RNA purification, Real-time PCR
Total RNA from nasopharyngeal swabs samples were obtained by extraction and purification using the QIAamp Viral RNA Extraction Kit (QIAGEN, Germany) with the QIAcube Connect automatic station (QIAGEN, Germany) according to the manufacturers recommendations. Samples were eluted and stored at -70° C until further analysis. For SARS-CoV-2 detection and to assess viral load, swabs were thoroughly analyzed using LightMix® Modular Wuhan CoV E-gene reagents (Roche SAP) according to manufacturer’s recommendations. SARS-CoV-2-positive samples featuring Ct values of 25 or less were selected and studied further. 