Corner Canyon High in Draper is moving to a hybrid schedule of remote and in-person instruction after 15 or more coronavirus cases were reported at the school — a departure from state health guidance advising schools to go all-virtual if they experience an outbreak of this size.

It’s not clear how many coronavirus cases are associated with the high school, but the Salt Lake County Health Department is reporting there have been at least 15 in the last 14 days.

“Once a school hits 15 or more, then our recommendation from a public health standpoint is to go 100% virtual, as the state school manual advises,” county health department spokesman Nicholas Rupp wrote in a text message Saturday. “But it’s up to the school district. They are very concerned about it as well and have been very responsive."

Corner Canyon High’s one-week switch to a hybrid schedule is meant “to keep students in school while also reducing the number of students in the building on school days,” according to an announcement posted Friday on the Canyons School District website. The message described a “sudden increase” in COVID-19 cases but didn’t give an exact number.

No students will attend school Monday, as teachers, administrators, staff and families prepare to switch to a blend of remote and in-person learning, the announcement states.

Students whose last names begin with the letters A through K will attend classes in person Tuesday and Wednesday, while the rest will head to school Thursday and Friday. When students aren’t present at school, they’ll participate in remote learning.

District officials hope to resume all in-person classes Sept. 21, although those plans could change if the number of coronavirus cases continues to rise. The announcement states that “there has been no clustering of cases on the Corner Canyon High campus” and that no classrooms have had to be placed on quarantine.

Rupp said that means Corner Canyon High’s cases are spread across the school and there haven’t been any classroom-based clusters.

State health officials have advised schools to shut down completely for two weeks if 15 or more individuals test positive for COVID-19 in the same time frame. Individual classrooms should go online if three or more people contract the disease, according to the health guidance.

The state defines an outbreak as “two or more cases associated with a setting outside of the household within 14 days.”

County health officials had two calls with school district leaders Thursday, “trying to work through the cases and help them make the best decisions,” Rupp said.

In its announcement, district officials encouraged parents to monitor their family for COVID-19 symptoms and contact a health provider if they notice their children start to fall ill.

“Now, more than ever, it is important that we observe physical distancing recommendations and wear face coverings while on campus or participating in after-school activities,” the announcement stated.