Local physician defending PCR tests
Over the past several months, I’ve read that PCR tests were never intended to be used as primary diagnostic tools, their results are less useful the more virus-free people you test, and that the results are almost useless if a corresponding Ct count is not provided as well. I’m curious whether anyone can point me toward some authoritative research that warns about these and/or other inadequacies of PCR testing? I ask because a local physician who seems to have the trust of many on social media has recently posted a brief discussion attempting to debunk the PCR “misinformation”. I’m not a doctor, and have no intention of getting into a public debate with the physician, but am considering sending a private message or email. I aim to keep it friendly and non-confrontational, while supplying some quality research/reports/opinions that hopefully won’t be dismissed before being read. I have some general ideas of where I disagree with the physician, but I’m confident I wouldn’t stand a chance getting into a debate over the details.
For reference, here’s the physician’s post that inspired my question:
“I’ve been wanting address the huge amounts of misinformation about PCR testing for some time. This post will go into a great deal of detail, but if you want the summary: PCR testing for COVID-19 is extremely accurate, false positives are extremely rare, and all global and national agencies, including the WHO, continue to recommend this test with no significant changes as the most important tool in the accurate diagnosis of COVID-19.
Myth #1 “PCR tests are notoriously inaccurate”. This is the myth behind such false statements excess false positives, and false claims that governments or world organizations are about to dramatically change PCR tests. PCR tests have revolutionized medicine for the speed, accuracy and reliability in the diagnosis of hundreds of diseases. In fact, if you’ve ever been diagnosed with a viral infection, from influenza to herpes to hepatitis to shingles to HIV with a lab test, it probably involved PCR. The COVID-19 PCR is no different – it is accurate (>99.9% accurate) and false positives are extremely rare. In fact, I can say with a high degree of confidence that more than 99% (probably 99.9%) of people who have had a positive COVID-19 test had had COVID-19. The few false positive tests out there are largely due to errors in labelling samples or the very rare accidental cross-contamination of a positive sample with a negative one. Overall, these false positive tests account for <0.1% of tests.
With tests that work so well, are so accurate and have so much experience behind them, don’t expect any changes in how they are used in the lab to diagnose COVID-19 – not here or anywhere else. Sure we will and have added other technologies to test for COVID-19, but PCR tests are here to stay!
Myth #2 “PCR tests are too sensitive and don’t mean you’re infectious” This myth is often combined with the high Ct value myth, where conspiracy theorists speculate that PCR tests over call COVID-19 cases that are low positives (or high Ct value) as true cases. This is a misinformed statement. As I said above, almost all (>99%) of positives are true positives. First I need to explain what a Ct value is. A Ct (Cycle threshold) is the point at which a PCR test is able to detect the positive sample. It is measured in “cycles”. In PCR, each “cycle” doubles the amount of DNA in the sample and at one point, the instrument can detect the viral gene when it reaches a threshold of detection. As you can imagine, the more virus there was in the sample, the sooner the test will become positive. The later it becomes positive, the less virus (or virus RNA) there was. There is truth to this – we use this to determine viral load of certain viruses in blood (like HIV). We can therefore correctly assume that the longer it takes for the instrument to detect SARS-CoV-2, the less there was at the beginning. So what does this really mean? Well, in some studies, low amount of virus detected by PCR (Ct values >~24) in a swab are less likely to be infectious in a lab. Here I insert the warning that much still needs to be done to confirm these findings, and infection in the lab is not necessarily equivalent to infection from person to person. Also, we know that people who have fully recovered from COVID-19 can test positive by PCR for weeks afterwards, but as long as their symptoms are gone and they had symptoms more than 10 days ago, they aren’t considered infectious anymore. This is where the misinformation starts. People have suggested wrongly that anyone with a “low” virus load is therefore a false positive, or at least not infectious. This is very inaccurate. First, a swab in the nose isn’t like a blood sample – nobody really knows how many cells you picked up on the swab – it is not a standardized sample. Therefore another likely explanation for a high Ct (low virus load) is a poor sample. This happens a lot! Who doesn’t recoil when that swab hits the back of your throat?). But the most concerning reason that is is wrong, is that there are two possible times where low viral loads occur even if you get a good sample. Yes, one of them is that you are at the tail end of your infection and if the load is low enough you MIGHT no longer be infectious (YOU STILL HAD COVID-19!), but the other reason is that you are right at the beginning of your infection and about to have a very high viral load!! We know that the viral load starts very low, increases rapidly and by day 2 or so of symptoms, viral loads are typically high. So as you can see, there is nothing about a single isolated test that tell us anything about how infectious you are.
So what are Ct values or “low versus high” positives good for in COVID-19 detection? Not a whole lot to the average person. In the hospital setting, multiple tests over several days, in combination with symptoms can sometimes give you an idea of whether or not it is safe to transfer someone out of the COVID unit. They might be used to see if it is safe to remove someone from an isolation room when they are getting intubated or need a lot of oxygen. In the lab, they can also tell you if a sample is good enough for more testing (like determining the strain). Some studies have suggested that very low Ct values might be common in superspreaders.
So the bottom line with these values is that they aren’t easy to interpret on their own, don’t mean much in terms of how infectious the person is, and certainly don’t mean they are false positive. The meaning of that positive test has to be interpreted indeopendantly of the Ct value because of all these factors – it almost impossible to know how good a swab was, and often not possible to tell if a person is at the begining or the end of their illness. Sure, if you have a very low positive (high Ct) and had a COVID-like illness where symptoms started 10 days ago, and you no longer have symptoms, then you are probably not infectious anymore.”
The inventor of the PCR test, Kary Mullis, former Berkley scientist who received Nobel Prize for his work spoke about how the test is sometimes misused or misinterpreted. This was in the context of HIV but the concepts apply to C19
Check out his comments in the beginning of this audio and at @12min
Many more resources here, including people from Harvard, Oxford and other research. There are links to Chris’ coverage of the issue.
Well, in some studies, low amount of virus detected by PCR (Ct values >~24) in a swab are less likely to be infectious in a lab
This is an odd statement since I understood the Ct values for Covid tests are around 35-40 which means that all positive tests are detecting both high virus loads and low virus loads that would be non-infective in a lab. This seems to be contradicting his argument. Maybe I’m not understanding Covid PCR procedures.
Overall his analysis seems cursory and needs to go into a lot more detail to be able to draw a conclusion.
In response to the “local physician”, why did they not include in the test results the number of cycles that the lab interpreted as positive for SARS2?
The experts at the lab knew the various flaws of the PCR. They knew that there was not good data on which threshold would correlate with false negatives, resulting in super spreader situations.
So if HONESTY was the goal, they would have included the number of cycles that caused the positive test result. Doctors and public health authorities would have been able to use that information to better track the situation with individual patients and the general public.
The local doctor mentions the possibility that the high CT number was in a pre-symptomatic person. That’s true but all the more reason to include that CT number on the test result.
A followup test of that potentially pre-symptomatic person a few days later would have resulted in a lower CT number and the doctor would have had valuable information about the growing health threat.
The only thing that makes sense is that the health authorities were using PCR test to deceive the public. They wanted to make the pandemic seem much worse than it really was–and is. This enables their friends to sell more experimental vaccines, to trash the economy prior to the election and to justify weaker election laws to allow for easier cheating.
And it’s not only the Ct value fraud, there are 10+ fraudulent aspects to the whole Corman-Drosten PCR paper that the WHO and EU use as an official guideline document. That “physician” should be absolutely ASHAMED of himself, and should be mocked and shamed by decent people everywhere until he addresses the actual arguments.
Thanks for all the feedback and links! I’ll be sure to work my way through it, and hopefully be able to use it to good effect when trying to spread the facts/truth.
Good stuff TBP, I’ll be sharing this with others. Much of this forum is dedicated to wealth, the knowledge shared by all here contributes greatly.