SOC Istituto di Igiene ed Epidemiologia Clinica, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy.
SOC Cardiologia e riabilitazione cardiologica, Azienda Sanitaria Universitaria Friuli Centrale, San Daniele del Friuli, Italy.
Clin Microbiol Infect. 2020 Dec;26(12):1686.e1-1686.e4. doi: 10.1016/j.cmi.2020.08.041. Epub 2020 Sep 6.
Duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the upper respiratory tract is extremely variable, but its relation to disease severity is unknown. We investigated this relation in the 530 000 inhabitants of the northeastern Italian province of Udine.
We analysed real-time RT-PCR tests for SARS-CoV-2 in upper respiratory specimens conducted at the Virology Laboratory of the University Hospital of Udine, Italy (which serves the whole province) from 1 March to 30 April 2020 Specimens were from positive individuals in four groups characterized by different disease severity (critically ill patients admitted to intensive care units, patients admitted to infectious disease units, symptomatic patients visiting the emergency department and not hospitalized, and asymptomatic individuals tested during contact tracing or screening activities). Duration of viral positivity was assessed from the first positive test to the day of the first of two consecutive negative tests. Univariate and multivariate analyses were conducted to investigate differences in the four groups.
From 1 March to 30 April, 39 483 RT-PCR tests for SARS-CoV-2 were conducted on 23 778 individuals, and 974 individuals had a positive test result. Among those with multiple tests (n = 878), mean time to negativity was 23.7 days (standard error 0.3639; median 23, interquartile range 16-30 days). Mean time to negativity was longer in the group admitted to the intensive care unit than in the others, whereas no difference was observed between asymptomatic patients and those with mild disease.
Disease control measures should not be adjusted to account for differences in viral shedding according to symptomatic status.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）在上呼吸道中的持续时间极长，但目前尚不清楚其与疾病严重程度的关系。我们对意大利东北部乌迪内省的 53 万居民进行了此项研究。
我们分析了意大利乌迪内大学医院病毒学实验室于 2020 年 3 月 1 日至 4 月 30 日期间进行的上呼吸道标本的实时 RT-PCR SARS-CoV-2 检测结果。标本取自重症监护病房、传染病病房、急诊科未住院和无症状人群（在接触追踪或筛查活动中进行检测）4 组不同疾病严重程度的阳性个体。从第一次阳性检测到连续两次阴性检测的第一天，评估病毒阳性持续时间。进行单变量和多变量分析以调查四组之间的差异。
3 月 1 日至 4 月 30 日，对 23778 人进行了 39483 次 SARS-CoV-2 RT-PCR 检测，974 人检测结果为阳性。在多次检测的人群（n=878）中，平均转阴时间为 23.7 天（标准误差 0.3639；中位数 23，四分位距 16-30 天）。与其他组相比，入住重症监护病房的患者的平均转阴时间更长，而无症状患者与轻症患者之间没有差异。
不应根据症状状态调整疾病控制措施以考虑病毒脱落的差异。
