virus.
Also, please supply how the Delta variant is tested for and whether this has been done on the general public.
We said
Thank you for your request.
The COVID-19 Infection Survey is a household survey that estimates the number of people testing positive for infection and for antibodies in the UK. Our statistics refer to individuals in the community, by which we mean private households. These figures exclude infections reported in hospitals, care homes or other institutional settings.
Unfortunately, we do not hold any data relating to the isolation of the COVID-19 virus.
The Delta variant (B.1.617.2) tests positive on all three genes that COVID-19 swab tests detect, with the pattern ORF1ab+S+N. Almost all ORF1ab+S+N cases in the UK will now be the Delta variant, so this group was labelled "compatible with the Delta variant" in our previously published variant analysis. For every positive nose and throat swab where there is sufficient virus to do so (Ct less than 30), a process called whole genome sequencing is used to read all letters of the virus' genetic material. Where we successfully sequence over half of the genome, we use the sequence data to work out which type of variant is present in each virus. You can find more information about this in our weekly bulletin and methods article. As the COVID-19 Infection Survey is a sample survey, your query about testing on the general public may be better placed with Public Health England. They can be contacted via email at wn_coronavirus@phe.gov.uk.
For further information and an overview of all the data published across the ONS, please check our ONS COVID Insights Tool.