Risk of infection and contribution to transmission of SARS-CoV-2 in school staff: a systematic review

OBJECTIVE: To summarise the comparative risk of infection in school staff and their contribution to SARS-CoV-2 transmission. DESIGN: Systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. DATA SOURCES: MEDLINE, WHO COVID-19 database and preView were searched on 29 January 2021. ELIGIBILITY CRITERIA: We included studies that reported risk of SARS-CoV-2 infection in school staff or transmission of SARS-CoV-2 in school settings. DATA EXTRACTION AND SYNTHESIS: Data extraction was done in duplicates. Data synthesis was qualitative. We report attack rates and infection risk in school settings for staff and students stratified by control measures taken and infection dynamics at the point of data collection. RESULTS: Eighteen studies were included. Three studies in low incidence settings showed low attack rates similar for teachers and students. Five studies in medium incidence settings and two studies in high incidence settings showed secondary attack rates up to 16% in school staff. Seroprevalence studies, two in each low and high incidence settings showed an infection risk of 0%–0.2% and 1.7%–28% for teachers. The risk of infection for teachers compared with students were similar in one study in low incidence setting, higher in three studies (RR 1.2–4.4) and lower in three studies in medium to high incidence settings. The risk of infection for teachers in a high infection environment is higher in face-to-face than in distance classes when compared with general population groups. The risk of infections as well as risk of hospitalisation both increased for teachers during school openings compared with school closure. CONCLUSION: While in low incidence settings there is little evidence for school staff to be at high risk of SARS-CoV-2 infection, in high incidence settings there is an increased risk of SARS-CoV-2 infection in school staff teaching face-to-face compared to staff teaching digitally and general population. PROSPERO REGISTRATION NUMBER: CRD42021239225.