The Chaleur Regional Hospital in Bathurst has confirmed three cases of norovirus within the last two weeks.
Luc Foulem, a spokesperson for the Vitalité Health network, said all three patients came to the facility with symptoms.
They were kept in isolation and tests for the virus came back positive.
The symptoms for the norovirus are typical of stomach flu, although more aggressive. The symptoms include diarrhea, nausea and fever.
Foulem was unable to say whether any or all of the patients are still at the hospital.
The Dr. Georges-L.-Dumont University Hospital Centre in Moncton also had an issue with norovirus in June. The hospital had to suspend public visitation to try to prevent its spread.
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.