Modeling the Comparative Impact of Individual Quarantine vs. Active Monitoring of Contacts for the Mitigation of COVID-19

Corey M Peak; Rebecca Kahn; Yonatan H Grad; Lauren M Childs; Ruoran Li; Marc Lipsitch; Caroline O Buckee

In a setting where the COVID-19 case count continues to grow, resources may be prioritized for scalable community interventions such as social distancing; however, close contacts such as family members of a patient may still undergo targeted interventions. In our modeling framework, social distancing functions synergistically by reducing the reproductive number of infected individuals in the community who are not in quarantine or isolation. If social distancing reduces the reproductive number to 1.25 (e.g., 50% of person-to-person contact is removed in a setting where , active monitoring of 50% of contacts can result in overall outbreak .5) R 0 = 2 control (ie, ) ( Figure 6 ). Tracing 10%, 50%, or 90% of contacts on top of social distancing R e < 1 resulted in a median reduction in of 3.2%, 15% and 33%, respectively, for active monitoring R e and 5.8%, 32%, and 66%, respectively, for individual quarantine.