Pathways of Covid-19 infection in school settings: What does the data tell us?
The first population-level study of Covid-19 transmission between pupils and staff in a school environment has shown that the opening of schools in Wales between September and December 2020 was not associated with an increased subsequent risk of staff testing positive. The study, which was carried out by a team that included senior researchers from ADR Wales as part of the One Wales Covid-19 response, found that only pupils—not staff—were at increased risk of testing positive, following cases appearing within their own year group.
Findings from the study have directly informed Welsh Government’s Covid-19 Technical Advisory Group (TAG) and the UK’s Scientific Advisory Group for Emergencies (SAGE). In Wales, this has informed decision making around school openings following prolonged school closures during the national lockdown that began at the end of 2020.
The research team used linked data anonymised at the individual and household level for the population of Wales, held within the SAIL Databank. Creating an e-cohort of school children (ages four-17), school staff, and linked household members for both children and staff, the sample size of tests studied, and the numbers of infections, was substantial. The researchers assessed the likelihood of test positivity in pupils and staff in relation to other recent cases in linked pupils, staff or their households over the period from August to December 2020.
Findings from this study suggest that pupil to pupil Covid-19 transmission is likely, but the absolute effects on the wider school population and staff can be minimised through the implementation of strict mitigation measures. Whilst the study was conducted in Wales, it is highly likely that the findings can be generalised to the UK and many parts of the world in temperate climates where schools have around 30 pupils per class and are largely educated indoors.
Dr Daniel A. Thompson, one of the lead authors of the study, said: “National school closures are a topic of ongoing debate. Understanding the potential transmission pathways within the school setting is crucial to understand and balance with concerns of the negative impacts and widening inequalities in children’s health, wellbeing and educational attainment, and the broader economic and societal impact.
“As schools reopen across the UK following prolonged periods of school closures, evidence is required that examines the role of the school setting in transmission between pupils and school staff.”
The study was led by researchers across teams in ADR Wales, Health Data Research UK, Welsh Government and the SAIL Databank, which have worked alongside BREATHE, the Adolescent Data Platform, Public Health Wales and Digital Health and Care Wales to form the One Wales cross-institutional partnership. The One Wales team works together to identify gaps in knowledge and streamline efforts to deliver vital intelligence to help policymakers understand and plan around the issue of Covid-19 in Wales and across the UK.
The study’s authors are Daniel A. Thompson, Hoda Abbasizanjani, Richard Fry, Ronan Lyons, Ashley Akbari, Gareth Davies, Mike B. Gravenor, Lucy Griffiths, Joe Hollinghurst, Jane Lyons, Emily Marchant, Laura North, and Fatemeh Torabi.
This work uses data provided by patients and collected by the NHS as part of their care and support. The study authors wish to acknowledge all data providers who make anonymised data available for research and the collaborative partnership that enabled acquisition and access to the de-identified data, which led to this output.
The collaboration was led by the Swansea University Health Data Research UK team under the direction of the Welsh Government Technical Advisory Cell (TAC) and includes the following groups and organisations: the Secure Anonymised Information Linkage (SAIL) Databank, Administrative Data Research (ADR) Wales, Digital Health and Care Wales (DHCW), Public Health Wales, NHS Shared Services Partnership and the Welsh Ambulance Service Trust (WAST). All research conducted has been completed under the permission and approval of the SAIL independent Information Governance Review Panel (IGRP) project number 0911.