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

JAMA Pediatr. 2021 Jun 1;175(6):586-593. doi: 10.1001/jamapediatrics.2021.0001.


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.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Age Distribution
  • Age Factors
  • Aged
  • Antibodies, Viral / blood*
  • COVID-19 / blood
  • COVID-19 / diagnosis*
  • COVID-19 / epidemiology*
  • COVID-19 Serological Testing
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Germany / epidemiology
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Male
  • Middle Aged
  • Parents
  • Prevalence
  • SARS-CoV-2 / isolation & purification*
  • Seroepidemiologic Studies


  • Antibodies, Viral
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M