Evaluation of Group Testing for SARS-CoV-2 RNA

Nasa Sinnott-Armstrong; Daniel Klein; Brendan Hickey

We additionally wanted to estimate the total saved tests relative to those conducted so far, under the hypothetical that pooling had been used throughout the pandemic. Using testing and positive test estimates from Our World in Data [15] , we chose an optimal testing strategy per country from between 4-well pooling; 96-well plates; and 384-well plates. We chose the strategy per country which minimized the tests needed at the observed prevalence. This resulted in an expected total of 670,849 tests globally to re-test everyone who has previously been screened for SARS-CoV-2 (1.85M individuals), corresponding to a three-fold improvement in cases per test. Ignoring country-specific prevalence data, 96-well plates and between 5-way and 8-way well pooling resulted in an expected ≈ 780, 000 tests (Table S1 ). When considering country-specific prevalence, however, the single strategy which performed best on average across countries was the 96-well plate (at just under a third as many tests as standard approaches; Figure S3 ). These findings suggests that the 96-well plate row and column pooling approach is a straightforward compromise if no information on population prevalence is available.