The Dr. Georges-L.-Dumont University Hospital Centre in Moncton has confirmed the presence of norovirus in three units and has suspended public visitation to try to prevent the spread.
The visiting ban to general medicine (3A), geriatrics (3E) and rehabilitation (3F) will remain in effect until further notice, officials said in a statement on Thursday.
Several patients and employees in the geriatrics unit began experiencing symptoms of gastroenteritis earlier this week.
Norovirus was confirmed on Thursday.
The hospital is asking visitors to other wards to ensure they wash their hands thoroughly, for at least 15 seconds, with soap and water or an alcohol-based gel upon entering the hospital and upon leaving a patient's room.
Visitors should also proceed directly home once they leave the hospital, officials said.
People who are not feeling well should avoid visiting any patients, they added.
Norovirus — once known as Norwalk virus — is highly contagious and often spreads in places such as hospitals, nursing homes, schools and cruise ships.
The stomach bug causes bouts of vomiting and diarrhea, which can last for a few days.
Norovirus can be spread by sharing food or cutlery with an infected person or by touching objects contaminated with the virus.
There are no drugs to treat norovirus itself, although it is important to drink lots of fluids to guard against dehydration.