By Christina Hager

MEDFIELD (CBS) – A year ago, it would have been strange to see students swabbing their noses in a high school hallway. “Five circles in each nostril and they’re done, so they know the drill,” said Medfield Superintendent Jeffrey Marsden.

“The idea is all the kids take a self-swab and they put it into one tube, and so that tube is that classroom,” explained Matthew McKnight, of Ginkgo Bioworks, the Seaport District company that runs COVID-19 pool testing in schools. “So you test the tube, and you get an answer for that group of students.”

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U.S Representative Jake Auchincloss toured Medfield High School Thursday, as positive cases in Massachusetts schools creep up. The state reported 821 positive COVID cases among students this week and 157 cases among staff members statewide.

Medfield is an exception. “We have almost 80% of our classes and staff participate, and we have yet to find a positive student in our school testing,” said school nurse Brittany Hardiman.

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Even though Medfield’s numbers have improved, there is concern around April vacation, and students returning after travel, with variants spreading across the country. “We’re looking at doing additional tests that week, Monday, also Thursday, just to see if we find it,” said Superintendent Marsden.

Sudbury school officials share the same concern. They’re offering drive-through testing for kindergarten through 8th grade students during April vacation.

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These precautions come as Massachusetts schools start to fully reopen. Medfield High School students return full-time Monday, and soon state officials are expected to announce when all Massachusetts schools have to do the same.

Christina Hager