At least 37 people reportedly fell ill Saturday evening while at the Delta Delta Delta sorority house on Tappan Street in Ann Arbor.
University spokesman Rick Fitzgerald said three people were transported to the hospital via ambulance and three others visited the hospital of their own accord.
They were all treated and released that night, Fitzgerald said, adding that the students have been advised to stay at home until they feel better.
Out of the 37 affected, one or two of the people do not live at the Delta Delta Delta house, Fitzgerald said.
Fitzgerald added that while at first the illness was speculated to be severe food poisoning, officials now believe that it may be norovirus, which often gives rise to stomach flu. Symptoms typically manifest suddenly between 24 to 48 hours after the initial infection.
According to documents issued by the Washtenaw County Public Health Department, the stomach flu runs its course in two or three days but is communicable to healthy individuals for up to two weeks.
Fitzgerald went on to say that the health department took the lead on this case, because the sorority house is off-campus. They will conclude tests and be able to confirm the cause of the illnesses within the week, he said.
For now, the health department is conducting interviews of those affected by the illness and taking inventory of what the people ate in order to figure out the cause of contamination, Fitzgerald said.
The sorority house — located at 718 Tappan St. — has been thoroughly cleaned and the University has advised students to stay away from others who are sick, wash their hands and cover up their mouths when they cough in order to minimize contamination.
Chapter Advisor Susan Lucus wrote in an e-mail interview that sorority officials are not sure yet what caused the sicknesses.
Taylor Robinson, a sophomore in Delta Delta Delta, said the members of the sorority have been asked not to comment on the issue until they know more.
As of yesterday afternoon, Fitzgerald said there were no new cases reported.
The last major outbreak of norovirus occurred at the Ross School of Business shortly after the completion of its construction in January. Ten people who had eaten at the Siegle Café and 13 of the café’s workers fell ill and reported intestinal and stomach issues characteristic of the virus.