School officials say they believe nearly half of the student body at one Ohio elementary school is infected with the norovirus, Fox 19 reports.

Public health authorities said Wednesday that 100 to 200 students at Mt. Airy Elementary School in Cincinnati have caught the stomach virus.

Dr. Marilyn Crumpton, a medical director with the Cincinnati Health Department, said the school nurse first noticed the health issue two weeks ago, after about 20 students a day complained of symptoms.

The school nurse collected samples, and the state confirmed the strain was the highly contagious norovirus.

The Centers for Disease Control reports anyone can get norovirus, and they can have the illness multiple times during their lifetime.

Norovirus is the most common cause of acute gastroenteritis in the U.S., and is commonly spread on cruise ships.

The CDC says people with norovirus are contagious from the moment they begin feeling ill to at least three days and perhaps for as long as two weeks after recovery, making control of this disease difficult.

Symptoms include vomiting, diarrhea and cramps.

"We have been disinfecting surfaces and disinfecting the whole school," Janet Walsh, spokesperson for Cincinnati Public Schools, told the station. "We're also appealing to parents to help us because we don't want kids to come back too soon. That would put other students at risk and prolong the virus outbreak."

Click here to read more on the norovirus outbreak at Mt. Airy Elementary School from Fox19.com