Fig. 1.

Snapshots of nasopharyngeal SARS-CoV-2 RNA detection by RT-PCR after hospital discharge. The results of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) real-time PCR (RT-PCR) on nasopharyngeal swabs are reported at different time-intervals after hospital discharge, for patients who recovered from Coronavirus Disease 2019 (COVID-19). The total number of nasopharyngeal swabs processed are also reported (blue line). RT-PCR was performed d by AllplexTM 2019-nCoV assay (Seegene) and Cobas^Ⓡ SARS-CoV-2 assay (Roche Diagnostics). Positive RT-PCR results are defined by the detection of at least two of three target genes (N, E and RdRP genes), while weakly positive RT-PCR results are defined by the detection of one of them.