Older age is associated with sustained detection of SARS-CoV-2 in nasopharyngeal swab samples

PCR testing of nasopharyngeal swab samples is used for the diagnosis of coronavirus disease 2019 (COVID-19) and for determining timing of discharge. The viral load usually declines at convalescent phase, but sometimes remained positive for a long time even after relief of symptoms. In this study, we identified older age is associated with sustained detection of SARS-CoV-2 in nasopharyngeal swab samples.