I thought I'd do a bit of number crunching looking at the Government's site.
https://coronavirus.data.gov.uk/

I've looked at the averages of the last six weeks data for:
- Number of cases
- Number of tests processed (pillar 1 and pillar 2)
- Cases as a percentage of tests processed
- Number of hospital admissions for covid
- Number of people with covid in hospital
- Number of people on a ventilator
- Number of covid deaths

The most recent end week date is 2nd September since this is the last date that every category is available. I've only taken England rather than the UK as a whole since the Scottish figures are skewed for number of people in hospital. Apparently they include everybody who has ever had a test for covid regardless of whether they still have it. But they don't do that for their admission figures.

02-Sep-20 - 1,180 - 135,986 - 0.87% - 56 - 451 - 56 - 6
26-Aug-20 - 948 - 138,249 - 0.69% - 45 - 484 - 63 - 9
19-Aug-20 - 935 - 138,598 - 0.67% - 50 - 569 - 65 - 9
12-Aug-20 - 850 - 129,070 - 0.66% - 58 - 611 - 60 - 10
05-Aug-20 - 757 - 119,024 - 0.64% - 61 - 779 - 68 - 8
29-Jul-20 - 669 - 104,955 - 0.64% - 78 - 895 - 84 - 17

It seems pretty clear that the case numbers detected are going up even when taking account of the increased testing. But every other category is still going the right way, either dropping or stable. Possible explanations that have been suggested for this apparent contradiction are:

- Mainly young people being infected, who are less prone to the disease.
- Social distancing has meant the viral load people are getting has fallen enabling the immune system to more easily fight off the virus. So if you come into contact with somebody with the virus you may be less close to them than in the past.
- The virus test is so sensitive it is picking up fragments of old infections. More on this here: https://www.bbc.co.uk/news/health-54000629

Whatever the reason, it is when hospital admissions start picking up that we should start getting more concerned rather than increased case detection numbers.