Population-scale testing can suppress the spread of COVID-19

Abstract

We propose an additional intervention that would contribute to the control of the COVID-19 pandemic, offer more protection for people working in essential jobs, and help guide an eventual reopening of society. The intervention is based on: (1) testing every individual (2) repeatedly, and (3) isolation of infected individuals. We show here that at a sufficient rate of testing and isolation, the R0 of SARS-CoV-2 would be reduced well below 1.0, and the epidemic would collapse. The approach does not rely on strong and/or unrealistic assumptions about test accuracy, compliance to isolation, population structure or epidemiological parameters, and its success can be monitored in real time by measuring the change of the test positivity rate over time. In addition to the rate of compliance and false negatives, the required rate of testing is dependent on the design of the testing regime, with concurrent testing outperforming random sampling of individuals. Provided that results are reported rapidly, the test frequency required to suppress an epidemic is linear with respect to R0, to the infectious period, and to the fraction of susceptible individuals. Importantly, the testing regime would be effective at any level of prevalence, and additive to other interventions such as contact tracing and social distancing. It would also be robust to failure, as even in the case where the testing rate would be insufficient to collapse the epidemic, it would still reduce the number of infected individuals in the population, improving both public health and economic conditions. A mass-produced, disposable antigen or RNA test that could be used at home would be ideal, due to the optimal performance of concurrent tests that return immediate results.