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.
Are there other tests available that do not have this issue, I wonder.
Center for Evidence-Based Medicine at Oxford University>>>
says it all. Clearly not the “Center for Non-Evidence Based Medicine”
The gal from China that infected that German company never did show symptoms.>>> Actually this is not true as she had symptoms. The report has been corrected. She was taking some type of cold medicine.
original story here:
https://www.nbcboston.com/news/coronavirus/woman-who-hid-coronavirus-symptoms-to-fly-to-china-faces-criminal-charges/2093876/
and then this
https://www.dailymail.co.uk/news/article-8380627/Coronavirus-China-Woman-hid-symptoms-arrested.html
Thank you for the corrections!
An elderly couple at our church have the CV. The wife, 87, spent a couple of days at the hospital and was released. Her husband, age 90 was tested for it. He has/had it as well, but no symptoms!!??
It is always amazing how folks handle different things. My grandfather drank and smoked and died of a broken hip at 97.
My old man never smoked but had a glass of wine on the weekend. He died of cancer at the age of 72.
Re: Are there other tests available that do not have this issue, I wonder.
***
There is something called a paper test. It yields results in ~ 15 minutes and tells you if you are infectious or not. Costs about $1 - $2 and could be sold over the counter for home use
Plus:
“From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,” Dr. Maria Van Kerkhove, head of WHO’s emerging diseases and zoonosis unit, said at a news briefing from the United Nations agency’s Geneva headquarters. “It’s very rare,”
https://www.cnbc.com/2020/06/08/asymptomatic-coronavirus-patients-arent-spreading-new-infections-who-says.html?__source=twitter%7Cmain
Fauxci, Birx, Redfield et al did not bother to up date the public with this information
Does any of those drivers enter into a close confine space (in a building with poor air circulation) where they share air with others? I would be interested in this answer.
Is your business in a densely populated areas? I think it a big city issue where people are pack like rats.
Here is some facts from my observations:
Our factories are pack with people. Those are located in multiply states
We have about 1000 people infected in my company. The infections are on the factory line where workers work side by side. Out of 1000 we lose two people. One sales person and one factory worker. (My company briefs us weekly)
Coworkers 32 year old daughter die from it: She is a nurse taking care of Covid patients. (found out about it via meetings)
Coworker girl friend (in her 40s) died: She was a nurse in a retirement center (first hand: I meet with him weekly)
Aunt in her 70s infected, tooks some of those new drugs. Now is fully recovered. Not sure were she caught it. My Uncle never did catch it, not sure why.
Nephew and his girl friend infected. She did not get sick, just tested postive. My nephew is currently very sick in bed. He caught it at Clemson University.
My company’s local office has about 400 people coming in to work, since the beginning. We do temperature checks, and have a mask mandate. We also have an educated workforce.
We have had 10 confirmed cases of COVID, meaning “people who got tested and were positive”. All 10 cases were outside of work. We’ve had close to 100 people who were “close contacts” of those 10, not one got COVID.
We’ve also had 20 “false positives”, meaning people who were sick enough to think they had it, who then got tested and were found to be negative.
It is hard sometimes to imagine this thing is all that contageous. There seems to be a few people who are highly contageous, and they sometimes do stupid stuff.
But worldwide, we have had a total of 30 million cases. In 2009, the US had 69 million cases of H1N1, which was “just a flu”.
Now we are getting high positive rates for people with no symptoms, and contact tracing is showing little spread, outside the occasional huge college party.
I also just read a report that there has been no outbreaks related to theme park openings.
I’m looking for data on total “COVID + Pnemonia” deaths for the 2019-2020 season, to compare to the “Flu + Pnemonia” deaths for the 2017-2018 and 2018-2019 seasons. It is weird how hard it is to find out how many people die each year from the “flu-related illnesses”, we report “flu deaths”, and the rest are just reported as whatever killed people.
BTW, I expect their to be a large uptick in flu cases this year, although maybe our social distancing and mask-wearing and hand-washing might mitigate it. NOT because more people get the flu, but because every person with a symptom is going to get tested. We’ve already had one positive flu case at my facility, they got tested for COVID and it was negative.
In the past, most people with mild cases would not bother to get tested for flu, but with COVID everybody gets tested.
I first tested positive on July 27 and I am a walking textbook example of a Covid patient; High blood pressure, high chloresterol, high triglcerides, stint implant for coronary artery diseas, diabetes 2.. You name it, I’ve got it.
The worst symptom I’ve had was a temp. of 99.1 on July 24. Everything including my blood oxygen has been great. But I have tested positive 4 times with the latest this week on Sept. 15th. Maybe I’m like the legendary Typhoid Mary of the 1800s with no symptoms but still infectious???
p
Your rationality and knowledge in invaluable.
He’s trying to win a presidential election against a well-funded, well-organized psychos who will literally stop at nothing and employ any tactic to see him lose.
He’s saying what he needs to say to win over gullible sheep and idiots who think wearing masks helps, and that it’s good that an entire summer of people’s lives has been cancelled and economies destroyed because it’s “saving lives”. Not to mention scarring the minds of a generation of children whose lives and development is “on pause” because of this fraud.
He’s trying to get votes.
slow done there. Viruses can be and are contagious before symptoms. That does not mean the whole reaction to this is greatly overblown and misguided. You are attacking the wrong person.
that does not mean the whole reaction is not greatly overblown and misguided. Worked late last night....
“He’s trying to win a presidential election against a well-funded, well-organized psychos who will literally stop at nothing and employ any tactic to see him lose.
He’s saying what he needs to say to win over gullible sheep and idiots”
wow, just blew my mind. Lie to win, wow. So ............. darn wow. oh my........
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Politicians lie. Everybody lies. A little white lie to the wife to get a couple hours of free time on a Sunday. Five-year-old tells mommy a white lie to avoid getting in trouble. It’s just how life is. If you’ve never told a lie then I applaud you sir, you’re a better person than 97.224% of the people on earth.
Donald Trump realizes what is at stake here, and he’s maintaining his good humor and natural, easy-going-but-very-shrewd personage through it all. If he needs to lie to gain the vote of some f#@%ing idiot sheep to save this nation from the jaws of doom and outright communism at the hands of Kamala and AOC, then I applaud him for it and support him to the end of all things.
Lie your ass off Donnie, if it preserves “truth, justice, and the American Way”. This is a street fight, not Marquis of Queensbury rules. ‘Win at all costs’ means more than it used to, and it means different things to “us” than it does to “them”. Scorched earth to save the USA.
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