3 ms·

> Maximum shedding duration was 83 days in the upper respiratory tract So covid-19 is transmissible for up to 83 days once infected?

krona 6y ago
PCR tests detect fragments of a virus, not necessarily an active/viable virus.
_Microft 6y ago
Their interpretation does not make it sound like this is the case: "Although SARS-CoV-2 RNA shedding in respiratory and stool samples can be prolonged, duration of viable virus is relatively short-lived. SARS-CoV-2 titres in the upper respiratory tract peak in the first week of illness. Early case finding and isolation, and public education on the spectrum of illness and period of infectiousness are key to the effective containment of SARS-CoV-2."
zelos 6y ago
But: > no live virus was isolated from culture beyond day 9 of symptoms despite persistently high viral RNA loads. > This finding is supported by several studies demonstrating an association between viral load and viability of virus, with no successful culture from samples below a certain viral load threshold. So the amount shed is too low to infect anyone beyond 9-10 days (I think, I am not a virologist, etc.)
- Aerroon 6y ago
  >So the amount shed is too low to infect anyone beyond 9-10 days (I think, I am not a virologist, etc.) Is it possible to acquire immunity against the virus (in a similar way that vaccines work) by being in contact with someone at say day 20+?
  - lnsru 6y ago
    If it would be possible, pandemic would be over months ago and there would be no need to develop any vaccine.
    - kadoban 6y ago
      It could be possible, just unlikely enough that immunity doesn't spread fast enough.
  - Geeflow 6y ago
    Sounds reasonable - but I'd still prefer to stay away from people who are shedding the virus. There is also a similar theory that cloth masks might have the unintended positive side effect of building immunity. They are not perfect, so the virus might still reach its target. But the viral load could be reduced enough that instead of infection it leads to immunity.

krona 6y ago

PCR tests detect fragments of a virus, not necessarily an active/viable virus.

_Microft 6y ago

Their interpretation does not make it sound like this is the case: "Although SARS-CoV-2 RNA shedding in respiratory and stool samples can be prolonged, duration of viable virus is relatively short-lived. SARS-CoV-2 titres in the upper respiratory tract peak in the first week of illness. Early case finding and isolation, and public education on the spectrum of illness and period of infectiousness are key to the effective containment of SARS-CoV-2."

zelos 6y ago

But: > no live virus was isolated from culture beyond day 9 of symptoms despite persistently high viral RNA loads. > This finding is supported by several studies demonstrating an association between viral load and viability of virus, with no successful culture from samples below a certain viral load threshold. So the amount shed is too low to infect anyone beyond 9-10 days (I think, I am not a virologist, etc.)

Aerroon 6y ago
>So the amount shed is too low to infect anyone beyond 9-10 days (I think, I am not a virologist, etc.) Is it possible to acquire immunity against the virus (in a similar way that vaccines work) by being in contact with someone at say day 20+?
- lnsru 6y ago
  If it would be possible, pandemic would be over months ago and there would be no need to develop any vaccine.
  - kadoban 6y ago
    It could be possible, just unlikely enough that immunity doesn't spread fast enough.
- Geeflow 6y ago
  Sounds reasonable - but I'd still prefer to stay away from people who are shedding the virus. There is also a similar theory that cloth masks might have the unintended positive side effect of building immunity. They are not perfect, so the virus might still reach its target. But the viral load could be reduced enough that instead of infection it leads to immunity.