A suspected norovirus outbreak has forced an elementary school in Medford, Massachusetts to close after more than 100 students got sick.

There will be no school for students and staff Thursday, Dec. 11 at the Roberts Elementary School. All other Medford schools are open.

"There were over 130 student absences at the Roberts today, with further students and staff reporting at school today feeling symptoms of an upset stomach," school administrators wrote in a message to students' families on Wednesday. 

"Deep clean" after norovirus outbreak

Professionals will "deep clean" the school while it's closed on Thursday. The Medford Board of Health is also examining the school cafeteria equipment "to rule out any other potential causes," administrators said.

Students and staff will have to make up the missed school day later in the year.

The Board of Health is recommending that anyone who is sick wait 24 hours after experiencing vomit-like symptoms before they return to school.

What is norovirus?

According to the Centers for Disease Control, norovirus is the leading cause of vomiting, diarrhea and foodborne illness in the country.

It is "very contagious," the agency says, and can spread from person-to-person or via contaminated food and surfaces.

The best way to prevent norovirus is to stay away from others if you're feeling sick, and to wash your hands with soap and water for at least 20 seconds. Experts say hand sanitizer is not very effective against norovirus.

The CDC said in late November that norovirus cases were rising around the United States in recent weeks ahead of the holiday season.