1
COVID‐19 Outbreaks in Washington State K‐12 Schools
Washington State Department of Health
December 23, 2022
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Publication Number: 420-312
Executive Summary
•
This report describes COVID-19 outbreaks in K-12 schools that have been reported to the Washington State
Department of Health (DOH) during the 2022/2023 school year.
•
A total of 262 COVID‐19 outbreaks were reported in K‐12 schools between August 1, 2022 and November 30, 2022.
•
1201 COVID-19 cases were associated with outbreaks in K‐12 schools.
•
There may be underreporting of outbreaks due to ongoing limitations of capacity to investigate and report COVID-19
outbreaks in K-12 schools.
Methods
This report was created using information from COVID-19 case data and COVID-19 outbreaks reported by local health
jurisdictions (LHJs) to DOH. The investigation of COVID-19 outbreaks to confirm that an event meets Washington
State’s outbreak definition is time intensive. Therefore, the number of cases and outbreaks reported by a LHJ may
change over time as additional details become available.
Definition of a COVID‐19 Outbreak in Washington State K‐12 Schools
The DOH defines an outbreak in a K-12 school as follows:
•
At least 5 cases within a specified core group
1
meeting criteria for a COVID-19 case from a positive test
OR
•
Multiple COVID-19 cases from positive tests comprising at least 20% of students, teachers, or staff within a
specified core group;
1
•
AND
•
The following three criteria are met:
1. Cases have a symptom onset or positive test result within 7 days of each other,
AND
2. There is no evidence that transmission was more likely to have occurred in another setting (e.g.,
household or outside social contact) outside of the school,
AND
3. Cases were epidemiologically linked
2
in the school setting or a school-sanctioned extracurricular activity
3
.
1
A “core group” includes but is not limited to an extracurricular activity
3
, cohort group, classroom, before/after school care, etc.
2
All groups of 5 cases or 20% within a specified core group that meet criteria 1 and 2 will be presumed to have an epi-link and
must be reported to the LHJ as a suspected outbreak. The LHJ will make the final determination for classifying an outbreak.
3
A school- or child care-sanctioned extracurricular activity is defined as a voluntary activity sponsored by the school, local education
agency (LEA), organization sanctioned by the LEA, or child care. Extracurricular activities include, but are not limited to, preparation
for and involvement in public performances, contests, athletic competitions, demonstrations, displays, and club activities.
2
COVID‐19 outbreaks in Washington State K‐12 schools between August 1, 2022 and November
30, 2022.
The following epidemiologic curve shows the weekly count of the 262 COVID-19 outbreaks in Washington State K-12
schools by week of approximate outbreak start date. Reporting of COVID-19 outbreaks and associated cases for the
most recent months is ongoing, so the number of outbreaks and associated cases may change.
Cases associated with COVID‐19 outbreaks in Washington State K‐12 schools between August 1,
2022 and November 30, 2022.
The following epidemiologic curve shows the week of approximate outbreak start date of the 1201 COVID-19 cases
that were associated with outbreaks in K-12 schools. Cases from a specific outbreak can be spread out over time, so
the cases reported as associated with a specific outbreak may not all have tested positive with COVID-19 or become
sick in the same week that the outbreak was reported. Reporting of COVID-19 outbreaks and associated cases is
ongoing, so the number of outbreaks and associated cases may change.
0
10
20
30
40
50
60
70
80
Number of Outbreaks
Week of Approximate Outbreak Start Date
0
50
100
150
200
250
300
350
Number of Cases
Week of Approximate Outbreak Start Date
3
COVID-19 outbreaks in Washington State K‐12 schools, by county, between August 1, 2022 and
November 30, 2022.
Local health jurisdictions reported 262 COVID-19 outbreaks that occurred in K-12 schools across 18 counties. Of these
outbreaks, 2 started in November 2022. The number of outbreaks by county ranged from 1 to 56. A total of 1201 COVID-
19 cases were associated with these outbreaks. Reporting of COVID-19 outbreaks and associated cases is still occurring,
so the number of outbreaks and associated cases may change
County
Number of
Outbreaks
Outbreaks
occurring in
November 2022
Number of
Associated
Cases
Cases from
outbreaks in
November 2022
Benton
6
0
38
0
Clallam
1
0
10
0
Clark
24
0
111
0
Cowlitz
4
0
17
0
Douglas*
1
0
NA
0
Franklin
6
0
26
0
Grant*
1
0
NA
0
Grays Harbor*
1
0
NA
0
Kitsap*
29
1
110
NA
Pend Oreille*
1
0
NA
0
Pierce
45
0
228
0
Skagit*
8
1
45
NA
Snohomish
56
0
214
0
Spokane
39
0
199
0
Thurston
22
0
98
0
Walla Walla*
1
0
NA
0
Whatcom
16
0
82
0
Yakima*
1
0
NA
0
Total
262
2
1201
NA
4
Characteristics of COVID-19 Outbreaks in Washington State K-12 schools, between August 1, 2022
and November 30, 2022.
Among the 262 COVID-19 outbreaks that occurred in K-12 schools, 245 (94%) were in public schools, and 17 (6%) were
in private schools. Fifty-nine percent of outbreaks involved elementary schools, and 66% impacted classroom settings.
The 52 outbreaks with an undetermined suspected transmission location could have been in classroom, sports,
lunchroom, or other locations, though the data are incomplete.
N
%
Public/Private
Public
245
94
Private
17
6
Grade Level Served*
Elementary
155
59
Middle
66
25
High
62
24
Settings Affected by Outbreak
Classroom
173
66
Performing Arts
4
2
Sports
19
7
Transportation
7
3
Other
9
3
Undetermined
52
20
*Grade level served is not a mutually exclusive category. Percent
reflects the percentage of total schools serving each grade level.
Proportion of K-12 schools reporting COVID-19 Outbreaks in Washington State, between August 1,
2022 and November 30, 2022.
There were 262 COVID-19 outbreaks in K-12 schools between August 1, 2022 and November 30, 2022. The Washington
State Office of the Superintendent (OSPI) education directory lists 2,556 public K-12 schools on their website. Among
these 2,556 public K-12 schools, 160 (6%) have experienced a COVID-19 outbreak since the beginning of the school
year. The Washington State Board of Education licenses 558 private K-12 schools, and among them, 11 (2%) have
experienced a COVID-19 outbreak since the beginning of the school year.
Total K-12 schools
with outbreaks (N)
Total Schools (N)
%
Public
160
2556
6
Private
11
558
2
Total
171
3114
5