Posted on 09/18/2020 4:03:47 AM PDT by gattaca
Elevated 'cycle thresholds' may be detecting virus long after it is past the point of infection.
A growing body of research suggests that a significant number of confirmed COVID-19 infections in the U.S. — perhaps as many as 9 out of every 10 — may not be infectious at all, with much of the country's testing equipment possibly picking up mere fragments of the disease rather than full-blown infections.
Confirmed cases of the disease have been the focal point of public health authorities and governments worldwide for many months, with countries across the globe working frantically to shore up their testing infrastructure and ensure that most citizens who want a COVID-19 test can obtain one with relative ease.
Many politicians, meanwhile — including most state governors in the U.S. — have tied reopening policies to the number of cases detected in the local community, with regions and localities often being permitted to reopen in staggered "phases" only when they have reached successively lower benchmarks of average new daily cases in the area.
Numerous institutions, meanwhile, have adopted testing protocols in an attempt to preempt the spread of the virus. American colleges and universities, for instance, have turned to mass testing in order to closely monitor incidences of the disease among students, particularly residential students living on campus.
Yet a burgeoning line of scientific inquiry suggests that many confirmed infections of COVID-19 may actually be just residual traces of the virus itself, a contention that — if true — may suggest both that current high levels of positive viruses are clinically insignificant and that the mitigation measures used to suppress them may be excessive.
'Cycle threshold' set very high for many tests
At issue is the method by which many COVID-19 tests detect a patient's viral load within a given sample. Polymerase chain reaction tests, which have been widely deployed to determine if individuals are infected with the disease, function by amplifying DNA samples to the point that an antigen can be detected and classified.
The "cycle threshold" is the number of amplification cycles a PCR test goes through before a target pathogen is detected. A lower cycle threshold means that a higher amount of the virus was present in the sample; a higher threshold means the machine had to work harder to detect the virus in the sample, indicating a lower viral load and more likely a non-infectious patient.
According to a rundown of PCR tests compiled by the Foundation for Innovative New Diagnostics, many manufacturers of PCR tests set the cycle threshold cutoff for a positive sample at up to around 40 cycles, a level numerous public health officials believe is guaranteed to return what are effectively false positive results that have detected fragments of the virus.
"I'm shocked that people would think that 40 could represent a positive," Juliet Morrison, a virology professor at the University of California, Riverside, told the New York Times in August.
Health authorities elsewhere have indicated similar skepticism of high-threshold tests. A spokeswoman for Taiwan's Central Epidemic Command Center said in June that the agency only assigns positive cases to samples with Cts of 35 or less, with authorities there believing that any samples with Cts of more than 32 are likely (though not definitely) non-infectious.
A team of researchers at Oxford, meanwhile, wrote in a preprint paper last week that, based on a review of various sample collections, swabs requiring more than 30 cycles were "associated with non-infectious samples."
Binary positive-negative test results — in which cycle thresholds are not considered — will "result in false positives with segregation of large numbers of people who are no longer infectious and hence not a threat to public health," they wrote.
Preprint papers have not yet been through the peer review process, so their results and conclusions can be changed prior to full publication. Yet several other research projects have indicated similar results. One, published in April by public health authorities out of France, found that "patients with Ct values equal or above 34 do not excrete infectious viral particles."
Similarly, a study out of Ireland seeking to determine "the duration of infectivity" of COVID-19 patients found that, of numerous samples subject to PCR testing, scientists were unable to achieve positive culture growth in any that required more than 34.3 cycles.
Both of those thresholds are notably smaller than the maximum number of cycles instituted by many test manufacturers, suggesting that there may be many nominally positive COVID-19 cases that are innocuous far as infectiousness and illness are concerned.
Echoing those concerns, researchers at Harvard in May argued that "the Ct value from positive test results, when interpreted in context, can help to refine clinical decision making," and that a cycle threshold of around 34 may be a useful tool for determining when a patient is truly infectious and when he or she is merely carrying remnants of the virus.
Such a policy, if implemented, could have momentous implications for public health policy in the U.S. and elsewhere. Presently, in many industries and at many institutions, a single positive COVID-19 case can result in a complete shutdown of the affected company or university or elementary school, followed by a rush to have everyone tested out of concern that the virus may have spread.
A greater emphasis on the cycle threshold of positive tests may preempt such disruptive policies by signaling which positive test results are truly infectious and which are detecting low viral loads at much less threat of infectivity.
Early indications suggest the number of clinically trivial positive cases in the U.S. might be startlingly high. The New York Times said last month that a review of the cycle thresholds of positive cases in Nevada, New York and Massachusetts indicated that "up to 90 percent of people testing positive carried barely any virus."
Those numbers, if extrapolated nationwide, could suggest that a significant proportion of the mitigation and preparation measures currently in place across the U.S. might be excessive relative to the actual level of infectious cases around the country.
Ultimately it can be difficult to determine the cycle thresholds used at laboratories across the country, making that kind of extrapolation difficult. A spokeswoman for LabCorp — one of the largest clinical laboratory groups in the world — said the company "does not include the CT value in result reporting."
"Our CT cutoff is based on extensive validation," she said, "and is within the accepted range to accurately identify individuals currently infected with SARS-CoV-2." The company on its website says it has performed 13.5 million COVID-19 tests, about 15% of the country's total number of tests.
At the Center for Evidence-Based Medicine at Oxford University, researchers stressed last month that "PCR detection of viruses is helpful so long as its limitations are understood; while it detects RNA in minute quantities, caution needs to be applied to the results as it often does not detect infectious virus."
"If this is not understood, PCR results may lead to restrictions for large groups of people who do not present an infection risk," they wrote.
Fear of the virus has been a useful tool of political control.
The virus itself? Inconsequential.
Actual cases and deaths from Covid I believe are around 10% of reported. Great majority of (senior citizen) deaths would have died anyway from regular flu or other ancillary causes due to pre-existing conditions. Case numbers greatly inflated by false positives and/or outright manipulation. Great percentage of positives have a cold or minor flu symptoms.
“Follow the science” is as hollow as “Russian collusion”.
Even if you get infected it does not mean you are at some high level of transmission nor does it mean everyone around you is some high level to get infected.
I have a friend who rarely gets sick while her husband gets sick every year.
What are the factors that make that possible?
And that is one example.
I get sick every year. in the doctors office or emergency room because I can’t breathe, while others around me do not get sick.
What gives?
All rhetoricial as I don’t give a flip about any explanation.
Treat this like any other viral. Wash hands, cover mouth when coughing, limit exposure to others if you are sick.
Virals are only transmissible when you have symptoms.
CDC says it takes 15 minutes of face to face to "catch it"....or "give it". When's the last time you spent 15 minutes of face to face in a store? For myself...I can say....NEVER.
*** click pic ***
Inconsequential? No. That destroyed your credibility. Am overblown testing phase with way to sensitive of a test? Absolutely.
Here are the facts and I hope we can reach agreement. Corona virus can be incredibly dangerous to the susceptible people. Really this is no different from any other disease. All diseases have a proclivity for certain populations. Influenza is an incredibly dangerous disease to the susceptible populations (remember lots of us have said from the get it’s just the flu bro and been panned for it). We vaccinate against the flu for two reasons. To create herd immunity to protest the population and to protect the individual from a potentially dangerous disease. I am required to be vaccinated for my job in order to prevent me from infecting people who might otherwise have a really tough time with influenza. I will also get the corona virus vaccine for two reasons. To protect me as I am around it daily. And to protect my family and patients so I don’t spread it
I don’t disagree in the least that the reaction is completely irrational. There should be no shirt down nor should there be masks etc. it’s ridiculous. But we have come to the point in America where we are majority sniveling snowflake and want to live in a bubble. Life has risks. The whole game of life is mitigating risks with an unacceptable profile and taking the risks that have a good reward profile.
This is the second disease that has been weaponized as a political function. The first one was HIV. We clearly are at a fork in the road. We either shall regain our American spirit and independence including celebrating American can do to bring forth a vaccine quickly and safely and create therapeutics. Or we can accept being discrete to and losing freedom from increasingly small things.
But this is not an inconsequential disease. I believe that close to 100,000 Americans have dies from this (about 50% of what is reported). But let’s discuss the facts. I share your frustration. We can figure this out using free market and conservative principles not the government mandates.
Does anyone have the link to this study?
False. Many viruses are transmissible for a few days before symptoms. Chickenpox, the common cold, mumps, etc. The gal from China that infected that German company never did show symptoms.
Key words “cycle threshold” ....if set over 35 people can test positive when all the test finds is dead strands of old virus indicating You may have treated positive in the past. The USA needs a uniform cycle threshold to know where we stand.
Thank you Dr. Fauci mini me.
Not the point
I cringe thinking of the lives and businesses that have been destroyed or set back for decades because of this fiasco. Now just wait for property taxes to skyrocket due to a years loss of revenue by the state and local govts.
It’s exactly the point. We take grave risks when we deny the truth. The statement was no virus is contagious prior to symptoms. This is simply false. Your response of ad hominem attack is exactly why we as conservatives are always at a rhetorical disadvantage
Fact is many virus transmit prior to symptoms. I am not sure this is the case with corona but we don’t know. So a blanket statement that is against what we know is completely indefensible as evidenced by the non responsive attack.
Every person in America who took a virology 101 has known this all along. I even made up my own virology phrase for it. Detectable does not mean infectable. It may be found for 99 billion years on a cardboard box from china. But it is dead.
No one with a kindegarten knowledge of viruses allows molecular testing on themselves or their families. Then the FDA changed a pos to single target and made it even more fake.
Okay..
Grow up or die.
I actually don’t give a fig what you think except that your argument is poisonous and some weird covert hateful argument against life and living
crawl back to whatever back water swamp you live in and the rest of will end this fraud.
If I don’t respond to whatever lame response you have, it’s because I’m headed to take of a business thing I can’t get out of, and then I’m headed over to a friend and then pick up the ashes that made his home an put them in a dumpster from the fires here in CA.
But, I will respond to whatever other “letter of the law” idiocy you want spout .
Yuh muck...
You and your idiotic sycophant tribe are why we are here and you thoughts are just plain hateful to America and humanity.
“We are all going to die....!!!”
Pound sand.
I’ve been at work every single day and still nothing
same with my colleagues.
Yet, everyone knows someone, who knows someone who “supposedly” died of Covid.
Go sell your crap somewhere else.
We are all out of crazy around here...
Oh, and you and your ilk are why I am building a network to end this insanity beginning Nov 4th.
Feel free to sit this one out.
We don’t need you...
If you want to come to rational agreement which you start here: http://freerepublic.com/focus/news/3885240/posts?page=8#8
fine
otherwise, no need to respond to me
I am beyond angry at this irrational “response” which I experienced in Mexico 2009 and thought “That’ll never happen again” and here we are globally
Seems to me you have no rational basis but anger. The science is the science. You made an incorrect statement and become this angry over a factual rebuke. It’s not personal. How we have responded I agree is outrageous. But you are entitled to THE facts. Not YOUR facts
Take a break. Go for a walk. Work out your anger. Life will be better for you
When you say you are at work everyday with your colleagues. What kind of work are you in so we understand your perspective
Rational?
I’ll give you rational and every single fact you want.
I have spent the last 8 months studying this fraud
Your response and mine may have been absolutes that aren’t true but, the fact is not every one will get sick and not everyone who carries a viral will transmit for a variety of reasons
Don’t back off now on your position if that is the most important thing...to you.
Or you can come over here to valid and rationally provable side that the response to this is immoral and irrational and political
or you can argue over things like “Well no. Virals, particularly....blah blah blah have been proven to be and then you make the supposed moral argument of “keeping those around who are susceptible safe” or my favorite “You don’t have the right infect someone else” or any other infantile facile argument
Your move...
Sure
1 I am in sales. Business to business. Seeing 8-19 new people each week and whoever else is in their office.
Today I had three appointments and 2-3 people each appointment, not counting the numerous I passed during the appointment and the homeless chumps just to get there.
2. I go to an office every day
3. 10 drivers go and see as many as 15 customers each day and whoever else is in their office
Those drivers bring whatever they ran into while on route that day
8 months and no one has taken a sick day or come to the office presenting anything like a symptom
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