Editor’s note: This article was updated with the current number of student cases at 10:34 a.m. Wednesday. 

Nearly half the 468 students at Washington Middle School have been kept off campus for two weeks following a possible exposure from four people who were at the school and later tested positive for COVID-19.

The Mehlville School District does not provide details such as whether the people who tested positive were teachers, since that could identify them. But the exposure from the four people was so broad that the district asked an entire cohort of 219 students to stay home. The first case to test positive was a student, and a total of three students have also tested positive, for a total of seven cases related to the outbreak.

“When conducting contact tracing to determine close (or primary) contacts, we err on the side of caution,” Communications Director Jessica Pupillo said.

The district conducts its own contact tracing, with administrators trained through Johns Hopkins University. A primary contact is considered someone who spent 15 minutes within 6 feet of a person who tested positive for COVID-19.

The district does not have the authority to order students or staff to quarantine, but officials do ask primary contacts of someone who tested positive to stay off campus for 14 days following a possible exposure. That is a “critical part of our COVID-19 safety plan,” said Pupillo. “Washington Middle staff are working hard and being flexible to meet the needs of students during this unprecedented time.”

Superintendent Chris Gaines said before schools reopened in person that once they were opened, he would try to close classrooms before schools and schools before the district, with a goal of as few closures as possible.

The district has set up a weekly data dashboard showing how many students and staff are off campus and how many have tested positive.

“At Washington Middle, we reached a tipping point where so many students/staff were identified as primary contacts that out of an abundance of caution, we pivoted how learning was delivered across grade-level cohorts. In this instance, not all of the 218 students asked to remain off campus at WMS were primary contacts. However, we felt it was best for the safety of our students and for instruction to pivot an entire cohort of eighth-graders (last names A-K) to virtual learning for two weeks, almost the entire seventh grade and some sixth-graders to virtual learning for two weeks. The eighth-graders missed four days of in-person instruction and will return to campus on Tuesday, Oct. 27,” Pupillo wrote in an email. “The seventh-graders and sixth-graders missed four days of in-person instruction and will return to campus on Oct. 29 or 30 depending on cohort. These students have been engaging in virtual learning led by their teachers.”