Finals are not the only things making students feel queasy this week.

In the days following Saturday’s holiday dinners — in Commons for freshmen and in the residential colleges for upperclassmen — a slew of students found themselves with food poisoning that resulted in upset stomachs, vomiting and diarrhea.  Although the source of the food poisoning has yet to be officially determined, all students interviewed who fell ill said they consumed seafood, in the form of sushi, over the weekend before becoming sick.

“I was in [Yale Health] myself with food poisoning on Saturday night,” Shelby Baird ’14 said. “While I was there students were calling in left and right about having the same thing. There must have been 25 calls while I was there. The nurses seems to think it had something to do with the seafood.”

Paul Genecin, the director of Yale Health, told the News Monday evening that Yale Health had heard from about 20 students with food poisoning, but that most of them were staying in their dorm rooms and calling Yale Health for instructions on how to deal with their sickness.

According to Genecin, no students required more serious care at Yale-New Haven Hospital. All students interviewed said they recovered within “a couple of days.”

On Saturday evening, 1,200 students were served during the freshman holiday dinner in Commons and 4,200 upperclassmen were served in the residential colleges, according to Cathy Van Dyke, the University Director of Residential Dining.

“Yale Dining has been working collaboratively with Yale Health administrators to find the cause of these incidents and we  continue to monitor the situation,” Van Dyke said. “There has been no indication that food served by Yale Dining has been the source of these issues.”

Nevertheless, there are indications that sushi may be the main cause. Sushi was served at the freshman dinner and as an appetizer before the holiday dinners in the residential colleges. According to Van Dyke, Yale Dining gets its sushi from from an out-of-state commercial supplier.

Several other students who went to Sushi Mizu on Whalley Avenue also became sick over the weekend. Sushi Mizu could not be reached for comment on Wednesday.

The New Haven Department of Health is responsible for inspecting and licensing restaurants in the city to ensure they meet sanitary conditions. Shellie Longo, the Senior Sanitarian at the Department of Health, said Wednesday that she could not disclose whether the department had initiated an investigation of the sushi restaurant.

Furthermore, at an event for students working in the Admissions Office on Friday evening, several students who ate sushi provided also fell ill. The events organizers could not be reached to comment on the source of the sushi.

Shannon Farrell ’15, who works in the Admissions Office and was at the event, said that she was sick for about two days after consuming sushi on Friday evening, but has since recovered. Farrell said that most of the other students at the event also fell ill.

Yale Dining serves over 14,000 meals per day.