Some Montgomery County Public Schools students could again be asked to wear masks as COVID-19 cases increase across the district.

In a message to the community Thursday, MCPS wrote that classrooms or schools that have reported three or more positive cases in the past 10 days could require students and staff members to temporarily revert to wearing masks.

MCPS implemented a universal mask mandate to start the school year, but the school board voted to end the mandate in February.

MCPS is in the middle of its largest surge in cases since a difficult return from winter break in January. At that time, for about three weeks, the district reported hundreds — sometimes more than 1,000 — cases each day. So many students were moved into quarantine that the district’s live online learning platform couldn’t accommodate them all. Dozens of bus routes couldn’t run because too many drivers were out sick. Similarly, hundreds of substitute teacher requests went unfilled every day, prompting some county leaders to question whether the district would be able to stay open for in-person classes.

It did, and by mid-February things had calmed down, with MCPS reporting just a couple dozen cases each day, on average.

The most recent spike in cases started when schools reopened post-spring break in April. MCPS asked all students to take a rapid COVID-19 test, provided by the school district, before returning to classes. MCPS only asked families to report positive tests, and it was not required that students test before returning.

As of Friday morning, 2,379 positive cases were reported across MCPS in the past 10 days. More than 200 cases were reported each day from May 9-12.

About 1.3% of students have tested positive in the past 10 days, according to MCPS data, but some schools’ rates are significantly higher. Forty-six cases have been reported at Sherwood Elementary School in Sandy Spring, equal to about 8.3% of its total population. Twenty-four schools had 3% or more of students report positive tests in the past 10 days.

MCPS this month also stopped contact tracing when positive cases are reported. At the time, MCPS said students — including those who are not vaccinated — would no longer be asked by the district to quarantine after an exposure to the virus.

In its message this week, MCPS wrote that students who are not “up-to-date on their COVID-19 vaccinations or boosters may be required to quarantine.”

The message did not say how such decisions would be made, or how school leaders will differentiate between those who are vaccinated or not.

A school district spokesman could not be reached for comment Friday.

It is not a requirement that students be vaccinated against COVID-19. The exception is that student-athletes must either be vaccinated or have received a medical or religious exemption to participate in sports.

MCPS’ message said the changes to mask use and quarantine procedures are “consistent with Montgomery County Department of Health and Human Services recommendations.”

A spokeswoman for the department and a county spokesman could not be reached for comment Thursday.

On Twitter, Montgomery County Assistant Chief Administrative Officer Earl Stoddard wrote that the Department of Health might recommend masks if a COVID-19 outbreak was confirmed in a classroom or school.

“Beyond that would be MCPS’s decision,” he wrote.

MCPS in April hired its first-ever medical officer, Patricia Kapunan, who is the liaison to the county and state health departments and gives MCPS guidance about COVID-19 protocols.

Caitlynn Peetz can be reached at