POLAND — Regional School Unit 16 shut down all of its schools Monday and shifted everyone to remote learning for three days after a student at Poland Regional High School tested positive for COVID-19.

In a letter to staff members and parents, Superintendent Kenneth Healey wrote Monday that the school system was closing all schools in Poland, Minot and Mechanic Falls for cleaning “out of an abundance of caution,” and to help prevent spread of the virus.

He said the infected student was part of cohort B at the high school. Poland Regional High School shares its building with Bruce M. Whittier Middle School.

Cohort A students will now be taught remotely Tuesday and Wednesday. Cohort B students will be taught remotely Thursday and are to return to school Friday.

Families needing meal deliveries during the shutdown and not already receiving them should contact the food service director, Ellen Dore, at edore@rsu16.org.

Healey asked parents to monitor themselves and their children for signs of the virus, including fever or chills, cough, shortness of breath or difficulty breathing, headache, new loss of taste or smell, sore throat, muscle or body aches, congestion or runny nose, nausea or vomiting, diarrhea and fatigue.

The Maine Center for Disease Control & Prevention or a school representative will contact staff or students who may have been in close contact with the student who tested positive, according to Healey.

Close contacts will be asked to quarantine for 14 days, regardless of a negative test.