Cover of EconPol Policy Brief 24

Group Testing Against Covid-19

Christian Gollier (EconPol Europe, Toulouse School of Economics University of Toulouse- Capitole), Olivier Gossner (CNRS – CREST, Ecole Polytechnique, London School of Economics)

Testing for Covid-19 is a bottleneck that we face in front of the pandemic. Test production is currently much below what is necessary for mass testing strategies which are required in order to control the pandemic while letting people go back to work. In this paper, Christian Gollier (EconPol Europe, Toulouse School of Economics University of Toulouse- Capitole) and Olivier Gossner (CNRS – CREST, Ecole Polytechnique, London School of Economics) show how group testing can be optimized in three applications to multiply the efficiency of tests against Covid-19: Estimating virus prevalence to measure the evolution of the pandemic; bringing negative groups back to work to exit the current lockdown; and testing for individual infectious status to treat sick people. 

Abstract

It is well-known that group testing is an efficient strategy to screen for the presence of a virus. It consists in pooling n individual samples with a single test using RT-PCR. If at least one individual is infected, the test is positive, and it is negative otherwise. We show how group testing can be optimized in three applications to multiply the efficiency of tests against Covid-19: Estimating virus prevalence to measure the evolution of the pandemic; bringing negative groups back to work to exit the current lockdown; and testing for individual infectious status to treat sick people. For an infection level around 2%, group testing could multiply the power of testing by a factor 20. The implementation of this strategy in the short run requires limited investments and could bypass the current immense shortage of testing capacity.

Citation

Christian Gollier, Olivier Gossner: Group Testing Against Covid-19, EconPol Policy Brief 24, April 2020