March 25, 2021

In-Person Schooling and COVID-19 Transmission in Canada’s Three Largest Cities

Category: Article Summary

Topic: Non-Pharmaceutical Interventions

Keywords (Tags): canada, non-pharm interventions, schools

• [Pre-print, not peer-reviewed] Mandatory in-person instruction without universal mask mandates may contribute to increased community transmission of SARS-CoV-2, according to a comparative case study that examined weekly incidence among children ages 0-19 years in Canada’s three largest cities from August 2020 to January 2021. The highest incidence among children ages 0-19 years by the end of the study period was observed in Montreal, where mask mandates were delayed as late as January 2021 in elementary schools. Trends show that incidence among adults 30-49 years old were preceded by increases among school-aged children, suggesting in-person schooling may have contributed to community transmission. In contrast, no such patterns exist in Toronto and Calgary, where mask mandates were implemented at the beginning of the school year. [EDITORIAL NOTE: Uncontrolled ecological comparisons such as this are limited in their ability to attribute differences in incidence between cities to a specific policy.]

Bignami et al. (Mar 23, 2021). In-Person Schooling and COVID-19 Transmission in Canada’s Three Largest Cities. Pre-print downloaded Mar 25 from https://doi.org/10.1101/2021.03.21.21254064