Go back
The science of face masks

The science of face masks

Science


@metal-brain said
That article is about antigen tests, NOT PCR tests!

The only part of your article that addresses PCRs says "when they are administered properly". Now you have to prove they are administered properly and we are back to that 2 out of 3 instead of 3 out of 3 thing we started with.
Somehow I knew you would respond this way if I posted that article. You only read the headline, again? The article specifies that health care professionals are needed for proper administration.

2 out of 3 is not required for distinguishing COVID-19 from common cold. Your article did not say it was.

2 edits

@wildgrass said
Somehow I knew you would respond this way if I posted that article. You only read the headline, again? The article specifies that health care professionals are needed for proper administration.

2 out of 3 is not required for distinguishing COVID-19 from common cold. Your article did not say it was.
From the link below:

According to scientific opinion:

“if someone is tested by PCR as positive when a threshold of 35 cycles or higher is used (as is the case in most laboratories in Europe & the US), the probability that said person is actually infected is less than 3%, the probability that said result is a false positive is 97% (Pieter Borger, Bobby Rajesh Malhotra, Michael Yeadon, Clare Craig, Kevin McKernan, et al, Critique of Drosten Study)"

https://www.globalresearch.ca/nucleic-acid-testing-technologies-use-polymerase-chain-reaction-pcr-detection-sars-cov-2/5739959

https://cormandrostenreview.com/report/

"The article specifies that health care professionals are needed for proper administration."

And just what specifically is " proper administration"?


@metal-brain said
From the link below:

According to scientific opinion:

“if someone is tested by PCR as positive when a threshold of 35 cycles or higher is used (as is the case in most laboratories in Europe & the US), the probability that said person is actually infected is less than 3%, the probability that said result is a false positive is 97% (Pieter Borger, Bobby Rajesh Malhot ...[text shortened]... ls are needed for proper administration."

And just what specifically is " proper administration"?
Proper administration depends on the test.

I'm still not seeing your point. You are providing basic and general technical information on PCR tests. How about practical information? The data on the accuracy of this specific test seems quite good, as opposed to the rapid test, especially when you seem to have a potential gripe with false positives. The best number I could find for the rate of false positives was 0.8-4.0%... I consider this an acceptable degree of error.

https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30453-7/fulltext


@wildgrass said
Proper administration depends on the test.

I'm still not seeing your point. You are providing basic and general technical information on PCR tests. How about practical information? The data on the accuracy of this specific test seems quite good, as opposed to the rapid test, especially when you seem to have a potential gripe with false positives. The best number I could ...[text shortened]... ree of error.

https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30453-7/fulltext
I'll post this excerpt again:

“if someone is tested by PCR as positive when a threshold of 35 cycles or higher is used (as is the case in most laboratories in Europe & the US), the probability that said person is actually infected is less than 3%, the probability that said result is a false positive is 97% (Pieter Borger, Bobby Rajesh Malhotra, Michael Yeadon, Clare Craig, Kevin McKernan, et al, Critique of Drosten Study)"

https://www.globalresearch.ca/nucleic-acid-testing-technologies-use-polymerase-chain-reaction-pcr-detection-sars-cov-2/5739959

Are you disputing the above statement?


@metal-brain said
I'll post this excerpt again:

“if someone is tested by PCR as positive when a threshold of 35 cycles or higher is used (as is the case in most laboratories in Europe & the US), the probability that said person is actually infected is less than 3%, the probability that said result is a false positive is 97% (Pieter Borger, Bobby Rajesh Malhotra, Michael Yeadon, Clare Cr ...[text shortened]... polymerase-chain-reaction-pcr-detection-sars-cov-2/5739959

Are you disputing the above statement?
I have no clue what data they are basing that statement on. Do you? It sounds like overgeneralized handwaving. But, clearly, from a practical standpoint in this conversation the evidence with COVID-19 testing demonstrates that testing is reasonably accurate.

1 edit

@wildgrass said
I have no clue what data they are basing that statement on. Do you? It sounds like overgeneralized handwaving. But, clearly, from a practical standpoint in this conversation the evidence with COVID-19 testing demonstrates that testing is reasonably accurate.
Then you do dispute it, right?
Yes or no?

https://cormandrostenreview.com/report/


@metal-brain said
Then you do dispute it, right?
Yes or no?

https://cormandrostenreview.com/report/
As a general statement, it may be relevant in some contexts. But just googling PCR protocols I found lots of labs use anywhere between 30-40 cycles for testing without problems. Based on real data showing false positive rates ranging from 0.8-4%, that statement does not apply to COVID-19 testing.

https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30453-7/fulltext


@wildgrass said
As a general statement, it may be relevant in some contexts. But just googling PCR protocols I found lots of labs use anywhere between 30-40 cycles for testing without problems. Based on real data showing false positive rates ranging from 0.8-4%, that statement does not apply to COVID-19 testing.

https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30453-7/fulltext
Your source is the one that published fraudulent data on HCQ?

How about you post another source?


@metal-brain said
Your source is the one that published fraudulent data on HCQ?

How about you post another source?
I thought we were discussing testing, in which case I value evidence over baseless statements. The Lancet is one of the top 3 medical journals in the world. If it was fraudulent, certainly it would be retracted.


@wildgrass said
I thought we were discussing testing, in which case I value evidence over baseless statements. The Lancet is one of the top 3 medical journals in the world. If it was fraudulent, certainly it would be retracted.
You said that statement does not apply to COVID-19 testing.
Irrelevant.

1 edit

@metal-brain said
You said that statement does not apply to COVID-19 testing.
Irrelevant.
You have not addressed my questions about the source material you provided on testing. It does not appear to address the actual, practical use of COVID-19 testing, only speaking in the abstract about PCR in general. But PCR technology has been around for almost 40 years and used in a large number of diagnostic tests for a long time. I don't understand. Why don't the use the actual data on false positives, as other studies have done?

From the Lancet article: "... estimates [of false positives] show it could be somewhere between 0·8% and 4·0%."

From the cited materials:
Our meta-analysis of EQAs of similar diagnostic tests found FPRs with an interquartile range of 0.8-4.0%. These false positives were probably not generated by cross-reactivity, since test protocols are typically tested against the likeliest reactants including similar viruses, and because many tests target multiple genomic regions. Nor were they likely to be due to reagent contamination during manufacture, which in most cases would be detected by negative controls. Rather, the likeliest source of these false positives is sample contamination or human error. Samples can be contaminated by a positive sample analyzed at the same time (cross-contamination), or more likely by target genes amplified from prior positive samples or positive controls (carryover contamination). False positives can also be produced by sample mix-ups7 or data entry errors.


@wildgrass said
You have not addressed my questions about the source material you provided on testing. It does not appear to address the actual, practical use of COVID-19 testing, only speaking in the abstract about PCR in general. But PCR technology has been around for almost 40 years and used in a large number of diagnostic tests for a long time. I don't understand. Why don't the use the ...[text shortened]... ontamination). False positives can also be produced by sample mix-ups7 or data entry errors.[/quote]
You said that does not apply to COVID-19 testing. Why do you now insist it is relevant?