Department of Family Medicine, Queen's University, Kingston, Ontario, Canada.
Public Health Sciences, Queen's University, Kingston, Ontario, Canada.
PLoS One. 2021 Jun 17;16(6):e0252217. doi: 10.1371/journal.pone.0252217. eCollection 2021.
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.
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.
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.
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.
关于 SARS-CoV-2 的脱落持续时间及其在不同护理环境中的变异性，以及年龄、性别、收入和合并症等方面的证据存在差距。这些证据是了解传染性和再感染的一部分。我们使用基于人群的健康管理数据集来检查病毒脱落的直接测量值。
将加拿大安大略省的实验室和社会人口学数据库进行链接，以确定在 2020 年 1 月 15 日至 4 月 30 日期间检测呈阳性（RT-PCR）并在 2020 年 5 月 31 日之前进行后续检测的人。为了最大限度地利用现有数据，我们计算了两个脱落持续时间估计值，定义为初始阳性和最近一次阳性（记录脱落）之间的时间，或两次阴性测试中的第二次（记录分辨率）之间的时间。我们还使用分位数回归报告多变量结果，以检查亚组差异。
在安大略省，在 2020 年 4 月 30 日之前检测呈阳性的 16595 人中，有 6604 人有足够的后续检测来计算脱落持续时间。在 4889 名（16595 名患者的 29%）患者中计算出的记录脱落中位持续时间为 19 天（IQR 12-28）。在 3219 名（16595 名患者的 19%）患者中计算出的记录分辨率中位持续时间为 25 天（IQR 18-34）。使用这两种定义，长期护理居民的脱落持续时间长 3-5 天。在收入较高的社区居住的人观察到 2-4 天的记录脱落持续时间较短。在年龄在 20-49 岁的分布的第 25%处观察到记录分辨率持续时间较短的 2-3 天。只有 11.5%的确诊阴性检测结果在第 14 天前转为阴性。
在 COVID-19 人群的这一大亚组中，病毒脱落持续时间远远超过 14 天，而对于长期护理居民和居住在较贫困社区的人来说，脱落持续时间更长。我们的研究结果不能说明传染性的持续时间，但对于了解 RT-PCR 阳性的预期持续时间和识别再感染很有用。
