The OST report on schools argues against serial rapid testing (https://covid19-sciencetable.ca/sciencebrief/school-operation-for-the-2021-2022-academic-year-in-the-context-of-the-covid-19-pandemic/#:~:text=Asymptomatic%20screen%20testing%20(i.e.%2C%20asymptomatic%20testing%20in%20the%20absence%20of%20documented%20exposure)%2C%20is%20not%20routinely%20recommended%2C%20especially%20in%20the%20low%20to%20moderate%20COVID-19%20risk%20scenarios.). It cites one short letter which claims antigen testing is “low-yield”: https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/low-yield-of-severe-acute-respiratory-coronavirus-virus-2-sarscov2-asymptomatic-routine-screen-testing-despite-high-community-incidence/176BA478C1D529E0DACCE0D6FA8DADC0

This conclusion comes from serial antigen screening having a positivity rate of “only” 0.36% at a time when the weekly case rate in Ontario was 0.1% and public health test positivity rate was 5%. Comparing positivity rates like this is flawed logic.

If you take the high risk people out of the pool (symptomatic / close-contact) then of course those remaining will have a lower risk of being infected. But rapid testing STILL caught cases at 3x the presumed prevalence, suggesting public health containment was completely failing!

The important comparison is not positivity rates but cost of interrupting one transmission chain. If you give antigen tests to people to do at home and have rapid molecular testing handy to confirm any positives, they can be about 1/10th the cost of PCR tests.

The question is: how much value is there to society in each COVID transmission that gets interrupted (that case and all downstream cases)? I don’t know how to calculate that, but in the cited study, if done efficiently it would have cost about $2000.

I don’t know how the authors of this paper would compute a value for human suffering, but calling $2,000 (or even $20k, assuming 10x admin overhead) to prevent a nursing home outbreak “low yield” and “not cost effective” seems pretty callous and inhumane to me.🤷