3 ms·

Is community spread of zero a worthwhile goal? SF still has thousands of people (maybe tens of thousands) coming in and out of the city every day to deliver thi

by bb2018 6y ago

Is community spread of zero a worthwhile goal? SF still has thousands of people (maybe tens of thousands) coming in and out of the city every day to deliver things, see family, return home, etc. As long as this is still happening (there is no way for SF to prevent this) what is the point of fixating on zero new cases. Consider two cases: - On May 15 SF has had no new cases since May 1st. It decides to reopen. - On May 15 SF has had 150 new cases (ten a day) since May 1st. It decides to reopen. By June 15th, is the total number of cases any different under these scenarios? In either case, has the city been able to function without having to reclose? I'm not sure the answer to these - but my instinct is that the situations would be virtually the same.

mmmBacon 6y ago
Community spread of zero is not the goal. The goal is to get the transmission rate below 1. A transmission rate of 1 means no average 1 person infects 1 other person. You need a transmission rate below 1 to start reducing the rate of new infections. Above 1, you have exponential growth. Right now we are hovering around 0.9. To reopen we need a rate of about 0.75. For comparison the lockdowns in Wuhan achieved a rate of 0.3.
- adrr 6y ago
  Wuhan is a good example why community spread of near 0 is the primary goal. The restaurants have opened but are struggling because people are still afraid of getting sick and have changed their behavior. White collar jobs will keep telecommuting if there’s a risk of community spread. No hr/leg department wants the liability. The secondary effects are decrease in demand on automobile related businesses like gas stations, servicing. Also decrease in car sales. Also the company ban on business travel which hits airlines, hotels, conferences etc.
  - SpicyLemonZest 6y ago
    I don't follow the example. If people in Wuhan are still avoiding restaurants, it can't be because they haven't reduced community spread enough - the city's reported no new cases for weeks.
    - smcameron 6y ago
      It's because people are afraid. Fear is not perfectly rational.
      - SpicyLemonZest 6y ago
        That's my point. Wuhan demonstrates that reducing community spread to 0 has nothing to do with restoring confidence or reducing fear. In a year, I expect the regions aiming for 0 community spread will still be devastated, because they've taught their populace that the coronavirus is the worst thing ever and they must be constantly scared of it.

by bb2018 6y ago

mmmBacon 6y ago

Community spread of zero is not the goal. The goal is to get the transmission rate below 1. A transmission rate of 1 means no average 1 person infects 1 other person. You need a transmission rate below 1 to start reducing the rate of new infections. Above 1, you have exponential growth. Right now we are hovering around 0.9. To reopen we need a rate of about 0.75. For comparison the lockdowns in Wuhan achieved a rate of 0.3.

adrr 6y ago
Wuhan is a good example why community spread of near 0 is the primary goal. The restaurants have opened but are struggling because people are still afraid of getting sick and have changed their behavior. White collar jobs will keep telecommuting if there’s a risk of community spread. No hr/leg department wants the liability. The secondary effects are decrease in demand on automobile related businesses like gas stations, servicing. Also decrease in car sales. Also the company ban on business travel which hits airlines, hotels, conferences etc.
- SpicyLemonZest 6y ago
  I don't follow the example. If people in Wuhan are still avoiding restaurants, it can't be because they haven't reduced community spread enough - the city's reported no new cases for weeks.
  - smcameron 6y ago
    It's because people are afraid. Fear is not perfectly rational.
    - SpicyLemonZest 6y ago
      That's my point. Wuhan demonstrates that reducing community spread to 0 has nothing to do with restoring confidence or reducing fear. In a year, I expect the regions aiming for 0 community spread will still be devastated, because they've taught their populace that the coronavirus is the worst thing ever and they must be constantly scared of it.