Is a Covid RT-PCR test the same as a regular PCR test?

[daydreamer]

Thailand currently requires the RT-PCR test before arriving in country under the Thailand Pass rules.  I have looked up numerous testing locations in the US, and have been left confused over RT-PCR, regular PCR, rapid test, etc.  I recently found the following explanation of the RT-PCR test from someone with a licensed background in the medical field very useful.  It clearly explains to those of us who are not scientists or work in the medical field what may have been perplexing.

I was also confused after reading some references as to to the "RT" in RT-PCR being referred to to as a Rapid Test, and in other instances called Reverse Transcription.  There certainly is rapid testing, however that refers to the timeframe that the test results are forwarded to you, and is not what the RT in RT-PCR means.  The RT means Reverse Transcription which is explained below.

Yesterday I called a local CVS pharmacy, and they confirmed that although their website states they give only PCR and Antigen tests, they told me their PCR tests are in fact RT-PCR tests.

In the US, there are far more testing locations that advertise PCR tests than RT-PCR tests.  Looking at the US CDC website, there are a dizzying variety of tests that can be used to detect Covid.  You almost need to be a scientist or a Philadelphia lawyer to decipher and understand their explanation of tests.

The following info from a Thailand based expat Registered Nurse who is a regular poster on the aseannow message board may help to clear up any confusion over the Covid test currently required before entering Thailand, and what you should look for when seeking a test.  This is from the poster named Sheryl, who is also a moderator of the aseannow message board.  She explains it better than I can:

"RT = reverse transcription. It is a process whereby RNA is used ("transcribed") to produce DNA.

PCR tests identify the presence of DNA.

The COVID virus contains only RNA so it is impossible to do a PCR test for it without the RT step. All COVID PCR tests  are RT-PCR. There is no other way it can be done. The only time a PCR test can be done without the RT step is if it is identifying an organism that contains DNA. COVID does not.

However most non-medical people do not know this - certainly airline staff, Imm officers etc do not -- and labs do not always state "RT-PCR" on their reports. It will have been an RT-PCR though, for sure. So before using a particular lab find out how their results will be worded. If not including the phrase "RT-PCT" then ask if they can specify it.

Just a matter of wording, no difference in the tests, but given the way Thailand's requirements are phrased it is an important one.

Of course there is a difference between plain PCR and RT-PCR but what I was explaining is that all COVID PCR's are RT-PCR even if not explicitly stated as such.
It is a physical impossibility to do a COVID PCR without the initial RT step. Because the COVID virus does not contain any DNA, only RNA.

So it is not a matter of needing a special sort of test, any place doing COVCID PCR is doing RT-PCR. But for entry into Thailand you need to be sure the results will clearly state RT-PCR."

In another post, Sheryl mentioned that she received her test for return to Thailand at a CVS pharmacy, and it stated RT-PCR test in the written results:

 

For US residents traveling to Thailand, CVS gives free Covid tests, either billed to your health insurance, or billed to Uncle Sam if you have no insurance.  I have read that Walgreens does the same.

From what I have learned, some testing centers still offer a "Fit to Fly" certificate along with the test results, and some labs even charge an extra fee for this certificate.  Many testing facilities in Bangkok are currently offering this "Fit to Fly" certificate, and a few I have seen in the US are also.  I understand the Fit to Fly certificate was a previous Thailand requirement earlier in the pandemic, however as of April 1, 2021, foreign travelers are no longer required to provide the fit-to-fly certificate, as long as they present the COVID 19 RT-PCR test result under the Thailand Pass, or if required upon departure from Thailand.

Neither airlines nor the Thailand Pass or Thai checkpoints on arrival or departure require this certificate.  On arrival, they only want the test results.  On departure from Thailand, a test is only needed if your country of arrival and/or your airline requires a test.  So don't go out of your way to get a "Fit to Fly" certificate, or pay any extra for it, as it will just be an obsolete souvenir for you.  The US requires no Fit to Fly to return home from overseas.  Citizens of other countries returning home should check the requirements of their home countries and airlines.

I wasn't trying to complicate this or overthink the situation, but to me, this cleared up a lot of uncertainty.  I know I went in great detail here, but I like definitive answers, not hearsay, hot air, and speculation.  The results of Sheryl's test for her recent return to Thailand and her lucid professional explanation that she shared with the message board provided me the clarity that I was seeking in this sea of confusion over testing requirements.  

I have been searching for a clear explanation of this info in planning a future trip of my own.  So just verify that your test results will clearly state RT-PCR, not PCR, before getting a test and you should be good to fly and enter the Kingdom.  I am posting this extensive explanation so it may help other potential travelers to Thailand, and make it a bit easier to understand the rules.