Visitation has been restricted on a unit at Bon Secours DePaul Medical Center this week because of an outbreak of norovirus, a highly contagious stomach bug that causes vomiting, diarrhea and fever.

Lynne Zultanky, spokeswoman for the hospital, said staff identified the symptoms of norovirus in patients on a transitional care unit on Friday, and the diagnosis was confirmed by the Norfolk Department of Public Health on Monday. She said a dozen patients were identified with symptoms of norovirus, along with 10 staff members.

No further admissions are being made to the transitional care unit, and no visitors have been allowed on that unit. Zultanky said the hospital is working with the health department to prevent the spread of the virus.

John Monroe, epidemiologist with the Norfolk health department, said the restrictions will be in place until three days have passed with no new illnesses.

Norovirus is a viral illness that can cause nausea, vomiting, diarrhea, stomach cramping, low-grade fever, chills, headache, muscle aches, and tiredness. It usually lasts one or two days and rarely has complications.

Larry Hill, spokesman for the eastern region of the Virginia Department of Health, said norovirus outbreaks are more common in late fall, winter and early spring because people congregate together, making the virus easier to spread, particularly in nursing homes, assisted living facilities, day care centers and schools.