We determined secondary attack rates (SAR) among close contacts of 59 asymptomatic and symptomatic coronavirus disease case-patients by presymptomatic and symptomatic exposure. We observed no transmission from asymptomatic case-patients and highest SAR through presymptomatic exposure. Rapid quarantine of close contacts with or without symptoms is needed to prevent presymptomatic transmission.
Keywords: COVID-19; Germany; SARS-CoV-2; asymptomatic diseases; contact; coronavirus disease; disease transmission; epidemiology; infectious; respiratory infections; risk; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.