Department of Epidemiology, School of Public Health (Guangdong Provincial Key Laboratory of Tropical Disease Research), Southern Medical University, Guangzhou 510515, China.
Guangzhou Eighth People's Hospital, Guangzhou 510000, China.
Int J Infect Dis. 2020 Jul;96:288-290. doi: 10.1016/j.ijid.2020.05.030. Epub 2020 May 11.
Data are limited on the viral load, viral shedding patterns, and potential infectivity of asymptomatic patients (APs) with coronavirus disease 2019 (COVID-19). This study included 31 adult patients who were virologically confirmed to have COVID-19 but were asymptomatic on admission. Among these 31 patients, 22 presented symptoms after admission and were defined as asymptomatic patients in the incubation period (APIs); the other nine patients remained asymptomatic during hospitalization and were defined as asymptomatic patients (APs). The median cycle threshold (Ct) value of APs (39.0, interquartile range (IQR) 37.5-39.5) was significantly higher than that of APIs (34.5, IQR 32.2-37.0), indicating a lower viral load in APs. However, the duration of viral shedding remained similar in the two groups (7 days, IQR 5-14 days vs. 8 days, IQR 5-16 days). The study findings demonstrated that although APs with COVID-19 have a lower viral load, they still have certain period of viral shedding, which suggests the possibility of transmission during their asymptomatic period. Further longitudinal surveillance of these asymptomatic cases via virus nucleic acid testing are warranted.
关于无症状的 2019 冠状病毒病(COVID-19)患者的病毒载量、病毒脱落模式和潜在传染性的数据有限。本研究纳入了 31 名成人患者,他们的病毒学检测均证实患有 COVID-19,但入院时无症状。在这 31 名患者中,22 名在入院后出现症状,被定义为潜伏期无症状患者(APIs);另外 9 名患者在住院期间一直无症状,被定义为无症状患者(APs)。APs 的中位循环阈值(Ct)值(39.0,四分位间距 37.5-39.5)明显高于 APIs(34.5,四分位间距 32.2-37.0),表明 APs 的病毒载量较低。然而,两组患者的病毒脱落持续时间相似(7 天,四分位间距 5-14 天与 8 天,四分位间距 5-16 天)。研究结果表明,尽管 COVID-19 的无症状患者病毒载量较低,但仍具有一定的病毒脱落期,这表明他们在无症状期可能具有传播性。需要通过病毒核酸检测对这些无症状病例进行进一步的纵向监测。