PCR False Positives?

[cabmandone]

I can't.... there's no link

Since JD is link adverse: https://www.cdc.gov/library/covid19/pdf/2020-09-04-Science-Update_FINAL_public_v2.pdf

Make sure you read it all.

[javadog]

Question you need to ask yourselves:

What is the likelihood of finding a sufficient live viral load to be infectious if it took at least 40 cycles to generate a positive test result?

The next question will be, why did the CDC recommend at least 40 cycles in a PCR test, early on in this mess?

The next question you might want to ask yourselves is why they changed their mind about that, and when?

[Sooner or later]

At 40 cycles the false positive rate may approach 97%. That does not mean that all tests have a false positive rate of 97%.

[javadog]

Originally Posted by cabmando

I can't.... there's no link

Lazy little ****er, aren’t you?

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.32.2001483#html_fulltext

That’s not where I first read it, most likely I first discovered this nonsense somewhere on the CDC website eight or 10 months ago, but one Google search which took all of six seconds of one finger typing yielded the result I linked above.

[cabmandone]

Originally Posted by javadog

Lazy little ****er, aren’t you?

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.32.2001483#html_fulltext

That’s not where I first read it, most likely I first discovered this nonsense somewhere on the CDC website eight or 10 months ago, but one Google search which took all of six seconds of one finger typing yielded the result I linked above.

One search my ass. Who are you trying to bullsh.t here? You got called out and have been looking for something... ANYTHING to support your bullsh.t ever since.

[javadog]

Originally Posted by Sooner or later

At 40 cycles the false positive rate may approach 97%. That does not mean that all tests have a false positive rate of 97%.

Mathematically, that is true, but how concerned would you be if you tested positive, only after 40 cycles?

More importantly, why did the CDC recommend a 40 cycle minimum as the standard, when they knew, from their own goddamn research, that there was almost no possibility of the presence of live virus and a test taken to that point?

Why is it that they almost never will give you the number of cycles when reporting the results of a test?

When did the CDC sees to be a useful arm of the federal government and instead become a politically useful tool?

[cabmandone]

Now, from MIT
https://medical.mit.edu/covid-19-updates/2020/11/pcr-test-result

[javadog]

Originally Posted by cabmando

One search my ass. Who are you trying to bullsh.t here? You got called out and have been looking for something... ANYTHING to support your bullsh.t ever since.

No, I’ve been on a long distance call to a hospital in Las Vegas. For a portion of that time I was on hold and did a search, just for you. You should feel special.

[cabmandone]

Originally Posted by javadog

No, I’ve been on a long distance call to a hospital in Las Vegas. For a portion of that time I was on hold and did a search, just for you. You should feel special.

Your lie bud... tell it however you want.

[cabmandone]

And I didn't see a 97% false positive rate quoted in that article but I'm still reading so you've got that going in your favor.

[thor66]

Originally Posted by javadog

Feel free to disregard my claim, there’s no prize for winning an argument on the Internet.

The vast majority of my posts are on the 911 technical forum. After dispensing advice for 10 years there, I grew tired of answering the same question a dozen or two dozen different times, which is why one day I decided to walk away from that forum and spend some time here.

Guess what? I’m not going to spend any time rehashing arguments I had here a year ago, with someone that hasn’t stayed up to speed on the topic. I have found that to be a complete waste of my time.

This entire forum is a complete waste of time, for the most part. I anticipate departing for more productive pastures in the near future.

more productive pastures that produce more false positives?

[cabmandone]

Originally Posted by javadog

You geniuses figure it out:

I don't need to figure it out since you've linked the article
"Virus propagation was successful from five of 60 samples with Ct > 35; all five were from symptomatic cases and none had severe illness."

[javadog]

Originally Posted by cabmando

Your lie bud... tell it however you want.

**** you, Nick. My oldest kid was in a motorcycle wreck at mile marker 47 on interstate 40, 2 miles south of Kingsmen Arizona at 4:47 PM Saturday. He was life-flighted to Sunrise Medical Center in Las Vegas and I’m spending a fair amount of time on the phone with his caregivers.

If you think I give even a half a **** about you and your little question on Covid, you’re sorely mistaken, mother****er.

[cabmandone]

Originally Posted by javadog

**** you, Nick. My oldest kid was in a motorcycle wreck at mile marker 47 on interstate 40, 2 miles south of Kingsmen Arizona at 4:47 PM Saturday. He was life-flighted to Sunrise Medical Center in Las Vegas and I’m spending a fair amount of time on the phone with his caregivers.

If you think I give even a half a **** about you and your little question on Covid, you’re sorely mistaken, mother****er.

Oh ouch! Breaking out the big boy words. You're SAVAGE. Sorry to hear about your son... and sorry I called out your bulls..t for being bulls..t. but it's still bulls..t

[brainz01]

Originally Posted by cabmando

If they're finding live virus at 40... they're infected right? Can they spread the virus if detected at 40? The article from MIT stated the lower the cycles the more viral load a person had. And for what it's worth, no he's not on point. It's absurd IMO to say "If we would have stopped at...." The accepted threshold seems to be 40. Is there an argument for lowering it? Maybe... but it is where it is and at 40 they were finding live virus which creates a positive test for covid.

The test doesn't measure live virus - - it could be "live" or not. It measures the concentration of indicative DNA fragments that have been multiplied/doubled to the Nth power, where N is the number of cycles. If patient X tests positive at 30 cycles, but patient Y only at 40 cycles, then the viral load of X is roughly 1000 times higher than Y (2^10=1024), so we agree there. The issue, as highlighted in the article, is that many in the industry believe that anything above 30 cycles leads to false positives - - that was Java's point and the point I highlighted - - and no, 40 cycles is not universally accepted as evidenced by the article I posted . The article even goes on to highlight that 40 cycles generates up to 90% false positives, which was another of Java's points. And yes, It's possible to have been exposed to the virus without becoming sick or being at a viral load where others are at risk from you. That's why we have an immune system and didn't always have to wear a mask on the grocery story... 'Twas a simpler time, when one didn't have to think for oneself (or Google) and could could trust that governments and media had our best interests in mind.

[javadog]

Originally Posted by cabmando

Oh ouch! Breaking out the big boy words. You're SAVAGE. Sorry to hear about your son... and sorry I called out your bulls..t for being bulls..t. but it's still bulls..t

I get a little pissed off when some idiot on the Internet calls me a liar. Mark that down for future reference.

[cabmandone]

Originally Posted by brainz01

The test doesn't measure live virus - - it could be "live" or not. It measures the concentration of indicative DNA fragments that have been multiplied/doubled to the Nth power, where N is the number of cycles. If patient X tests positive at 30 cycles, but patient Y only at 40 cycles, then the viral load of X is roughly 1000 times higher than Y (2^10=1024), so we agree there. The issue, as highlighted in the article, is that many in the industry believe that anything above 30 cycles leads to false positives - - that was Java's point and the point I highlighted - - and no, 40 cycles is not universally accepted as evidenced by the article I posted . The article even goes on to highlight that 40 cycles generates up to 90% false positives, which was another of Java's points. And yes, It's possible to have been exposed to the virus without becoming sick or being at a viral load where others are at risk from you. That's why we have an immune system and didn't always have to wear a mask on the grocery story... 'Twas a simpler time, when one didn't have to think for oneself (or Google) and could could trust that governments and media had our best interests in mind.

I saw this in your post. I'll have to go back and read the link to see where it says using 40 cycles creates a 90% false positive situation because that's not what this quote is saying.
"In Massachusetts, from 85 to 90 percent of people who tested positive in July with a cycle threshold of 40 would have been deemed negative if the threshold were 30 cycles,"

I went back and read it again and couldn't find where it stated that 40 cycles generates up to 90% false positive.

[cabmandone]

Originally Posted by javadog

I get a little pissed off when some idiot on the Internet calls me a liar. Mark that down for future reference.

Then don't lie to me and we're good. Mark that down for future reference.

Stealth edited... Just sayin.

[1990C4S]

Originally Posted by cabmando

Which vaccine did they get? The Pfizer and Moderna aren't supposed to create a positive because they don't use live virus so essentially they should be able to run the test for about as long as they want and not find live virus. J&J and AZ use live virus if I'm not mistaken... which I could be.

Pfizer.

[cstreit]

Originally Posted by Sooner or later

I did find this...

https://www.thejournal.ie/factcheck-pcr-tests-irish-video-5304097-Dec2020/

“You get a lot of false positives because you start to identify things that are nothing to do with the current infection,” Dr Carroll said. “It might be fragments of DNA from other coronaviruses.” This happens because the original sample is amplified “through too many cycles”, he added.

Dr Carroll, who has a master’s degree in public health medicine, says that a positive PCR test does not correspond to an active case of Covid-19.

Experts in PCR contacted by  TheJournal.ie  viewed the 97% figure for false positives as a misunderstanding.

“This is not true. This demonstrates a clear misunderstanding of the PCR primers,” says Michael Mina, a professor at the Harvard T.H. Chan School of Public Health.

Primers are the reason why the PCR test for SARS-CoV-2 will only pick up that specific virus and not any other coronaviruses.

“When setting up a PCR test, you need to know what you are looking for, otherwise you won’t amplify anything,” says Dr Cillian De Gascun, director of the National Virus Reference Laboratory in UCD.

Verdict

The video is wrong that the PCR test for SARS-CoV-2 gives a false positive rate of 97%. Also, PCR tests do not wrongly confuse genetic material from other viruses with SARS-CoV-2.

The scientific consensus is that PCR tests are the best option for public health screening right now.

Dr Cillian de Gascun of the National Virus Reference Laboratory in UCD says the actual false positive rate is between 0.1% and 0.2%.

As a result, we rate the claim that PCR tests have a 97% false positive rate as FALSE.

As per our verdict guide, this means: The claim is inaccurate.

What I read from this is one doctor says it’s wrong and other says it’s right.