[Goose]

From the number of active cases in SCC and the total population, the probability that nobody in a random selection of 30 people has COVID-19 is 93%.  The probability of any randomly selected individual having COVED-19 is 0.238% Naturally, this is based on cases confirmed by testing, so those out there with COVID-19 who are not tested don't show up.

I would argue that the meeting had a pretty good chance of not spreading the infection. However, one has to weigh that against the consequences of having 30 people quarantined for two weeks, best case, and worse if somebody dies. How many meetings have we all attended that were not really necessary, or even useful? How many meetings in this time of COVID-19 work just fine on Zoom? IMHO that is what makes it not worth the risk.

What if the estimates I’ve read — that there are 10 cases of C-19 for every one that’s been diagnosed — are correct? That would reduce the probability of no one out of a group of 30 having the virus to 49%.

It is undoubtedly true that there number of cases in the population is larger than the number of cases confirmed by testing. How much bigger is largely unknown. It is difficult to use random testing to measure this value because the incidence is so low a very large number of people must be tested. There are also problems with interpreting antibody testing as have been discussed here. So it is an issue, but hard to quantify.

[Goose]

From the number of active cases in SCC and the total population, the probability that nobody in a random selection of 30 people has COVID-19 is 93%.  The probability of any randomly selected individual having COVED-19 is 0.238% Naturally, this is based on cases confirmed by testing, so those out there with COVID-19 who are not tested don't show up.

I would argue that the meeting had a pretty good chance of not spreading the infection. However, one has to weigh that against the consequences of having 30 people quarantined for two weeks, best case, and worse if somebody dies. How many meetings have we all attended that were not really necessary, or even useful? How many meetings in this time of COVID-19 work just fine on Zoom? IMHO that is what makes it not worth the risk.

What if the estimates I’ve read — that there are 10 cases of C-19 for every one that’s been diagnosed — are correct? That would reduce the probability of no one out of a group of 30 having the virus to 49%.

It is undoubtedly true that there number of cases in the population is larger than the number of cases confirmed by testing. How much bigger is largely unknown. It is difficult to use random testing to measure this value because the incidence is so low a very large number of people must be tested. There are also problems with interpreting antibody testing as have been discussed here. So it is an issue, but hard to quantify.