The evidence is mounting that much of the spread of SARS-CoV-2 is asymptotic or presymptomatic: https://www.wbur.org/commonhealth/2020/04/14/coronavirus-boston-homeless-testing

This has significant implications: we must be regularly screening all healthcare workers and other essential workers if we want to control the spread. Eg: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30917-X/fulltext

Which in turn suggests that to be practical, we should leverage pooled-sample qPCR, eg: https://www.medrxiv.org/content/10.1101/2020.03.26.20039438v1