Viral kinetics of SARS-CoV-2 in asymptomatic carriers and presymptomatic patients

•There are carriers of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the asymptomatic population.•The duration of viral shedding may be short in asymptomatic carriers.•Fourteen days of isolation after diagnosis may be sufficient in entirely asymptomatic cases. From a total of 71 laboratory-confirmed cases, three presymptomatic patients and 10 patients with entirely asymptomatic infections were identified. In two of the three incubation period patients, the viral titer in the presymptomatic period was very high (Ct value35 within 14 days after diagnosis. Patients who have COVID-19 may already be infectious before there are symptoms, and 14 days of isolation after diagnosis may be sufficient in entirely asymptomatic cases.