Lateral flow at home testing
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URL: http://www.avianflutalk.com/forum_posts.asp?TID=44575
Printed Date: April 24 2024 at 5:28pm
Topic: Lateral flow at home testing
Posted By: Dutch Josh
Subject: Lateral flow at home testing
Date Posted: December 29 2021 at 12:26am
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DJ In the US the FDA came up with a warning at home tests may not detect Omicron. In the UK the story is lateral flow tests DO detect Omicron, just as good as with Delta; 2.1 Performance of diagnostic lateral flow devices UKHSA has performed an initial laboratory evaluation of the current lateral flow devices (LFDs) for COVID-19 in current use by NHS Test and Trace. Preliminary laboratory data assess these devices as detecting Omicron. Initial data from contrived samples indicate a comparable sensitivity to that observed for previous strains of SARS-CoV-2 including Delta, which has been the predominant strain in the UK from May to December 2021. All LFDs eligible for DHSC procurement within the UK specifically detect the nucleocapsid protein of SARS-CoV-2 using a combination of 2 or more different antibodies, each targeting a distinct epitope. There is a significantly lower selective pressure for mutations on the nucleocapsid protein when compared to the spike. Omicron’s nucleocapsid protein has a single unique mutational difference from other SARS-CoV-2 variants, a deletion at aa31-33, as such the general risk to LFD performance being impacted by Omicron was considered low. To ensure that the sensitivity of the 5 tests that have been (or could rapidly be) deployed by NHS Test and Trace has not been significantly reduced by Omicron the following work is underway: • routine and enhanced Real World Performance Monitoring of the LFDs deployed within NHS Test and Trace • wet lab testing with contrived samples from sequence confirmed cultures of Omicron has been performed at Porton Down Real World Performance Monitoring data from LFDs in Deployment Real world data for Omicron are currently being processed and a separate technical report will be released when analysis has been completed. Laboratory evaluation results Laboratory evaluation has currently been performed on 5 tests which are: SARS-CoV-2 variants of concern and variants under investigation in England Technical briefing 32 15 • Acon Flow Flex ‘self-test’ • Innova Biotime ‘self-test and professional use test’ • Orient Gene ‘self-test’ • SureScreen ‘professional use test’ • SureScreen ‘self-test’ The evaluation is performed using dilutions of cultured virus stock in Hanks Balanced Salt Solution (HBSS) plus mucin with 5 samples at each dilution. The dilutions provide 3 concentrations of virus in the following ranges, >1,000,000, >100,000, >10,000 viral copies per millilitre (ml). The Omicron variant was isolated from a primary clinical sample sourced in the UK and confirmed as being Omicron by sequencing. In summary, the LFDs evaluated, all of which target the nucleocapsid protein, have detected the new Omicron variant that contains 4 amino acid changes from the original viral sequence. This does not affect their performance in the laboratory setting and we will monitor further variant changes as they arise as part of our ongoing evaluation programme. DJ Since at home testing is getting more important we have to know how good they are. ------------- We cannot solve our problems with the same thinking we used when we created them. ~Albert Einstein |
Replies:
Posted By: Dutch Josh
Date Posted: December 29 2021 at 12:32am
Posted By: Dutch Josh
Date Posted: December 29 2021 at 1:05am
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Copying from twitter can give complications. What I make of Michael Mina his comments is timing is the issue, not Omicron. The FDA has not published a science study indicating lateral flow-do it yourself at home testing is not doing such a great job...The UK did publish a study those tests (they name 5 of them) DO a good enough job...but if you have been incontact with someone testing positive, have symptoms yourself it is advised to take a PCR-test doing a much better job... The goal for lateral flow tests is to see if it is safe to make a visit, meet some other people...if you test positive then do NOT make such a visit and go for a PCR test ! The problem for the PCR-tests is limits to capacity...Micheal Mina's "idea" that FDA/CDC may be limiting lateral flow tests could be related to US testing capacity over its limits ? So NO at home tests showing positive results is NO further increase on PCR-testing...saving capacity (maybe even bringing numbers down ? Another round of "don't test, don't tell" ?) My conclusion is lateral flow tests can give indication of infection. May still be a good tool ! But if you have symptoms are had contact with someone testing positive and/or with symptoms try to get a PCR-test ! Most people have good enough thinking and sense of responsibility ! Sometimes one could ask people if they are willing to do a self-test before meeting them...if they refuse you may also get relevant info... DJ-Lateral flow tests are still cheap and easy to get in most of Western Europe...I did get the story these tests are limited and expensive in the US... Also there are "lots of tests" on the market...Some criminals could even decide to repackage old used tests...So try to get those tests from shops you can trust (with also a real adress, phone number may give an indication !) ------------- We cannot solve our problems with the same thinking we used when we created them. ~Albert Einstein |
Posted By: KiwiMum
Date Posted: December 29 2021 at 11:21am
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Josh, have a read of this. It popped up in my newsfeed yesterday. https://www.paulcraigroberts.org/2021/12/27/cdc-admits-that-the-covid-pandemic-was-the-product-of-an-inappropriate-test/ - https://www.paulcraigroberts.org/2021/12/27/cdc-admits-that-the-covid-pandemic-was-the-product-of-an-inappropriate-test/ ------------- Those who got it wrong, for whatever reason, may feel defensive and retrench into a position that doesn’t accord with the facts. |
Posted By: ksc
Date Posted: December 29 2021 at 11:26am
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Did you believe it? That misinformation about the CDC EUA test has been circulating for months. It's amazing what these loon sites get their followers to believe.... |
Posted By: Dutch Josh
Date Posted: December 30 2021 at 3:14am
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Kiwimum, I did read the Paul Craig Roberts link you provided....seen these "claims" before (a.o. at Hal turner reporting a lot of non-sense sometimes mixed with relevant stories...). What I made of this the CDC had a test supposed to test for BOTH; CoViD AND Flu...they stopped using that test...because their review showed it was not good enough (if I remeber well). - One major limitation of PCR is that prior information about the target sequence is necessary in order to generate the primers that will allow its selective amplification. https://en.wikipedia.org/wiki/Polymerase_chain_reaction#cite_note-Garibyan,_Avashia_1%E2%80%934-26" style="text-decoration: none; color: rgb(6, 69, 173); background: none; - [26] This means that, typically, PCR users must know the precise sequence(s) upstream of the target region on each of the two single-stranded templates in order to ensure that the DNA polymerase properly binds to the primer-template hybrids and subsequently generates the entire target region during DNA synthesis. Like all enzymes, DNA polymerases are also prone to error, which in turn causes mutations in the PCR fragments that are generated. https://en.wikipedia.org/wiki/Polymerase_chain_reaction#cite_note-43" style="text-decoration: none; color: rgb(6, 69, 173); background: none; - [43] Another limitation of PCR is that even the smallest amount of contaminating DNA can be amplified, resulting in misleading or ambiguous results. To minimize the chance of contamination, investigators should reserve separate rooms for reagent preparation, the PCR, and analysis of product. Reagents should be dispensed into single-use https://en.wikipedia.org/wiki/Sample_(material)" style="text-decoration: none; color: rgb(6, 69, 173); background: none;" title="Sample (material) - aliquots . Pipettors with disposable plungers and extra-long pipette tips should be routinely used. https://en.wikipedia.org/wiki/Polymerase_chain_reaction#cite_note-Schochetman_1988_1154%E2%80%931157-15" style="text-decoration: none; color: rgb(6, 69, 173); background: none; - [15] It is moreover recommended to ensure that the lab set-up follows a unidirectional workflow. No materials or reagents used in the PCR and analysis rooms should ever be taken into the PCR preparation room without thorough decontamination. https://en.wikipedia.org/wiki/Polymerase_chain_reaction#cite_note-44" style="text-decoration: none; color: rgb(6, 69, 173); background: none; - [44] Environmental samples that contain humic acids may inhibit PCR amplification and lead to inaccurate results. One of the-many-wrong points PaulCR-is making PCR testing (Does Paul Craig Roberts [url]https://en.wikipedia.org/wiki/Paul_Craig_Roberts[/url] or https://en.wikipedia.org/wiki/Paul_Craig_Roberts - https://en.wikipedia.org/wiki/Paul_Craig_Roberts have a problem with PCR being not used for his name ?) only PCR testing would find CoViD-19....[url]https://outbreak.info/situation-reports[/url] or https://outbreak.info/situation-reports - https://outbreak.info/situation-reports has 6,370,533 sequences.... KiwiMum; Paul Craig Roberts in the link you provided is talking non-sense.....I think he is a very intelligent man talking-this time-very intelligent non-sense...He may need to visit a hospital to see how very wrong he is.... -Let me share an emotion...I remember a video of a patient being told he would need intubation...the horror in his eyes...knowing he most likely would not get out of it alive....Intubated babies at special ICU's..... Then some very intelligent people basically claiming "CoViD is a hoax because PCR is fake" is giving me a feeling of "shocked anger"... "Being in the middle of a house on fire and the other person; "No problem just open the window".....maybe reacting this crazy because reality simply is that bad ? ------------- We cannot solve our problems with the same thinking we used when we created them. ~Albert Einstein |
Posted By: ksc
Date Posted: December 30 2021 at 4:10am
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In the lab alert, the CDC said it was withdrawing the EUA request because, rather than testing only for the COVID virus, it wants labs to test people for multiple viruses simultaneously, using what is known as a multiplexed method. The CDCs 2019-nCoV RT-PCR panel tests only for COVID-19." |