Quote:
Originally Posted by tarcone
My county borders St. Louis county but is pretty rural. A few cities of around 10k or less. One of maybe 20k.
We opened up 2 weeks ago. Wide open. We have had one new case in our county in that time period.
I think this is turning into an urban issue. As well as, a nursing home and meat packing plant issue.
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A county with almost no cases will not suddenly see many. It is more and more safe to say that this is not spread in 3s an 4s but in 1s and 15s.
Those maybe 5-10 concurrent infected in your county first need to be at one of the, for Arguments sake, 10% open businesses that pose an elevated risk and be there at the right time (peak infectiousness is a short period). 5 of 10 might be most infectious on days they don't go out much. 2 might not go out much in general.
At low levels, chance comes into play. Which is why it took time to go from imported cases to catastrophe. Critical Mass is a concept that originated in Epidemiology, after all !
Household transmission is generally 1 in 4 chance with the highest propability by far being the spouse (which makes sense).Lots if places are safe, especially with basic precautions (even just keeping a bit distance, not stop in the same place and talk for a long while), but lots more avenues than Meatpacking Plants, too ...
In Germany we have very few cases and excellent contact tracing (not SK et al level but just about the next best thing) so the true number now will not be as much larger by far than in March.
And still in the last 2 weeks we had: 2 church outbreaks of 60-100 cases, a private even at a restaurant (30+), a series of private family Parties (scope yet unclear), a UPS sorting center (50+). This does not happen via droplets, this is Aerosol infection.
The place does not matter as much as These Basic conditions:
- indoor vs outdoor. Air displacement outdoors just mitigates a lot
- lots of people literally sharing the same air
- staying stationary for 15 + minutes OR moving around the same space over and over along with everybody else
- close contact and face-to-face interaction up close
-loud and animated speaking, singing or heavy breathing
The problem is that it would be guaranteed desaster if everything was done the same as a year ago, everything will be super if done like in April. Finding the sweet spot in between is the hard part.
As for retirement homes: These are vulnerable to spread the same way all closed systems are (a Party same as a meatpacking plant). However, it is much easier to keep the virus out in the first place when few peope carry it in general and with less draconic measures (isolating them for months or a year is NOT desirable) It's just Basic propability.
These propabilities come into play Rural vs Urban as well. How many Potential spreading events happen in a big city vs a small ? How many events with different people is one likely to infect ? How likely is it contact tracing works because participants knew each other ?
If it happens and is missed, the virus does not care much. Look of Heinsberg or Tirschenreuth in Germany or Vo in Italy. One party gone wrong = things spreads like wildfire.