Lower Household Transmission Rates of SARS-CoV-2 from Children Compared to Adults - Results from the FamilyCoviDD19-Study

Abstract

Background: While lockdown and social distancing measures effectively reduce transmission rates of SARS-CoV-2 in public spaces crowded indoor spaces remain a significant venue for SARS-CoV-2 transmission. Analyzing seroprevalence in households with confirmed index-cases we can assess transmissibility and risk factors associated with infectivity and susceptibility more accurately than PCR based studies.Methods: Households with a confirmed SARS-CoV-2 infected member in Dresden (Saxony, Germany) were invited to participate in the FamilyCoviDD19 study between June 2020 and January 2021. Personal history and characteristics of the households were obtained and seroprevalence of SARS-CoV-2 antibodies was assessed.Findings:150 households with 414 participating household-members were enrolled. 51% of all study participants were seropositive. The secondary attack rate (SAR) in households with an index-case Interpretation: Household transmissions are detected more frequently by seroprevalence than observed in PCR based studies. Children and adolescents are less likely to transmit the disease compared to adults. Temporal separation and mask wearing reduces transmission rates in households significantly.Trial Registration: clinical trial number DRKS00022564Funding Statement: This study was supported by a grant by the Federal State of Saxony.Declaration of Interests: Dr. Berner reports grants from Federal State of Saxony/Germany, during the conduct of the study; Dr. Dalpke reports grants from Federal State of Saxony, during the conduct of the study; Dr. Armann reports grants from Federal State of Saxony, during the conduct of the study; all other authors have nothing to disclose. Ethics Approval Statement: The investigation is part of the FamilyCoviDD19-study which was approved by the Ethics Committee of the Technische Universität (TU) Dresden (BO-EK 342072020).