By CBSBoston.com Staff

BOSTON (CBS) – There have been 669 new COVID-19 cases among students and staff in Massachusetts schools in the last week, according to the latest data from the Department of Elementary and Secondary Education.

That’s 146 more total cases than the previous week, an increase of nearly 22-percent.

READ MORE: Return To The Classroom: Massachusetts Sets Deadlines For Elementary, Middle Schools To Shift To In-Person Learning

Districts, collaboratives and special education schools reported 476 cases among students and 193 among staff members between March 11th and March 17th.

Schools are not required to report positive cases to the state.

Since September 24th, when the weekly release of data started, 8,010 students and 5,039 staff have tested positive.

The weekly report released every Thursday shows the number of positive cases for students who are in hybrid or in-person models. It does not include students in remote-only programs.

READ MORE: Schools Have ‘More Than Enough Time’ To Prepare For Return To In-Person Learning, Riley Says

Overall, the state estimates there are about 450,000 students and 75,000 staff in Massachusetts public schools.

Although the number of high-risk towns increased this week to 20, many of the school-reported cases were not in those towns.

Some of the school districts with the highest number of cases were Andover (8 students), Barnstable (9 students, 3 staff), Braintree (26 students), Brockton (4 students, 16 staff), Canton (9 students, 1 staff), Dennis-Yarmouth (12 students, 1 staff), Framingham (9 students, 2 staff), Hanover (6 students, 2 staff), Methuen (9 students, 1 staff), Melrose (7 students), Milford (9 students, 1 staff), North Attleboro (12 students, 1 staff), Quincy (11 students, 5 staff) and Shrewsbury (8 students, 3 staff).

Of those, only Barnstable, Methuen and Yarmouth also were listed as high-risk towns.

Elementary and Secondary Education Commissioner Jeffrey Riley is requiring elementary schools to have “full-time, in-person instruction five days per week” starting Monday, April 5. Middle schools will have to do the same by Wednesday, April 28. A date has not yet been set for high schools.

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For the district breakdown on coronavirus cases, visit the DESE website.

CBSBoston.com Staff