Excerpted from executive summary
Background
As jurisdictions continue to lift restrictions implemented to slow the spread of coronavirus disease 2019 (COVID-19), they face major decisions about when and how to re-open and operate schools and daycares. While children are known to be effective vectors for other viruses, such as influenza, their role in the transmission of COVID-19 is much less clear. This rapid review was produced to support public health decision makers’ response to the COVID-19 pandemic. This review seeks to identify, appraise and summarize emerging research evidence to support evidence-informed decision making. This rapid review is based on the most recent research evidence available at the time of release. A previous version was completed on June 26, 2020. This updated version includes evidence available up to July 20, 2020. In this rapid evidence review, we answer the question: What is the specific role of daycares and schools in COVID-19 transmission?
Key Points
- Based on the published reports to date, young children are not a major source of transmission of COVID-19. The quality of evidence is moderate, and findings are consistent.
- Analyses of infection clusters revealed that for children who were infected, transmission was traced back to community and home settings or adults, rather than amongst children within daycares or schools. Within household clusters, adults were much more likely to be the index case than children. The quality of evidence is moderate, and findings are consistent.
Overview of Evidence and Knowledge Gaps
- Studies evaluating the transmission of COVID-19 in daycare and school settings are limited to case reports of contact tracing and prevalence studies. As schools and daycares continue to open around the world and more evidence becomes available, this question should be reviewed again as findings may change.
- The prevalence of COVID-19 infection in children in daycare and school settings was lower than the prevalence of COVID-19 in adults working in daycare and school settings. The quality of evidence is low, and findings are consistent.
- Contact tracing studies have identified very limited transmission by children in school settings. The likelihood of infected teachers or staff transmitting to students is unknown.
- It is not yet possible to evaluate the impact of specific infection prevention and control measures or make best practice recommendations for daycare or school settings. Many studies were conducted prior to implementation of infection prevention measures, and those that examine re-opening do not include descriptions of infection control measures.
- Across studies there appears to be a linear relationship between age and likelihood of contracting and transmitting COVID-19. More research is needed to understand why this may occur, and what the absolute and relative risk differences are across age ranges. The study quality is low, and findings are consistent