A surge of stomach flu cases at Princeton University appears to be confined to the campus. While some cases of gastroenteritis have cropped up at public and private schools in the area, none are reporting the kind of outbreak being experienced at the University, where some 51 cases have been registered since January 8.

“We’re up to about three people a day visiting the infirmary with symptoms,” said spokesman Daniel Day, the University’s director of news and editorial services. “But relative to last year, it is not as intense.”

Last year, the University reported at least 288 students with the intestinal illness including 80 who got sick the week of February 10-16. That was the largest outbreak of the virus in 10 years, and the campus infirmary had to send sick students to the University Medical Center at Princeton when it ran out of beds.

A Campus Health Advisory from University Health Services was issued last Friday to undergraduate students. According to The Daily Princetonian, the New Jersey Department of Health and Senior Services confirmed that samples taken from some cases tested positive for norovirus, which is the most common cause of gastroenteritis. Students were emailed about the presence of the virus and given advice on how best to avoid it.

Calls to area public and private schools confirmed that the increase in cases is confined, for the most part, to the Princeton University campus. “We’ve had normal absences for this time of year, with no outbreak,” said Lew Goldstein, the assistant superintendent of Princeton Regional Schools. “We’re dealing with flu and stomach flu symptoms here and there, but so far nothing of a major concern.”

Westminster Choir College of Rider University is currently on a break, eliminating concerns about the virus. Spokespersons for private institutions including Stuart Country Day School, Princeton Day School, The Lawrenceville School, and The Hun School said cases of the virus are isolated.

“We don’t have any kind of an outbreak, but I think the school is probably being affected much like other schools in the area,” said Kathryn Rosko, communications director at Princeton Day School. “Some people are out with the flu, some with the stomach bug. But of course we’re encouraging people to wash their hands and to stay home if they feel ill.”

Symptoms of norovirus, which is common in confined spaces such as dormitories and cruise ships, include nausea, vomiting, intestinal distress, and lethargy. It is transmitted through contaminated food or water and person-to-person contact.