SARS-CoV-2 incidence among teaching staff in primary and secondary schools-Wales, 2020-2021

During the COVID-19 pandemic, face-to-face delivery of education in schools across Wales was disrupted with repeated school closures to limit risk of infection. Evidence describing the incidence of infection amongst school staff during times when schools were open is limited. A previous research study found infection rates were higher in English primary school settings when compared with secondary. An Italian study suggested teachers weren't at greater risk of infection in comparison to the general population. The aim of this study was to identify whether educational staff had higher incidence rates than their counterparts in the general population in Wales, and secondly whether incidence rates amongst staff differed between primary and secondary school settings and by teacher age.

We performed a retrospective observational cohort study using the national case detection and contact tracing system implemented during the COVID pandemic. Age stratified person-day COVID-19 incidence rates amongst teaching staff linked to primary or secondary schools in Wales were calculated for the autumn and summer terms during 2020-2021.

The observed pooled COVID-19 incidence rates for staff across both terms was 23.30 per 100,000 person days (95% CI: 22.31-24.33). By comparison, the rate in the general population aged 19-65, was 21.68 per 100,000 person days (95%: CI 21.53-21.84). Incidence among teaching staff was highest in the two youngest age groups (< 25 years and 25-29 years). When compared to the age matched general population, incidence was higher in the autumn term amongst primary school teachers aged ≤ 39 years, and in the summer term higher only in the primary school teachers aged < 25 years.

The data were consistent with an elevated risk of COVID-19 amongst younger teaching staff in primary schools when compared to the general population, however differences in case ascertainment couldn't be excluded as a possible reason for this. Rate differences by age group in teaching staff mirrored those in the general population. The risk in older teachers (≥ 50 years) in both settings was the same or lower than in the general population. Amongst all age groups of teachers maintaining the key risk mitigations within periods of COVID transmission remain important.