Chapel Hill, N.C. — Norovirus has spread across the University of North Carolina at Chapel Hill campus in recent days, leaving dozens of students with flu-like symptoms, health officials said Monday.

Students have sought medical attention for vomiting, nausea, diarrhea and fever since last week, said Stacy Shelp, spokeswoman of the Orange County Health Department. The number of cases has declined since hitting a peak Wednesday and Thursday, she said.

Only five new cases were reported Monday.

"Generally, it has been a mild and self-limited illness," said Dr. Mary Covington, executive director of UNC Campus Health Services. "They feel terrible while it is happening, but they soon get better and start to get back to normal within a day or two."

About 85 students were given surveys to help the health department and Campus Health Services determine the cause of the illnesses. The surveys focused mostly on what the students had eaten in recent days and helped eliminate residence halls, cafeterias and local restaurants as the source.

Samples from some of the afflicted students tested positive Monday for norovirus. The state lab found no positive results for salmonella, E. coli or other bacteria, officials said.

Campus Health Services issued an alert Thursday advising the public about the illness and urging people to maintain good hygiene and stay home if they feel sick.

Covington said officials are working with campus housekeepers and dining hall workers so that they use bleach products to disinfect instead of cleaning solutions. The bleach will kill the highly contagious norovirus.