Published by Public Health England on the 28th of October 2020 (page 6 of the PDF document)
https://www.gov.uk/guidance/high-consequence-infectious-diseases-hcid
Statistics
Map
https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/causesof
They also admit via the FOI request that they have no evidence of its existence!! https://www.whatdotheyknow.com/request/679704/response/1666239/attach/4/IR 1243364.pdf?cookie_passthrough=1
GOV.UK
Cycle threshold (Ct) in SARS-CoV-2 RT-PCR
A guide for health protection teams about interpreting Ct in real-time, reverse transcription polymerase chain reaction (RT-PCR) assays performed for Sars-CoV-2.