Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 in Households with Children, Southwest Germany, May-August 2020.

Maximilian Stich,Tessa Görne,Alexandra Nieters,Linus Fritsch,Sven F Garbade,Aleš Janda,Hanna Renk,Thomas Iftner,Roland Elling,Hartmut Hengel,Andreas Peter,Kathrin Jeltsch,Maria Zernickel,Corinna Engel,Philipp Henneke,Tina Ganzenmueller,Thomas Stamminger,Daniela Huzly,Burkhard Tönshoff,Jonathan Remppis,Tim Waterboer,Dorit Fabricius,Jürgen Grulich–Henn ,Klaus‐Michael Debatin ,Natalia Ruétalo ,Georg F Hoffmann ,Bárbara Müller ,Andrea Dietz ,Benedikt D Spielberger ,Anneke Haddad ,Hans‐Georg Kräusslich ,Peter Meißner ,Axel Franz

doi:10.3201/eid2712.210978

Abstract

Resolving the role of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in households with members from different generations is crucial for containing the current pandemic. We conducted a large-scale, multicenter, cross-sectional seroepidemiologic household transmission study in southwest Germany during May 11–August 1, 2020. We included 1,625 study participants from 405 households that each had ≥1 child and 1 reverse transcription PCR–confirmed SARS-CoV-2–infected index case-patient. The overall secondary attack rate was 31.6% and was significantly higher in exposed adults (37.5%) than in children (24.6%–29.2%; p = <0.015); the rate was also significantly higher when the index case-patient was >60 years of age (72.9%; p = 0.039). Other risk factors for infectiousness of the index case-patient were SARS-CoV-2–seropositivity (odds ratio [OR] 27.8, 95% CI 8.26–93.5), fever (OR 1.93, 95% CI 1.14–3.31), and cough (OR 2.07, 95% CI 1.21–3.53). Secondary infections in household contacts generate a substantial disease burden.

Highlights

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally since its emergence in December 2019
Our objectives were to determine the SARS-CoV-2 seroprevalence and secondary attack rate (SAR) in children compared with adults from the same households and, second, to identify risk factors associated with infectiousness of index case-patients and susceptibility of contacts
Study Design and Conduct We conducted a multicenter, cross-sectional SARSCoV-2 transmission study on the prevalence of SARSCoV-2 antibodies in members of households with 1 index case-patient with a previous SARS-CoV-2 infection confirmed by RT-PCR from a nasopharyngeal or oropharyngeal swab specimen

Summary

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally since its emergence in December 2019. Low detection rates of SARS-CoV-2 RNA by RT-PCR in children might not precisely reflect the frequency of infections. Mild or even asymptomatic disease in children combined with higher rates of aversion and incorrect swab collection might lead to underestimation of the infection risk, especially in symptom-based transmission studies. Previous household transmission studies found SARS-CoV-2–specific IgG in 28% [17], 34% [18], 42% [19], 45% [20] and 52% [21] of exposed children; SARs were lower [18], similar to [17,21], or higher [19] than in exposed adult household members. Our objectives were to determine the SARS-CoV-2 seroprevalence and SAR in children compared with adults from the same households and, second, to identify risk factors associated with infectiousness of index case-patients and susceptibility of contacts

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Conclusion