ABSTRACT
Background: Viral load kinetics and duration of viral shedding are important determinants for disease transmission. The aim of this review was to characterize viral load dynamics, duration of viral RNA and viable virus shedding of SARS-CoV-2 in various body fluids, and to compare SARS-CoV-2, SARS-CoV-1 and MERS-CoV viral dynamics.Methods: Medline, EMBASE, Europe PMC, medRxiv, bioRxiv, and grey literature from January 1st 2003 to June 6th 2020. Two authors independently extracted data and assessed study quality and risk of bias using the Joanna Briggs Institute Critical Appraisal Checklist tools. PROSPERO registration: CRD42020181914.Findings: Seventy-nine studies on SARS-CoV-2, 8 on SARS-CoV-1, and 11 on MERS-CoV were included. Mean SARS-CoV-2 RNA shedding duration in the upper respiratory tract (URT), lower respiratory tract (LRT), stool and serum were 17.0, 14.6, 17.2 and 16.6 days, respectively. Maximum shedding duration in URT, LRT, stool and serum were 83, 59, 35 and 60 days, respectively. Pooled mean SARS-CoV-2 shedding duration was positively associated with age. No study has detected live virus beyond day nine of illness, despite persistently high viral loads. SARS-CoV-2 viral load in the upper URT appears to peak in the first week of illness, while SARS-CoV-1 and MERS-CoV peak later.Conclusion: Although SARS-CoV-2 RNA shedding in respiratory and stool samples can be prolonged, duration of viable virus is relatively short-lived. SARS-CoV-2 titers in URT peak in the first week of illness. Early case finding and isolation, and public education on the spectrum of illness are key to the effective containment of SARS-CoV-2.Funding Statement: There was no funding for this study.Declaration of Interests: All authors have nothing to disclose.