Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts

Hellewell, Joel; Abbott, Sam; Gimma, Amy; Bosse, Nikos I; Jarvis, Christopher I; Russell, Timothy W; Munday, James D; Kucharski, Adam J; Edmunds, W John; Funk, Sebastian; Eggo, Rosalind M

Evidence before this study Contact tracing and isolation of cases is a common intervention for controlling infectious disease outbreaks. It can be effective but might require intensive public health effort and cooperation to effectively reach and monitor all contacts. Previous work has shown that when the pathogen has infectiousness before symptom onset, control of outbreaks using contact tracing and isolation is more challenging. Further introduction of coronavirus disease 2019 (COVID-19) to new territories is likely in the coming days and weeks, and interventions to prevent an outbreak following these introductions are a key mitigating strategy. Current planning is focused on tracing of contacts of introduced cases, and rapid isolation. These methods have been used previously for other novel outbreaks, but it is not clear if they will be effective for COVID-19.