Patterns of viral clearance in the natural course of asymptomatic COVID-19: Comparison with symptomatic non-severe COVID-19
Authors
Jae-Sun Uhm ; Jin Young Ahn ; JongHoon Hyun ; Yujin Sohn ; Jung Ho Kim ; Su Jin Jeong ; Nam Su Ku ; Jun Yong Choi ; Yu-Kyung Park ; Ho-Sung Yi ; Sung Kyu Park ; Bong-Ok Kim ; Hyewon Kim ; Jinwoo Choi ; Seung-Mo Kang ; Yeong Ho Choi ; Hae Kyoung Yoon ; Sunkyung Jung ; Hyeong Nyeon Kim ; Joon-Sup Yeom ; Yoon Soo Park
Citation
INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, Vol.99 : 279-285, 2020-10
Objectives: 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).
Methods: 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.
Results: 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%).
Conclusions: Time until negative conversion is shorter in asymptomatic COVID-19 than in symptomatic COVID-19. Rebound of Ct values is not uncommon.