Background: The aim of this study was to investigate the host factors of patients with COVID-19 that were associated with delayed viral RNA clearance in specimens obtained from the upper respiratory tract.

Results: A median of a 32-day period of viral RNA shedding was observed, ranging from 4 days to 111 days. On multivariate analysis, elderly age was independently associated with prolonged viral shedding (OR = 1.02, 95% CI: 1.01–1.04, P = 0.003). An incremental increase in the duration of viral RNA shedding was observed with increasing age (P < 0.05). The median (quartile) duration of viral RNA shedding was 23 (22) days (≤ 40 years), 30 (18) days (41–50 years), 33 (21) days (51–60 years), 34 (17) days (61–70 years) and 34 (17) days (> 70 years).

Conclusions: Viral RNA shedding can persist for as long as 111 days in the upper respiratory tract. Increasing age is associated with viral RNA persistence.

Method: The demographic and virological data of patients with laboratory-confirmed COVID-19 were retrospectively analyzed. A multivariate logistic regression analysis was performed to identify significant risk factors associated with delayed viral RNA clearance. The duration of viral shedding was compared among age-stratified groups.