Asymptomatic Subclinical Cases Of Coronavirus Disease 2019 Without Viral Transmission In Three Independent Families

Purpose: There is increasing evidence indicating that considerable fractions of cases of SARS-CoV-2 infection are asymptomatic. We traced three asymptomatic clusters to investigate the infectivity of subclinical cases of coronavirus disease 2019 (COVID-19).Patients and Methods: Three medical staff who were asymptomatic were diagnosed with coronavirus disease 2019 by serological tests. Their close contacts were systematically evaluated based on COVID-19-related symptoms, nucleic acid tests, serological tests, and chest computed tomography (CT) as needed to determine if they were infected by SARS-CoV-2.Results: None of the staff's close contacts, including 10 family members, were infected by the indexes, even though no protective measures were taken.Conclusion: The infectivity of asymptomatic subclinical infection patients of coronavirus disease 2019 seems to be low.