Stonington — Superintendent of Schools Van Riley informed families on Thursday that a member of the high school community has tested positive for COVID-19.

It was the first positive case in the Stonington school system since schools reopened Sept. 8. After consulting with the Ledge Light Health District, Riley said all schools in the system will remain open.

Separately, a case was reported in the Colchester Elementary School community Thursday.

Stonington

Riley did not say whether the infected person in Stonington is a student or staff member, but the person has been instructed to continue to remain home and has been provided with instructions to follow prior to returning to school.

Riley said the last day the person attended Stonington High School was Sept. 29, when Cohort A was in the school. Like most area school systems, students have been divided up into two groups: Cohort A and Cohort B. Each group is in school two days per week — one on Mondays and Tuesdays and the other on Thursdays and Fridays — and attends class remotely the other three days.

Riley said that upon being notified of the positive case, the school system immediately contacted the health district to begin contact tracing efforts. He said anyone who is considered having been in “close contact” with the infected person, which is defined as being within 6 feet for at least 15 minutes, has been or will be contacted by school or local health officials and provided with instructions on steps to take.

Riley told families the school system will continue to communicate with the community about any positive cases within the school buildings.

“We are monitoring this situation and will continue to work closely with officials from Ledge Light Health District, and will provide you with updates as we know more. If you have questions about your child’s health condition, as always, please contact your physician and keep your school nurse apprised of symptoms,” Riley wrote to families.

Meanwhile, the town announced Thursday that Yale New Haven Health will offer free COVID-19 testing from 9 a.m. to 3:30 p.m. on Friday and Wednesday, Oct. 14, behind the Stonington Human Services Department. No appointments are required. More information is available at http://YNHHS.org or (833) ASK-YNHH.

Colchester

Colchester Superintendent Jeffrey Burt sent a notification to families Thursday, saying that the school district notified the Chatham Health District of the case in the elementary school. “Due to the closure of CES, the student had no contact with staff or students,” he wrote in the notice.

He did not elaborate further, citing privacy concerns, but said the person has been following “medical recommendations to isolate.” The schools are working with the health district staff to conduct contact tracing, he added.

Burt said Colchester schools will continue to remain open at this time, with students being taught in alternating cohorts. “The District will continue to monitor this situation and will use sound decision making based on guidance from the Centers for Disease Control and CHD to maintain safety and continue instruction,” he wrote.

j.wojtas@theday.com