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

There is a close genetic relatedness between severe acute respiratory syndrome coronavirus (SARS-CoV) and the causative agent of COVID-19, SARS-CoV-2. The predominant expression of ACE2 in the lower respiratory tract is believed to have determined the natural history of SARS as a lower respiratory tract infection. Whereas positive SARS-CoV-2 detection in clinical specimens from the upper respiratory tract has been described 9 , these observations do not address principal differences between SARS and COVID-19 in terms of clinical pathology. The here-studied patients were enrolled because they acquired their infections upon known close contact to an index case, thereby avoiding representational biases due to symptom-based case definitions. All patients were treated in a single hospital in Munich, Germany. Virological testing was done by two closely-collaborating laboratories using the same standards of technology for RT-PCR and virus isolation, confirming each other's results based on almost all individual samples. Due to extremely high congruence of results, all data are presented together. Only the serological data are based on results from one laboratory. The patients are part of a larger cluster of epidemiologically-linked cases that occurred after January 23 rd , 2020 in Munich, Germany, as discovered on January 27 th (Böhmer et al., accompanying manuscript) . The present study uses samples taken during the clinical course in the hospital, as well as from initial diagnostic testing before admission. In cases when this initial diagnostic testing was done by other laboratories, the original samples were retrieved and re-tested under the rigorous quality standards of the present study.