Clinical presentation and virological assessment of hospitalized cases of coronavirus disease 2019 in a travel-associated transmission cluster

Roman Woelfel; Victor Max Corman; Wolfgang Guggemos; Michael Seilmaier; Sabine Zange; Marcel A Mueller; Daniela Niemeyer; Patrick Vollmar; Camilla Rothe; Michael Hoelscher; Tobias Bleicker; Sebastian Bruenink; Julia Schneider; Rosina Ehmann; Katrin Zwirglmaier; Christian Drosten; Clemens Wendtner

Successful live virus isolation from throat swabs is another striking difference from SARS, for which such isolation was rarely successful [16] [17] [18] . Altogether, this suggests active virus replication in upper respiratory tract tissues, where only minimal ACE-2 expression is found and SARS-CoV is therefore not thought to replicate 19 . At the same time, the concurrent use of ACE-2 as a receptor by SARS-CoV and SARS-CoV-2 corresponds to a highly similar excretion kinetic in sputum, with active replication in the lung. SARS-CoV was found in sputum at mean concentrations of 1.2-2.8x10 6 copies per mL, which corresponds to observations made here 13 . Whereas proof of replication by histopathology is awaited, extended tissue tropism of SARS-CoV-2 with replication in the throat is strongly supported by our studies of sgRNAtranscribing cells in throat swab samples, particularly during the first 5 days of symptoms.