This is where lateral flow tests (LFTs) come in. Unlike PCR, they don’t test for viral RNA but particular proteins made by the virus. Instead of taking two days to get a result, they take half an hour or so. They’re also cheap and easy to mass-produce; some brands are simply strips of paper, like Litmus tests. The idea is that you make them by the million, and test people at mass testing stations or before they enter workplaces.
But what’s crucial — either the crucial design flaw or the crucial design feature, depending on whom you ask — is that LFTs only return a positive result for about four to eight days in the infection cycle. If their proponents are right, that means they only pick up infectious cases, and it could mean that you – or your child – could have a test in the morning, wait 30 minutes for the result, and then go to work, or school, or university classes, or whatever. “The idea is to move on to event screening,” says Tim Peto, a professor of medicine at Oxford University who has been involved in the testing of LFTs in the UK. “You have a test 24 hours before and if it works you can go to the football match.”
The impacts
If Mina and Peto are right, it could be transformative. Mina envisages a large proportion of the population testing itself regularly — in a Time article he suggests 50% of the population every four days. That would break enough chains of transmission to reduce the R value below one, so that the pandemic would die down to manageable levels and we could get our lives back to normal.
Others, though, disagree. They say that the tests are gigantically unreliable; that they do indeed miss non-infectious cases, but that they also miss a huge percentage of dangerous, infectious cases. And that will mean that people will be given false reassurance, and will unknowingly carry the virus with them into the places they now have the permission — or confidence — to visit.
Both sides agree that LFTs are much less likely to detect dead virus floating about in the system. But what is contested is whether they reliably detect people in whom there is real virus at infectious levels.
Mina and Peto say that above a reasonable level of viral load, it will detect the large majority of cases. But Jon Deeks, a biostatistician at the University of Birmingham, disagrees, and has done so loudly.
Deeks has repeatedly argued that LFTs will miss a large — perhaps overwhelming — percentage of positive cases. He and other senior academics, such as Prof Sheila Bird and Prof Sylvia Richardson, both of the Cambridge Biostatistics Unit, say that it missed more than a third of cases that have high viral loads in a mass testing trial in Liverpool. Other scientists tend to agree that the false negative issue is real.
Deeks also ran a study of his own, testing 7,000 students in Birmingham with LFTs: they found just two positive cases, a startlingly low positive rate in December when the virus was circulating widely. They then took a random sample of 10% of the negative cases, tested them again with PCR, and found six cases. Deeks extrapolated from that to say that there were probably 60-ish cases in the full sample, so, he says, the LFTs had just a 3% sensitivity rate.
Mina, on the other hand, says this is a straightforward misunderstanding. First, he says, the Liverpool study doesn’t show what Deeks thinks it does. The high viral loads Deeks mentions in the Liverpool case are determined by how many PCR cycles are required, but, says Mina, you can’t directly compare those values between different PCR tests, and the Liverpool numbers are very unusual. He expounds on that in this Twitter thread.
And in the Birmingham study, says Mina, there’s another misunderstanding. None of the six cases that LFT missed but PCR caught had high viral loads; they were all low and probably non-infectious. This was, he says, the LFT doing exactly what it is intended to do
Both Mina and Peto are insistent that the LFTs should not be compared to PCR, because they’re simply doing different things. “We don’t want the lateral flow to be 100% effective,” says Peto. They only want it to detect people with a high viral load, because the rest probably won’t be infectious.
Deeks doubts that – “these tests are not designed to tell if you’re infectious or not,” he says – and points out that there is no straightforward cutoff between infectious and non-infectious; it’s a continuum of risk. He also says that Peto et al, in their studies with Porton Down using the LFTs in schools, never checked any of their negative results against PCR to get a clear picture of the false-negative rate.
Test and release
The other question is what the tests should be used for. The manufacturers say that they should be carried out by experts, and that they should be used for determining the prevalence in the population and for detecting symptomatic cases. But they are being used to screen pupils going to school, and students going to university. The MHRA has given emergency use exemption to allow healthcare workers to do their test at home. Comments from the Prime Minister suggest that they will be used to allow people to attend weddings, theatres and sporting venues.
This isn’t just Boris Johnson’s usual overpromising. Peto and Mina both think that this is exactly the sort of thing they should be used for. “The idea is to have a more focused approach where you only lock down people who’ve tested positive,” says Peto.
But others think this “test and release” is dangerous. “They’re certainly good enough for a lot of purposes, like prevalence studies,” says Dr Rob Wootton, a scientist with many years experience developing point of care diagnostics. “But they are no damned good for test and release. That is not what they are for.” Deeks points out that a low viral load could be because you had the virus a week ago and are now recovered – or it could be because you’ve just got the virus and you will be infectious tomorrow. Peto and Mina say that testing every two days would minimise that problem, and besides a PCR test would take two days to get a result to you anyway.
And Deeks, Wootton and others worry about false-negative results leading to false assurance. “Watching the news after the Liverpool pilot study,” says Deeks, “there were people coming out of the test saying they’ll visit the care homes to see their mother.”
Costs and benefits
This is a complex, technical question. Credentialled experts on each side disagree not just on what will happen in the future, but on the facts of the matter now.
The question at issue is: should we roll out mass home testing using LFTs, and let people with negative results out into society? It’s a hard question, but here is my best effort to unpick it, from my non-expert position. What we need to do is look at this not as a rigorous scientific question but as a cost-benefit analysis, decision-making under uncertainty.
In the debit column is the risk that a false negative will increase the likelihood of someone going out and spreading the disease.
In the credit column there are two entries. First, the likelihood that the LFTs will spot an otherwise undetected case and keep them inside, stopping further transmissions. And second, the rapid turnaround of the tests allowing people back into economic life and restarting society faster.
I’m less concerned about risk compensation behaviour than are Deeks and others. It was floated early in the pandemic as a reason not to wear masks, but a literature review in the BMJ found that the evidence in other contexts was weak. I had a look myself for research on false negative results providing false reassurance, for instance in cancer screening, and again found no real support for it (1, 2, 3). I’m not hugely confident, but that’s my best guess.
On the other hand, individual risk compensation behaviour isn’t the whole issue. If institutions are explicitly saying that a negative LFT result gives permission to engage in more Covid-risky behaviour, such as attending schools or universities, whether or not it makes people individually more likely to lick lampposts. And since that is what is happening, it seems very likely that false negatives will lead to some non-trivial increase in risk spread.
The trouble is that I can’t assess how common those false negatives will be. Deeks says common, even in high viral loads; Peto and Mina say rare. Both agree that they’ll be lower in lab settings than when used by trained professionals, and lower when used by professionals than when self-administered. But Deeks thinks that’s crucial, while Peto is largely unfazed. “It’s like boiling an egg,” he says. “You won’t get it right the first time. But after a week the error rate goes down.” Mina agrees: “It doesn’t have to be perfect. It just has to get R below 1.”
The next question is whether the number of asymptomatic cases caught will outweigh the cost of the false negatives. Peto thinks it’s a clear yes: “We’ve only had two million used,” he says, “and found at least 30,000 asymptomatics, so it’s already reduced the number.” Mina says that in some cases, people stay infectious for longer than usual, and PCR can’t tell – you’d still be PCR-positive after 10 days’ isolation, so there’s no point testing again. But in his studies in Harvard, LFTs find those rare people and get them to stay isolated. Mass testing in Slovakia has been credited with possibly reducing infection rates there.
Deeks, though, says that the issue is that comparison shouldn’t be between getting tested or staying out in the community. “The comparator is what you used to do,” he says. In the case of schools, if you sit next to someone who gets a positive PCR test, you are required to self-isolate. “Now they stay in the classroom, and if they get a false negative they’ll infect the person next to them and you get an outbreak in the school,” he says. He thinks this sort of mechanism was behind an outbreak at the Jaguar-Land Rover plant in Halewood, Liverpool.
And finally, the question is how useful shortening the quarantine will be. Peto and Mina think it’s vital; Deeks, obviously, less so. It strikes me that with the vaccine on the way, the calculations change somewhat, and it may be that the pressure to get the economy started in any way possible is less dramatic than it used to be.
Imperfect solutions
Dr Alexander Edwards, a biomedical engineer at Reading University, agreed with Deeks that the false negative rate probably is quite high, especially when self-administered. But, he said: what’s the alternative?
“You can take two approaches,” he said. “One, push on and do what you can, or two, you can wait for a better solution. But it’s difficult to see how a better solution will appear magically.” Lateral flow tests are “extraordinarily good” for what they are: scalable, cheap, easily mass-produced. They will miss cases, but we’re not going to be able to build anything better quickly. In situations like HIV, he says, LFTs proved useful as part of a wider testing toolkit. He added that Liverpool’s public health authorities have said that they won’t use them to allow people to visit care home residents: that seems the sort of sensible measure that can prevent the worst harms even if the tests do lead to some further spreading.
Deeks’s concerns have got attention. Mina says that he is constantly fielding calls from government officials worrying that the 1.5 billion LFT tests that they plan to buy are a bad idea. “I advise the government in the US,” he says. “And because of Jon I’m getting call after call from people saying that they’re seeing tests of 3% sensitivity. It’s confusing people the world over.”
There isn’t time, in a pandemic, to do RCTs on everything. Sometimes decisions have to be made quickly; an imperfect decision taken quickly is better than a perfect one two weeks later. Deeks, though, thinks that it would be easy to do good tests, quickly: “In a pandemic, it’s easy to do studies, because you have enough patients.” He wants more testing, with PCR checks for false negatives, before full rollout.
Deeks is absolutely right that testing should carry on, but delaying the rollout until then seems too cautious. I think the Slovakian experience suggests that mass testing can be effective; the possible benefits of catching asymptomatics seem significant, and there are real advantages over PCR testing alone. But it would be mad to use LFTs as a passport to go and visit care homes; avoiding obvious pitfalls like that should reduce harms.
Edwards compares the situation to a hand of poker. The reason that it’s tense is because the stakes are high – getting it wrong could kill thousands – and because both players have good hands; there are excellent reasons to push forward, and excellent reasons to be cautious. And, as in poker, we have to operate with imperfect information. When the cards are turned over, we will learn who was right.
His bet, and mine, is on rolling out the lateral flow tests, with caution and pragmatism and constant evaluation. “We’re in an urgent situation, with huge health and economic costs,” he says. “I genuinely don’t think there’s a better alternative.”
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SubscribeThis long article clearly articulates which seeking technological “solutions” to respiratory viruses is a fools errand.
There are only two end states – eradication or endemic with herd immunity. The eradication boat sailed for Europe in Feb 2020 while scientists advocated for well researched and thought through positions which considered costs vs benefits and wider societal impacts.
From April onwards all that was thrown out the window and “fight Covid at all costs” became the only game in town, being argued for by the same scientists who 2 months earlier had sat back while 10,000s of cases were seeded.
Wind the clock forward, scientists are having serious debates about the effectiveness of a test at the door to a theatre, while no fever hospitals exist, no quarantine facilities exist, no training of healthcare support workers is being done and no mention is made of the £100bn price tag of this “technical solution”.
Absolutely, couldn’t have said it better
Eradication possibly sailed once the disease spread heavily anywhere, probably well before Feb 2020.
The current UK border farce could maybe slow infections. It clearly isn’t going to stop the spread of new variants if they’re genuinely worried about them.
Negative test within 3 days and promise you’ll quarantine yourself for 10 days is laughable.
As you say herd immunity remains the only way out of this mess. Mass testing is both hugely expensive and ineffective.
In the sad situation we’re in we need to continue vaccinating the vulnerable asap, hopefully see deaths (excess deaths) reduce sharply and then start moving back to true normality asap.
Some in power dream of stretching this out for years.
You are correct we never had the original option of full eradication, we were infected before most countries and before we could possibly of known. Germany and Australia et el just go lucky.
In theory we could still achieve eradication through almost 100% lockdown (house arrest etc). If there is no human contact between households, then the virus will eventually die out. In theory it would happen in 2 to 3 weeks with absolute adherence.
But we would also need to seal the borders and not let anyone in or out indefinitely. Which is what Australia / NZ are doing.
We may block the air and ship routes but the small boats are still getting through by the hundred.
Give it a rest. There are more pressing issues to deal with than a few brown women and children in a dingy.
I received a test thing to do from the NHS. It said that it is completely private and you will get the results. But there was a paragraph which said if you are positive we will give your name to the authorities. I thought that I could be tested positive when I wasn’t and then have to isolate for two weeks, as it was then, so I dumped the testing stuff.
Sorry, mate, that sounds entirely too sensible. I’m afraid it will just have to be ignored. And if you keep on talking sense we might have to have you barred.
Yeah and don’t mention Ivermectin which is curing thousands in Brasil and other places or you will be cancelled.
Do we know the effectg of Ivermectin on the new variant?
Sounds good, but factually incorrect. Hospital capacity has been massively increased, as has the number of doctors and nurses. There are however limitations to how quickly you can do either.
The herd immunity approach also ignores that COVID causes morbidity as well as mortality. You will leave hundreds of thousands with some form of disability, even if only temporary for most. You also overlook that mutations may make herd immunity redundant, or at least less effective, as a solution.
I am not suggesting herd immunity is not an option. But suggesting it’s the ‘obvious’ or ‘easy’ solution is mistaken. It comes with massive morbidity, fear, death and economic destruction.
I feel we maybe losing the wood for the trees. Isn’t the real debate whether we should mass test at all at some point? And just test those who are ill? Especially once the elderly and most vulnerable are all vaccinated. Mass testing from say May 2021 feels more like it could be a mass waste of money and a mass loss of focus. Wouldn’t we be better off with an emphasis on overall health including the importance of fresh air, a bit of sunshine, healthy eating, hydration, spending time with friends and loved ones, laughing with friends and taking at least an hours exercise a day.
A ‘war’ on obesity and mental health, if you will, save lives, protect the NHS…
It’s not mutually exclusive, you can do both.
Spitting into a tube to detect whether you are carrying a virus that could make millions of individuals seriously ill, then staying at home for 10 days if positive, is really not too much to ask. Particularly when the alternative is to either destroy the economy and infringe on everyone’s liberty, or just let people die in hospital car parks (which will also destroy the economy).
COVID hospitalises and kills old people, irrespective of commodities. You can’t ‘educate’ people not to be old.
Are you really suggesting that after the elderly and vulnerable are all vaccinated, the whole adult population spits into a tube every day/week in perpetuity? And then presumably drop it off somewhere to be screened and tested for Covid 19? I’m not sure that’s the best use of scarce resources – I would like this money to be spent on boosting NHS capacity e.g. beds and frontline headcount. And I’d like the focus to be ‘spent’ on promoting healthier living.
You brush your teeth each morning, this would be far less odious and time consuming. The testing device is self contained so it will give you a result instantly (presumably it could be connected to wifi if we need to monitor)
We would not need to do this if the vaccine is extremely effective at preventing death and serious illness. It’s an alternative to lockdown.
And also look more into Ivermectin which if given early in the illness has proved to eradicate Covid 19 in Brasil and other countries.
We cannot trust any of the tests, unless perhaps they are performed by medical professionals in laboratory conditions. We have known that since last summer. It is just one of the many lunacies of the whole Covid farrago.
I say test and release. I would rather the Sweden/Belarus method of individual responsibility but as the fear industry has blocked this I think the exceedingly imperfect testing will be fine, as lockdown cure is worse than the disease.
I have a friend who has been tested three times with a different result every time.
TOM Chivers I am not at all sure you are right to say that the false positive rate on PCR is below 0.05% and if you are wrong, as I suspect you are, you really should correct that statement. If the number of people tested inludes vey few who have been infected, the false positive rate will inevitably be low, and could be less than 0.05%. But when you have a large number of non-infectious people, and a much larger number of tests there is a greater possibility of cross contamination as well as ‘dead’ virus (see Dr. Yeadon’s papers on this).
The problem with experts is that they have unmoveable opinions.
Agreed, the two parties in the article above might as well be from different planets. Any discussion where one side says a test is 90% anything, and the other says 3% isn’t working on a scientific basis. They’re each starting from a political or philosophical position, and picking the data to suit their argument. And that’s not going to get us anywhere. There are too many obvious questions not being asked, because the news media are having more fun arguing than reporting.
And funding induced bias.
A bit like politics then.
Some research has false positive rate between 0.8% and 4%. With 500,000 tests per day that’s quite a few false positive results.
https://www.medrxiv.org/con…“
Also “Dr Paul Birrell, a statistician at the Medical Research Council’s
Biostatistics Unit at the University of Cambridge, says: “The false
positive rate is not well understood and could potentially vary
according to where and why the test is being taken. A figure of 0.5% for
the false positive rate is often assumed.”
Though it is worth bearing in mind people being tested are not a random cross section but are more likely to have symptoms.
The fact that they are more likely to have symptoms will NOT change the false positive rate. It will only change the proportion of positive results that are false.
That’s not correct, Mike. The false positive rate is NOT the proportion of positive results that are false. It is the proportion of tests that will be positive, in the absence of any truly positive specimins.
For example, if you test 1,000 people and the false positive rate is 0.5%, then there will be 5 positive results that are false. That is true whether you have 1, 10 or 50 real positive results in the sample.
We had positive rates of sub 1% during mass testing from June to August. False positive rates therefore cannot be higher than this.
His point is that they can be because FPR rates aren’t static if they’re driven by cross-contamination.
To suggest there is mass cross contamination of testing that just happens to be followed by increasing hospital admission and increasing excess deaths is just silly.
So cross continuation grows in exactly the same ratio as excess deaths?
It’s my understanding that PCR tests on the current number of cycles used are actually so unreliable and misleading that they are the subject of an upcoming class action in Germany, and the scientist whose recommendation to use the test was followed, Peter Drosten, is being seriously accused of misrepresenting his qualifications. Such that he may be struck off.
PCR tests also produce false positives, and were the cause of the Liverpool testing scheme being abandoned. The Army stated privately that no pool of infection was detected.
The lockdown must be lifted, they should never have been imposed at all. The infringement of our civil liberties must end, plus the disregard of the Human Rights Act, and the entirety of SAGE should be sacked. Their mismanagement, failure to understand statistics, abuse of the death certificates regime, and failure to ensure basic infection control in hospitals and care homes is indefensible.
Well said.
Seconded. It is little short of a scandal. A public inquiry with serious civil and criminal consequences needs to be instituted. We can be quite sure our devious pols and their advisers are already at work on devising their exits.
Spot on. The concept of “lockdown” was always a wild idea. It’s the worst political action outside of a War that I can remember, and it’s going to be a long time before the whole truth is known, as there will be a degree of manipulation about various statistical records to avoid it.
As to public inquiries, there might be some value – at least for the organisers and participants, but that will take a long time. Remember that there is at least one major one (Grenfell) that is still suspended at present.
Being proved wrong later doesn’t help the present position but I suppose it might help us learn for the future.
Great read with lots of interesting points and facts. But sometimes don’t you just think we are focusing on something that ‘may’ help alleviate the spread, simply to be doing something. No matter how you slice it a test is a moment in time. After that moment passes the test is no longer valid. To have local and national authorities making ad hoc decisions on a moment in time to govern our own personal behaviour is nutty to me. To spend ridiculous amounts of money to test for a moment in time seems a fools errand to me.
Exactly.
Don’t just stand there do something although sometimes doing nothing is the correct thing to do.
First of all, let me say that the explanation was brilliant. I understood the words, even if I am not a medical scientist.
Here is my problem. The medical scientists have axes to grind and are biased, as are all people who work closely with a problem. Government can’t do anything because they are usually not scientists. So the blind lead the blind. Jargon is king.
I am a scientist and I believe that ALL scientific arguments can be expounded in a way that other good scientists can understand – jargon and special knowledge can be overcome. If you get a team of non-medical people around a table, including at least one statistician it should be possible to come up with a compromise regime which satisfies all requirements.
Spot on – it seems neither test method is actually 100% fit for purpose hence the “scientists” descend into tribal name calling and leveraging their pet test for income. So much for the mertonian norms of universalism and communality. So we need another, better test pdq. Imagine having a test for explosive atmosphere at a gas plant which sometimes only gave you part of info you need and sometimes a false positive or negative result. You’d be shutdown, hopefully before fatalities not after!
Mike: Unfortunately ALL of the Mertonian norms go by the board when policy-related sciences confront an emergency. Perhaps the first to go is Scepticism, which has now extraordinarily become a term of abuse (see Freddie Sayer’s recent article). Of course the Mertonian scientist was always an ideal type, but in the past this ideal had some resemblance to reality. I am examining this within the context of a PhD thesis on the Philosophy of Computer Modelling. I think one source of the dissolution of a normative order in science is Postmodernism in collusion with Managerialism in academia. See Pluckrose and Lindsay “Cynical Theories”.
H’m. Interesting
I have read cynical theories and its great – up there with Scruton’s fools, frauds and firebrands. I think the philosophical questions will become more of an issue for modelling /simulation as it spreads away from the world of physical science into the voodoo of social science and now even life sciences jumping off the Popper/Mertonian/Rigourous methods raft to board the ship of fools. We use FEA and CFD methods at work which are effective because we only ask questions that we can usemodels to answer. Post modernists denythe concept of knowledge and claim its an imperialist or racist plot. Fine but they should not be allowed near policy making as their idiocy is dangerous like a chimp with an AK47. I wonder if your future research will look at modelling using “AI” by which i think they mean databases and “algorithms” – God knows what they mean by that but it ain’t Laplace Transforms!!
anti-second amendment chimpist
Classic! there is a chimp on youtube who lets go at what i think are African Peace Keeper troops who are goading him. He’s certainly taking his 2nd amendment rights in full. Tom Morello said “arm the homeless” and i intend to trump his virtue signal with a guitar graffiti’d with “arm the simians”
Jargon is king. nailed it-the land of the soundbite -all these wretched matras- ” Don’t let a coffee cost a life!!!!!”I despair.
Hi Tom – I’d love it if you could give us a further piece about the latest figures from Israel. As a layman my understanding is that the most vulnerable in that nation were vaccinated in the last week of December. However here on the 19th of Jan it doesn’t seem to have made any impact whatsoever on the number of infections and the number of deaths. What’s going on? Does the Pfizer vaccine work in real life? Because I thought we might have had a big fall in fatalities over there by now. Anyone else here got some wisdom on this?
The high (90+%) efficacy numbers determined for both vaccines were after the full 2 doses, so that could be part of it, e.g., from the US FDA about the Pfizer/BioNTech vaccine: “The data to support the EUA include an analysis of 36,523 participants in the ongoing randomized, placebo-controlled international study, the majority of whom are U.S. participants, who completed the 2-dose vaccination regimen and did not have evidence of SARS-CoV-2 infection through 7 days after the second dose. Among these participants, 18,198 received the vaccine and 18,325 received saline placebo. The vaccine was 95 percent effective in preventing COVID-19 disease among these clinical trial participants.”
So, following the above, efficacy for the Pfizer/BioNTech vaccine was calculated beginning 28 days after the first dose (21 days from first dose to second, plus another 7 days).
“Cases” are also difficult to put in context without knowing if testing numbers have changed. I can’t readily locate a place with good details for Israel – i.e., numbers with time series on cases, testing levels, and testing positivity.
I don’t think we’d see change in reported death numbers show up very quickly. Some of that is the lag from infection to death. Lots of places also have lags from actual date of death to reporting deaths. I don’t know whether or not there are reporting lags in Israel.
Looking at UK charts there seems to be a lag of around 10 days from case peak to hospital admission peak, and another 10 days from admission peak to death peak. Add 2 weeks for a person’s immune system to be primed by the vaccine, and this back-of-then envelope calculation would indicate that measurable impact on death rate should be seen about 5 weeks after a significant proportion of the at-risk population have been vaccinated.
So after the first week of Feb there should be a significant improvement in Israel’s death rate.
I agree that’s pretty reasonable – maybe add ~1 week from infection date to someone appearing in stats as a “case” – *if* there’s fairly high efficacy after 1 dose of the vaccine. I thought that was still a matter of debate.
Realize that I should have said what I *do* think would be a good statistic to track for Israel to get an idea if vaccines are working: either reported COVID hospital census or reported COVID hospital admissions, ideally for those 65+ (since they’ve been prioritized for vaccination).
It still might take several weeks to show up in the numbers, it’s (1) easier to interpret than cases (not skewed by testing levels and criteria) and (2) it logically shows up in the numbers before deaths.
It takes two weeks for the vaccine to become effective. Mots deaths occur 3 weeks after infection. So the death rate should start falling about now. Cases are irrelevant.
I note that daily deaths fell from 46 to 36 yesterday, the first fall in a long time.
I would suspect, that given the very low number of deaths in Isreal, the vaccine would make the number of deaths appear to go up.
This is a classic case where you need to count the actual numbers of people dying from all causes, and have a good hard look at their ages.
Since vaccinated people are likely to test positive, and because predominantly old people are being vaccinated, and because old people tend to die, the numebr of appearent deaths within 28 days of a positive test Covid will increase.
Imagine we colour all Ebola victims purple.
Number of purple people dying, would usually correlate with the numebr of people dying of Ebola.
Now, if you vaccinate everyone against Ebola, and colour all vaccinees purple, the number of purple people dying will shoot up, since everyone is now coloured purple.
The Lateral Flow tests do not follow The Narrative when compared to the oh-so-good PCR tests.
Until we have the perfect test then we should all lock down hard however long it takes. Let the cancer and cardiac patients continue to die in increasing numbers – who cares. What does destruction of mental health and the economy matter? We need tests and more of them to tell us ….umm…well, whatever fits The Narrative.
well, as SAGE would say. ‘if it saves one life’……
You sight a PCR positive rate of 0.05% (2nd paragraph of The Tests section), which is out by a factor of 10, the actual value through the summer was 0.5%.
https://ourworldindata.org/…®ion=World&positiveTestRate=true&interval=smoothed&perCapita=true&smoothing=7&pickerMetric=total_deaths&pickerSort=desc
[As discussed below and pointed out by Paul, it is incorrect that the Lighthouse Labs opened in September, they opened in April]
As I suspect you know, through summer, PCR tests were performed by NHS labs. Since September, the Lighthouse Labs have become active and postive tests have begun to rise.
Needless to say, there’s a growing body of evidence that the Lighthouse Labs fall short of the expected standards and this may contribute to an increase in false-positive-rates.
Ultimately, I don’t see it as beyond reason, that there is a non-linear relationship between total number of tests and the false-positive-rate, such that the more tests performed, the higher the false-positive-rate. This in turn calls into questions whether the PCR tests can be used as a measure the acuracy for lateral-flow tests or whether a more appropriate gold standard is needs that can be used to evaluate both types of test.
Where’d you get this from? Lighthouse Labs were established from April (see Coronavirus (COVID-19): Scaling Up Our Testing Programmes by the Department of Health and Social Care). Pillar 1 testing is done in NHS labs, Pillar 2 in the Lighthouse Labs.
If you click the link in the paragraph of Tom’ Chivers’s you refer to, you’ll find it’s talking about the ONS survey, not pillar 2 testing. In COVID-19 Infection Survey (Pilot): methods and further information ONS say: “The nose and throat swabs are sent to the National Biosample Centre at Milton Keynes. Here, they are tested for SARS-CoV-2 using reverse transcriptase polymerase chain reaction (RT-PCR). This is an accredited test that is part of the national testing programme.” The National Biosample Centre is a Lighthouse Lab, in fact, it was the first one established, in April, not as you say, September (see Hancock launches first of three mega-labs for Covid-19 testing in Research Professional News from April).
ONS’s Coronavirus (COVID-19) Infection Survey pilot: England, 17 July 2020 which says “For example, in our most recent six weeks of data, 50 of the 112,776 total samples tested positive. Even if all these positives were false, specificity would still be 99.96%” (and so the FPR 100% – 99.96% = 0.04%).
So, the same lab which does some proportion of pillar 2 also does the ONS survey. The ONS survey’s FPR over the summer cannot be more than 0.04%. If that lab has a problem, how did ONS get so few positive tests?
This is speculation. Show your working.
I think it is very reasonable speculation. If the number of ‘tests’ conducted daily is ramped up from 0 to 600,000 in 9 months I think it is reasonable to assume that many new staff are required to conduct these ‘tests’. Presumably some training is required to qualify a technician for this purpose. For commercial reasons the organisation doing this will probably ensure that as many ‘tests’ are done as physically possible.
It’s also worth remembering that the man who devised the PCR method always said it was a research tool, not a diagnostic test.
Not a direct quote from the inventor Kary Mullis but from an article written by John Lauritsen about HIV and AIDS. He didn’t believe at that time (1996) that HIV was terminal. This notion (at that time) didn’t age too well.
You are correct. I read that too although he is now deceased.
My mistake on the opening of the lighthouse labs – I’d associated, incorrectly, the opening of the lighthouse labs with the dramatic ramp up in testing, these new labs providing that additional capacity. I’d be interested to see any data you have on the split between NHS and lighthouse labs over this period.
And thank you for the clarification on where the numbers in this piece came from – although they do conflict with those I quoted, by some considerable margin, so something is amiss. I guess without further information, cycle thresholds for example, the comparison may invalid.
When it comes to my speculation, that is indeed what it is, hence the qualification I put at the start of the sentence. I’m not aware that fine grained data regarding the testing is published, which would allow me to go beyond speculation – but again if you’re aware of such datasets I’d love to see them.
Right, but the real problem with PCR tests is how they are used. As PHE say, a positive PCR test is not proof of infection and it should be backed up by clinical diagnosis. Scandalously, this has not happened for the vast majority of tests so people have been tagged as PCR positive and forced to self-quarantine even though they are most likely of no danger to others.
The meta-analysis of research into household transmission performed by The University of Florida showed a secondary attack rate for symptomatic cases of 18% but only 0.7% for asymptomatic cases – and the confidence range of the later extended to zero.
The inventor of the PCR tests, the Nobel Prizewinner Kary Mullis repeatedly emphasised that PCR tests are not able to ascertain infection let alone illness. Indeed it is a scandal that they have been used on people who are not suffering any symptoms whatsoever. The WHO now says that if such a person tests positive then that test must be done again.
PCR testing is absurd and hugely damaging, in every respect, to societies. It has never before been used in such an irresponsible way. This is all political BS with interested parties and abuse of power and so forth.
This is just another flu-like virus/condition, and it is massively less severe in terms of epidemiological impact than flu itself, and especially if an apples-to-apples comparison is performed. That would be a comparison of the first season(s) of each novel virus — i.e. 1918..1920 (Spanish flu) vs. 2020…2021 for SARS-CoV-2.
The ratio of virulence and societal impact is 100:1 (at least) — two orders of magnitude. Properly measured, it is total years of life expectancy lost per capita that must be the measure of comparison. Not only are deaths from SARS-2 hugely exaggerated by the novel (and ridiculous) recording methods being now applied, but more importantly the number of months of life lost for the average death recorded as due to SARS-2, per case, is tiny in comparison to that for Spanish flu.
The importance of this mild/weak pandemic has been hyped up so far beyond any reasonable justification that it boggles the mind. Western societies have become weak and fragile and overmedicalized and overreliant upon provision of government/industry-supplied solutions that just do not exist. A comparison of attitude to the Spanish flu vs. SARS-CoV-2 should enlighten — the same Western societies that are now hysterical simply got on with finishing up WWI a century ago. There were no medical interventions (other than palliative such as morphine, even in the public imagination) then, and no internet, and so forth.
MDs themselves are part of the problem, because they rarely understand anything whatsoever about the underlying biology. They themselves are trained by rote in practices and concepts that are usually incorrect, but sustain the specific institutional environment and industry in which they work. So they themselves have an even more exaggerated idea of what clinical solutions can, or should, be delivered than even that of the public at large.
This virus is NOT particularly “dangerous”. One cannot stay “safe” from an endemic virus spread by respiratory means, short of sealing oneself up in a closed chamber indefinitely. The terms “safe” and “safety” applies to setting up ladders, and that kind of thing — it is absolutely inappropriate in the context of a flu-like virus and epidemic.
One of the apparent causes of hyperbolic response by MDs and others in the medical field is the fact that many or most deaths with SARS-2 occur by suffocation. This is understandably distressing for those faced with it day-in and day-out for many, many weeks in a row. This is how people also die from lung cancer and other common conditions, but there simply would not be quite as many such patients dying in-hospital in one day as during a local/regional surge or outbreak of virus.
But while the human emotional reaction is understandable, especially initially, it is NOT justifiable by any stretch of imagination. For the society overall it is hugely IRRESPONSIBLE. There is very little that medical practice can do to prevent deaths from flu and flu-like illnesses. The body’s own host defenses are largely the only effective response to viral infections especially — drugs can do a LOT, by targeting with high selectivity and specificity, to address infections by living organisms/pathogens such as bacteria. Not so for viruses — this is just the fundamental biological difference.
Medicine is largely impotent, and will remain so, wrt interventions for viral infections. The only exceptions are inoculations by vaccine (but this is really a preventative/preemptive tool rather than an intervention) and manufactured virus-specific antibodies. The manufactured a/b’s are enormously powerful, but I am not sure if their cost makes them feasible to use on any significant scale.
All of the rest, such as antivirals and corticosteroids (and other immunosuppressants) are mostly a waste of effort and investment — pretty ineffective as a whole. MDs are fooling themselves about these interventions — again, they totally lack any scientific understanding with few exceptions. Use of immunotherapies for cancer is equally an inappropriate and ineffective and unnecessary and extremely expensive medical intervention for a condition that can easily be prevented by the individual himself, and which also has a massively more powerful intervention that is, unfortunately, a commercial showstopper for the pharma and clinical and medical equipment industries (it would destroy a lot of the existing business models for each).
People in Western societies are really foolhardy to accept and blindly follow along with all of this nonsense and no skepticism and no self-education. It is tragic what is happening, but there are enormous flaws in human nature wrt modern urban societal makeup and structure.
Hmm, your strategy seems to be one of, just let the virus take its course. It’s a strategy of sorts I suppose .
I’m puzzled by your repeated references to Western societies . Are you suggesting that other societies have behaved differently in respect of imposing restrictions and investing in vaccines etc? I haven’t t seen much evidence of this and am left wondering if your target is simply Western societies and that you are using the pandemic as just some useful ammunition to ‘ have a go at the West’.
China did its show lockdowns to fake the theory that it also hurt them, but it does not, 3 deaths per million, the huge festivals where everyone goes back to their town were 100% open and MASSIVE with zero spread. China is basically immune, as are all its neighbors where 0 (Cambodia) to Korea, Japan, Indonesia (98 the highest) Vietnam (0.4) and so on show they are immune from thousands of years of it being endemic, or something of a ‘Dark Matter Immunity’.
This is a disease of the West, 1300 deaths per million, with Massive counter measures not taken elsewhere) and New World, and it has had Amazingly good uses for the declared progress of China to world dominance.
A lot of points here. Just one from me. The flu virus 100 years ago came when people were much poorer, thousands dies from TB and many had been gassed or weakened during the war. In fact, the first season of Spanish flu in the UK started in February, late in the season, and was not especially bad. The second season the following autumn/winter was indeed devastating.
Kenneth: you are absolutely right about “the novel and ridiculous recording methods”. It is shocking that when war-gaming the next pandemic in 2016 nobody addressed the issue whether the death records and their underlying certification practices were fit for purpose.
What underlying certification practices ?
Anecdata alert.
Over Christmas I developed a ‘lurgy’. Aches, pains and debilitation. My son had tested positive (LFT) for Covid, so I took the test – Negative. Symptons continued and got worse over the next few days, so, during that period, I took two more Lateral Flow tests – both Negative.
Meanwhile, my temperature had started to increase and my wife insisted we go to a drive-in PCR test centre. Tested – Positive.
Conclusion. LTF’s are pretty innaccurate. Three tests, over six days, failed to detect Covid in me.
That’s one interpretation. Another is that you don’t have COVID-19 but some other virus that is a PCR false positive. Even people who have been ill and had A PCR positive are told they still need vaccine. If they were confident in PCR they would say having the disease is going to give you more immunity than a vaccine ever will. Mass testing is pointless and has never been done before for good reason.
I think you are implying that contamination of a sample with a different virus can produce a false positive. This is incorrect. The PCR tests for Sars Cov 2 contain 3 primers – portions of the Sars Cov 2 genome unique to Sars Cov 2. All 3 primers have to give a positive result for that sample to be deemed “positive”.
The Phase 1/2 trials of the Astra/Zeneca, Moderna and Pfizer vaccines all showed neutralising antibody levels equivalent to those seen in convalescent plasma from patients recovering from Covid. How long effective immunity lasts for, either in “natural” infections or after a vaccination is still being investigated.
Mass testing is pointless. Depends how it is done. Personally, I think the ONS have done pretty well with their ongoing infection survey – all sorts of nuggets of information coming out of that over and above giving an overall prevalence for the UK, weekly.
A good article, but it ceased to have any practical relevance as soon as the author mentioned a cost-benefit analysis. That is the one approach which our Government will under no circumstances tolerate.
Should I I upvote this or downvote it? The latter if the writer is serious; the former if sarcastic.
I like the author’s recommendation as practical and an improvement over current practice. I also wonder why we don’t revisit the PCR threshold standard. There seems to be universal recognition that the high threshold is unproductive because it is too sensitive and weakens its usefulness and trustworthiness. With a lower and standard threshold, the test becomes a more trustworthy predictor of infectiousness.
Why doesn’t this article mention the enormous scientific retraction scandal surrounding the Drosten PCR test that broke in November/December last year?
point is nothing works. apparently. very apparently. despite the most draconian measure the infection spreads.
leave it alone – because that’s apparently essentially what’s happening anyway despite what you think you’re doing – and let people figure out for themselves what’s the best way.
govt interference has prolonged and exacerbated.
let them concentrate on getting hospital beds and finding cures, assessing real potency of Vit D and Ivermectin and whatever and erecting quarantine barriers around old folks homes.
It’s like a bunch of people standing around a fire and shouting at it.
There are many pragmatic ‘half-way houses’ which can be tried, such as operating the full proposed LFT regime in a limited section of the country.
Since we know so little about what will happen, observation should trump theory. We should try as many approaches to the problem as possible and see what happens rather than closing down possibly helpful activities on disputed theoretical grounds.
As the article above stated, it is easy to set temporary rules to shield the most vulnerable in places where experimental trials are taking place. And we should not lose our sense of proportion. This is not a plague year. It is the equivalent of a particularly bad flu year, and we have gone through many of those in the past…
“… observation should trump theory….”
Yes, it should. However, in recent years theory tends to trump reality as reality is disfigured by vested interests.
I’m not hopeful.
Well the one positive, everyone is still talking to each other. So, I for one feel the conflict and the problem will be quickly resolved. Three cheers for the knowledge and the science.
No Talk – ALL is telling. The insane governments of Europe, UK, and Democrat portions of USA made completely illegal rules up and enforced them with police. NO DISCUSSION!!! Biden will ride in as Caesar and lay out the laws with as much personal authority and as capriciously, and for his own political ends.
Tom’s half right, which is better than usual.
Tom doesn’t understand that a “false positive” rate not false positives measured only in the positive samples collected, but across all samples corrected.
What Tom calls “mad” is really just the basic understanding that with, say 100 tests and a FPR of 1%, 1 reported positive is 100% likely to be a false positive. With 2 reported positives, 1 of them is likely to be false, and so on.
So when the false positive rate = the reported rate, you really can’t have faith that the tests are finding “real” positives.
Currently, rates of infection are high, so false positives are less an issue. But when we’re out of this winter period, rates will fall and FPR’s will again be a problem.
Until next winter when we get another spike …
What is the point in testing symptomatic people who are not ill enough to go to hospital ? The only benefit will be if you can trace and isolate all of their contacts. This only works when the numbers are really low, and when the test has negligible false negative rate. If you are ill with any respiratory infection you isolate as best you can – tell your close contacts to be wary, and possibly they could get a test to see if they are asymptomatic carriers. If you are ill why have the test? If there is any false negative rate the test will likely make things worse.
One thing is certain, we are not going to eliminate Covid 19 even if we look up the entire population for 6 months, with no one going outside for exercise, to buy food, get medial attention, etc. So we have no choice, we have to learn to live with the disease.
The idea that we can just wait until every scientists says it’s safe is impossible. We need to do the best with what we have and let people get on with their lives. LFT appears to offer a solution that cuts transmission and that is the best we can do, so lets do it and get life moving again.
Yes. This is essentially a severe flu, and it will get less severe as it adapts itself to our bodies.
Ideally, we would use HCQ like India is doing, and cut our cases by 3/4…
This is journalism of the highest order. Nothing like this would be found even in the more thoughful print media. It is too detailed. As for the soundbite broadcast media…forget it. The issues raised here will have to be debated to a resolution and become public health policy. Because one thing is for sure. This pandemic will not be the last. The next time, we MUST respond better.
It’s not at all clear why the talk of a false positive epidemic is mad. The World Health Organisation wrote to all Governments recently warning them not to run the PCR test above 30 cycles because doing so yields high false positive rates: we routinely run it above 40 (one cycle is a doubling of “amplification”).
The test is extremely sensitive to contamination and is intended to be performed at low volumes, using low cycles, in clinical settings, by highly trained staff. We run it at absurd volumes and absurd cycles, in labs that didn’t exist a few months ago, using staff that weren’t trained a few months ago, on samples that have been obtained in supermarket carparks. It can’t discriminate between active virus from the infected, dead virus fragments from the recovered, similar looking things that aren’t virus, and whatever got into the test from grubby handling methods.
The original estimate for deaths for the 2009 swine flu “epidemic” – 65,000 – was derived from tests that were assumed to be true positives. We even bought £560m worth of vaccine. In the end, “cases” occurred at exactly the false positive rate. Almost every “case” was a false positive, and the “epidemic” vanished when we stopped testing, yielding an eventual death count of 392.
I presume that mentioning all this is “mad” because the current clown show is assumed to be capable of producing a more reliable outcome. Bless.
You’ve put it succinctly and persuasively well – congratulations! Even the inventor of the PCR test has utterly decried its unsuitability for viral detection, yet here we are: utterly reliant on this unreliable testing mechanism which “informs” political decisions and what they’d have us believe is a strategy or key determinant of what underpins (the sheer lack of a) coherent public health policy. On the basis of this dodgy test and the data it supposedly generates (I was tempted to say spits out), the misery of lockdowns and curtailment of civic freedoms is predicated.
As for the Cycle Threshold: is there any public data available on what number the NHS is using / mandating? I gather it can vary, but c.45-50 is a number I’ve been made aware of from within the NHS – so is it any wonder the so-called case numbers are so high? So basically any corona, old or new is capable of ‘identification’. And then, how to define a ‘case’? A positive test, or a positive test requiring hospitalisation?
I realise highlighting these controversial aspects of testing are – in too many circles – regarded as not merely sceptical but heretical. Merely to question is to attract accusations of denial, being a refusenik and the intolerant, dogmatic attacks similar – it feels – to the era of religious dissent in C17th England. I am no Leveller, Digger, Ranter or what have you – but I seriously welcome the injection of truth and greater transparency into this crucial but seriously hijacked debate.
Interestingly, World Health Organisation have published guidance (2020/5, version 2) that, for a “case” to be considered as evidence of infection, a “positive” test that is obtained for an asymptomatic patient must be repeated. Just this protocol alone will slash the “case-ademic” – they applied this protocol in testing of Cambridge University students prior to Christmas and every single “positive” result was false.
Also the much heralded vaccine, Pandemrix, turned out to be a little less than effective and was quietly withdrawn after evidence started to emerge of narcolepsy as a recurrent side-effect. Not before an eerie parallel sequence of events that don’t exactly compare well to the present. As in: rushed Phase III trials (not sure how large / wide the samples were), accelerated MHRA (regulatory) approval, a media campaign to compel utter belief in / acceptance of the vaccine and similar elements of shaming / stigmatism to those expressing doubt (scepticism!). That went well. And yet, the utterly unquestioned assumption that everyone must accept vaccines as a panacea.
I just hope some or all of these vaccines work, as in prevent infection and transmission. As yet we – nobody – knows.
I’ve seen the term “cold positive” used for detection of dead virus in recovered people, and my impression is it’s widely agreed that’s an issue when PCR tests at run at high cycles.
Testing is imperfect but is the only way to understand the trends, which are real. Deaths are a mixture of people dying from COVID and people dying with COVID (the latter being the greater proportion) – ONS all cause deaths are very interesting as they are way below the first peak, despite deaths from / with COVID being way above it.
However the number of people on life support with COVID is totally real and not subject to inaccuracies and they are not all over 65, far from it. There are more people in hospital now with COVID than during the first peak. Those are facts and no amount of entirely valid discussion around the imperfections of various tests and various control strategies alters them. As the new case rate, as measured by imperfect tests giving false absolute numbers but reliable trends, has thankfully peaked with the latest lock down, it looks like we might get away without the NHS collapsing by the skin of our teeth, as the lag between new case peak and numbers in hospital is about 3 weeks.
Our priority now must be to get our kids back to school as soon as possible and get our economy moving again. To do this we need to use every imperfect tool we have in the best way we currently know how. We can only do that when we have created enough headroom in the hospitals to get back to treating other killer diseases with sufficient margin so we can effectively manage the risk of NHS collapse from another resurgence either due to being too bold in opening up or another mutation. This is a judgement call based on the trends arising from new case data from imperfect testing. I share your scepticism about the ability of politicians of all parties to make those judgements well.
Whilst I am highly critical of the NHS as an institution, the medical staff and those who enable them to do their job are worthy of our admiration and praise. Anyone who dismisses how tough the pandemic has been and continues to be on their physical and mental health is “mad”, as is anyone who thinks an NHS collapse would not be such a bad thing.
I would disagree. A trend that derives from a variable rate of testing, comprising a likely significant and variable number of false positives, is essentially meaningless. It can go up because of any combination of increased test frequency, increased asymptomatic tests yielding false positives, or increased Cycle Thresholds yielding false positives. What is the physical interpretation of a line drawn through with a ruler?
The age-standardised mortality rate in 2020, even with Covid, was lower than it used to be every single year until only a decade ago–these are not uncharted waters. Since the NHS did not collapsed when seasonal loads were much higher, and has benefitted recently from considerable expenditure on reinforcement, it’s not obvious why you believe it might now.
I agree with you that the number of people on life support is real, and of no less concern than in any other year. But PHE data (as helpfully tracked daily in The Spectator) shows that critical care bed spare capacity in 20/21 has never fallen below the spare capacity available in 18/19 and 19/20, and general and acute occupancy is below the January 2020 level. Some beds are being occupied for longer–because of a failure in the insurance market (reported in the FT) that has lead to uninsured care homes refusing to take back discharged patients. Not because Covid has extended care requirements.
Meanwhile, in addition to the false positive rate, the Covid death trend used by many to estimate the impact on the NHS is grossly inflated in two more ways: (1) non-Covid mortality has halved, meaning either there is been a miracle in 2020 in the treatment of life threatening illness, or a colossal miscoding of non-Covid death is taking place. (2) Flu–which is the leading cause of acute respiratory infection in the winter–has fallen 95% as SAR-CoV-2 has replaced it in the virome. If “zero covid” was achieved tomorrow, the people currently dying of Covid would presumably revert to dying of flu, or we would experience another medical miracle. The net Covid burden on the NHS is proxied by the gross Covid death rate minus the missing non-Covid death rate, minus the missing flu death rate–which is significantly lower.
NHS is pressured in significant part because a number of healthy staff in receipt of a false positive test are sitting at home with a box of Quality Street and Netflix.
So I think your claim that Covid threatens the near collapse of an NHS that received an extra £3 billion in reinforcement funding, had nine months to prepare for the perfectly foreseeable annual increase in winter morbidity, and is now experiencing a net load increase that is a fraction of the published Covid death rate, is weak.
The solution to sending healthy staff home, and failure in the insurance industry, is not the mandatory closure of businesses and confinement of the healthy population to their homes for months–a solution the government estimated at the end of the first lockdown would lead to the deaths of 200,000 people, and Bristol University now estimates at closer to 540,000.
The author misses a lot of the reality of PCR testing. He has explained what we have been told, like a teacher to a bunch of kids, without examining whether what we have been told is in fact true or not. And sadly, a lot of what we have been told is not scientifically or factually correct.
Exactly what evidence do have for your wild claim the a lot of what we have been told is not scientifically or factually correct?
See above.
Lateral flow tests are completely inaccurate my brother works in a hospital and tests himself twice a week as do most NHS staff. Over Christmas like Mark Bailey below he had a negative test in the morning and by the afternoon could barely breathe he had a PCR test and had covid he’s still recovering. We also heard of another friend whose whole family have been infected by a junior doctor who did exactly the same, LFT test then developed COVID. She only visited the family in question for a short time on Christmas Day and also infected her own parents. It makes me question if the current wave of infections has not been caused by all the people, many working in the health service going out into the community thinking they are safe and then unwittingly infecting others. How many responsible students were also guilty of infecting their grannies I wonder after trying to do the right thing.
Im just a bit baffled by this argument. Isnt it a bit late in the day discussing which test is superior?
The crucial question is whether the efficacy of the vaccine in the real world compares with the trial data. . If it does why on earth would we want to have weekly surveillance tests. The vaccine will not prevent a positive Covid test. It will decrease hospitalizations and death rates. If that happens does it matter how many people test positive and what the specificity and sensitivity of that test is.
If the vaccine works the infection rate is meaningless.
What this article really confirms is that when politicians say they are following the science, they are kidding themselves. Because science opinion is not singular or lateral, it can go in many different directions.
STOP PRESS: After this article was published, World Health Organisation published guidance (2020/5, version 2) that, for a “case” obtained from a PCR test to be considered as evidence of infection, a “positive” test that is obtained for an asymptomatic candidate must be repeated, and in any event must report the Cycle Threshold that was used to obtain it.
This is in direct response to concerns about the high prevalence of PCR false positives at high cycle thresholds with low viral load i.e. asymptomatic candidates. Which is to say – 90% of the UK’s mass testing subjects.
Just this protocol alone–if observed–will slash the “case-ademic”. They applied it (presumably, accidentally) when testing Cambridge University students prior to Christmas and every “positive” result was discovered to be false.
The claim in this article that concerns about PCR false positives are unfounded is unfounded.
Why would anyone down vote this?
Not playing into their covid ideologies, narratives maybe?
“For all the mad talk of a false-positive epidemic, the false-positive rate of PCRs must be very low, because for a long time in the summer, the total number of positives ““ false and true ““ was around the 0.05% mark. The false positive rate must be lower than that.”
Just checked the figures. You have slipped a decimal point. Actually it went down to about 0.5% not 0.05%. That is consistent with the PCR false positive rate being 0.5%, and the virus essentially disappearing over the summer.
Further, as you mention later in the article, the PCR critically depends on the number of PCR cycles. The government refuses to publish cycle numbers, so we don’t even know their definition of a “positive” result.
The crucial question is: did the number of cycles being used change during 2020? We simply don’t know. If it changed, then the rate of false positives would change.
What we do know is that the WHO has today urged positive PCR tests in asymptomatic people to be retested.
www dot who dot int/news/item/14-12-2020-who-information-notice-for-ivd-users
“Where test results do not correspond with the clinical presentation, a new specimen should be taken and retested using the same or different NAT technology.”
Thus far, there is no sign of the government heeding that advice, or indeed of the mainstream media picking this up.
The previous version of that WHO page can be found on the Wayback Machine. This previous version did NOT contain the advice to retest.
Twitter obviously full of conspiracy stuff about this being on the date Joe Biden was inaugurated, but regardless of that, the UK government clearly needs a big change in its testing regime.
Check out the Cormandrosten review by Eurosurveillance. Lays bare the entire fallacy of PCR testing. Thankfully the German state prosecutor is on the case: the lies upon which everything has been based is now exposed. Ever wondered why the British government won’t publish which CT level they’re using? This will tell you why. It’s devastating. Expect it to be rubbished or suppressed (I keep having to find new links to it) but something approximating to the underlying truth is now out there.
I’ve read the paper and really don’t understand your point . It most certainly does not rubbish anything ( it also not really relevant as it wasn’t actually using the Covid 19 virus)
I don’t, with respect, understand yours either. The inventor of PCR declared it utterly useless for viral detection, the CR review lists the corner-cutting, lack of SOPs and susceptibility to inaccurate results if the CT number is set too high. Even the WHO, which also says lockdowns don’t work, published a communiqué on January 13th advocating not using CTs of >30. Anything above this number will pick up virtually anything and everything including dead fragments of coronavirus from recovered previous positive cases.
Also both Corman and Rosten were on the EU board of approval for what they were promoting, the selfsame board outdoing our own MHRA in the speed of its approval (<24h).
It may not ‘rubbish’ anything but it asks serious questions as to why everything is keyed off a flawed test.
Not correct. Search the ONS website for Coronavirus (COVID-19) Infection Survey pilot: 2 July 2020 which says
There has been an outbreak of Covid amongst family members in Brazil. It is a country of NOW, deep distrust of authorities, and a system in which budgets are often diverted into politician’s pockets.
When people started having symptoms there was a wide variety of responses. The conscientious ones did a pharmacy test (I’m assuming these are LFTs), many (generally male) refused to have a test at all, and I think that only those who were hospitalized had a PCR test.
The refusal to have a test at all stems, I think, from a desire to avoid pressure from the family to self-isolate if positive. One sister-in-law refused to take another LFT after testing negative, because she wanted to go on holiday. The other sister-in-law (who is a health academic) tested negative (LFT), but had symptoms and was positive on a re-test.
The take-away from this small sample of about 10 people is:
* Those who place self-interest about the interests of others will do what they want, anyway.
* The pharmacy-test used in Brazil was right more often than not (my guess around 75%)
* In this group there were no false positives from that test.
The living-in-the moment nature of life in Brazil resulted in the tests being taken by people who were mostly in early stages of infection. It’s clear that they were helpful in getting most family members to take the infection seriously. Of those who didn’t take the spread of infection in the family seriously, the refusal to take or re-take the LFT implies that they at least think it works.
Maybe this does not shed much light on the points made in the article, which is about using LFTs as a way to reduce risk. Perhaps one way to deploy them effectively will be with an appropriate name e.g. “screening test” so that they are not confused with PCR tests.
The PCR vs LTF is a false dichotomy because their use achieves different things.
LTF can help us understand where there are clusters of infection. It shouldn’t be talked about as telling you if you individually are positive or negative.
Once clusters are found we could then do PCR tests on contacts.
The problem is we intuitively see a test as giving a binary answer about an individual. LTF doesn’t do this… it is useful for society, but it can’t reliably tell someone they aren’t infectious.
The real strength of mass testing is in finding the clusters that cause the majority of Covid spread, and helping us stop those clusters growing. This is especially important as 10-20% of cases cause 80-90% of infection (See https://www.theatlantic.com… )
Hi Tom,
A very interesting article, but I have to respectfully disagree with your point about ‘mad talk of a false positive epidemic’ in relation to the PCR test in as much as I don’t think the impact of false positives should be underestimated.
Whatever the false positive rate (FPR) is it is a constant across the number of tests being conducted and so the number of false positive tests will be a higher percentage of the total positives when the level of infection is low.
But this is not to say at higher rates of infection the FPR cannot be significant. If the FPR is say 3% for arguments sake, and if there are a total of 20,000 positive PCR results out of a total of say 250,000 people tested, then the total number of false positives would be 7,500 (250,000 x 3%). This represents 37.5% of the total positive tests – by no means insignificant I’m sure you would agree.
I accept it depends of course on what the actual FPR is. I have seen figures ranging from 0.2% to 5%, and the rationale for a FPR of 2%-3% does not seem an unreasonable assumption when the PCR test is being utilised on an industrial scale, processed by individuals with very limited training and being run at a cycle rate above 30. (It is of course widely known the PCR test was never developed for such a mass testing purpose).
My only concern is getting to the truth and so my interest is to know what the actual FPR is. However, this is something the Govt seem very reluctant to disclose and without the actual figure it is very difficult, if not impossible, to make any meaningful judgements about the PCR test.
So, the burning question is why is the Gov’t not prepared to release this information; they must have it. One can postulate numerous reasons as to why, but whatever it may be, a lack of transparency as to the FPR (and also the cycle rate labs are running) is very worrying and suggests it is significantly higher than the Gov’t would want us to believe. And this just adds credibility to a figure of 2-3% being close to the truth.
The argument over PCR tests seems to be a local UK thing. I live in Melbourne, Australia, I’ve been tested three times. I have asked the doctors involved, my GP and the head of my GP’s practice whether there is a problem with false positives. No. The numbers bear this out. tens of thousands of tests are done every day yet we get only a handful of new cases and they remain cases until either they test negative or die. All the positive results are linked by genome to other positive test results. We have maps of the spread by genome. We know who caught it from whom, where and when.
Australia uses the same suppliers as the rest of the world. All the test kits approved for use in Australia are listed on the website of the Therapeutic Goods Administration (TGA). The effectiveness of each testing kit is monitored in the field so TGA knows both what the manufacturers certify and what is achieved in practice. TGA also monitors the performance of testing centres/labs so there is assurance that all are performing properly. There are different types of test in use, most are PCR.
There was a false positive a month or so ago (in South Australia, if memory serves) which was so rare it made the media headlines.
There is no problem with false positives in Australia and never has been. Why is there in UK?
It’s not just a U.K. issue – legal action has commenced in Germany to try to force the retraction of the Corman-Drosten et al paper which defined the original PCR test for SARS-CoV-2. A team of 20 scientists reviewed the paper and found several major issues.
The action is headed up by the eminent lawyer Reiner Fuellmich who was previously part of the legal teams which successfully sued VW over the emissions scandal and also Deutsche Bank.
If you’re interested, details can easily be found if you search for cormandrostenreview.
A couple thoughts:
(1) One category is what I’ve seen called a “cold positive” – detecting dead virus after a person was infected and recovered (sometimes long after – weeks). That depends in part on the cycle threshold of the PCR test.
(2) Another concern could be cross-contamination, either at the collection stage or in the lab. I don’t know if anyone has determined this to be a big problem, though there are anecdotal reports of it happening. Extreme examples can of course be spotted by monitoring for outlier results – if a lab has 90% of its tests come back positive for a day, then one would hope someone says they need to assume contamination rather than blithely report those results.
It stands to reason that neither of those are issues in a place with extremely low prevalence of COVID, such as Australia.
So what do we make of this?
https://www.who.int/news/it…
…or, stay home if you’re sick. Don’t hug granny.
What Covid tests can we trust?
None, according to the latest WHO Guidelines on PCR tests released yesterday
https://www.who.int/news/it…
https://redstate.com/michae…
See the cormandrosten Eurosurveillance review. Why this isn’t headline news is a disgrace, but no surprise given the woeful MSM.
Wow, thanks for the links
So two sides of the coin contesting the accuracy of the tests. This may mean that the cases in our statistics cannot be proved and therefore we could be trashing our economy for nothing. The only thing we can be sure of is there are people dying from Covid 19 but even that is contested in some circles saying a lot of it is other illnesses or has been counted twice. I just hope the truth is stabilised soon so that we know what we are supposed to be doing.
I think this is rather out of date. The WHO has updated its advice regarding the PCR test. It says that any person who is not presenting symptoms yet tests positive for Covid should be retested. It also stated that the CT rate of the test should be disclosed. Further more, some weeks ago, an appeal court in Portugal ruled that the PCR tests are not able to ascertain infection let alone illness, which is exactly what the inventor of the PCR tests, the Nobel Prizewinner Kary Mullis repeatedly emphasised.
Which
“Unlike PCR, they (LFTs) don’t test for viral RNA but particular proteins made by the body in response to the virus.”
I think I’m right in saying that the current generation of LFTs actually test for the presence of SARS-CoV-2 proteins ““ in the case of Innova’s LFT detecting nucleocapsid proteins – not antibodies as implied by the author.
Correct.
I think the trick is not to see LFT as a replacement for PCR. Then, even if LFT picks up only 50% of genuine positive cases, that is 50% more than we would of otherwise picked up. Of course we still need to work out the cost benefit, but mass produced testing does become very cheap per unit.
During much of the pandemic, the average number of people infected at any one time was about 1% of the population. I would rather we spent a fortune trying to identify and lockdown this 1% rather than locking down the entire population.
The lesser of two evils is mandatory mass testing and isolation of infected people, rather than mandatory isolation of an entire country.
To put testing into perspective, consider than this is the first disease we have had where we need a test to tell us that we have it.
What about cancer screening?
That is not really the point of the test. It’s to try to identify if we are infectious and then ensure we isolate. Incidentally the later part is the real issue, not the former, but it’s largely been ignored. Mainly because the fault lies with individuals and not the Government.
The lesser of two evils is mandatory mass testing and isolation of infected people, rather than mandatory isolation of an entire country.
I realize it’s a turn of phrase, but the choice still leaves an evil in place. And what of the vaccination refuseniks; will they be un-personed in some way, forced to wear some identifying marker so that jabbed society might shun them?
This whole affair is so politicized that every step is magnified, to include reports of people dying after getting the vaccine. And if this shot is required, then a precedent has been set for the next virus and the one after that. Maybe we can stop pretending that this virus is the new black death and treat it with the level of concern that it merits.
jabbed society might shun them..presumably if you’ve been vaccinated then from a purely personal point of view you don’t care if the other person hasn’t?
Presumably, but this parallels the question on masks. The people who wear them insist that you do as well; I suspect that would apply to vaccines. I could be wrong.
The principle that we infringe on an individual’s liberty to protect a greater infringement on another individual’s liberty is well established. It’s the basis of a liberal democracy.
If you are infected, then you stand the chance of causing serious illness to another individual. We are therefore justified in making you spit into a tube and then insisting, if positive, you spend 10 days at home watching netflix and being paid for the pleasure. That infringement is far less than the infringement of becoming seriously ill.
COVID is not all about deaths. It hospitalises 2% to 4% of those it infects and unlike deaths, it also impacts a lot of those under the age of 50. That’s millions of people in the UK. We can’t handle that many people in hospital, even if spread out over months.
Asking people to spend 10 days at home whilst being paid is not that big an infringement. We need to stop pretending it’s the equivalent of being tortured or sent to prison, its not. Neither is it the start of a slippery slope. It’s a reasonable and proportional response to a catastrophic event.
“We”? Who the f*ck are you to arrogate this term to yourself or your line of argument?
You pop up regularly to promulgate your views, fair enough. But now you presume to speak to / for us all.
I am not the first to ask: do you work for the government?
I am not attempting to speak for the everyone, you big noddy.
I meant ‘We’ as in our legal system. We arrest, imprison and / or punish / sanction people all of the time. The justification is that you are deemed to be infringing on another individuals liberty (by physically attacking them, stealing their property or otherwise infringing on their rights as individuals)
Which government am I supposed to work for? You do realise the internet is global and there are 200 countries in the world?
The real question is whether mass testing has stopped the spread of the virus. It’s estimated that one in ten had antibodies in December and lots more have already been infected or had prior immunity. Care home residents are still being infected and ending up in hospital despite extra measures. The virus is now unstoppable and the only option is to hope community immunity happens soon aided by a vaccine. All other measures are a waste of time and are causing huge collateral damage to health and economy. The zero covid ship sailed long ago.
I agree the new variant is a game changer and ultimate herd immunity aided by the vaccine may be the only practical way out whether we like it or not.
However the mass testing concept has intriguing possibilities beyond COVID. It could help us suppress future pandemics without closing down our economies. It could also provide fascinating information on existing infectious diseases, and could help to reduce or eliminate them. For this reason, we should continue to pursue.
Tend to think that the issue is being approached fro. two , quite different perspectives. At a population level I can well see that Lateral Flow Tests can help keep the R number below one, perhaps way below one if combined with other measures,
At an individual level, however, I certainly wouldn’t accept the results of one test taken at home by e.g everyone attending a Theatre performance as being any sort of guarantee that it’s quite safe for me to sit for a couple of hours with several hundred others in what are generally rather airless and close seated rows of a cheering audience. Similarly, I would be nervous about pubs, bars, and restaurants, trains, planes and ships , and most of all visiting care homes that weren’t taking other measures.
Hi, the same old myth persists regarding RT-PCR testing that it requires a lab and takes days to process submitted samples
With out partners, MBS, we provide a full RT-PCR testing instrument that processes up to 400 samples in around 20-25 minutes with an accuracy / efficacy of better than 99.99%
It does not require a laboratory environment, just a dedicated space – its the size of a shoe box and indeed being considered for installation in a vehicle to provide testing at remote locations
The price per test including the PCR test instrument, the sealer and scanner plus a relatively small number of test kits is comparable with that of an Antigen test
No special skills are required to collect the sample or to operate the PCR instrument , the Sealer, or results Analyser
We believe the actual testing is only one part of the testing process, the other include the provision of a dynamic, highly secure, cloud based International Health Passport that is used to record the test results, and also the vaccination time; none alcohol based long term disinfecting and cleansing material for all surfaces, approved by Boeing for use on their aircraft fleet, a similar approval process is underway with Airbus Industries
We add to that a track, trace and distancing app, misting tunnels for baggage and freight, etc; UV lighting for areas such as elevators, lifts, kitchens, etc
Paper covid -19! Testing results documents required by HMG for entry to the U.K. are really not worth the paper they are written on- I have heard that “official” blank covid testing forms are available for 75 euro on the internet – one simply add that they have had a negative COVID test result together with the appropriate date and time – and this seems to be acceptable- madness
The U.K. government currently only uses Antigen / Lateral Flow testing with the results that we now have
> We believe the actual testing is only one part of the testing process, the other include the provision of a dynamic, highly secure, cloud based International Health Passport
Why cloud based? (I’ve done plenty of technology strategy work on identity for government and this goes against the grain.)
A central database with everyone’s id + health data presents a lot of privacy and security issues. Why not store the data decentralised, secured with cryptography like the data on a passport chip? (This data can also be held/validated on a mobile phone)
We provide many database solutions, this one is already in operation in several countries
We operate in the real/time market and for this specific application we decided a cloud based solution was the best option
The database can be only be updated by an authorised and registered health care professional, the status can be read on a user mobile device or by an authorised system user- for example an airline check-in agent
Obviously the validity period of the covid test and the covid vaccination are both limited- timers are set independently, say for 72 hours for the covid test, 6 months for the vaccination but both can be set to any time required – but not by the owner of the mobile phone, only as configured in the DB.
The ability for a user to update their own phone is as bad as providing a piece of paper
> The ability for a user to update their own phone is as bad as providing a piece of paper
No, that’s not correct. That’s not how asymmetric key encryption works.
The data package stored on the chip of a passport is signed by the private key of the passport authority. It cannot be changed without invalidating the signature.
There is no reason the data on a passport could not be stored on a mobile. It is substrate agnostic.
> we decided a cloud based solution was the best option
A central repository for this data will be a big draw for hackers. Once it is accessed there is no way back. Your company would be finished.
Rethink this.
My friend, we deal in real world, real time solutions – not conceptual government strategy
I note the the Home Office could not even keep it own records safe – so much for strategic government systems implementation – a joke
We have worked in database technology for the best part of 40 years as part of complete real-time solutions.
Happily to shall continue to earn our crust through delivering fully functional solutions, not simple strategic studies that generally end up in the bin
Maybe you could learn the very basics of digital security before making these bold statements, starting with the abcs of asymmetric encryption.
That is your very simple understanding and interpretation of digital technology – obviously an armchair scientific “expert”- the fact is clear, two of the government most recent failures, the HMR prisons data loss fiasco and the “track and trace” failure are obvious the result of “experts” who determine government strategy but without the technical knowledge or skills to actually achieve any results
Our International Health Passport is operating on three continents, our track, “trace and distancing “on two, including several hospitals
Where exactly have your projects been implemented?
Zero Covid = Acceptable Covid
Seems the former wants continued lockdowns and economic devastation, possibly with the intent of destroying the government, whilst the latter doesn’t want continued lockdowns and economic devastation, possibly with the intent of saving the government.
Politics and Science are like oil and water.
Agreed. And the truth is…?
Is the LFT false negative probability reduced by administering multiple tests in the same session, or soon after a negative result?
Thanks for clearing this up for me.
The real debate seems to me to be when to start mass testing. If LFT false negatives result in many more deaths that is a bad outcome. But if, sometime in the next 6 weeks we have vaccinated the over 65s (who make up 90% of those who are going to die) then mass testing accompanied by rules that provide protection for the over 50s (who make up all but 1% of the remaining deaths) mean those under 50 can visit pubs and restaurants etc safe in the knowledge that even if they’ve had a false negative LFT they probably aren’t going to kill anybody.
The cost of roll out will be more than compensated for by the beneficial impact of the reopening of the hospitality and other sectors.
Well, I include a false positive return as anything that says I’m infectious when I’m not.
It is interesting to read the government’s position on the PCR test:
https://www.whatdotheyknow….
Here’s the interesting part, when talking about the test labs:
“These laboratories have a statutory duty to report positive cases to PHE, but they are not obliged to advise PHE which tests they are using, nor submit Ct values used to PHE.”
The labs choose the specific test assays and what CT values to apply. If you are a lab and want more business, what level would you apply (especially if you don’t have to tell anybody and more positive cases generate more track and test).
The whole thing has gotten so out of hand that the WHO has had to remind labs that they should follow the instructions from the manufacturers and that they should publish the Ct value on the test results.
https://www.who.int/news/it…
Despite the simplistic dismissal of significant false positives above, the UK govt were not so sure in October claiming:
The PCR “operational false positive rate is unknown” but estimating the “median false positive rate of 2.3%”.
https://questions-statement…
Why would the government not know such a critical aspect of our testing infrastructure?
The only thing we can rely on is excess deaths but even that is not straight forward because increasingly where excess deaths appear it is impossible to distinguish covid as the cause versus the impacts of lockdowns.
If you are a PCR problem denier, I’ll just point you to Mr Fauci:
https://twitter.com/i/statu…
Of course, the response is that those testing positive must have had the infection at some point. Maybe (or maybe not) but I doubt that is what people think when they see the case numbers.
Lets bring in the judges:
https://www.portugalresiden…
Joe Biden, since becoming President, has said on camera that “there is nothing we can do to change the trajectory of the pandemic”. In other words, testing and vaccinations will have no effect.
You are making a mistake in thinking that the false positive rate is fixed it isn’t. As you increase the cycles, it will increase dramatically, also you have chosen to ignore cross contamination huge laboratories doing millions of tests with untrained inexperienced staff will lead to massive quality issues.
DO BOTH !!!
What has not been taken into consideration is the amount of resources devoted to alternative methods for detection of small particles including Cov-2 which has inspired exciting and novel technologies which could affect all aspects of infection diagnostics.
In the main, a sensible article, good explanations and a broadly correct exposition of the debate.
My take: just get everyone vaccinated, as soon as possible. The priority system adopted is fine, but don’t let it hold back the vaccination rate.
What if you want to wait and get the vaccine in a couple of years when we all know what the ADR’s are?
ADR?
Adverse Drug Reaction
Ah thank you! I am used to that being American Depositary Receipt. It would be very poor judgement since the likelihood of and risk from these are by comparison tiny, much less than that of long term adverse reactions to the virus itself. Unherd does not like links but if you search there is a useful discussion on Medium written by Shin Jie Yong, entitled “Hypothetical Lasting Healthcare Problems of mRNA………………….”.
At-home LFTs make absolutely no sense in the current context. If the only reason you’re taking one is so that you can do something you want to do, you have every incentive in the world to do it incorrectly to get a false negative. As no one is monitoring the testing, the false negative rate will be orders of magnitude higher in the home setting compared to a clinic. Human nature would render LFTs completely useless and a huge risk to society.
Scientists have been running the UK for the past year and all they’ve done is prove how utterly incompetent they are.
Wrong. Bad scientists have been advising government and the government doesn’t know what to do. Arts degrees in government people lead to this. PPE is about reading books and having theories but doesn’t tell you anything about how to deal with real things.
Where exactly has the government diverged from scientific consensus? If these are “bad” scientists in charge, then the good ones are being awfully quiet about their faults.
I say this so many times that I get boring. The problem is not really the scientists (or maybe it is). Think of what happens. Government asks, ‘Is wearing a mask any use?.’ This is passed to a toady, then another toady, then a scientist, who says ‘Yes, if..if..if’ Back to government – The scientist says ‘Yes’
But everybody has a different view, everybody wears the mask differently so the problem has become a management problem instead of a scientific problem. How can we train 64million people to handle masks correctly? The problem is with the management of the situation, not the scientific solutions.
If a scientist can’t understand how a theory operates in the real world, then they’re incompetent.
Again, where has the government diverged from the scientific consensus?
Have to ask, which consensus. Wearing masks is one area.
You do not get a reliable scientific consensus on any topic until many years have passed, and often not then.
Science, in any case, does not recognise ‘consensus’ as being a proof of anything. The word ‘Consensus’ is used by establishment politicians like the President of the Royal Society to mean ‘We’ve all agreed this, haven’t we?’. Getting group agreement is a deeply political act. Not a scientific one…
How about the WHO stating that lockdowns don’t work?
Your first paragraph describes management consultants to perfection. Alas, to adopt our bumbling idiot PM’s turn of phrase, we are paying rather a lot of them rather a shed load of taxpayer money notwithstanding. We always do, to the same consulting firms who seemingly always fail but never get called to account. First lawyers, now consultants – massive fees, zero liability.
Depends what you mean by ‘Bad’. I speak as a retired scientist, with experience of Regulatory capture, an economic theory that says regulatory
agencies may come to be dominated by the industries or interests they
are charged with regulating. The result is that an agency, charged with
acting in the public interest, instead acts in ways that benefit the
industry it is supposed to be regulating. SAGE, NERVTAG and the Joint
Committee on Vaccines and Immunisation, to name a few, are dominated by
scientists that are funded, directly or indirectly by the pharmaceutical
industry. For example see:
https://www.zoeharcombe.com…
You’ve nailed it.