Prevalence of SARS-CoV-2 Infection in Children and Their Parents in Southwest Germany
Authors: Burkhard Tönshoff, Barbara Müller, Roland Elling, Hanna Renk, Peter Meissner, Hartmut Hengel, Sven F. Garbade, Meinhard Kieser, Kathrin Jeltsch, Jürgen Grulich-Henn, Julia Euler, Maximilian Stich, Kristine Chobanyan-Jürgens, Maria Zernickel, Aleš Janda, Lena Wölfle, Thomas Stamminger, Thomas Iftner, Tina Ganzenmueller, Christian Schmitt, Tessa Görne, Vibor Laketa, Sylvia Olberg, Anna Plaszczyca, Mirko Cortese, Ralf Bartenschlager, Constantin Pape, Roman Remme, Daniela Huzly, Marcus Panning, Sebastian Weigang, Sebastian Giese, Kevin Ciminski, Jakob Ankerhold, Georg Kochs, Martin Schwemmle, Rupert Handgretinger, Charlotte M. Niemeyer, Corinna Engel, Winfried V. Kern, Georg Friedrich Hoffmann, Axel R. Franz, Philipp Henneke, Klaus-Michael Debatin, Hans-Georg Kräusslich
Journal: JAMA Pediatrics (2021)

<h3>Importance</h3> School and daycare closures were enforced as measures to confine the novel coronavirus disease 2019 (COVID-19) pandemic, based on the assumption that young children may play a key role in severe acute respiratory coronavirus 2 (SARS-CoV-2) spread. Given the grave consequences of contact restrictions for children, a better understanding of their contribution to the COVID-19 pandemic is of great importance. <h3>Objective</h3> To describe the rate of SARS-CoV-2 infections and the seroprevalence of SARS-CoV-2 antibodies in children aged 1 to 10 years, compared with a corresponding parent of each child, in a population-based sample. <h3>Design, Setting, and Participants</h3> This large-scale, multicenter, cross-sectional investigation (the COVID-19 BaWü study) enrolled children aged 1 to 10 years and a corresponding parent between April 22 and May 15, 2020, in southwest Germany. <h3>Exposures</h3> Potential exposure to SARS-CoV-2. <h3>Main Outcomes and Measures</h3> The main outcomes were infection and seroprevalence of SARS-CoV-2. Participants were tested for SARS-CoV-2 RNA from nasopharyngeal swabs by reverse transcription–polymerase chain reaction and SARS-CoV-2 specific IgG antibodies in serum by enzyme-linked immunosorbent assays and immunofluorescence tests. Discordant results were clarified by electrochemiluminescence immunoassays, a second enzyme-linked immunosorbent assay, or an in-house Luminex-based assay. <h3>Results</h3> This study included 4964 participants: 2482 children (median age, 6 [range, 1-10] years; 1265 boys [51.0%]) and 2482 parents (median age, 40 [range, 23-66] years; 615 men [24.8%]). Two participants (0.04%) tested positive for SARS-CoV-2 RNA. The estimated SARS-CoV-2 seroprevalence was low in parents (1.8% [95% CI, 1.2–2.4%]) and 3-fold lower in children (0.6% [95% CI, 0.3-1.0%]). Among 56 families with at least 1 child or parent with seropositivity, the combination of a parent with seropositivity and a corresponding child with seronegativity was 4.3 (95% CI, 1.19-15.52) times higher than the combination of a parent who was seronegative and a corresponding child with seropositivity. We observed virus-neutralizing activity for 66 of 70 IgG-positive serum samples (94.3%). <h3>Conclusions and Relevance</h3> In this cross-sectional study, the spread of SARS-CoV-2 infection during a period of lockdown in southwest Germany was particularly low in children aged 1 to 10 years. Accordingly, it is unlikely that children have boosted the pandemic. This SARS-CoV-2 prevalence study, which appears to be the largest focusing on children, is instructive for how ad hoc mass testing provides the basis for rational political decision-making in a pandemic.