An interesting study published as a preprint in medRxiv.org looked at this in
17 schools in Wisconsin, America.
The study by Falk and others looked at the specific mitigation strategies employed at these schools during a time of exceptionally high COVID-19 community disease prevalence to discover whether in school transmission was minimal.
5,530 students and staff from 17 schools in four school districts were studied.
The main outcomes and measures were:
- Distancing between primary and secondary students in school.
- School ventilation details.
- Masking among teachers.
- Lunch recess and bussing practices.
89.3% of elementary students included in the study did not maintain a 2 metre physical distance in the classroom and 94.8% were within the 2 metres in lunchrooms.
The majority of the secondary students, 86.2%, were able to maintain some form of distancing in the classroom but no students were greater than 2 metres in the hallways.
58.8% of schools did not install new ventilation systems prior to the school year.
Students ate lunch indoors.
Bussing of students continued and elementary children were allowed to go without masks during recesses.
The results showed that minimal in school disease transmission was reported despite a community test positivity rate between 7 and 41.6% in the 13 week study period.
During this time, the vast majority of elementary schools did not maintain a 2 metre distance between students in classroom cohorts whilst the majority but not all of the secondary schools did.
The results suggested that maintaining a 2 metre distance between students, particularly not at the elementary level, is not required to effectively mitigate in school SARS-CoV-2 spread.
During recess most students did not wear masks or distance and were allowed to play with playground equipment within their cohorts. This has important implications for the wellbeing of children. Recess provides necessary physical activity as well as a break from masking, which may make it easier for children to resume required indoor mitigation strategies.
Opening windows to increase airflow was not commonly done.
Approximately half of the school changed air filtration systems without any obvious detriment to those that did not.
Within the range of mitigation strategies outlined above including nearly universal indoor masking, cohorting and distance as much as possible, there was a minimal transmission amongst students and staff. This was despite a high community disease prevalence at the time.
Of the 191 cases identified in schools during the 13 week study period, only seven cases were determined to be contracted in school and zero cases were contracted by staff in school.
This would suggest that the reintroduction of schooling for our school aged children is not a concern for the increased transmission of SARS-CoV-2.
The London General Practice, however, encourages COVID testing, particularly using the lateral flow antigen test to provide an indication of those who are SARS-CoV-2 positive within any population.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed