Prevalence of SARS-CoV-2 Infection in Children and Their Parents in Southwest Germany

Abstract

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.

Lessons from low seroprevalence of SARS‐CoV‐2 antibodies in schoolchildren: A cross‐sectional study

“…Focusing only on children (50% in the age of 0-10 years), PCR positivity was 0.02% (1 case), and the seroprevalence was 0.8% (19 cases). 18 In concordance with the German data, our findings suggest that children may be less affected by a SARS-CoV-2 infection compared to adults. 7,14,19,20 TA B L E 1 RT-PCR analysis and seroprevalence of SARS-CoV-2 by general characteristics: Absolute Values and Percentages (Row percent) are shown.…”

“…A nationwide French surveillance revealed a seroprevalence in children of 2.7%. 17 In a preliminary report of a German study detecting acute SARS-CoV-2 infections and seroprevalence in 4932 parent-child pairs, a mRNA prevalence of 0.04% and a seroprevalence of 1.3% were found 18 . Focusing only on children (50% in the age of 0-10 years), PCR positivity was 0.02% (1 case), and the seroprevalence was 0.8% (19 cases).…”

SARS-CoV-2 Seroepidemiology in Children and Adolescents

“…Antibody positivity in a smaller population-based study in Switzerland in mid-May 2020 1 was lowest in children 0-9 years at 0.8%, compared with adults aged 20-49, at 9.9% [4]. Similarly, in 1 Germany a low seropositivity rate of 0.6% was reported in children aged 1-10 years [5], 1 An investigation in spring 2020 evaluated children for SARS-CoV-2 antibodies 8-10 weeks after a large 1 school outbreak in Santiago, Chile. Anti-SARS-CoV-2 antibodies were present in 10% of children, 1 whereas 17% of adult staff were seropositive.…”

“…Antibody positivity in a smaller population-based study in Switzerland in mid-May 2020 was lowest in children 0-9 years at 0.8%, compared with adults aged 20-49, at 9.9% [4]. Similarly, in Germany a low seropositivity rate of 0.6% was reported in children aged 1-10 years [5],…”

Comparaison de l’infectivité du coronavirus du syndrome respiratoire aigu sévère 2 chez les enfants et les adultes

“…Cependant, ces résultats sont cohérents avec les études épidémiologiques qui montrent une transmission limitée du SRAS-CoV-2 chez les enfants de moins de 10 ans 16,17 . Une récente étude de séroprévalence réalisée en Allemagne a démontré que les enfants, surtout ceux de 1-10 ans, présentent une séropositivité considérablement plus faible que leurs parents, rendant moins probables les infections asymptomatiques non détectées chez les enfants 18 . Une méta-analyse a révélé une susceptibilité moins élevée au SRAS-CoV-2 chez les enfants qui ne seraient donc pas des vecteurs de transmission communautaire de même ampleur que les adultes 19 .…”