5 ms·

> SARS originated in China and killed more than 800 people worldwide in 2002 and 2003 Only 800, yet it felt like such a big deal back then...

peeters 6y ago
The mortality rate is what terrified people about SARS. It was a big deal. 50% for people 65 and older. 15% in the general population. This incidentally made it far less reproductive.
- samatman 6y ago
  > This incidentally made it far less reproductive. Unfortunately not. SARS-1 reproduced slowly (long onset), wasn't all that contagious, and was quite deadly. These are independent variables. Smallpox had a high R0 and was quite deadly.
  - littlestymaar 6y ago
    And most importantly, was contagious before the beginning of the symptoms, which always included fever so it was pretty easy to scan people with thermometer to catch the contagious ones. > And the fact that SARS was only contagious several days after the beginning of the symptoms is the reason why we have been able to control it […] and had contagiousness begun far earlier after the beginning of the symptoms or even before them like for the flu, the outbreak would have exploded and we wouldn't have been able to halt it. [1] [1]: quick translation from French from https://www.college-de-france.fr/site/arnaud-fontanet/course-2019-02-18-17h00.htm https://www.college-de-france.fr/site/arnaud-fontanet/course... (24'05)
  - tlb 6y ago
    In the modern world, deadliness decreases transmissibility (Re, not R0), because people make organized efforts to contain deadly diseases. Covid's death rate was low enough that a good fraction of people thought we should just take it on the chin. By contrast, Smallpox was eradicated because it was so deadly, meaning we pushed its Re below 1.
    - peeters 6y ago
      Yeah that's what I was getting at. SARS-COV-2 seems to have hit this sweet spot of being deadly enough to eclipse the death toll of similar viruses like influenza, but not deadly enough for people to take it as an existential threat. I'll take GP's word that it's also less transmissable, I was just saying that all things being equal, if SARS had a lower mortality rate, there's a chance it wouldn't have been dealt with in the same way.
      - samatman 6y ago
        Ah, fair play. I thought you were purveying the common misconception that a virus which kills its host is less effective at finding new hosts than one which doesn't, but this is unfortunately not the case. Alas, your actual theory doesn't really hold up either. It's tough to remember the mood thirteen months ago, but China was under a real lockdown, we were seeing videos of people passing out in the street (funny, that doesn't seem to have kept happening?) and apartment building being welded shut, there were reports circulating of nitrogen-rich plumes of smoke in Wuhan which might be mass incineration of bodies: people were really scared. America even closed the border to China, against the explicit policy of WHO, but didn't shut down travel from Europe fast enough; also, the current consensus is that SARS-2 was circulating in the US by mid-December 2019 at the latest, so it's unclear how much benefit a total travel ban would have provided. But, no: SARS-1 doesn't become highly infectious until after symptoms set in, that was what saved us last time. It does seem to be true that countries which experienced the SARS epidemic first-hand developed what we might call institutional antibodies, and were quick to impose various controls (especially contact tracing) which were more effective at controlling COVID-19. But COVID-19 has a long period of presymptomatic infectivity, it sheds for almost a week during which the patient feels fine. If SARS presented with that etiology, there is a good chance that it would have swept the planet, killing, potentially, hundreds of millions of people. Just dumb luck.
        peeters 6y ago
        > It does seem to be true that countries which experienced the SARS epidemic first-hand developed what we might call institutional antibodies, and were quick to impose various controls (especially contact tracing) which were more effective at controlling COVID-19. Ironically in some ways it had the opposite effect in Canada. We remembered how hard-hit Toronto's tourism industry was as a result of travel advisories from SARS-1 and so were initially supportive of China+WHO's argument against banning travel. But like you said, it's really hard to see this not being a pandemic either way, it might've just bought a bit of valuable time.

peeters 6y ago

The mortality rate is what terrified people about SARS. It was a big deal. 50% for people 65 and older. 15% in the general population. This incidentally made it far less reproductive.

samatman 6y ago
> This incidentally made it far less reproductive. Unfortunately not. SARS-1 reproduced slowly (long onset), wasn't all that contagious, and was quite deadly. These are independent variables. Smallpox had a high R0 and was quite deadly.
- littlestymaar 6y ago
  And most importantly, was contagious before the beginning of the symptoms, which always included fever so it was pretty easy to scan people with thermometer to catch the contagious ones. > And the fact that SARS was only contagious several days after the beginning of the symptoms is the reason why we have been able to control it […] and had contagiousness begun far earlier after the beginning of the symptoms or even before them like for the flu, the outbreak would have exploded and we wouldn't have been able to halt it. [1] [1]: quick translation from French from https://www.college-de-france.fr/site/arnaud-fontanet/course-2019-02-18-17h00.htm https://www.college-de-france.fr/site/arnaud-fontanet/course... (24'05)
- tlb 6y ago
  In the modern world, deadliness decreases transmissibility (Re, not R0), because people make organized efforts to contain deadly diseases. Covid's death rate was low enough that a good fraction of people thought we should just take it on the chin. By contrast, Smallpox was eradicated because it was so deadly, meaning we pushed its Re below 1.
  - peeters 6y ago
    Yeah that's what I was getting at. SARS-COV-2 seems to have hit this sweet spot of being deadly enough to eclipse the death toll of similar viruses like influenza, but not deadly enough for people to take it as an existential threat. I'll take GP's word that it's also less transmissable, I was just saying that all things being equal, if SARS had a lower mortality rate, there's a chance it wouldn't have been dealt with in the same way.
    - samatman 6y ago
      Ah, fair play. I thought you were purveying the common misconception that a virus which kills its host is less effective at finding new hosts than one which doesn't, but this is unfortunately not the case. Alas, your actual theory doesn't really hold up either. It's tough to remember the mood thirteen months ago, but China was under a real lockdown, we were seeing videos of people passing out in the street (funny, that doesn't seem to have kept happening?) and apartment building being welded shut, there were reports circulating of nitrogen-rich plumes of smoke in Wuhan which might be mass incineration of bodies: people were really scared. America even closed the border to China, against the explicit policy of WHO, but didn't shut down travel from Europe fast enough; also, the current consensus is that SARS-2 was circulating in the US by mid-December 2019 at the latest, so it's unclear how much benefit a total travel ban would have provided. But, no: SARS-1 doesn't become highly infectious until after symptoms set in, that was what saved us last time. It does seem to be true that countries which experienced the SARS epidemic first-hand developed what we might call institutional antibodies, and were quick to impose various controls (especially contact tracing) which were more effective at controlling COVID-19. But COVID-19 has a long period of presymptomatic infectivity, it sheds for almost a week during which the patient feels fine. If SARS presented with that etiology, there is a good chance that it would have swept the planet, killing, potentially, hundreds of millions of people. Just dumb luck.
      - peeters 6y ago
        > It does seem to be true that countries which experienced the SARS epidemic first-hand developed what we might call institutional antibodies, and were quick to impose various controls (especially contact tracing) which were more effective at controlling COVID-19. Ironically in some ways it had the opposite effect in Canada. We remembered how hard-hit Toronto's tourism industry was as a result of travel advisories from SARS-1 and so were initially supportive of China+WHO's argument against banning travel. But like you said, it's really hard to see this not being a pandemic either way, it might've just bought a bit of valuable time.