Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data

Background: In late March 2020, a “Stay Home, Stay Healthy” order was issued in Washington State in response to the COVID-19 pandemic. On May 1, a 4-phase reopening plan began. We investigated whether adjunctive prevention strategies would allow less restrictive physical distancing to avoid second e...

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Main Authors: Chloe Bracis, Eileen Burns, Mia Moore, David Swan, Daniel B. Reeves, Joshua T. Schiffer, Dobromir Dimitrov
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2021-01-01
Series:Infectious Disease Modelling
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2468042720300737
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author Chloe Bracis
Eileen Burns
Mia Moore
David Swan
Daniel B. Reeves
Joshua T. Schiffer
Dobromir Dimitrov
author_facet Chloe Bracis
Eileen Burns
Mia Moore
David Swan
Daniel B. Reeves
Joshua T. Schiffer
Dobromir Dimitrov
author_sort Chloe Bracis
collection DOAJ
description Background: In late March 2020, a “Stay Home, Stay Healthy” order was issued in Washington State in response to the COVID-19 pandemic. On May 1, a 4-phase reopening plan began. We investigated whether adjunctive prevention strategies would allow less restrictive physical distancing to avoid second epidemic waves and secure safe school reopening. Methods: We developed a mathematical model, stratifying the population by age, infection status and treatment status to project SARS-CoV-2 transmission during and after the reopening period. The model was parameterized with demographic and contact data from King County, WA and calibrated to confirmed cases, deaths and epidemic peak timing. Adjunctive prevention interventions were simulated assuming different levels of pre-COVID physical interactions (pC_PI) restored. Results: The best model fit estimated ~35% pC_PI under the lockdown which prevented ~17,000 deaths by May 15. Gradually restoring 75% pC_PI for all age groups between May 15-July 15 would have resulted in ~350 daily deaths by early September 2020. Maintaining <45% pC_PI was required with current testing practices to ensure low levels of daily infections and deaths. Increased testing, isolation of symptomatic infections, and contact tracing permitted 60% pC_PI without significant increases in daily deaths before November and allowed opening of schools with <15 daily deaths. Inpatient antiviral treatment was predicted to reduce deaths significantly without lowering cases or hospitalizations. Conclusions: We predict that widespread testing, contact tracing and case isolation would allow relaxation of physical distancing, as well as opening of schools, without a surge in local cases and deaths.
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spelling doaj.art-0465e53985234187a2c30775f2762a7f2024-04-16T18:53:27ZengKeAi Communications Co., Ltd.Infectious Disease Modelling2468-04272021-01-0162435Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA dataChloe Bracis0Eileen Burns1Mia Moore2David Swan3Daniel B. Reeves4Joshua T. Schiffer5Dobromir Dimitrov6Université Grenoble Alpes, TIMC-IMAG/BCM, 38000, Grenoble, FranceIndependent Researcher, Seattle, WA, USAVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USAVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USAVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USAVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Department of Medicine, University of Washington, Seattle, WA, USAVaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Department of Applied Mathematics, University of Washington, Seattle, WA, USA; Corresponding author. Vaccine and Infectious Disease Division Fred Hutchinson Cancer Research Center 1100 Fairview Ave N., M2-C200 P.O. Box 19024, Seattle, WA, 98109-1024, USA.Background: In late March 2020, a “Stay Home, Stay Healthy” order was issued in Washington State in response to the COVID-19 pandemic. On May 1, a 4-phase reopening plan began. We investigated whether adjunctive prevention strategies would allow less restrictive physical distancing to avoid second epidemic waves and secure safe school reopening. Methods: We developed a mathematical model, stratifying the population by age, infection status and treatment status to project SARS-CoV-2 transmission during and after the reopening period. The model was parameterized with demographic and contact data from King County, WA and calibrated to confirmed cases, deaths and epidemic peak timing. Adjunctive prevention interventions were simulated assuming different levels of pre-COVID physical interactions (pC_PI) restored. Results: The best model fit estimated ~35% pC_PI under the lockdown which prevented ~17,000 deaths by May 15. Gradually restoring 75% pC_PI for all age groups between May 15-July 15 would have resulted in ~350 daily deaths by early September 2020. Maintaining <45% pC_PI was required with current testing practices to ensure low levels of daily infections and deaths. Increased testing, isolation of symptomatic infections, and contact tracing permitted 60% pC_PI without significant increases in daily deaths before November and allowed opening of schools with <15 daily deaths. Inpatient antiviral treatment was predicted to reduce deaths significantly without lowering cases or hospitalizations. Conclusions: We predict that widespread testing, contact tracing and case isolation would allow relaxation of physical distancing, as well as opening of schools, without a surge in local cases and deaths.http://www.sciencedirect.com/science/article/pii/S2468042720300737Mathematical modelingEpidemiologyAge structured modelPhysical distancingContact tracing
spellingShingle Chloe Bracis
Eileen Burns
Mia Moore
David Swan
Daniel B. Reeves
Joshua T. Schiffer
Dobromir Dimitrov
Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
Infectious Disease Modelling
Mathematical modeling
Epidemiology
Age structured model
Physical distancing
Contact tracing
title Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
title_full Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
title_fullStr Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
title_full_unstemmed Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
title_short Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data
title_sort widespread testing case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing a modeling analysis of king county wa data
topic Mathematical modeling
Epidemiology
Age structured model
Physical distancing
Contact tracing
url http://www.sciencedirect.com/science/article/pii/S2468042720300737
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