Patients
We conducted a retrospective, single-center study within the Emergency Department (ED) of Saint-Louis Hospital (Assistance Publique - Hôpitaux de Paris, Paris, France) spanning from March 9th, 2020, to May 6th, 2020. The study encompassed all patients diagnosed with SARS-CoV-2 infections. We categorized the patients into three groups: (i) individuals with acute respiratory distress syndrome attributed to COVID-19, who were subsequently transferred to the medical intensive care unit; (ii) patients admitted to a non-intensive care unit for COVID-19 treatment; and (iii) patients displaying no indications of severity and subsequently discharged from the hospital. Qualified trained medical or nursing personnel conducted the collection of nasopharyngeal secretions using standardized methods, employing nylon flocked swabs which were then placed in 3 ml of Universal Transport Medium (Copan Diagnostics Inc.). The swabs were gently inserted along the nasal septums into the nasopharynx until a sense of resistance was encountered, as described (11).