Modeling the early temporal dynamics of viral load in respiratory tract specimens of COVID-19 patients in Incheon, the Republic of Korea.
Lim, Ah-Young;
Cheong, Hae-Kwan;
Oh, Yoon Ju;
Lee, Jae Kap;
So, Jae Bum;
Kim, Hyun Jin;
Han, Boram;
Park, Sung Won;
Jang, Yongsun;
Yoon, Chang Yong;
+3 more...Park, Yun Ok;
Kim, Jong-Hun;
Kim, Jin Yong;
(2021)
Modeling the early temporal dynamics of viral load in respiratory tract specimens of COVID-19 patients in Incheon, the Republic of Korea.
INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES, 108.
pp. 428-434.
ISSN 1201-9712
DOI: https://doi.org/10.1016/j.ijid.2021.05.062
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OBJECTIVE: To investigate the duration and peak of severe acute respiratory syndrome coronavirus 2 shedding as infectivity markers for determining the isolation period. METHODS: A total of 2,558 upper respiratory tract (URT) and lower respiratory tract (LRT) specimens from 138 patients with laboratory-confirmed coronavirus disease were analyzed. Measurements of sequential viral loads were aggregated using the cubic spline smoothing function of a generalized additive model. The time to negative conversion was compared between symptom groups using survival analysis. RESULTS: In URT samples, viral RNA levels peaked on day 4 after symptom onset and rapidly decreased until day 10 for both E and RdRp genes, whereas those in LRT samples immediately peaked from symptom onset and decreased until days 15.6 and 15.0 for E and RdRp genes, respectively. Median (interquartile range) time to negative conversion was significantly longer in symptomatic (18.0 [13.0-25.0] days) patients than in asymptomatic (13.0 [9.5-17.5] days) patients. The more types of symptoms a patient had, the longer the time to negative conversion. CONCLUSIONS: The viral load rapidly changes depending on the time after symptom onset; the viral shedding period may be longer with more clinical symptoms. Different isolation policies should be applied depending on disease severity.