Dynamics of SARS-CoV-2 shedding in the respiratory tract depends on the severity of disease in COVID-19 patients.

A fraction of COVID-19 patients progress to a severe disease manifestation with respiratory failure and the necessity of mechanical ventilation. Identifying patients at risk is critical for optimised care and early therapeutic interventions. We investigated the dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shedding relative to disease severity.We analysed nasopharyngeal and tracheal shedding of SARS-CoV-2 in 92 patients with diagnosed COVID-19. Upon admission, standardised nasopharyngeal swab or sputum samples were collected. If patients were mechanically ventilated, endotracheal aspirate samples were additionally obtained. Viral shedding was quantified by real-time PCR detection of SARS-CoV-2 RNA.45% (41 out of 92) of COVID-19 patients had a severe disease course with the need for mechanical ventilation (severe group). At week 1, the initial viral shedding determined from nasopharyngeal swabs showed no significant difference between nonsevere and severe cases. At week 2, a difference could be observed as the viral shedding remained elevated in severely ill patients. A time-course of C-reactive protein, interleukin-6 and procalcitonin revealed an even more protracted inflammatory response following the delayed drop of virus shedding load in severely ill patients. A significant proportion (47.8%) of patients showed evidence of prolonged viral shedding (>17 days), which was associated with severe disease courses (73.2%).We report that viral shedding does not differ significantly between severe and nonsevere COVID-19 cases upon admission to the hospital. Elevated SARS-CoV-2 shedding in the second week of hospitalisation, a systemic inflammatory reaction peaking between the second and third week, and prolonged viral shedding are associated with a more severe disease course.
Competing Interests: Conflict of interest: D. Munker has nothing to disclose. Conflict of interest: A. Osterman has nothing to disclose. Conflict of interest: H. Stubbe has nothing to disclose. Conflict of interest: M. Muenchhoff has nothing to disclose. Conflict of interest: T. Veit has nothing to disclose. Conflict of interest: T. Weinberger has nothing to disclose. Conflict of interest: M. Barnikel has nothing to disclose. Conflict of interest: J-N. Mumm has nothing to disclose. Conflict of interest: K. Milger has nothing to disclose. Conflict of interest: E. Khatamzas has nothing to disclose. Conflict of interest: S. Klauss has nothing to disclose. Conflict of interest: C. Scherer has nothing to disclose. Conflict of interest: J.C. Hellmuth has nothing to disclose. Conflict of interest: C. Giessen-Jung has nothing to disclose. Conflict of interest: M. Zoller has nothing to disclose. Conflict of interest: T. Herold has nothing to disclose. Conflict of interest: S. Stecher has nothing to disclose. Conflict of interest: E.N. De Toni has nothing to disclose. Conflict of interest: C. Schulz has nothing to disclose. Conflict of interest: N. Kneidinger has nothing to disclose. Conflict of interest: O.T. Keppler has nothing to disclose. Conflict of interest: J. Behr has nothing to disclose. Conflict of interest: J. Mayerle has nothing to disclose. Conflict of interest: S. Munker has nothing to disclose.
(Copyright ©ERS 2021.)