More than one hundred students, faculty and staff on Georgetown University’s campus have reported nausea, vomiting, diarrhea and stomach cramps — all symptoms that could be consistent with norovirus, officials said Monday.

University leaders first reported the gastrointestinal illness Sept. 21, after about 12 students on the main campus in Northwest Washington reported severe stomach pains, vomiting and diarrhea. Days later, that number grew to 90 and “fewer than 15” people had been transported to emergency rooms, officials said. As of Monday, 130 students and employees had reported some combination of symptoms.

Testing from two stool samples revealed norovirus — a contagious family of viruses — could be the culprit behind the illness, officials said Friday. But it remains unclear how the illness got on campus in the first place, said Ruth McBain, a spokesperson for the university.

Georgetown students and employees have been instructed to practice good hygiene and social distancing as officials try to identify the outbreak’s source.

“We are continuing to take appropriate steps to respond to the needs of our community and to prevent the spread of the virus,” officials said in a message to the community. “We are in regular contact with DC Health and continue to follow its guidance.”

Norovirus symptoms typically appears between 12 and 48 hours after exposure; most people recover within three days, officials said. In most cases of the gastrointestinal illness identified on campus, symptoms improved after 12 hours and individuals did not need any medical treatment.

Officials said the university is trying to keep the illness under control. Facilities crews spent the weekend sanitizing common areas in residence halls and the rooms of sickened students. Dining facilities are being cleaned regularly and, following a visit from the D.C. health department, the areas have been deemed safe to remain open.

Out of an abundance of caution, prepackaged and prewashed foods commonly associated with foodborne illnesses have been removed from dining facilities, officials said.

The university is advising students with and without symptoms to limit social gatherings — advice reminiscent of the guidance doled out to prevent the spread of the coronavirus. The campus reopened this semester after the pandemic forced it to close in March 2020.

The campus has managed to keep coronavirus cases relatively low, reporting 184 cases among students and employees across all of its campuses and maintaining a weekly test positivity rate below 1 percent since the first week of classes.