Superintendent Carol Cavanaugh emailed schools families Friday afternoon requesting that they check their children for symptoms of COVID-19 and hold them out of school if any exist.

There have been 16 confirmed cases in the district over the past 10 days — 13 of which were at the high school — and Cavanaugh noted that most of the people testing positive entered the schools with symptoms.

Update, March 14: An additional two cases were reported at the high school, according to an email Sunday from principal Evan Bishop.

“A single person’s positive status can result in many, many others being required to quarantine,” Cavanaugh wrote. “Further, a single positive person puts many others at risk. COVID-19 remains a public health crisis; accordingly, the Hopkinton Public Schools need everyone’s participation in mitigating risk and increasing safety for all.”

During Thursday’s School Committee meeting, when the committee voted to have students return to school full-time April 5 (elementary schools) or April 26 (middle/high school), Hopkinton High School principal Evan Bishop said the work toward reopening has been slowed because administrators have had to spend so much time addressing the recent surge in cases.