One of the most important and adopted safety measures for the prevention and containment of COVID-19 has been the implementation of physical distancing when outside of one’s home. Physical distancing (also known as social distancing) is the act of distancing oneself from others whenever possible, by staying at least 2 metres (or 6 feet) away from other people who are not in your household [1]. Minimizing close contact with others will potentially help to slow down the spread of COVID-19 from person to person. Additionally, physical distancing calls for avoiding large and non-essential gatherings, limiting contact with those who are most vulnerable and who have pre-existing underlying health conditions, staying home whenever possible and especially when sick, and avoiding handshakes or hugs in the form of greetings. Overall, the practice of physical distancing, in addition to frequent hand hygiene and the use of masks, has been shown to play a major role in controlling the spread of COVID-19 amongst individuals within a community.
A cohort is a small group of individuals who are able to interact with one another regularly that might not always be able to maintain physical distance. Members of a cohort are required to stay 2 metres apart when interacting with each other, but if distancing is not possible then masks are required. Smaller cohorts allow for physical distancing. Cohorting reduces the amount of people that an individual may come in contact with, aids in the process of contact tracing in the event a member of a cohort contracts the virus, and hopefully limits the spread of the virus only to the people within the same cohort.
Physical distancing, in addition to frequent hand washing and the usage of masks, plays an important role in reducing the transmission of COVID-19 from person to person. COVID-19 transmits from one person to another when they are in close contact. Specifically, the virus tends to spread when an infected individual sneezes, coughs, or talks, releasing water droplets containing the virus into the air which can be inhaled into the airways of an individual in close proximity. A person infected with COVID-19, whether asymptomatic or symptomatic, can transmit the virus to other people. It is believed that each individual infected with COVID-19 passes the virus to approximately 2-3 people on average. In a recent study conducted in Nanjing, China, 24 asymptomatic carriers of COVID-19 (that ranged in age from 5- 95 years old) transmitted the virus to their household members who developed severe symptoms of viral pneumonia.
It is important that every individual plays their part in practicing physical distancing and maintaining consistent cohort groups to slow the progression of the virus as the virus has been found to spread immensely when individuals are in close proximity to one another. Cohorting and physical distancing play a role in our social gatherings with friends, in our workplaces, and within schools and child care centres.
Physical distancing and cohorting are safety measures that have been greatly implemented within educational settings across the entire world. Following lockdown restrictions for several months, which led to the full closure of schools across the globe, cohorting and physical distancing have been shown to be a prominent mitigation strategy that has been put to the test substantiallyby various countries around the world, including Denmark, Germany, Norway, France, Greece and Albania. As countries around the world have already reopened schools amidst the COVID-19 pandemic, cohorting has been a mechanism in use to socially isolate small class groups and minimize interactions among multiple students and teachers within schools.
Countries such as Denmark and Germany have adopted a school reopening model that reopened schools in phases and continues to strongly implement the isolation and distancing of cohorts consisting of 10-15 students in classrooms with one teacher. The cohorts implemented within schools across Europe follow specific protocols and guidelines: multiple cohort groups are not allowed to come into close contact with one other, cohorts have to arrive at school at different times and within different entrances. Additionally, staggered lunch/break times are implemented throughout the day for each cohort, and cohorts also have specified regions/zones to play in during recess, promoting physical activity for students particularly in the younger grades. All of these implications in conjunction with frequent handwashing has been proven to be very successful in Denmark, resulting in an increase in students attending in-class learning, in comparison to when schools first originally reopened in Denmark following the lift of lockdown restrictions on April 15th, 2020. To further promote physical distancing protocols within classrooms, multiple schools in Europe and Asia have arranged classrooms so that desks are 2 metres apart.
Currently in Canada, it is unfortunate to see that most provinces have not had these same standards for physical distancing and cohorting in schools. Many provinces are only recommending 1 metre distancing, which likely cannot even be achieved as elementary school classes are re-opening without cohorting.
Ryan Imgrund, a biostatistician who calculates the Rt value of COVID-19 for Ontario, illustrates how smaller class sizes/cohorts matter. Taking into account the active cases on a particular day, he calculates the Rt values for public health units in Ontario, and demonstrates how the chances that at least one student or teacher can transmit COVID-19 increases as the size of the cohort increases.
This table was last updated on Sept. 5, 2020.
If you would like to see changes so that class sizes are reduced to cohorts of 15 students maximum and physical distancing of 2 meters is required in order for our children and students to have a safer school year, please write to your Premier, Minister of Education, and School Board Trustees and Director of Education. See our Calls to Action for email templates. If you are in Ontario, you can follow Ontario SAFE and write to your representatives.