What is the PCR cycle test threshold in Thailand? Less than 25

[The Hammer2021]

 

What is the PCR cycle test threshold in Thailand? Less than 25...

[The Hammer2021]

I am not anti vax nor anti science nor do I really have a dog in this fight but can the threshold be changed on these tests to skew the results?

What is the level set in Thailand?

Is it in line with international norms.

Thank you

[The Hammer2021]

Thank you for your opinion

What is the level set in Thailand for the PCR tests?

Is it in line with international norms.

[The Hammer2021]

To avoid any issue of bad information or anti science links I would still like an answer to my question

What is the PCR cycle test threshold in used in Thailand? Less or more than 25 cycles?

Is it in line with international standards.

Can the test be skewed by setting the cycle rate higher than 25 cycles to create more false positives

[richard_smith237]

I do not know what ‘Amplification cycle threshold’ above which Thailand clarifies a test is negative. 

However, as I understand it the ‘internationally accepted standard’ is 35 amplification cycles - I believe Thailand follows international standards. 

 

Many positive cases will show up much earlier, i.e. after 10, 15 or 20 amplification cycles. 

It is also now suspect that ease of RT-PCR detection (i.e. with fewer amplification cycles) is indicative of infectiousness.

 

IF a positive result is not established after 35 amplification cycles the test is considered negative.

 

IF I was tested and found to be positive, I would want to know how many amplification cycles were carried out, because if it was 35 it could be a false positive, if it was 40 the test has not been carried out to international standards. But if it was 20, then I have Covid-19 !!!... (but would still want a re-test anyway to be sure - simply because a positive test impacts my travel so significantly - or, if its on arrival, test & go there may be ‘costly quarantine implications’). 

 

That said - I’ve had nearly 30 PCR test... (all negative), none of them have listed the number of amplification cycles used in their testing methods. 

 

[MajorTom]

I tried really hard to get the CT-Value when i tested in BKK hospital a few weeks ago. Not possible.

 

Reason behind this was i recently had Covid. My employer wanted to send me to Taiwan, which apparently have a strict CT-value of 36. They worried i might still test positive on arrival, and asked if i could get a test document in Thailand which showed a negative result at CT 36 or above..

 

Well.. After explaining this to check-in staff and a few nurses at bangkok hospital they said: Yes no problem, can do.

Got the result on e-mail: No CT-value given. Just "Not detected".

I went back to the hospital and explained again, but then they said not possible.. (already got my money) ????

 

What they did tell me in the end after i got to talk to the laboratory was that "not detected' means its done at a CT value of 40 or more. They refused to put this on paper.

 

 

[placeholder]

22 hours ago, The Hammer2021 said:

 

What is the PCR cycle test threshold in used in Thailand? Less or more than 25 cycles?

Is it in line with international standards.

Can the test be skewed by setting the cycle rate higher than 25 cycles to create more false positives

 

I guess you're looking for an aha! moment when the whole charade comes tumbling down. Both your posts are resting on the false assumption that there is or should be a limit on cycles. That too many cycles will somehow yield a false positive.

 

Here's a link to Ian Mackay explanation.

https://virologydownunder.com/the-false-positive-pcr-problem-is-not-a-problem/

 

, a virologist who now specializes in designing, optimising and validating "molecular tests for new and existing viruses of public health significance."

 

https://virologydownunder.com/about-me/

 

Here are some more links to info about cycles:

https://health-desk.org/articles/what-do-we-know-about-pcr-threshold-cycles

 

https://www.publichealthontario.ca/en/about/blog/2021/explained-covid19-pcr-testing-and-cycle-thresholds

 

Edited February 16, 2022 by onthedarkside
disallowed social media source removed

[The Hammer2021]

20 hours ago, placeholder said:

 

I guess you're looking for an aha! moment when the whole charade comes tumbling down. Both your posts are resting on the false assumption that there is or should be a limit on cycles. That too many cycles will somehow yield a false positive. Here's a link to Ian Mackay explanation.

https://virologydownunder.com/the-false-positive-pcr-problem-is-not-a-problem/

, a virologist who now specializes in designing, optimising and validating "molecular tests for new and existing viruses of public health significance."

https://virologydownunder.com/about-me/

 

 

Here are some more links to info about cycles:

https://health-desk.org/articles/what-do-we-know-about-pcr-threshold-cycles

https://www.publichealthontario.ca/en/about/blog/2021/explained-covid19-pcr-testing-and-cycle-thresholds

 

"I guess you're looking for an aha! moment when the whole charade comes tumbling down."

 

I have no preconceptions or agenda!

I want to avoid a false positive here in Thailand on my PCR test having recovered from Covid

 

I want information on this subject

But you are preaching to the choir.

Thus is what I asked. No one answered. Two people sent irrelevant links about FLU..

 

Others presumed wrongly and arrogantly that I was a conspiracy theorist who needed slapping down.

Others sent dense links so..I will ask again:

 

What is the PCR cycle test threshold in used in Thailand? Less or more than 25 cycles?

Is it in line with international standards.

Can the test be skewed by setting the cycle rate higher than 25 cycles to create more false positives?

 

If you can advise me please do and thank you.

My PCR test is 10th Marc

I recovered from covid January 10th

[The Hammer2021]

1 hour ago, MajorTom said:

I tried really hard to get the CT-Value when i tested in BKK hospital a few weeks ago. Not possible.

 

Reason behind this was i recently had Covid. My employer wanted to send me to Taiwan, which apparently have a strict CT-value of 36. They worried i might still test positive on arrival, and asked if i could get a test document in Thailand which showed a negative result at CT 36 or above..

 

Well.. After explaining this to check-in staff and a few nurses at bangkok hospital they said: Yes no problem, can do.

Got the result on e-mail: No CT-value given. Just "Not detected".

I went back to the hospital and explained again, but then they said not possible.. (already got my money) ????

 

What they did tell me in the end after i got to talk to the laboratory was that "not detected' means its done at a CT value of 40 or more. They refused to put this on paper.

 

 

Thank you. 40 is too high. I am also in your situation which is why I wanted the information

[The Hammer2021]

2 hours ago, richard_smith237 said:

I do not know what ‘Amplification cycle threshold’ above which Thailand clarifies a test is negative. 

However, as I understand it the ‘internationally accepted standard’ is 35 amplification cycles - I believe Thailand follows international standards. 

 

Many positive cases will show up much earlier, i.e. after 10, 15 or 20 amplification cycles. 

It is also now suspect that ease of RT-PCR detection (i.e. with fewer amplification cycles) is indicative of infectiousness.

 

IF a positive result is not established after 35 amplification cycles the test is considered negative.

 

IF I was tested and found to be positive, I would want to know how many amplification cycles were carried out, because if it was 35 it could be a false positive, if it was 40 the test has not been carried out to international standards. But if it was 20, then I have Covid-19 !!!... (but would still want a re-test anyway to be sure - simply because a positive test impacts my travel so significantly - or, if its on arrival, test & go there may be ‘costly quarantine implications’). 

 

That said - I’ve had nearly 30 PCR test... (all negative), none of them have listed the number of amplification cycles used in their testing methods. 

 

Thank you

[The Hammer2021]

22 hours ago, Chomper Higgot said:

 

Please take time to read my posts and answer an honest question if you are able but if not please don't just answer that which suits you.

I want to avoid a false positive here in Thailand on my PCR test having recovered from Covid

I want information on this subject

But you are preaching to the choir.

Thus is what I asked. No one answered. Two people sent irrelevant links about FLU..

Others presumed wrongly and arrogantly that I was a conspiracy theorist who needed slapping down.

Others sent dense links so..I will ask again:

 

What is the PCR cycle test threshold in used in Thailand? Less or more than 25 cycles?

Is it in line with international standards.

Can the test be skewed by setting the cycle rate higher than 25 cycles to create more false positives?

 

If you can advise me please do and thank you.

 

My PCR test is 10th Marc

I recovered from covid January 10th

 

[placeholder]

20 hours ago, The Hammer2021 said:

"I guess you're looking for an aha! moment when the whole charade comes tumbling down."

 

I have no preconceptions or agenda!

I want to avoid a false positive here in Thailand on my PCR test having recovered from Covid

I want information on this subject

But you are preaching to the choir.

Thus is what I asked. No one answered. Two people sent irrelevant links about FLU..

Others presumed wrongly and arrogantly that I was a conspiracy theorist who needed slapping down.

Others sent dense links so..I will ask again:

What is the PCR cycle test threshold in used in Thailand? Less or more than 25 cycles?

Is it in line with international standards.

Can the test be skewed by setting the cycle rate higher than 25 cycles to create more false positives?

If you can't answer without being presumptive,arrogant or patronising then don't!

If you can advise me please do and thank you.

My PCR test is 10th Marc

I recovered from covid January 10th

 

 

I know that you're really not interested in an answer since I posted several links that could explain whatever you needed to know about the count. But you've chose to ignore that.

[Chomper Higgot]

If as the OP now suggests, he wishes to avoid a false positive for a PCR test booked on March 10, what use is knowledge of how many cycles the PCR test employs?

 

The test will be performed to the procedure that is applied and the result will be whatever the test determines the result is.

 

Neither the OP nor anyone else is going to be offered a test procedure different to that which is employed.

 

[placeholder]

18 hours ago, Chomper Higgot said:

If as the OP now suggests, he wishes to avoid a false positive for a PCR test booked on March 10, what use is knowledge of how many cycles the PCR test employs?

 

The test will be performed to the procedure that is applied and the result will be whatever the test determines the result is.

 

Neither the OP nor anyone else is going to be offered a test procedure different to that which is employed.

 

What he's referring to is the false claim made by the covid denialists that too many cycles will yield a false positive.

 

Actually, that's like saying that if you keep on enlarging a photo of a tree sooner or later you'll see a bird. You're not gonna see a bird if there was no bird there in the first place.

[Danderman123]

https://chulalongkornhospital.go.th/kcmh/wp-content/uploads/2020/12/2-covid.pdf

 

This report says 35 is the number of cycles for Thailand. 

[Virt]

It's more than 25 for sure.

Or else they wouldn't find so many tourists testing positive on arrival.

I wouldn't be surprised if they did 35-40 cycles.

 

 

During the European championships in handball some players were allowed to play if they tested positive, but had high numbers of cycles.

 

It's reasonable to say that positives cases that are higher than 30-35 cycles have so little virus that it is hard to infect others.

[onthedarkside]

This thread has been edited to remove a weblink and reference in the OP post to a COVID misinformation website, and then the ensuing debate over that now removed source.

[Puccini]

On 2/14/2022 at 8:20 PM, The Hammer2021 said:

What is the PCR cycle test threshold in Thailand? Less than 25...

1. As far as I know, there is currently no government-mandated cycle threshold (Ct) for PCR tests in Thailand.

 

2. As far as I know, there is currently no international standard for the cycle threshold (Ct) for PCR tests.

 

3. As far as I know, there is currently no specific cycle threshold (Ct) for PCR tests recommended by the WHO (Wold Health Organisation)

 

4. The page https://www.who.int/news/item/20-01-2021-who-information-notice-for-ivd-users-2020-05 on the website of the WHO has, among other information, the following guidelines:

a) WHO requests users to follow the instructions for use (IFU) when interpreting results for specimens tested using PCR methodology.

b) Users of IVDs (In Vitro Diagnostic Medical Devices) must read and follow the IFU carefully to determine if manual adjustment of the PCR positivity threshold is recommended by the manufacturer.

c) Actions to be taken by IVD users:

1. Please read carefully the IFU in its entirety.
2. Contact your local representative if there is any aspect of the IFU that is unclear to you.
3. Check the IFU for each incoming consignment to detect any changes to the IFU.
4. Provide the Ct value in the report to the requesting health care provider.

 

I do not know whether the WHO guidelines dated 13 January 2021 quoted under point 4 above are the latest and current guidelines. If anybody has a link to more recent ones, please post it in this topic.

Edited February 16, 2022 by Puccini

[Puccini]

Of the four PCR test reports issued to travellers, two in Italy and the other two in Thailand, which I have seen so far, none showed the cycles employed for the test.

Edited February 16, 2022 by Puccini