Transmission of SARS-CoV-2 by children and young people in households and schools: A meta-analysis of population-based and contact-tracing studies

Abstract

Background The role of children and young people (CYP) in transmission of SARS-CoV-2 in household and educational settings remains unclear. We undertook a systematic review and meta-analysis of contact-tracing and population-based studies at low risk of bias. Methods We searched 4 electronic databases on 28 July 2021 for contact-tracing studies and population-based studies informative about transmission of SARS-CoV-2 from 0-19 year olds in household or educational settings. We excluded studies at high risk of bias, including from under-ascertainment of asymptomatic infections. We undertook multilevel random effects meta-analyses of secondary attack rates (SAR: contact-tracing studies) and school infection prevalence, and used meta-regression to examine the impact of community SARS-CoV-2 incidence on school infection prevalence. Findings 4529 abstracts were reviewed, resulting in 37 included studies (16 contact-tracing; 19 population studies; 2 mixed studies). The pooled relative transmissibility of CYP compared with adults was 0.92 (0.68, 1.26) in adjusted household studies. The pooled SAR from CYP was lower (p=0.002) in school studies 0.7% (0.2, 2.7) than household studies (7.6% (3.6, 15.9) . There was no difference in SAR from CYP to child or adult contacts. School population studies showed some evidence of clustering in classes within schools. School infection prevalence was associated with contemporary community 14-day incidence (OR 1.003 (1.001, 1.004), p<0.001). Interpretation We found no difference in transmission of SARS-CoV-2 from CYP compared with adults within household settings. SAR were markedly lower in school compared with household settings, suggesting that household transmission is more important than school transmission in this pandemic. School infection prevalence was associated with community infection incidence, supporting hypotheses that school infections broadly reflect community infections. These findings are important for guiding policy decisions on shielding, vaccination school and operations during the pandemic.

The impact of SARS-CoV-2 on respiratory syndromic and sentinel surveillance in Israel, 2020: a new perspective on established systems

“…A recent systematic review and meta-analysis showed that children transmit the virus to other children at lower rates than to adults [ 17 ]. Another study found that there was no difference in the transmission of SARS-CoV-2 in children compared with adults in households [ 18 ]. Based on recent data, the average number of births per woman in Israel is 3.0, while it is about half of that in many European countries and the US [ 19 ].…”

Infancia y COVID-19: Los efectos indirectos de la pandemia COVID-19 en el bienestar de niños, niñas y adolescentes

“…Al igual que series internacionales, la incidencia en nuestro país de COVID-19 en NNA ha sido muy dependiente de la circulación comunitaria del virus, y no así de medidas específicas para limitar su exposición 11,12 . Esto apoya a las observaciones que refieren que los niños en su mayoría se exponen al virus en su domicilio, y su rol en la transmisión y circulación viral a nivel poblacional es baja, a diferencia de otros virus, como la influenza [13][14][15][16] .…”

Main changes in the “COVID-19 in paediatrics” clinical practice guideline

“…Recently published studies 35 , 36 , 37 have reported that reopening schools, as long as appropriate hygiene and social distancing measures were upheld, did not seem to have a deleterious impact, although most studies acknowledged that the behaviour of new variants of the virus could change this. At the same time, numerous studies highlighted the negative impact of school closures on different aspects of child and adolescent health.…”