PCR test sensitivity and false positives
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The retired government scientist I have mentioned before has been number crunching again, this time about the PCR test and false positives.
This is what he reports:
I’ve had some cracking discussions with a GP [referred to as DM] of Cumbria regarding nominal test sensitivity, specificity, disease prevalence, bench-marking and gold standards (lack thereof) and decided to treat everyone to a single slide that summarises everything we need to understand about false positives.
In plain English a false positive is when we tell somebody they are infected with a disease when they are not. All diagnostic tests have their limits and the RT-PCR test is no exception, but what governments and their expert advisors are doing is completely ignoring this basic fact and assuming everybody who tests positive is either sick with COVID symptoms, infectious or carrying the SARS-COV-2 virus.
Nothing could be further from the truth, as you are about to see for yourselves.
For this analysis I’ve set test sensitivity at a nominal 80% (a figure supplied by the Centre for Evidence Based Medicine at Oxford University). This figure tells us how good the test is at detecting presence of the virus in infected people and an 80% sensitivity means that the test will detect 8 out of every 10 infected people, thus two people will go home being told they don’t have the virus when they do.
RT-PCR test specificity is a most controversial subject, with initial nominal estimates set at 99.9%. This figure is essentially a guess based on previous research, bench studies and hand waving, with experts arguing over what the real figure is. Specificity tells us how good the test is at detecting absence of the virus in uninfected people, and 99.9% specificity means that the test will accidentally yield 1 infected case out of every 1000 uninfected cases, thus this person will be told they are carrying the virus when they are not.
What complicates matters is how much disease there is in the population. We call this prevalence and 1% prevalence means 1 in every 100 people are carrying the virus (SARS-COV-2) that causes the disease we call COVID-19. When a viral infection is highly prevalent diagnostic tests work well, but when prevalence starts to wane diagnostic tests start to produce nonsensical results.
Prevalence is another of those controversial guesstimates because it is hard to measure reliably and yet the latest UK government report suggests this may now be down to 0.1% (1 in every 1,000 people).
This chart enables you to see just how false positive cases are being generated for differing levels of test specificity for three levels of prevalence for an assumed nominal sensitivity of 80%. The first thing to notice is how low the red line is compared to the others. This reminds us that few false positives are generated when the virus is rampant at 10% prevalence.
With UK government estimates now down at 0.1% prevalence (green line) we can see that false positives are going to rocket at anything below the nominal 99.9% specificity. Since operational specificity (real world specificity) is likely down at 97% or even 95% we now see that virtually every positive test result the government is counting as a ‘case’ is almost certainly a false positive.
With estimate of prevalence down at just 6% for England even during the peak of the outbreak (Ward et al Nature Communications 12, Article number 905. 2021) and operational prevalence likely lying somewhere between 95% and 97%, then we can safely assume that lockdown, mandatory masks, social distancing, closure of health services, destruction of businesses, damage to the economy and all the rest of the shit shovelled upon us has been built on nothing more than a gigantic fiction so huge and so fraudulent that the public cannot even see it.
Perhaps they dare not see it for the price of listening to a few alleged experts has been great and terrible.
About the author: Andy Rowlands is a university graduate in space science and British Principia Scientific International researcher, writer and editor who co-edited the new climate science book, ‘The Sky Dragon Slayers: Victory Lap‘
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Charles Higley
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A couple of problems that do not appear addressed above:
1) Covid-19 virus has never been isolated, cultured, and shown to cause disease anywhere. Be definition the specificity of the PCR test cannot be high as there is no Gold Standard virus to use (even the CDC admits they do not have it nor can they get some). Genetic sequences common to coronaviruses, including influenza and rhinovirus, were used from a database in making the PCR test. So, it’s specificity is patently LOW.
2) The cycle number of the PCR test is very important and pretty much any number above 30 calls the test into question as it produces increased false positives with increased cycle number. This test is not fit for this purpose AT ALL, the method was never meant to be diagnostic in a medical setting.
3) Infectious viruses burn through a population and have to move on or die. They do not just hang around waiting for more victims. This is the nature of the annual flu season. Whatever virus or combination of viruses that made people sick in the 2019-2020 flu season is long gone and the 2020-2021 flu season was a new set of strains from these fast mutating RNA viruses. Thus, it is a given that all positive PCR tests this recent flu season and even now, are ALL FALSE POSITIVES.
It is time to stop testing and go back to identifying and treating symptoms, as these viruses are treated quite well by therapeutics that are easily available and sensible patient management. A final note is that asymptomatic carriers are rare (even Dr. Fauci agrees) and the myth that there are many carriers, based on this flawed PCR test, is simply a way to keep the public in fear.
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Andy
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You’re quite right Charles, the article does not address those points because it did not set out to.
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Roger Higgs
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Charles, that’s beautifully put, thank you.
I wish every adult in the world could read it.
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Mark Tapley
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Hello Charles:
When you have a fake virus, you have to have a fake test to make the livestock think their is a real pathogen. This germ theory hoax has been going on in one fake virus after another since the Rockefeller’s began with the 1918 “pandemic.”
The Boston studies conducted during the 1918 “flu”, rather than proving transmission of pathogens, proved as have all the many since then that there is no transmission. In fact viruses do not even exist as is shown in the video below by Dr. Tom Cowan. There is a large reward on the table by micro biologist Stephan Lanka for anyone who can prove that viruses even exit.
The medical con man and Fauci of his day, Pasteur in 40 years was never able to transmit so called “infectious diseases” but only succeeded by spiking his samples with poisons. It is ridiculous to talk about asymptomatic carriers, treatments, symptoms and management for a disease that is imaginary. But that is exactly what many on his site continue to do. There fore they perpetuate the Zionists program of miss information. This is the same thing that is happening with the fake climate change. Both off these frauds must be exposed as imaginary invisible false flags until the elites with their MSM can prove otherwise, Until then all the posturing around as is happening with the kites fake virus just gives the Zionists the credibility they need.
https://www.bitchute.com/video/4IIZA13JBxoj/
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Finn McCool
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I wrote an article for PSI last year on this very same problem and explained the mathematics of Bayes theorem behind it.
It is widely used in medicine. It is called the Positive Predictive Value. The lower the prevalence, the higher the false positives. No attempt has been made to communicate this to the general public. PCR is fear porn.
Real crimes against humanity have been committed by the use of DNR notices and reducing the medical care in “care” homes to zero. Millions of people have been denied treatment because of this nonsense.
If a person does not die from SARS, in no way can they be counted as a “covid” victim. And few have died from SARS.
The only question left now is, cui bono? The answer is pretty obvious.
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JaKo
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As much as must agree with Finn and Charles I have to raise a concern regarding this article very premise: “All diagnostic tests have their limits and the RT-PCR test is no exception…”
YES, IT IS AN EXCEPTION! — IT IS NOT AND IT WAS NEVER INTENDED TO BE A DIAGNOSTIC TEST!
If this was just I saying, nobody should pay attention, really: who am I? However, this was explicitly stated by the very person who invented this technology and got a Nobel Price for it. There should be a ghost of Dr. K. Mullis haunting all those who disrespect him and his pure intentions!
Cheers to all respectful, JaKo
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Tom
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The fake PCr testing method, for which there was never any standards or baselines created for all testing (as in the number of cycles) is the basis for creating a fake pandemic. Without a high number of cases and death rate, not enough fear and panic can be created to support the idea that everyone needs to be tested and injected if you want to survive (not die from CoV-2).
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Saeed Qureshi
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Absolutely! PCR should have never been used.
“Perhaps the absurdity of the whole situation is that no one isolated and identified the virus (the poked-material), but a test was developed to measure the unknown virus. Only physicians or virologists can pull such a trick. In reality, developing tests fall under analytical chemistry science; however, the job was never assigned to it but kept within the medicine area.
If chemistry scientists and laboratories had assigned the task of isolating the virus and developing its test, the pandemic would never have existed from day one. Scientifically, it is impossible to develop and validate a test without having the reference material in hand – isolated virus, i.e., no virus specimen, no valid test, no pandemic. Therefore, the declaration of the virus and its disease certainly reflect ignorance about the science of medicines.”
Continue here (http://www.drug-dissolution-testing.com/?p=3850).
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Mark Tapley
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There is no ignorance by the by the Zionist elite at the top. Ignorance and medical fear myths are only for the herd. All the countries had their fake PCR tests ordered back in 2018, ready to go. Mullis would have not gone along with the program so that situation had to be corrected. Like Stalin said, “no person, no problem.”
https://www.bitchute.com/video/1GvHI7JsPjBf/
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