Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, 363 Dongbaekjukjeon-daero, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea.
Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea.
Int J Infect Dis. 2020 Oct;99:279-285. doi: 10.1016/j.ijid.2020.07.070. Epub 2020 Aug 5.
The aim of this study was to elucidate patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance in the natural course of asymptomatic coronavirus disease 2019 (COVID-19).
Consecutive patients with non-severe COVID-19 were included retrospectively. Asymptomatic patients with a normal body temperature and no evidence of pneumonia throughout the disease course were assigned to the asymptomatic group. The reverse transcription PCR (RT-PCR) assay was repeated every two to five days after the first follow-up RT-PCR assay. Negative conversion was defined as two consecutive negative RT-PCR assay results within a 24-h interval. Rebound of the cycle threshold (Ct) value was defined as negative from the single RT-PCR assay and positive from the following assay.
Among a total of 396 patients identified (median age 42.5 years (interquartile range (IQR) 25.0-55.0 years), 35.6% male), 68 (17.2%) were assigned to the asymptomatic group and 328 (82.8%) to the symptomatic group. The time until negative conversion was significantly shorter in the asymptomatic group than in the symptomatic group: median 14.5 days (IQR 11.0-21.0 days) and 18.0 days (IQR 15.0-22.0 days), respectively (p = 0.001). Rebound of Ct values was observed in 78 patients (19.7%).
Time until negative conversion is shorter in asymptomatic COVID-19 than in symptomatic COVID-19. Rebound of Ct values is not uncommon.
本研究旨在阐明无症状 2019 冠状病毒病（COVID-19）自然病程中严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）清除的模式。
回顾性纳入非重症 COVID-19 连续患者。无症状患者在整个疾病过程中体温正常且无肺炎证据，被分配到无症状组。首次随访 RT-PCR 检测后，每 2-5 天重复进行 RT-PCR 检测。阴性转换定义为 24 小时内连续两次 RT-PCR 检测结果均为阴性。Ct 值的反弹定义为单次 RT-PCR 检测为阴性，随后的检测为阳性。
共确定 396 例患者（中位年龄 42.5 岁（四分位距 25.0-55.0 岁），35.6%为男性），68 例（17.2%）被分配到无症状组，328 例（82.8%）被分配到有症状组。无症状组的阴性转换时间明显短于有症状组：中位数分别为 14.5 天（四分位距 11.0-21.0 天）和 18.0 天（四分位距 15.0-22.0 天）（p=0.001）。78 例患者（19.7%）出现 Ct 值反弹。
无症状 COVID-19 患者的阴性转换时间短于有症状 COVID-19 患者。Ct 值反弹并不少见。
