WINTHROP — Schools in Winthrop reported their first positive COVID-19 case this week  while Maranacook Community High School in Readfield reported its second.

Superintendent James Hodgkin, who posted an announcement Sunday night to the Winthrop Public Schools website, said the three public schools in Winthrop are operating under the fully remote “red” model until Thursday.

Students are off Wednesday for Veterans Day.

Hodgkin has not disclosed where Winthrop’s first positive case occurred, saying only that steps have been taken to ensure no other students or staff members are at risk.

“We found out late Sunday night, and had to make the best decision — that’s why we closed all of the schools,” he said Tuesday. “We didn’t know at that point if there was potential to have more exposure (in the school system).”

Food packs are being offered at the high school from 12:30 p.m. to 2:30 p.m. through Wednesday.

The occurrence of COVID-19 infection in Maine has been on the rise for more than a week, and the state now has the highest reproduction rate for the coronavirus in the country, according to a website that tracks national case data.

The website rt.live uses public case data to estimate the average number of people who become infected by each infectious person — a key measurement for how quickly the virus is spreading.

If the R number is greater than 1.0, the virus is likely to spread quickly. If it is less than 1.0, infections should be slow to spread.

Maine’s R number is estimated at 1.54, which is greater than all other states.

School officials in Winthrop have released tips on how to stay safe and prevent COVID-19 exposure and transmission during the upcoming holiday season.

Hodgkin advised families to alert school nurses if they plan to travel to a state that is not exempted from the quarantine requirements, and to have an open conversation with nurses on symptoms that may arise.

Hodgkin also reminded families that a negative test within 72 hours of returning to Maine, or a 14-day quarantine, is required upon traveling outside of states approved by Gov. Janet Mills.

Maranacook High School announced its positive COVID-19 case Tuesday afternoon on the school’s website. This is the second case at the high school, with the first case reported Oct. 2.

The announcement, written by Superintendent Jay Charette, reported the infected person had not been in school since Nov. 2, but students are still advised to monitor for symptoms.

The high school will move to remote learning from Thursday until Tuesday, Nov. 17.

Maranacook Community High School is part of Regional School Unit 38. Officials said no other school in RSU 38 had been affected, and the other schools in the district will continue with in-person learning.