Prolonged viral clearance of severe acute respiratory syndrome coronavirus 2 in the older aged population

Introduction: The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) is the standard method for the diagnosis of coronavirus disease 2019 (COVID-19). This PCR test can be positive even in patients who have recovered from the disease, and the duration for achieving viral clearance has not been clarified yet. Methods: This study was conducted between April 3, 2020, and June 17, 2020, at the Toyama University Hospital and the Toyama Rehabilitation Home. We collected the data of patients with COVID-19, analyzing the duration until twice-consecutive negative qRT-PCR test. Results: A total of 42 patients were enrolled. The median duration of the twice-consecutive negative qRT-PCR test was 29.0 d (interquartile range: 25.75–35.25). The longest duration of viral shedding was 73 d. The duration of viral clearance was significantly longer in the older (>65 years) group than in the younger group (34.5 d vs. 25.0 d, P < 0.0001). Conclusion: This study demonstrated that viral clearance tends to be sustained in the older adults.