Perfect as the Enemy of the Good: Using Low-Sensitivity Tests to Mitigate SARS-CoV-2 Outbreaks

Abstract

Preventing future infection waves of COVID-19 will depend on effective and efficient contact tracing. SARS-CoV-2 transmission appears to be characterized by high individual variation and a large role of superspreading events. Taking this into account can improve the cost-benefit tradeoffs of contact tracing. In particular, an individual who is known to have transmitted the infection once is more likely to have transmitted to other individuals. We propose a strategy of identifying transmission events, making use of the variability in secondary case numbers. A rapid, high-specificity test with only 50% sensitivity can still identify the vast majority of these transmission events. This strategy can lead to the isolation of a large proportion of infected individuals while drastically reducing the isolation of uninfected contacts.