LITTLETON, Colo. (CBS4) – An elementary school is taking steps to protect students after more than a quarter of them got sick.

The children all attend Normandy Elementary in Jefferson County near Coal Mine and Pierce. The school has managed to stay open throughout the ordeal.

Monday’s absentee rate was an improvement over late last week. The enrollment is 665 students. On Monday only 85 stayed home, but on Friday the number was 180 students.

Parents were alerted to the problem Thursday by email from the principal.

“Sure enough, later Thursday night my little guy was in the bathroom not feeling too well,” parent Rebecca Clark said.

Jefferson County health investigated and quickly suspected an outbreak of norovirus.

“It’s a pretty common virus that we see this time of year. It includes vomiting and diarrhea,” Jody Erwin with Jefferson County health said.

Norovirus is often mistakenly referred to as stomach flu, but it’s not related. Instead, it’s an inflammation of the stomach and intestines.

Norovirous spreads quickly, so on the advice of health experts, steps are being taken to disinfect Normandy Elementary. That means cleaning all permanent surfaces and reinforcing good hygiene.

“It’s a good time to educate yourself and your child on good handwashing,” Erwin said.

Parents commend the school for acting quickly and say the young students are being more careful.

“They don’t want it again, so they’re all about washing hands and keeping a little bit of their distance,” parent Kathy Wilson said.

Norovirus doesn’t last long. Recovery occurs within 48 hours.