Debate Magazine

Is There Really a Dramatic Rise in Covid-19 Cases?

Posted on the 21 September 2020 by Markwadsworth @Mark_Wadsworth

There's a handy 'dashboard' at https://coronavirus.data.gov.uk/.
The chart for 'Cases' shows an apparently dramatic increase, from about 800 new cases per day in July to nearly 4,000 now (late September).
To interpret this properly, you have to also look at the chart for 'Testing'. The number of tests carried out has increased from about 100,000 to over 200,000. So the percentage of positive tests has increased from 0.8% to 1.8%. I am perfectly aware that there are a lot of false positives, so let's round that 1.8% down to 1% for sake of argument.
These tests have two quite distinct purposes:
1. Back in March/April, they would only do tests on people who were displaying symptoms, who had been admitted as patients, or who had good reason to assume they might have contracted it. About half of tests came back positive. That was important to know, so that they knew how to treat patients or who should self-isolate.
2. Nowadays, lots of people are being tested, whether they have any symptoms or not. As far as I can see, the people being tested are a fairly random cross section of the general population. So the relevance of these tests is telling us what percentage of the general population have contracted the virus. We know that the tests throw up a lot of false positives, but that doesn't matter if you are interested in the general trend rather than trying to pin down an exact but entirely unascertainable number. And that trend appears to be going ever so slightly upwards.

But what do we really care about here? We care about large numbers of preventable deaths and the NHS being "swamped". Neither of those things are happening, daily deaths have been in the 10 to 20 range for three months; daily admissions to the NHS are just over one hundred; and the total number of patients in hospitals is just over 1,000 (none of the Nightingale hospitals were ever used AFAIAA). The NHS has over one million staff, just quite how many does it take to look after one covid-19 patient?
If 1% of the general population has covid-19 at any point in time, that means 700,000 people have it. Of those, only 100 will be hospitalised and 10 or 20 will die every day. Assuming the illness comes and goes in two weeks (and you're either recovered or dead), that's a death rate of about 0.3%, which is so close to zero as to be meaningless.
Assuming two weeks to be a fair guess, that means about 50,000 new infections per day in the UK. Multiply that by nine months and that means about one-fifth of us have had it (and most won't even have realised). I'm not sure what the cut-off point for 'herd immunity' is, but it's only a matter of time, isn't it, vaccine or not?


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