The implications of silent transmission for the control of COVID-19 outbreaks
AuthorMoghadas, Seyed M
Fitzpatrick, Meagan C
Singer, Burton H
Galvani, Alison P
JournalProceedings of the National Academy of Sciences of the United States of America
PublisherNational Academy of Sciences
MetadataShow full item record
AbstractSince the emergence of coronavirus disease 2019 (COVID-19), unprecedented movement restrictions and social distancing measures have been implemented worldwide. The socioeconomic repercussions have fueled calls to lift these measures. In the absence of population-wide restrictions, isolation of infected individuals is key to curtailing transmission. However, the effectiveness of symptom-based isolation in preventing a resurgence depends on the extent of presymptomatic and asymptomatic transmission. We evaluate the contribution of presymptomatic and asymptomatic transmission based on recent individual-level data regarding infectiousness prior to symptom onset and the asymptomatic proportion among all infections. We found that the majority of incidences may be attributable to silent transmission from a combination of the presymptomatic stage and asymptomatic infections. Consequently, even if all symptomatic cases are isolated, a vast outbreak may nonetheless unfold. We further quantified the effect of isolating silent infections in addition to symptomatic cases, finding that over one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population. Our results indicate that symptom-based isolation must be supplemented by rapid contact tracing and testing that identifies asymptomatic and presymptomatic cases, in order to safely lift current restrictions and minimize the risk of resurgence.
Rights/TermsCopyright © 2020 the Author(s). Published by PNAS.
Identifier to cite or link to this itemhttp://hdl.handle.net/10713/13534
- Projected effects of nonpharmaceutical public health interventions to prevent resurgence of SARS-CoV-2 transmission in Canada.
- Authors: Ng V, Fazil A, Waddell LA, Bancej C, Turgeon P, Otten A, Atchessi N, Ogden NH
- Issue date: 2020 Sep 14
- Effectiveness of isolation, testing, contact tracing, and physical distancing on reducing transmission of SARS-CoV-2 in different settings: a mathematical modelling study.
- Authors: Kucharski AJ, Klepac P, Conlan AJK, Kissler SM, Tang ML, Fry H, Gog JR, Edmunds WJ, CMMID COVID-19 working group.
- Issue date: 2020 Oct
- Individual quarantine versus active monitoring of contacts for the mitigation of COVID-19: a modelling study.
- Authors: Peak CM, Kahn R, Grad YH, Childs LM, Li R, Lipsitch M, Buckee CO
- Issue date: 2020 Sep
- Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study.
- Authors: Jing QL, Liu MJ, Zhang ZB, Fang LQ, Yuan J, Zhang AR, Dean NE, Luo L, Ma MM, Longini I, Kenah E, Lu Y, Ma Y, Jalali N, Yang ZC, Yang Y
- Issue date: 2020 Oct
- Contact Tracing Assessment of COVID-19 Transmission Dynamics in Taiwan and Risk at Different Exposure Periods Before and After Symptom Onset.
- Authors: Cheng HY, Jian SW, Liu DP, Ng TC, Huang WT, Lin HH, Taiwan COVID-19 Outbreak Investigation Team.
- Issue date: 2020 Sep 1