Asymptomatic SARS-CoV-2 testing: predictors of effectiveness; risk of increasing transmission

Skittrall, J. P.

Testing asymptomatic people for SARS-CoV-2 aims to reduce COVID-19 transmission. Screening programs' effectiveness depends upon testing strategy, sample handling logistics, test sensitivity, and individual behavior, in addition to dynamics of viral transmission. We investigated the interaction between these factors to determine how to optimize reduction of transmission. We show that under idealistic assumptions 70% of transmission may be averted, but under realistic assumptions only 7% may be averted. We show that programs that overwhelm laboratory capacity or reduce isolation of those with minor symptoms have increased transmission compared with those that do not: programs need to be designed to avoid these issues. Our model allows optimal selection of whom to test, quantifies the balance between accuracy and timeliness, and quantifies potential impacts of behavioral interventions.