The Pillars of Testing
Proof, were proof needed, that many of the pillar 2 community covid-19 tests done recently were carried out on asymptomatic people came yesterday morning from Absolutely Mancock. Absolutely doing the morning’s media interview round, he confirmed that as many as a quarter of the tests were done on people who absolutely were not eligible because they absolutely did not have either symptoms, or what he sinisterly called a direction from an official, to have a test. The rest of us have absolutely known about this problem for a while (in Dr No’s case, for weeks, if not months), and the problem it causes, which is once again to pour mud on the question of when is a case not a case. True false positives (positive result when no viral fragments are present) aside, much of the problem has to do with fact that the PCR (swab, antigen) test checks not for the presence of disease, or even entire infectious virus, but instead looks for tiny fragments of genetic material from the virus.
This causes two related problems. The test works by scaling scales up these minute quantities of viral generic material, using a powerful exponential chain reaction, which makes it remarkably sensitive. It is like the sniffer dog that can detect residual molecules left over from a multiphase turbulent gas cloud emitted last week, even when culprit has long since left the building, and the air is now clean and sweet. This means the test can be a true positive — the test correctly identifies a residual but trivial viral fragment that is truly present — but it is both clinically and epidemiologically wrong, in that the person is not a case, and is not infectious. This is not about false positives, which are a separate problem, but about the interpretation of a real, but misleading, true positive result.
In clinical practice, we normally deal with this by not doing silly willy-nilly testing on asymptomatic people; instead, we do tests for a reason, and interpret the result within the clinical context. If a patient has symptoms and signs of a disease, and their tests for that disease come back abnormal, then we can say they have that disease, a concept neatly summed up by the idea that we treat patients, not lab results (and that can even mean not treating an abnormal lab result if the patient is well in themselves). The problem with the pillar 2 positive tests is that we have very little clinical context, apart from Mancock’s vague suggestion, if this is indeed what he meant, that around a quarter of recent pillar 2 tests have been done on asymptomatic people, some of whom may be carriers (infectious, but not symptomatic, so carriers, not cases) and some of whom may have residual but trivial viral fragments, perhaps because they have been cases long in the past, but are now in the clear, and so are not cases, even when they test positive. We have no way of knowing how many of these asymptomatic people test positive, meaning that instead of talking about daily numbers of cases, we would do much better to talk only about daily numbers of positives, which, lest we forget, will also of course include false positives.
The second problem is the gold standard used to assess the PCR test’s accuracy. The real gold standard in such cases is viral culture: you have patients with symptoms and signs, and so probably have the disease, and a positive viral cultures (you actually grow the virus from the patients, so they definitely have the disease), and some controls (no disease); you then run the PCR test and see how often it correctly identifies cases (real patients, with real disease) and controls. But in the rush to get covid–19 PCR tests out, this was, ahem, somewhat over-looked, and in many cases the PCR test was tested against…another PCR test. This is little better than echo chamber validation. The widely quoted sensitivity and specificity figures only apply to what another PCR would tell you, not whether the person has covid–19 or not. Instead of a table of analysis that should look like this:
Gold standard | PCR test positive | PCR test negative |
---|---|---|
Covid-19 present | True positives | False negatives |
Covid-19 absent | False positives | True negatives |
We have one that looks like this:
Gold standard | PCR test positive | PCR test negative |
---|---|---|
PCR test positive | True positives | False negatives |
PCR test negative | False positives | True negatives |
All we have done is identified (with whatever sensitivity and specificity the PCR test has) which people are likely also to test positive to another PCR test. For all we know, we have one bent ruler confirming the results of another bent ruler…
It is these likely bent rulers, compromised by their unproven validity and over-sensitivity, that have ‘confirmed’ the rise in cases, and given us the new national six is a party/seven is a criminal gang rule, and the covid marshals to police the new rules, measures which Dr No fears are just the beginning of a new round of insane anti-covid–19 measures futilely molesting normal life. And now, to cap it all, we have Operation Moonraker, another pop-eyed world beating project based yet again on flawed testing. Dr No seems to recall that a previous project of the same name by his colleague Hugo Drax didn’t end well.
Right at the start of the pandemic panic, possibly early March, I distinctly remember reading warning announcements from the key maker of the PCR test that it was unsuitable for mass testing, and only meant for research lab purposes. Tunes of course have been changed, and they all go ker-ching $$$, but if I, a lay person, know this (and I have obviously since discovered that many other researchers also know this, and that Kary Mullis never intended the PCR test for such a purpose, and that wise medics, as you outline above, have noted the serious discrepancies they throw up when used en masse or the results misunderstood), why does Super Simple not know this. Surely there must be someone on the SAGE team who is not intent on sending us into second lockdown.
Also I’m wondering about these recent deaths – again ‘of’ or ‘with’? Given that American MATH+ protocol doctors (and others) have been having good outcomes even with the elderly and health compromised, surely a complete review of clinical practise should be the key concern of a Health Sec, not utterances about pie-in-sky, ‘super-quick’ concocted vaccines. We have the medical knowledge of the whole planet to draw on. Doctors have been talking to doctors, a sort of peer-reviewing on the hoof; lessons have been learned; there is much good news out there on how to treat people; millions have recovered, including the very elderly (and these are only the ones known of, i.e. those who went to their doctors/hospital and so became a statistic.)
Yet the behavioural scientists on the SAGE team seem to have the upper hand: the main objective to keep us frightened and confined – a state ill suited to good health and well being. Apart from which, we STILL don’t know how many people have already had the virus! If we don’t know that, we surely don’t know how actually infectious it is, or the extent of existent immunity within the mass population.
Thank you yet again for your rational appraisal in these lunatic times.
Inserting some levity into the grimish outlook, Moonraker’s Hugo Drax menacingly quipped:
“Look after Mr Bond, see that some harm comes to him.”
Perhaps the same objective is the intention of the British government to impose on the general public? Or, hideous incompetence – perhaps both!
“new national six is a party/seven is a criminal gang …”
That’s a time-honoured tradition. In Anglo-Saxon times a group of a few thieves were “robbers”, six or more were a “band”, and thirty or more an “army”.
P.S. That means the cabinet is a band. Or, as you prefer, a gang. Ditto the Shadow Cabinet, of course. And many GP practices, I dare say.
But to be serious: for many weeks I enquired on blogs how the accuracy of tests was tested. It turned out that almost everyone opining on Covid had not the least idea. Presumably the same is true of journalists.
James, ‘Perhaps the same objective is the intention of the British government to impose on the general public? Or, hideous incompetence – perhaps both!’ – I was concerned at the first for some time, but the second is where I am now, with great and growing unease; finding a way through to those holding dodgy intentions is one thing, but finding a way through to those who have their facial nappies covering their entire heads, who are sense-less, and living a blanket incompetence, is truly unnerving….
Dr No, thank you for your ever growing clarity on these times. May the bent rulers be seen as bent at the earliest so we may salvage what we can of this world.
The great conflict of our times is that between people who are dedicated to integrity (never lying to themselves) and honesty (never lying to others); and the great majority, who have accepted an ideology in which success (as measured by money and celebrity) is all that matters.
Richard Feynman and other honest scientists often explained that, without utter integrity and honesty, science is a hopeless charade.
Unfortunately, like most other endeavours in today’s world, science has been taken over by the urgent quest for money, fame, and authority.