Abstract
Switzerland began a national lockdown on March 16, 2020, in response to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed the prevalence of SARS-CoV-2 infection among patients admitted to 4 hospitals in the canton of Zurich, Switzerland, in April 2020. These 4 acute care hospitals screened 2,807 patients, including 2,278 (81.2%) who did not have symptoms of coronavirus disease (COVID-19). Overall, 529 (18.8%) persons had >1 symptom of COVID-19, of whom 60 (11.3%) tested positive for SARS-CoV-2. Eight asymptomatic persons (0.4%) also tested positive for SARS-CoV-2. Our findings indicate that screening on the basis of COVID-19 symptoms, regardless of clinical suspicion, can identify most SARS-CoV-2-positive persons in a low-prevalence setting.