Key Points Question What is the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and the seroprevalence of SARS-CoV-2 antibodies in children aged 1 to 10 years and a corresponding parent in a population-based sample in southwest Germany? Findings This large-scale, multicenter, cross-sectional investigation of 4964 participants accurately determined anti–SARS-CoV-2 seropositivity by combining the results of enzyme-linked immunosorbent assay and immunofluorescence tests. The estimated SARS-CoV-2 seroprevalence was low in parents (1.8%) and 3-fold lower in children (0.6%). Meaning The low seroprevalence of SARS-CoV-2 antibodies in young children in this study may indicate that they do not play a key role in SARS-CoV-2 spreading during the current pandemic. This cross-sectional investigation conducted in southwest Germany describes the rate of severe acute respiratory syndrome coronavirus 2 infections and the seroprevalence of antibodies in children aged 1 to 10 years, compared with a parent of each child, in a population-based sample. Importance 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. Objective 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. Design, Setting, and Participants 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. Exposures Potential exposure to SARS-CoV-2. Main Outcomes and Measures 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. Results 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%). Conclusions and Relevance 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.
【초록키워드】 COVID-19, SARS-CoV-2, coronavirus, pandemic, antibody, lockdown, cross-sectional, SARS-COV-2 infection, children, COVID-19 pandemic, Infection, outcome, novel coronavirus disease, Spread, immunoassays, Nasopharyngeal swab, serum, enzyme-linked immunosorbent assay, SARS-CoV-2 seroprevalence, SARS-CoV-2 antibody, Germany, SARS-CoV-2 RNA, School, multicenter, immunofluorescence, seronegative, Combination, exposure, Contact, Seronegativity, acute respiratory syndrome, 95% CI, median age, measure, participant, parent, assumption, finding, positive, serum sample, prevalence study, men, objective, consequence, setting, Respiratory Coronavirus, enzyme-linked immunosorbent, Result, enrolled, tested, conducted, unlikely, appear, provide, virus-neutralizing, Importance, Potential, Point, Relevance, specific IgG antibody, 【제목키워드】 SARS-CoV-2, Germany, parent,