Systematic screening on admission for SARS-CoV-2 to detect asymptomatic infections

Stadler, Rahel N.; Maurer, Laura; Aguilar-Bultet, Lisandra; Franzeck, Fabian; Ruchti, Chantal; Kühl, Richard; Widmer, Andreas F.; Schindler, Ruth; Bingisser, Roland; Rentsch, Katharina M.; Pargger, Hans; Sutter, Raoul; Steiner, Luzius; Meier, Christoph; Kübler, Werner; Hirsch, Hans H.; Egli, Adrian; Battegay, Manuel; Bassetti, Stefano; Tschudin-Sutter, Sarah

The proportion of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains elusive and the potential benefit of systematic screening during the SARS-CoV-2-pandemic is controversial. We investigated the proportion of asymptomatic inpatients who were identified by systematic screening for SARS-CoV-2 upon hospital admission. Our analysis revealed that systematic screening of asymptomatic inpatients detects a low total number of SARS-CoV-2 infections (0.1%), questioning the cost–benefit ratio of this intervention. Even when the population-wide prevalence was low, the proportion of asymptomatic carriers remained stable, supporting the need for universal infection prevention and control strategies to avoid onward transmission by undetected SARS-CoV-2-carriers during the pandemic.