Duration of SARS-CoV-2 shedding: A population-based, Canadian study.

<h4>Introduction</h4>There is an evidence gap regarding the duration of SARS-CoV-2 shedding and of its variability across different care settings and by age, sex, income, and co-morbidities. Such evidence is part of understanding of infectivity and reinfection. We examine direct measures...

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Main Authors: Susan P Phillips, Xuejiao Wei, Jeffrey C Kwong, Jonathan Gubbay, Kevin L Schwartz, Anna Majury, Patti A Groome
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2021-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0252217
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author Susan P Phillips
Xuejiao Wei
Jeffrey C Kwong
Jonathan Gubbay
Kevin L Schwartz
Anna Majury
Patti A Groome
author_facet Susan P Phillips
Xuejiao Wei
Jeffrey C Kwong
Jonathan Gubbay
Kevin L Schwartz
Anna Majury
Patti A Groome
author_sort Susan P Phillips
collection DOAJ
description <h4>Introduction</h4>There is an evidence gap regarding the duration of SARS-CoV-2 shedding and of its variability across different care settings and by age, sex, income, and co-morbidities. Such evidence is part of understanding of infectivity and reinfection. We examine direct measures of viral shedding using a linked population-based health administrative dataset.<h4>Methods</h4>Laboratory and sociodemographic databases for Ontario, Canada were linked to identify those testing positive (RT-PCR) between Jan. 15 and April 30, 2020 who underwent subsequent testing by May 31, 2020. To maximise use of available data, we computed two shedding duration estimates defined as the time between initial positive and most recent positive (documented shedding) or second of two negative tests (documented resolution). We also report multivariable results using quantile regression to examine subgroup differences.<h4>Results</h4>In Ontario, of the 16,595 who tested positive before April 30, 2020, 6604 had sufficient subsequent testing to allow shedding duration calculation. Documented shedding median duration calculated in 4,889 (29% of 16,595) patients was 19 days (IQR 12-28). Documented resolution median duration calculated in 3,219 (19% of the 16,595) patients was 25 days (IQR 18-34). Long-term care residents had 3-5 day longer shedding durations using both definitions. Shorter documented shedding durations of 2-4 days were observed in those living in higher income neighbourhoods. Shorter documented resolution durations of 2-3 days were observed at the 25th% of the distribution in those aged 20-49. Only 11.5% of those with definitive negative test results reverted to negative status by day 14.<h4>Conclusions</h4>Viral shedding continued well beyond 14 days among this large subset of a population-based group with COVID-19, and longer still for long-term care residents and those living in less affluent neighborhoods. Our findings do not speak to duration of infectivity but are useful for understanding the expected duration of RT-PCR positivity and for identifying reinfection.
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spelling doaj.art-51bbe9765bb942d798abe93389f693ca2022-12-21T20:06:28ZengPublic Library of Science (PLoS)PLoS ONE1932-62032021-01-01166e025221710.1371/journal.pone.0252217Duration of SARS-CoV-2 shedding: A population-based, Canadian study.Susan P PhillipsXuejiao WeiJeffrey C KwongJonathan GubbayKevin L SchwartzAnna MajuryPatti A Groome<h4>Introduction</h4>There is an evidence gap regarding the duration of SARS-CoV-2 shedding and of its variability across different care settings and by age, sex, income, and co-morbidities. Such evidence is part of understanding of infectivity and reinfection. We examine direct measures of viral shedding using a linked population-based health administrative dataset.<h4>Methods</h4>Laboratory and sociodemographic databases for Ontario, Canada were linked to identify those testing positive (RT-PCR) between Jan. 15 and April 30, 2020 who underwent subsequent testing by May 31, 2020. To maximise use of available data, we computed two shedding duration estimates defined as the time between initial positive and most recent positive (documented shedding) or second of two negative tests (documented resolution). We also report multivariable results using quantile regression to examine subgroup differences.<h4>Results</h4>In Ontario, of the 16,595 who tested positive before April 30, 2020, 6604 had sufficient subsequent testing to allow shedding duration calculation. Documented shedding median duration calculated in 4,889 (29% of 16,595) patients was 19 days (IQR 12-28). Documented resolution median duration calculated in 3,219 (19% of the 16,595) patients was 25 days (IQR 18-34). Long-term care residents had 3-5 day longer shedding durations using both definitions. Shorter documented shedding durations of 2-4 days were observed in those living in higher income neighbourhoods. Shorter documented resolution durations of 2-3 days were observed at the 25th% of the distribution in those aged 20-49. Only 11.5% of those with definitive negative test results reverted to negative status by day 14.<h4>Conclusions</h4>Viral shedding continued well beyond 14 days among this large subset of a population-based group with COVID-19, and longer still for long-term care residents and those living in less affluent neighborhoods. Our findings do not speak to duration of infectivity but are useful for understanding the expected duration of RT-PCR positivity and for identifying reinfection.https://doi.org/10.1371/journal.pone.0252217
spellingShingle Susan P Phillips
Xuejiao Wei
Jeffrey C Kwong
Jonathan Gubbay
Kevin L Schwartz
Anna Majury
Patti A Groome
Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
PLoS ONE
title Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
title_full Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
title_fullStr Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
title_full_unstemmed Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
title_short Duration of SARS-CoV-2 shedding: A population-based, Canadian study.
title_sort duration of sars cov 2 shedding a population based canadian study
url https://doi.org/10.1371/journal.pone.0252217
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