How many COVID-19 infections are asymptomatic? Research shows it may be a lot more than thought

Discussion in 'Coronavirus (COVID-19) News' started by LangleyMan, Jul 21, 2020.

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  1. LangleyMan

    LangleyMan Well-Known Member

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    https://www.zdnet.com/article/how-many-covid-19-infections-are-asymptomatic-research-shows-it-may-be-a-lot-more-than-thought/?ftag=TREc64629f&bhid=25851661073862605603109632541317&mid=12937249&cid=717418104

    Apparently, a lot of people test negative for COVID-19 even though they were infected.

    "Qing Lei and colleagues from China's Tongji Medical College screened 177 people in the city of Wuhan, where the virus started, from February to April, they report this week in a paper posted on the medRxiv pre-print server. The study matched the 63 asymptomatic people with 51 people who showed mild symptoms of COVID-19, and 63 people who were healthy control subjects. All of the participants were followed for 65 days.

    Among the asymptomatic, 12 people who had no symptoms tested positive for COVID-19 according to the widely used RT-qPCR genetic test, the so-called asymptomatic carriers. Another 51 asymptomatic people came up negative on the genetic test but were found to have antibodies to COVID-19 in their blood, meaning they were infected. Antibodies are particles that form in the blood as the body's response to the virus.

    In other words, 81% of people with the disease in this sample who had no symptoms appeared negative on typical tests -- all false negatives."

    If this is true, a lot of people have had COVID-19 and don't even test positive if they get a test, the so-called "false negative."

    If people with antibodies don't get positive COVID-19 tests in the future, or have symptoms, they may be protected. A lot of ifs in this, of course.
     
    Last edited: Jul 21, 2020
  2. drluggit

    drluggit Well-Known Member

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    Hmm... so? Are you trying to tell us something here? If, as the study suggests such a large group tested inaccurately but also didn't either exhibit, or otherwise know they were exposed, what are we supposed to do?
     
  3. LangleyMan

    LangleyMan Well-Known Member

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    Realize you should get an antibody test if we find out people with mild infections have immunity.
     
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  4. Eleuthera

    Eleuthera Well-Known Member Donor

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    This peculiar situation you describe accurately is likely the result of the virus having been engineered IMO.
     
  5. LangleyMan

    LangleyMan Well-Known Member

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    The scientists looked at this long ago and concluded it wasn't engineered.
     
  6. Pred

    Pred Well-Known Member

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    You don’t need to be a scientist to realize tons of people have Covid and don’t know it which brings the death rate even more into focus. All we know is deaths of the tested. How many millions never bother getting tested because it’s basically a cold for the vast majority? I had a lousy cough for about 5 days in early Feb before the hysteria began. Easily could have been Covid....or an ordinary cold.
     
  7. 557

    557 Well-Known Member

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    There is emerging evidence a significant percentage of the population may have some existing immunity to C19 from previous coronavirus infections, possibly the common cold. How cool would that be?

    https://www.nature.com/articles/s41577-020-0389-z
     
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  8. AmericanNationalist

    AmericanNationalist Well-Known Member

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    Agreed, I feel like as more studies/tests are done and known, we may yet know more and more of the damage.
     
  9. LangleyMan

    LangleyMan Well-Known Member

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    It would be nice to catch a break. There hasn't been much definitive good news so far.
     
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  10. Quantum Nerd

    Quantum Nerd Well-Known Member

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    Thanks for posting that article. Here is the link to the original work:

    https://www.cell.com/cell/pdf/S0092...m/retrieve/pii/S0092867420306103?showall=true

    I know it is behind a paywall, I can access it through my institution. The cross-reactivity is definitely an interesting concept, although the T-cell stimulation index seems to be about 10-fold less in non-covid subjects than in covid positive subjects. However, the possibility is raised that the cross-reactivity could lead to a less severe disease progression. Still a lot of work to be done, but I think this may be an opportunity to take another stab at cold viruses in general by a large number of scientists, an area that didn't seem to garner lots of attention in the past. Maybe something positive will come from this pandemic.....
     
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  11. AmericanNationalist

    AmericanNationalist Well-Known Member

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    And a commonly thought theory is that the more the virus is passed around, the weaker it becomes(this was the case with SARS-1) and to a degree with the MERS virus as well.
     
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  12. Quantum Nerd

    Quantum Nerd Well-Known Member

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    That is true. Viruses like covid do not benefit from killing the host. The idea is that they evolutionary adapt to a form that has lower death rate. However, the rate of mutation is yet unknown.
     
  13. AmericanNationalist

    AmericanNationalist Well-Known Member

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    The way that that's worded, sounds to me like if the virus had a higher death rate it would paradoxically be good for us(IE: It would die out quicker, as the case was with Ebola.). It also means that if at the very beginning, we had contained the virus effectively we might've been able to lessen the damage.

    But now it's everywhere, and people don't have the psychological will to endure maybe a month or two months(that'd be needed) to starve the virus of hosts.
     
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  14. Collateral Damage

    Collateral Damage Well-Known Member

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    Personal opinion, but if some were to play up the idea that asymptomatic individuals are the 'spreaders', it would validate the idea some have about massive lockdown. Of course, one would have to also play up the idea that those who truly don't have it, should let themselves be locked down 'for the common good', and be involuntarily tested.
     
  15. FreshAir

    FreshAir Well-Known Member Past Donor

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    would be nice if they were easy to get
     
  16. Quantum Nerd

    Quantum Nerd Well-Known Member

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    That is, I believe, also a reasonable statement. Just think about it, if the virus had a 30%+ death rate, there would be no discussions about lockdowns, mask wearing etc. People like playing Russian Roulette only when the numbers are vastly in their favor (or so they think). In a sense, the virus is playing on human behavior, which apparently is largely irrational and almost impossible to control.
     
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  17. 557

    557 Well-Known Member

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    I envy your access. I find articles generally leave out a lot of interesting and often very relevant information produced by the studies. I’m tempted to just pay for access but I’d be like a gambling addict in a casino—broke. :)


    What we are learning about cross reactivity is exciting. Thanks for the details on stimulation index differences. Do you know if there is much variation between individuals in the non-Covid group?
     
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  18. Quantum Nerd

    Quantum Nerd Well-Known Member

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    Actually, I should have given you this link:

    https://pubmed.ncbi.nlm.nih.gov/32473127/

    Since the work was publically funded (our tax dollars at work), it has to be made available free of charge through PMC. So, if you want to get such original articles in the future, go search on pubmed.gov to get the free version.

    I like to read the original work, rather than someone's interpretation of it. That helps to remove biases.
     
  19. 557

    557 Well-Known Member

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    Thanks. I have a lot of stuff from ncbi show up in general searches but never tried searching through PMC directly. May save me lots of time digging things up.
    Absolutely. Bias of conclusions and my least favorite thing, omission of relevant information, is avoided if you can get your hands on the unadulterated research.
     
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  20. Sallyally

    Sallyally Well-Known Member Donor

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    Interesting article.
    “It is frequently assumed that pre-existing T cell memory against SARS-CoV-2 might be either beneficial or irrelevant. However, there is also the possibility that pre-existing immunity might actually be detrimental, through mechanisms such as ‘original antigenic sin’ (the propensity to elicit potentially inferior immune responses owing to pre-existing immune memory to a related pathogen), or through antibody-mediated disease enhancement.”
     
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  21. 557

    557 Well-Known Member

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    Yep, that’s a possibility.
     
  22. LangleyMan

    LangleyMan Well-Known Member

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    Trump needs to use the Defense Production Act to fix testing, get contact tracing going, and produce quality PPE for everyone to wants to buy it.
     
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  23. Sallyally

    Sallyally Well-Known Member Donor

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    He’s leaving his run a bit late. Do you think he knows about the Defence Production Act?
     
  24. LangleyMan

    LangleyMan Well-Known Member

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    Of course, he knows about the Defense Production Act.
     
  25. Sallyally

    Sallyally Well-Known Member Donor

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    Why doesn’t he invoke it then?
     

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