6 ms·

Just as a side note, asymptomatic spread is a contested topic. If asymptomatic spread were a major driver of infection, this would be the first respiratory viru

Just as a side note, asymptomatic spread is a contested topic. If asymptomatic spread were a major driver of infection, this would be the first respiratory virus to work that way. Sources: - Nature study, 20th Nov https://www.nature.com/articles/s41467-020-19802-w https://www.nature.com/articles/s41467-020-19802-w - Maria Van Kerkhove, head of the WHO Emerging Diseases and Zoonosis unit https://www.youtube.com/watch?v=NQTBlbx1Xjs https://www.youtube.com/watch?v=NQTBlbx1Xjs - Fauci in 2018 https://www.youtube.com/watch?v=vrAvjU2LBkg&feature=emb_title https://www.youtube.com/watch?v=vrAvjU2LBkg&feature=emb_titl...

madeofpalk 6y ago
My casual understanding was that there werent really any asymptomatic spreaders, just "not symptomatic yet". Is this wrong?
- Wintamute 6y ago
  I'm not aware of stats relating to how many asymptomatic individuals go on to develop full blown symptomatic Covid-19. My assumption is that testing PCR positive while remaining asymptomatic the entire time is by far the most common experience. Of course, whether you go on to develop symptoms or not, its still highly pertinent information if asymptomatic spread is not a major driver of infection. As long as you self isolate upon symptom onset that should be enough. It does call into question whether isolating the apparently healthy is an evidence-based public health policy intervention though.
  - doliveira 6y ago
    Asymptomatic individuals never develop any symptoms. And the viral load is high two days before the symptoms onset. If you want a proper RCT about it, good luck approving it in an ethics committee.
  - AlanSE 6y ago
    Truly asymptomatic spread is not a major driver of infection. There are been some major public relations problems when an organization said this, and were mistaken to mean pre-symptomatic, but the science is pretty clear. We used to think true asymptomatic infections (never develop any symptoms but test positive) were ~50% of those infected. More recent research puts it at closer to ~20%. Again, some reporting bungled this by reporting studies from controlled populations (like a cruise ship) before they knew if cases were asymptomatic or pre-symptomatic, causing people to quote the number as the former, when it was really a mix. COVID spreads like wildfire by pre-symptomatic people. There are mountains of evidence to support this. Spread by asymptomatic people is speculation. > Of course, whether you go on to develop symptoms or not, its still highly pertinent information if asymptomatic spread is not a major driver of infection. Not sure, but I think you may be using the word "asymptomatic" to denote pre-symptomatic in this sentence. > As long as you self isolate upon symptom onset that should be enough. It is not enough.
    - alistaira 6y ago
      If a person has no symptoms, I think it is reasonable to say they are "asymptomatic". There is absolutely a difference between 'yet to have' and 'never will have' but I think it is potentially confusing to attempt to delineate between asymptomatic and "pre-symptomatic". The main concern with messaging that causes confusion in this regard is that a superficial reading of "asymptomatic doesn't spread virus" would imply that if you aren't symptomatic, you aren't a danger.
  - scotty79 6y ago
    Every symptomatic person was asymptomatic before they started getting their first symptoms. It might have been few days that they already had the virus on their mucus membranes.
- bamboleo 6y ago
  That’s just word play. I’m asymptotic today, symptomatic tomorrow. I, asymptotic young person with nCoV 2, am spreading it today. The “yet” part is completely irrelevant to this point in time.
  - please-reread 6y ago
    Are you implying you might become a geometry concept? https://en.wikipedia.org/wiki/Asymptote https://en.wikipedia.org/wiki/Asymptote
  - frobozz 6y ago
    This is one of those situations where the overlap between colloquial and technical usage can cause confusion when one leaks into the other. In colloquial usage, asymptomatic encompasses presymptomatic. In technical usage, they are different. If you develop symptoms, then when you were a carrier before then, you were presymptomatic, rather than asymptomatic.
raverbashing 6y ago
This is missing the point and reeks of intellectual dishonesty. Asymptomatic has a strict definition. You get the virus and nothing happens to you. This is what the WHO and Fauci are referring to. But most "asymptomatic" cases aren't. They are either paucisymptomatic (you have mild symptoms - maybe too mild to notice) or pre-symptomatic. Obviously if people were only contagious if showing symptoms, the pandemic wouldn't be.
- tialaramex 6y ago
  I followed the New Zealand press conferences very closely and so often the initial story was this person had no symptoms, total surprise to them that they had the virus, and then a day later oh, well, actually they did have some symptoms but they didn't realise it was COVID-19... People will say to themselves well, it's just a cough right? Just a cough. I can't have COVID-19 that's something other people get, those people are sick but I'm healthy, this is just a cough. And that allows the virus to spread.
- doliveira 6y ago
  12 months in, I'd say we can already claim it more than "reeks": it is full-blown intellectual dishonesty. Viral load peeks before symptoms onset, we have quite a few case studies of transmission, but these people apparently want some dozens of RCTs before admitting it.
- Wintamute 6y ago
  I made a new point, so am I missing my own point? Confused. > Obviously if people were only contagious if showing symptoms, the pandemic wouldn't be. I don't think that is obviously the case at all. It would have to be proved. The dominant vectors of contagion are not yet well understood - we could be dealing with very highly infectious airborne virus, that is capable of spreading widely from a relatively small number of symptomatic and pre-symptomatic super spreaders. The fact remains that current public health interventions orientate around isolating individuals whether they are symptomatic, asymptomatic or paucisymptomatic. Moreover, to greater and lesser degrees we also isolate the healthy, assuming them to be asymptomatic in an abundance of caution. Considering the negative non-covid related knock on effects of these policies its at least worth investigating isn't it?
mikepurvis 6y ago
In Ontario (as elsewhere), there's been a giant ramp up in cases since the start of September, with an accompanying discussion about whether or not reopening schools is the cause. But a recent testing blitz at a single Toronto school uncovered 26 infected individuals scattered across 18 classrooms: https://www.theglobeandmail.com/canada/toronto/article-students-self-isolating-after-more-positive-covid-19-tests-at/ https://www.theglobeandmail.com/canada/toronto/article-stude... Still not obvious one way or the other about whether these students and staff are spreading it amongst themselves or if they all got it from other symptomatic cases in the community and independently brought it to school with them. But either way, it's sobering how much of it is going undetected.

madeofpalk 6y ago

My casual understanding was that there werent really any asymptomatic spreaders, just "not symptomatic yet". Is this wrong?

Wintamute 6y ago
I'm not aware of stats relating to how many asymptomatic individuals go on to develop full blown symptomatic Covid-19. My assumption is that testing PCR positive while remaining asymptomatic the entire time is by far the most common experience. Of course, whether you go on to develop symptoms or not, its still highly pertinent information if asymptomatic spread is not a major driver of infection. As long as you self isolate upon symptom onset that should be enough. It does call into question whether isolating the apparently healthy is an evidence-based public health policy intervention though.
- doliveira 6y ago
  Asymptomatic individuals never develop any symptoms. And the viral load is high two days before the symptoms onset. If you want a proper RCT about it, good luck approving it in an ethics committee.
- AlanSE 6y ago
  Truly asymptomatic spread is not a major driver of infection. There are been some major public relations problems when an organization said this, and were mistaken to mean pre-symptomatic, but the science is pretty clear. We used to think true asymptomatic infections (never develop any symptoms but test positive) were ~50% of those infected. More recent research puts it at closer to ~20%. Again, some reporting bungled this by reporting studies from controlled populations (like a cruise ship) before they knew if cases were asymptomatic or pre-symptomatic, causing people to quote the number as the former, when it was really a mix. COVID spreads like wildfire by pre-symptomatic people. There are mountains of evidence to support this. Spread by asymptomatic people is speculation. > Of course, whether you go on to develop symptoms or not, its still highly pertinent information if asymptomatic spread is not a major driver of infection. Not sure, but I think you may be using the word "asymptomatic" to denote pre-symptomatic in this sentence. > As long as you self isolate upon symptom onset that should be enough. It is not enough.
  - alistaira 6y ago
    If a person has no symptoms, I think it is reasonable to say they are "asymptomatic". There is absolutely a difference between 'yet to have' and 'never will have' but I think it is potentially confusing to attempt to delineate between asymptomatic and "pre-symptomatic". The main concern with messaging that causes confusion in this regard is that a superficial reading of "asymptomatic doesn't spread virus" would imply that if you aren't symptomatic, you aren't a danger.
- scotty79 6y ago
  Every symptomatic person was asymptomatic before they started getting their first symptoms. It might have been few days that they already had the virus on their mucus membranes.
bamboleo 6y ago
That’s just word play. I’m asymptotic today, symptomatic tomorrow. I, asymptotic young person with nCoV 2, am spreading it today. The “yet” part is completely irrelevant to this point in time.
- please-reread 6y ago
  Are you implying you might become a geometry concept? https://en.wikipedia.org/wiki/Asymptote https://en.wikipedia.org/wiki/Asymptote
- frobozz 6y ago
  This is one of those situations where the overlap between colloquial and technical usage can cause confusion when one leaks into the other. In colloquial usage, asymptomatic encompasses presymptomatic. In technical usage, they are different. If you develop symptoms, then when you were a carrier before then, you were presymptomatic, rather than asymptomatic.

raverbashing 6y ago

This is missing the point and reeks of intellectual dishonesty. Asymptomatic has a strict definition. You get the virus and nothing happens to you. This is what the WHO and Fauci are referring to. But most "asymptomatic" cases aren't. They are either paucisymptomatic (you have mild symptoms - maybe too mild to notice) or pre-symptomatic. Obviously if people were only contagious if showing symptoms, the pandemic wouldn't be.

tialaramex 6y ago
I followed the New Zealand press conferences very closely and so often the initial story was this person had no symptoms, total surprise to them that they had the virus, and then a day later oh, well, actually they did have some symptoms but they didn't realise it was COVID-19... People will say to themselves well, it's just a cough right? Just a cough. I can't have COVID-19 that's something other people get, those people are sick but I'm healthy, this is just a cough. And that allows the virus to spread.
doliveira 6y ago
12 months in, I'd say we can already claim it more than "reeks": it is full-blown intellectual dishonesty. Viral load peeks before symptoms onset, we have quite a few case studies of transmission, but these people apparently want some dozens of RCTs before admitting it.
Wintamute 6y ago
I made a new point, so am I missing my own point? Confused. > Obviously if people were only contagious if showing symptoms, the pandemic wouldn't be. I don't think that is obviously the case at all. It would have to be proved. The dominant vectors of contagion are not yet well understood - we could be dealing with very highly infectious airborne virus, that is capable of spreading widely from a relatively small number of symptomatic and pre-symptomatic super spreaders. The fact remains that current public health interventions orientate around isolating individuals whether they are symptomatic, asymptomatic or paucisymptomatic. Moreover, to greater and lesser degrees we also isolate the healthy, assuming them to be asymptomatic in an abundance of caution. Considering the negative non-covid related knock on effects of these policies its at least worth investigating isn't it?

mikepurvis 6y ago

In Ontario (as elsewhere), there's been a giant ramp up in cases since the start of September, with an accompanying discussion about whether or not reopening schools is the cause. But a recent testing blitz at a single Toronto school uncovered 26 infected individuals scattered across 18 classrooms: https://www.theglobeandmail.com/canada/toronto/article-students-self-isolating-after-more-positive-covid-19-tests-at/ https://www.theglobeandmail.com/canada/toronto/article-stude... Still not obvious one way or the other about whether these students and staff are spreading it amongst themselves or if they all got it from other symptomatic cases in the community and independently brought it to school with them. But either way, it's sobering how much of it is going undetected.