Individual quarantine versus active monitoring of contacts for the mitigation of COVID-19: a modelling study

Type Journal Article Author Corey M. Peak Author Rebecca Kahn Author Yonatan H. Grad Author Lauren M. Childs Author Ruaran Li Author Marc Lipsitch Author Caroline O. Buckee URL https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(20)30361-3.pdf Rights Copyright ©2020 Elsevier Ltd. All rights reserved. Series The Lancet Articles Publication The Lancet Infectious Diseases Date 20/05/2020 DOI https://doi.org/10.1016/ S1473-3099(20)30361-3 Language en Abstract Background Voluntary individual quarantine and voluntary active monitoring of contacts are core disease control strategies for emerging infectious diseases such as COVID-19. Given the impact of quarantine on resources and individual liberty, it is vital to assess under what conditions individual quarantine can more effectively control COVID-19 than active monitoring. As an epidemic grows, it is also important to consider when these interventions are no longer feasible and broader mitigation measures must be implemented.Methods To estimate the comparative efficacy of individual quarantine and active monitoring of contacts to control severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we fit a stochastic branching model to reported parameters for the dynamics of the disease. Specifically, we fit a model to the incubation period distribution (mean 5·2 days) and to two estimates of the serial interval distribution: a shorter one with a mean serial interval of 4·8 days and a longer one with a mean of 7·5 days. To assess variable resource settings, we considered two feasibility settings: a high-feasibility setting with 90% of contacts traced, a half-day average delay in tracing and symptom recognition, and 90% effective isolation; and a low-feasibility setting with 50% of contacts traced, a 2-day average delay, and 50% effective isolation