From the BBC: Having tested nearly 100,000 people, Liverpool mass-testing finds 700 cases with no symptoms. So, allowing for false negatives, about 1% of the population.
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From the BBC: Having tested nearly 100,000 people, Liverpool mass-testing finds 700 cases with no symptoms. So, allowing for false negatives, about 1% of the population.
https://www.thewestmorlandgazette.co...d-19-outbreak/
"53 pupils have so far tested positive for Covid-19 after an outbreak at a school."
and
"At the time of writing, a total of 53 pupils have been confirmed as having Covid-19"
see the subtle difference, the drift?
"The vast majority were asymptomatic" which suggests a few have some cold/flu symptoms which would be par in a school at this time of year.
False negatives are about 30%. So "true" cases about 910 - for simplicity let's call it 1,000. The 100,000 figure has already been rounded up - from what I am not sure. 1,000/100,000 = 1/100 = 1%. The assumption is that the 700 are a representative sample of the people in Liverpool.
All I think Mike T is saying is that approximately 1% of the population of Liverpool had covid without realising it. Obviously Liverpool has been hard hit so 1% isn’t a sensible figure necessarily for the whole country but, if it were, that would be getting on for 660,000 people still able to pass on covid without realising it
It’s just another reason to add to the list as to why the disease manages to spread so easily
Add in the symptomatic cases - at or above 1% in the NW, NE, Yorkshire and the Midlands.
And that 10% rate at Sedbergh school is quite a worry.
False negatives 30%? Where do you get that from?
Anyway, you need context.
The 100,000 tests seem to be split.
Attachment 8865
New LFT Test (claimed to be 99.7% accurate) shows 80% fewer cases than standard PCR test (as used in Sedbergh and rest of UK)
So maybe this will help our decision makers get their act together, although I doubt it. They are too invested in the current track of lockdown until vaccine.
I just googled false negative results and the 30% estimate is now looking out of date with something around 8% thought to be more likely now. On the flip side, false positive results are estimated to apply to something like 0.8% of tests.
So the system, by those figures, identifies 10 times as many as falsely negative than it identifies as falsely positive.
So, as we've said before in the current situation, false positives aren't as much of an issue as false negatives.
However, if we get to a situation of very low infection rates, but very high levels of screening, false positives become (relatively) more important.