Each year, 20 million people get sick from a common stomach virus. It's usually from close contact with someone who's sick, or food contaminated by a sick worker.

The last place you want to be sick is while you're away from home, but that's unfortunately what happened to a group of local students. It's a field trip of a lifetime for high school students.

The non-profit Close Up Foundation hosts high school students from around the country for hands-on programs in Washington D.C. It's to inspire them to learn and participate in government.

Saturday, 250 students and teachers from six states arrived in D.C. for their week-long conference. However, on Sunday, 17 to 18 local students got sick with a gastrointestinal bug. The symptoms are like the very common norovirus.

"It causes typically, vomiting, nausea, diarrhea, belly pain, sometimes even low grade fever and headaches and so that diarrhea and excessive vomiting could result in dehydration," explained Dr. Fred Lopez, an LSUHSC Infectious Disease specialist.

Dr. Lopez is not in contact with any of the students in D.C. Close Up confirms the students are from Ursuline Academy and one is from Brother Martin. Ursuline confirms that the sick students are all juniors. Brother Martin said it does not discuss medical information of any of its students. The students have been isolated in separate hotel rooms because if it's norovirus, that's highly contagious.

"Usually can be spread by being in close contact with somebody who is sick, sharing utensils with them for example, it can be from contaminated surfaces you touch that are fecally contaminated then you put it to your mouth. It can be from contaminated food or water," said Dr. Lopez.

The students are being treated by Georgetown Pediatricians. Dr. Lopez says it's best to let the virus run it's course and avoid dehydration with drinks like Pedialyte. Some patients could need IV fluids at the hospital. Though hand washing can help lower your risk.

"There's really no antiviral medication to treat this. You have to keep up with your fluids, stay away from other people," Dr. Lopez recommended.

No students at the schools in New Orleans have the stomach virus, so there is no need for concern or decontaminating either Ursuline or Brother Martin. Ursuline tells us that all the parents have of the sick students been contacted.

Norovirus can live on surfaces for two weeks and freezing food doesn't kill it. Neither do hand sanitizers.