spartacus Posted July 2, 2020 Posted July 2, 2020 16 hours ago, Hapless Bills Fan said: False positive RT- PCR tests are very rare. It's the nature of the test. The unreliability of the test lies in false negatives, which may not be the fault of the test - poor sample collection, poor sample storage, or simply virus hanging out somewhere else. "Simply colonized with the virus" could still be a problem if shedding live virus. Need studies to show whether such people (if they exist) are or are not infectious. I'd like to know how many people are on "endless quarantine" though - got any source or data? anytime your test requires the virus target (and everything else in the swab) to be doubled 35 -45 times, the test is subject to question at 35 times, you have increased virus in a single swab to 5 BILLION particles at 45 times, the particles explode to 35 TRILLION what could go wrong The PCR process was never intended to be used for diagnostic testing on any scale- due to the limitation of the very process at 45 times, positive tests are likely identifying some coronavirus since it is the most prevalent virus in the body (including the common cold) However, it may not be COVID-19 strain. 1
Mike in Horseheads Posted July 2, 2020 Posted July 2, 2020 Why don't they just give them one of those shots with the Bill Gates tracking device in it that some people are so afraid of.
Rochesterfan Posted July 2, 2020 Posted July 2, 2020 (edited) 2 hours ago, spartacus said: anytime your test requires the virus target (and everything else in the swab) to be doubled 35 -45 times, the test is subject to question at 35 times, you have increased virus in a single swab to 5 BILLION particles at 45 times, the particles explode to 35 TRILLION what could go wrong The PCR process was never intended to be used for diagnostic testing on any scale- due to the limitation of the very process at 45 times, positive tests are likely identifying some coronavirus since it is the most prevalent virus in the body (including the common cold) However, it may not be COVID-19 strain. What? This makes no sense at all and runs completely counter to RT-PCR testing in general. Yes - they make a ton of copies, but it is highly specific to RNA sequences specific to Covid 19. It does not identify positive tests for other Covid strains - that would be a useless test. The current PCR assays look specifically for typical 3-5 specific Covid 19 RNA sequences and is highly sensitive. The Positive specificity for these Assays is typically around 99+% and a positive almost always means you have the virus. It does not mean you are infective or can spread, but it does mean you have COVID-19. The false negative specificity is a bigger issue - telling people that are Actually positive that they are negative. This is an unfortunate side effect of the collection of the specimen. Nasal pharyngeal swabs are not the most comfortable collection and especially for people getting these done quickly at tents or more questionable sites - a poor collection creates a negative result. Many places are doing just a routine nasal swab - which has been shown to be effective in symptomatic people, but increases the false negative rate in asymptotic people - leading to missing more cases. The other big issue is believing things like the Abbott ID now assay touted by the White House is a good assay. The sensitivity of that instrument is significantly worse that other longer PCR assays. We finally got the instrument into the lab and it was striking how bad of an assay it is. If you are very symptomatic shedding lots of virus - it is fine, but if you are early in the cycle and are infective, but with few or minor symptoms- it produced many more negatives than the more sensitive assays. RT-PCR is a fabulous testing method for viruses and other infective agents because it is so specific and sensitive and ideally you want to be right when you are telling people they are positive. The biggest issue is almost always specimen collection because a the instrument has no way to know that you missed the virus in the cells you collected. It can only tell you got some cells. Additionally if you actually believe that PCR assays were never intended for testing - then you really need to move out of the 1800’s and get into a modern lab. A modern molecular lab has 100’s of different PCR assays available to help identify Things like flu strains, Tons of different respiratory virus, infectious diseases, and even bacterial infections of the blood in half the time of old methods and with much more specificity than older methods. To pair these types of tests with the rings that are designed to provide things like O2 levels, heart rate, and temperature should help the NBA catch some players before things spread. The issue becomes how much data can the team doctors see because it collects much more info and some of that like location and sleep patterns and even potential intercourse frequency based on heart rate, blood pressure, etc - can all be considered an invasion of privacy- especially if they are supposed of to be bubbled. Edited July 2, 2020 by Rochesterfan 1
Hapless Bills Fan Posted July 3, 2020 Posted July 3, 2020 8 hours ago, billsfan89 said: The accuracy of the swab test is estimated to be 95% and the rapid test 89% that is not good to this type of thing where 99% or higher is needed. But 90% or higher accuracy still provides valuable information. Countries like South Korea and Japan used these tests as the backbone of their containment plan and it was a helpful tool. So to dismiss these tests as having no value is simply not true. I would like to know where you got the "accuracy of the swab test is estimated to be 95%"? Something to remember with clinical testing: "accuracy" per se isn't too meaningful. There are two parameters: 1) sensitivity - meaning if you test 100 people who are actually infected, how many of them does the test pick up? There are two aspects of this, one is the actual sensitivity of the test, the other is its false-negative rate in use (which includes sample collection, sample storage, viral extraction etc etc) 2) selectivity - meaning if you test 100 people who are actually not infected, how many false positives does the test pick up? So the "accuracy" of the swab test is actually very good as far as selectivity (false positives), much better than 95% But the "accuracy" of the swab test as far as sensitivity may be much less than 95% - estimates have ranged from 66% to 88% It also depends when in the course of the infection the test is taken https://en.wikipedia.org/wiki/COVID-19_testing#Sensitivity_and_specificity SirAndrew raised a valid point that detecting viral RNA in people, may not indicate the presence of live virus. But I'd still like to know how many (of the millions infected) are caught in "endless quarantine" where they keep testing positive for months We do need studies of whether or not such people are still shedding live virus. 7 hours ago, spartacus said: anytime your test requires the virus target (and everything else in the swab) to be doubled 35 -45 times, the test is subject to question at 35 times, you have increased virus in a single swab to 5 BILLION particles at 45 times, the particles explode to 35 TRILLION what could go wrong The PCR process was never intended to be used for diagnostic testing on any scale- due to the limitation of the very process at 45 times, positive tests are likely identifying some coronavirus since it is the most prevalent virus in the body (including the common cold) However, it may not be COVID-19 strain. Spartacus, please stop with the misinformation here. The RT-PCR test is not increasing virus. It involves extracting the viral genetic material (RNA) and amplifying it. That's how RT-PCR works, and it's not "subject to question". RT-PCR is in common and widespread use as a diagnostic test for various diseases, animal and human, because of its high specificity and sensitivity. There is no "never intended for diagnostic testing" about it. The RT-PCR test for SARS-CoV2 will NOT detect any other coronavirus (such as the common cold) because the primers that bind to the viral RNA and allow it to be amplified were specifically designed to use RNA sequences that are not found in other coronaviruses, just in SARS-CoV2 (the virus that causes covid-19). This is "Basic RT-PCR test design 101" 2
Hapless Bills Fan Posted July 3, 2020 Posted July 3, 2020 7 hours ago, spartacus said: based on studying real live infected people, the main WHO researcher determined that it was "very rare" for those without symptoms to spread the virus However, this conclusion was quickly condemned for not fitting the narrative The entire mask farce would be exposed since it would be clear that only sick people should wear them The person who made the statement that asymptomatic transmission was "rare" was not "the main WHO researcher". She is an American epidemiologist serving as tech lead of covid and head of the emerging diseases and zoonosis unit at WHO. (that's a bit different than "main WHO researcher"). She didn't say it was "very rare" for "those without symptoms" to spread the virus. She said "From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual" and that "spread by asymptomatic patients is very rare" She walked her statement back, not because it didn't "fit the narrative" but because data to support it is not available : "Several experts were immediately skeptical. For one, the WHO provided no publicly available data to support that stance, while different types of studies have suggested that asymptomatic transmission plays an important role in the seeding and spread of outbreaks across the world. The statement also seemed vague about the distinction between asymptomatic and presymptomatic spread. Other research has shown that a person may be most infectious, judging by the level of virus shed from their body, right before symptoms appear." "Van Kerkhove and Ryan also clarified that there is a difference between people who are fully asymptomatic, meaning they are infected but never feel sick; people with mild symptoms that may go unnoticed; and those who are presymptomatic, meaning they are infected with the virus but haven’t begun feeling sick yet. Those in the last group may still be plenty infectious soon before they become sick, while we know less about the risk of transmission from the other two groups." PRESYMPTOMATIC people, meaning infected people who have the virus but have not yet developed symptoms, are well established to be spreading the virus, sometimes widely. The role of asymptomatic people in transmission is also still under study - emerging outbreaks in, for example, worker dorms in Singapore have challenged this. The point is, no one can tell if you're gonna be "asymptomatic" vs "presymptomatic" except 2 weeks later, in hindsight; it's a useless distinction from a disease prevention standpoint. So there goes your narrative about a "mask farce".
SirAndrew Posted July 3, 2020 Posted July 3, 2020 34 minutes ago, Hapless Bills Fan said: I would like to know where you got the "accuracy of the swab test is estimated to be 95%"? Something to remember with clinical testing: "accuracy" per se isn't too meaningful. There are two parameters: 1) sensitivity - meaning if you test 100 people who are actually infected, how many of them does the test pick up? There are two aspects of this, one is the actual sensitivity of the test, the other is its false-negative rate in use (which includes sample collection, sample storage, viral extraction etc etc) 2) selectivity - meaning if you test 100 people who are actually not infected, how many false positives does the test pick up? So the "accuracy" of the swab test is actually very good as far as selectivity (false positives), much better than 95% But the "accuracy" of the swab test as far as sensitivity may be much less than 95% - estimates have ranged from 66% to 88% It also depends when in the course of the infection the test is taken https://en.wikipedia.org/wiki/COVID-19_testing#Sensitivity_and_specificity SirAndrew raised a valid point that detecting viral RNA in people, may not indicate the presence of live virus. But I'd still like to know how many (of the millions infected) are caught in "endless quarantine" where they keep testing positive for months We do need studies of whether or not such people are still shedding live virus. Spartacus, please stop with the misinformation here. The RT-PCR test is not increasing virus. It involves extracting the viral genetic material (RNA) and amplifying it. That's how RT-PCR works, and it's not "subject to question". RT-PCR is in common and widespread use as a diagnostic test for various diseases, animal and human, because of its high specificity and sensitivity. There is no "never intended for diagnostic testing" about it. The RT-PCR test for SARS-CoV2 will NOT detect any other coronavirus (such as the common cold) because the primers that bind to the viral RNA and allow it to be amplified were specifically designed to use RNA sequences that are not found in other coronaviruses, just in SARS-CoV2 (the virus that causes covid-19). This is "Basic RT-PCR test design 101" My comment on “endless quarantine” really depends on what state you live in you, or who your employer is. I know people who’ve been quarantined for a month because they haven’t produced two negative tests proving they are safe to return to work. Below is an example about the “endless quarantine” people I’m referring to. I know that my workplace also has the two negative test policy, and I’m in the states, so this isn’t just a Canada thing. I simply hate to see crucial decisions made when the real science is lacking. https://www.statnews.com/2020/06/08/viral-shedding-covid19-pcr-montreal-baby/
spartacus Posted July 3, 2020 Posted July 3, 2020 12 hours ago, Hapless Bills Fan said: Spartacus, please stop with the misinformation here. The RT-PCR test is not increasing virus. It involves extracting the viral genetic material (RNA) and amplifying it. That's how RT-PCR works, and it's not "subject to question". RT-PCR is in common and widespread use as a diagnostic test for various diseases, animal and human, because of its high specificity and sensitivity. There is no "never intended for diagnostic testing" about it. The RT-PCR test for SARS-CoV2 will NOT detect any other coronavirus (such as the common cold) because the primers that bind to the viral RNA and allow it to be amplified were specifically designed to use RNA sequences that are not found in other coronaviruses, just in SARS-CoV2 (the virus that causes covid-19). This is "Basic RT-PCR test design 101" you highlight the challenge of with using PCR to test for the virus. The test is not binary- it does not prove if you have the virus or do not have the virus you are not testing the isolated virus. some brilliant scientist in a lab decided which portion of genetic RNA material should be tested then using best guesses decided which primers to bind to the RNA to create a fabricated DNA strip that can be compared to human DNA of course , none of this can be done without replicating that viral sample (and other genetic material in the swab) into 35 trillion items if the test is so specific, how can it be accurate when covid has mutated 18 times and changed the underlying genetic RNA material
Hapless Bills Fan Posted July 5, 2020 Posted July 5, 2020 On 7/3/2020 at 10:21 AM, spartacus said: you highlight the challenge of with using PCR to test for the virus. The test is not binary- it does not prove if you have the virus or do not have the virus you are not testing the isolated virus. some brilliant scientist in a lab decided which portion of genetic RNA material should be tested then using best guesses decided which primers to bind to the RNA to create a fabricated DNA strip that can be compared to human DNA of course , none of this can be done without replicating that viral sample (and other genetic material in the swab) into 35 trillion items if the test is so specific, how can it be accurate when covid has mutated 18 times and changed the underlying genetic RNA material Nope, this is not at all how it happened or works. -No comparison to human DNA whatsoever is involved in the diagnostic RT-PCR test for covid-19 -No "other genetic material in the swab" is replicated, because the primers specifically replicate a specific portion of the viral RNA -No guesses were involved in the test design The primers were designed by -identifying sequences that are unique to covid-19 and not found in other coronaviruses (this is usually done by computer) -choosing pieces of such sequence that have a base composition and length to bind and to dissociate at specific temperatures (this is based on known thermodynamic properties of nucleic acids) The test is robust to mutations in the virus because 1) unless they happen to hit the stretch of RNA where the primers bind, mutations don't matter 2) the US test uses 3 separate sets of primers so if enough mutations interfere with the binding of one primer, the others still work There's a tiny little grain of truth in here - the test is not detecting the intact virus (which would NOT be desireable for a clinical test due to infection control concerns), it is detecting the viral RNA. But RNA not protected by a virus shell is notoriously easy to degrade - we all have ribonucleases that degrade RNA on our skin and in our blood, this has been known for >40 years. So that little grain of truth? Not good enough. You were asked to stop spreading misinformation, apparently you can or will not. Where misinformation on this topic is concerned, I ain't playin' . Take heed. 1
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