Table 3:

School settings where transmission may have occurred for 55 cases of school-acquired SARS-CoV-2 infection^*

Exposure setting	No. of cases		No. (%) of cases
	Grades K–7 n = 35 exposure settings	Grades 8–12 n = 17 exposure settings	Staff only n = 7 exposure settings	All grades n = 59 exposure settings
Class	28 (26 students, 2 staff)	11 (10 students, 1 staff)	2 (2 staff)	41 (69.5)
Office, meeting or staff room	2 (2 staff)	1 (1 staff)	3 (3 staff)	6 (10.2)
Socializing at school	3 (3 students)	2 (2 students)	0	5 (8.5)
Unspecified interaction	0	1 (1 student)	2 (2 staff)	3 (5.1)
Field trip	0	2 (1 student, 1 staff)	0	2 (3.4)
Cohort†	2 (2 students)	0	0	2 (3.4)

Note: K = kindergarten.

^*There were multiple potential exposure settings for some cases; an assessment of which within-school exposure setting was most likely responsible for transmission was not included as part of this study.

^†A cohort is a group of students and staff who remain together throughout a school term, the composition of which is consistent for all activities that occur in schools.