Two Maine schools were closed on Monday after significant numbers of students and staff contracted the flu.
Edna Libby Elementary School in Standish and Sanford Christian Academy in Sanford had staff in classrooms cleaning instead of students learning.
"It's unusual, for me, it's the first time I had to do it," said Paul Penna, superintendent of MSAD 6, which includes the Edna Libby School.
At Edna Libby, about 75 youngsters, around 35%, have influenza.
At Sanford Christian Academy, the percentage is the same, but the student and staff body is smaller, with roughly 30 illnesses.
"It progressed all through the week," said Pastor Todd Bell, the school's principal. "Yesterday, we made that decision that this was an outbreak and we needed to deal with it."
The cleanup in Sanford includes wiping down desks and sanitizing surfaces.
In Standish, custodial workers have been "fogging" the building, according to Penna, in addition to sanitizing surfaces.
Edna Libby cafeteria workers are also changing their setup to make it more difficult to share germs.
"We'll change what they do there, so there's less contact between students and the products," said Penna.
If everything goes to plan, both schools will be back open on Tuesday, three full days for the virus to dissipate, with the preceding weekend days are taken into account.
That said, school leaders don't expect the problem to disappear suddenly.
Instead, they have one simple message — if kids have the flu, they should stay home.
"If we're sick, we don't need to be out in the community," said Bell.
The most recent state influenza report from the Centers for Disease Control in Maine was published on Jan. 29. It says the flu is "widespread" in the state, with at least 3,020 confirmed cases this season.