School was canceled Tuesday for St. Charles East High School in St. Charles, Illinois. The suburban high school also closed early on Monday.

According to WGN-TV, it all started over the weekend, when ten out of the 14 players on the Boy's Varsity Basketball team fell sick and couldn't play in Saturday night's game. A spokesman for the district, Jim Blaney, says it was then learned that multiple students across sport teams were ill.

That's when school principal, Dr. Charlie Kyle, sent an email to parents explaining the situation and asking them to respond as to whether child was ill and if so, what were their symptoms. There was an overwhelming response of information, and school officials learned that multiple students had similar symptoms.

As WGN-TV put it, however, it wasn't until Monday morning that the “full scope” of the illness came to light.

On Monday morning, 800 out of 2,500 students at the school were absent. According to WGN-TV, it's the worst outbreak in the school's history.

Blaney said officials suspect it's the norovirus — a common and highly contagious stomach bug — as student's symptoms were consistent with the illness. However, the exact cause has not been confirmed.

What is the norovirus and is it contagious? The CDC writes that anyone can get the norovirus from “an infected person, contaminated food or water, or by touching contaminated surfaces.” The CDC lists a pretty common sense approach to prevent catching the virus, and number one at the top of their list is hand washing.

Hand washing cannot be underestimated, as the norovirus is primarily spread, as the CDC explains, “through the fecal-oral route.”

Next on the prevention list is washing fruits and vegetables thoroughly and making sure seafood is properly cooked; if you are sick, do not prepare food or care for others; clean and disinfect contaminated surfaces; and lastly, thoroughly wash laundry that may be contaminated.

Although the norovirus can be serious for some people, it's fairly common, causing 19-21 million illnesses across the United States every year. However, its frequency does not mitigate the havoc wreaked on households when it strikes. As one mother explained to Independent Journal Review:

"My whole family came down with it once. I've never seen anything like it. One moment we were out at lunch, and then hours later, no one wanted to stray more than 10 feet from the bathroom. It was nothing but laundry and dry toast for days afterwards. The TV was stuck on TLC for hours on end because pushing the channel change button on the remote took too much strength.

It's actually still a haze. If I were ranking the worst mom challenges, it would go: 1. Super Lice 2. Norovirus 3. Consecutive C-sections."

The Daily Herald reports that St. Charles East consulted with the CDC and changed the cleaning solution used across the school to bleach. No word on whether classes have been cancelled for Wednesday.