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

Abstract

ObjectiveTo summarise the comparative risk of infection in school staff and their contribution to SARS-CoV-2 transmission.DesignSystematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline.Data sourcesMEDLINE, WHO COVID-19 database and preView were searched on 29 January 2021.Eligibility criteriaWe 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 synthesisData 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.ResultsEighteen 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.ConclusionWhile 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 numberCRD42021239225.

Epidemiology of SARS-CoV-2 infection among staff and students in a cohort of English primary and secondary schools during 2020–2021

“…38 , 39 Studies in Germany, 40 Norway, 41 Australia, 42 the UK, 43 , 44 and the USA 45 , 46 have all concluded that, with mitigations in place, the overall risk of transmission in schools was limited. A systematic review of the risk of transmission involving school staff found mixed evidence, 47 while other evidence from England suggests similar infection (ONS-CIS) and antibody rates (SIS) compared to working age adults. 29 A study in Italy also found antibody rates rise in teachers over the school year but concluded that school opening did not “amplify transmission”.…”

Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data

“…Based on population-level observational data, the cumulative risk SARS-CoV-2 infection among students in Germany was shown to be between 1% and 10%, depending on the phase of the pandemic [ 12 ]. A systematic review concluded that the risk of infection following a SARS-CoV-2 outbreak in a high-incidence setting was 1.7–28% for school teachers, which was usually higher than for students [ 58 ]. Furthermore, seroprevalence was 2.1–6.2% in Swiss schoolchildren (aged 6–16 years) during June-September 2020 [ 59 ], and 0–7% in rural and 11–29% in urban South African adolescents (aged 13–18 years) during July-September 2020, respectively [ 60 ].…”

Increased transmissibility of SARS-CoV-2 alpha variant (B.1.1.7) in children: three large primary school outbreaks revealed by whole genome sequencing in the Netherlands

“…Earlier studies on outbreaks in schools with the wild type original strain suggest transmission between staff members and staff-to-child plays a dominant role in transmission with low child-to-child transmission [ 9 ]. A meta-analysis determined that school staff have an increased chance of being infected compared to the general population [ 10 ]. While a higher AR observed among staff members compared to children suggests that staff-to-staff transmission played an important contributory role, we found ample evidence of child-to-child transmission, likely due to increased infectiousness of the alpha variant in children.…”