Upper Respiratory Tract Levels of Severe Acute Respiratory Syndrome Coronavirus 2 RNA and Duration of Viral RNA Shedding Do Not Differ Between Patients With Mild and Severe/Critical Coronavirus Disease 2019

J Infect Dis. 2021 Jan 4;223(1):15-18. doi: 10.1093/infdis/jiaa632.


This study reports longitudinal viral RNA loads from the nasopharynx/throat in patients with mild and severe/critical coronavirus disease 2019 (COVID-19). We also investigated whether the duration of symptoms correlated with the duration of viral RNA shedding. A total of 56 patients were included. The highest viral loads occurred early after onset of symptoms. Neither the viral RNA loads in the upper respiratory tract nor the time to viral RNA clearance differed between patients with mild or severe/critical disease. There was a moderate correlation between number of days with symptoms and number of days with viral RNA shedding in patients with mild COVID-19.

Keywords: COVID-19; SARS-CoV-2; nasopharynx; viral shedding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • COVID-19 / diagnosis*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nasopharynx / virology
  • Pharynx / virology
  • RNA, Viral / analysis*
  • Sweden
  • Viral Load*
  • Virus Shedding*
  • Young Adult


  • RNA, Viral