What is the evidence for transmission of COVID-19 by children in schools? A living systematic review

Xu, Wei; Li, Xue; Dozier, Marshall; He, Yazhou; Kirolos, Amir; Lang, Zhongyu; Mathews, Catherine; Siegfried, Nandi; Τheodoratou, Evropi

doi:10.1101/2020.10.11.20210658

Cited by 25 publications

(34 citation statements)

References 40 publications

(97 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These numbers are well in line with other published findings on risk of transmission in schools. [19][20][21][22][23][24] One other study from Germany based on 87 school index cases from the DPHA of Frankfurt calculated a slightly higher but comparable SAR of 1•9%. 19 Other studies from different settings in Australia, Italy, Ireland, and Singapore also report comparable SARs between 0% and 3%.…”

Section: Discussionmentioning

confidence: 99%

COVID-19 transmission in educational institutions August to December 2020 in Germany: a study of index cases and close contact cohorts

Schoeps

Hoffmann

Tamm³

et al. 2021

Preprint

View full text Add to dashboard Cite

Background The lack of precise estimates on transmission risk hampers rational decisions on closure of educational institutions during the COVID-19 pandemic. Methods Secondary attack rates (SARs) for schools and day-care centres were calculated using data from state-wide mandatory notification of SARS-CoV-2 index cases in educational institutions and additional information on routine contact tracing and PCR-testing. Findings From August to December 2020, every sixth of overall 784 independent index cases caused a transmission in educational institutions (risk 0.17, 95% CI 0.14-0.19). In a subgroup, monitoring of 14,594 institutional high-risk contacts (89% PCR-tested) of 441 index cases revealed 196 secondary cases (SAR 1.34%, 1.16-1.54). Transmission was more likely from teachers than from students/children (incidence risk ratio [IRR] 3.17, 1.79-5.59), and from index cases in day-care centres (IRR 3.23, 1.76-5.91) than from those in secondary schools. In 748 index cases, teachers caused four times more secondary cases than children (1.08 vs. 0.25 secondary cases per index, IRR 4.39, 2.67-7.21). This difference was mainly due to common transmission from teacher index cases to teacher contacts (mean secondary cases 0.56 teacher to teacher vs. 0.04 child to teacher, IRR 13.3, 6.6-26.7). Interpretation In educational institutions, the risk of contacts to a confirmed COVID-19 case for infection is one percent, but varies depending on type of institution and index case. Hygiene measures targeting the day-care setting and teacher-to-teacher transmission are priorities in reducing the burden of infection and may promote on-site education during the pandemic.

show abstract

Section: Discussionmentioning

confidence: 99%

COVID-19 transmission in educational institutions August to December 2020 in Germany: a study of index cases and close contact cohorts

Schoeps

Hoffmann

Tamm³

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The prevalence of infections was very low under current protective measures and regulations of authorities so that many children and school personnel would need to be tested to identify single unrecognized cases. And even then it is unclear if such asymptomatic or oligosymptomatic children would infect others as transmission rates are low (33), and outbreaks infrequent and local (34)(35)(36). Instead, acute virus testing of children seems more efficient only if they are at least moderately symptomatic (37).…”

Section: Discussionmentioning

confidence: 99%

“…It seems, that established Swiss procedures with school-based preventive measures (e.g., masks for teachers and children >12 years in the open space of schools, stable class constellations, tapering school breaks, the ban of group events such as school camps, physical distancing in class and teachers' rooms), contact tracing and leaving febrile and/or symptomatic children at home, seem to work in hindering the SARS-CoV-2 spread by and through children in schools. So far, preliminary evidence suggests lower transmission from children to teachers than the other way around ( 33 ).…”

Section: Discussionmentioning

confidence: 99%

Surveillance of Acute SARS-CoV-2 Infections in School Children and Point-Prevalence During a Time of High Community Transmission in Switzerland

et al. 2021

View full text Add to dashboard Cite

Background: Switzerland had one of the highest incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Europe during the second wave. Schools were open as in most of Europe with specific preventive measures in place. However, the frequency and transmission of acute unrecognized, asymptomatic or oligosymptomatic infections in schools during this time of high community transmission is unknown. Thereof, our aim was to pilot a surveillance system that detects acute SARS-CoV-2 infections in schools and possible transmission within classes.Methods: Fourteen out of the randomly selected sample of the Ciao Corona cohort study participated between December 1 and 11, a time when incidence rate for SARS-CoV-2 infections was high for the canton of Zurich. We determined point-prevalence of acute SARS-CoV-2 infections of school children attending primary and secondary school. A buccal swab for polymerase chain reaction (PCR) and a rapid diagnostic test (RDT) to detect SARS-CoV-2 were taken twice 1 week apart (T1 and T2) in a cohort of children from randomly selected classes. A questionnaire assessed demographics and symptoms compatible with a SARS-CoV-2 infection during the past 5 days.Results: Out of 1,299 invited children, 641 (49%) 6- to 16-year-old children and 66 teachers from 14 schools and 67 classes participated in at least one of two testings. None of the teachers but one child had a positive PCR at T1, corresponding to a point-prevalence in children of 0.2% (95% CI 0.0–1.1%), and no positive PCR was detected at T2. The child with positive PCR at T1 was negative on the RDT at T1 and both tests were negative at T2. There were 7 (0.6%) false positive RDTs in children and 2 (1.7%) false positive RDTs in teachers at T1 or T2 among 5 schools (overall prevalence 0.7%). All 9 initially positive RDTs were negative in a new buccal sample taken 2 h to 2 days later, also confirmed by PCR. Thirty-five percent of children and 8% of teachers reported mild symptoms during the 5 days prior to testing.Conclusion: In a setting of high incidence of SARS-CoV-2 infections, unrecognized virus spread within schools was very low. Schools appear to be safe with the protective measures in place (e.g., clearly symptomatic children have to stay at home, prompt contact tracing with individual and class-level quarantine, and structured infection prevention measures in school). Specificity of the RDT was within the lower boundary of performance and needs further evaluation for its use in schools. Given the low point prevalence even in a setting of very high incidence, a targeted test, track, isolate and quarantine (TTIQ) strategy for symptomatic children and school personnel adapted to school settings is likely more suitable approach than surveillance on entire classes and schools.Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT04448717, ClinicalTrials.gov NCT04448717.

show abstract

“…The balance of evidence thus far indicates low overall positivity rates in the school environment (5). A low overall risk of infection among staff and pupils within educational settings have been observed in countries that remained open for face-to-face teaching during the first wave in Spring 2020 in Australia (22) and Sweden (4).…”

Section: Discussionmentioning

confidence: 99%

“…Current evidence suggests that younger children are less susceptible to infection (3) and have considerably milder disease compared to adults (4). SARS-CoV-2 positivity rate within the school setting has been low (3,5) and higher positivity rates are observed in school staff compared to pupils (5). In the UK, enhanced surveillance was undertaken following the reopening of schools during the summer half-term 2020, confirming that whilst overall risk of infection was low among pupils and staff, there was a higher risk of SARS-CoV-2 infection among staff and staff-staff transmission was most common (6).…”

Section: Introductionmentioning

confidence: 99%

Staff-Pupil SARS-CoV-2 Infection Pathways in Schools: A Population Level Linked Data Approach

Thompson

Abbasizanjani

Fry

et al. 2021

Preprint

View full text Add to dashboard Cite

Background: Better understanding of the role that children and school staff play in the transmission of SARS-CoV-2 is essential to guide policy development on controlling infection whilst minimising disruption to children's education and wellbeing. Methods: Our national e-cohort (n=500,779) study used anonymised linked data for pupils, staff and associated households linked via educational settings. We estimated the risk of testing positive for SARS-CoV-2 infection for staff and pupils over the period August-December 2020, dependent on measures of recent exposure to known cases linked to their educational settings. Results: The total number of cases in a school was not associated with a subsequent increase in the risk of testing positive (Staff OR per case 0.92, 95%CI 0.85, 1.00; Pupils OR per case 0.98, 95%CI 0.93, 1.02). Amongst pupils, the number of recent cases within the same year group was significantly associated with subsequent increased risk of testing positive (OR per case 1.12, 95%CI 1.08 - 1.15). These effects were adjusted for a range of demographic covariates, and in particular any known cases within the same household, which had the strongest association with testing positive (Staff OR 39.86, 95%CI 35.01, 45.38, pupil OR 9.39, 95%CI 8.94 - 9.88). Conclusions: In a national school cohort, the odds of staff testing positive for SARS-CoV-2 infection were not significantly increased in the 14-day period after case detection in the school. However, pupils were found to be at increased risk, following cases appearing within their own year group, where most of their contacts occur. Strong mitigation measures over the whole of the study period may have reduced wider spread within the school environment.

show abstract

What is the evidence for transmission of COVID-19 by children in schools? A living systematic review

Cited by 25 publications

References 40 publications

COVID-19 transmission in educational institutions August to December 2020 in Germany: a study of index cases and close contact cohorts

COVID-19 transmission in educational institutions August to December 2020 in Germany: a study of index cases and close contact cohorts

Surveillance of Acute SARS-CoV-2 Infections in School Children and Point-Prevalence During a Time of High Community Transmission in Switzerland

Staff-Pupil SARS-CoV-2 Infection Pathways in Schools: A Population Level Linked Data Approach

Contact Info

Product

Resources

About