This is an interesting document, brought to my attention by @lizzyarrow https://www.gov.uk/government/publications/covid-19-management-of-exposed-healthcare-workers-and-patients-in-hospital-settings/covid-19-management-of-exposed-healthcare-workers-and-patients-in-hospital-settings

Eg. Para 37 implies a view that fragments of dead RNA can persist for up to about 90 days. That's a long time (more than the 'few weeks' mantra might suggest). In mid-epidemic, it means that a lot of +ve PCR results will be picked up from people who are not currently infectious.

Now look at para 3. This says that asymptomatic testing is prioritised by area of need, i.e. greatest Covid pressures. Targeting is a a good thing, *but only if you pick the right target*! It implies that there will be more +ve but not-infectious PCR test results in areas ...

... of greatest pressure. That in turn means sending more staff home unnecessarily in precisely the areas where the pressures on capacity are greatest. It is another aspect of what appears to be a dysfunctional NHS approach to managing capacity for peak loads. (Another aspect ...

... of the approach is taking beds out of current use to be available in case of greater demand in the future -- i.e. failing to meet a current, certain demand in order to be able to cope with a speculative further increase in demand later.) It doesn't make a whole lot of sense.