Jianhong Wu1,2, Francesca Scarabel1,2, Zachary McCarthy1,2, Yanyu Xiao3, Nicholas H Ogden4. 1. Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON. 2. Fields-CQAM Laboratory of Mathematics for Public Health, York University, Toronto, ON. 3. Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH, United States. 4. Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, St-Hyacinthe, QC.
Abstract
BACKGROUND: When public health interventions are being loosened after several days of decline in the number of coronavirus disease 2019 (COVID-19) cases, it is of critical importance to identify potential strategies to ease restrictions while mitigating a new wave of more transmissible variants of concern (VOCs). We estimated the necessary enhancements to public health interventions for a partial reopening of the economy while avoiding the worst consequences of a new outbreak, associated with more transmissible VOCs. METHODS: We used a transmission dynamics model to quantify conditions that combined public health interventions must meet to reopen the economy without a large outbreak. These conditions are those that maintain the control reproduction number below unity, while accounting for an increase in transmissibility due to VOC. RESULTS: We identified combinations of the proportion of individuals exposed to the virus who are traced and quarantined before becoming infectious, the proportion of symptomatic individuals confirmed and isolated, and individual daily contact rates needed to ensure the control reproduction number remains below unity. CONCLUSION: Our analysis indicates that the success of restrictive measures including lockdown and stay-at-home orders, as reflected by a reduction in number of cases, provides a narrow window of opportunity to intensify case detection and contact tracing efforts to prevent a new wave associated with circulation of more transmissible VOCs.
BACKGROUND: When public health interventions are being loosened after several days of decline in the number of coronavirus disease 2019 (COVID-19) cases, it is of critical importance to identify potential strategies to ease restrictions while mitigating a new wave of more transmissible variants of concern (VOCs). We estimated the necessary enhancements to public health interventions for a partial reopening of the economy while avoiding the worst consequences of a new outbreak, associated with more transmissible VOCs. METHODS: We used a transmission dynamics model to quantify conditions that combined public health interventions must meet to reopen the economy without a large outbreak. These conditions are those that maintain the control reproduction number below unity, while accounting for an increase in transmissibility due to VOC. RESULTS: We identified combinations of the proportion of individuals exposed to the virus who are traced and quarantined before becoming infectious, the proportion of symptomatic individuals confirmed and isolated, and individual daily contact rates needed to ensure the control reproduction number remains below unity. CONCLUSION: Our analysis indicates that the success of restrictive measures including lockdown and stay-at-home orders, as reflected by a reduction in number of cases, provides a narrow window of opportunity to intensify case detection and contact tracing efforts to prevent a new wave associated with circulation of more transmissible VOCs.
Entities:
Keywords:
SARS-CoV-2; non-pharmaceutical interventions; relaxations; variants of concern
Authors: Nick H Ogden; Aamir Fazil; Julien Arino; Philippe Berthiaume; David N Fisman; Amy L Greer; Antoinette Ludwig; Victoria Ng; Ashleigh R Tuite; Patricia Turgeon; Lisa A Waddell; Jianhong Wu Journal: Can Commun Dis Rep Date: 2020-06-04
Authors: Victoria Ng; Aamir Fazil; Lisa A Waddell; Christina Bancej; Patricia Turgeon; Ainsley Otten; Nicole Atchessi; Nicholas H Ogden Journal: CMAJ Date: 2020-08-09 Impact factor: 8.262
Authors: Biao Tang; Francesca Scarabel; Nicola Luigi Bragazzi; Zachary McCarthy; Michael Glazer; Yanyu Xiao; Jane M Heffernan; Ali Asgary; Nicholas Hume Ogden; Jianhong Wu Journal: Biology (Basel) Date: 2020-05-16
Authors: Zachary McCarthy; Yanyu Xiao; Francesca Scarabel; Biao Tang; Nicola Luigi Bragazzi; Kyeongah Nah; Jane M Heffernan; Ali Asgary; V Kumar Murty; Nicholas H Ogden; Jianhong Wu Journal: J Math Ind Date: 2020-12-01