Otago health officials are on high alert after a new suspected outbreak of norovirus closed two wards at Dunedin Hospital yesterday.
The wards have been closed to new patients and visitors after nine patients and three staff members fell ill with vomiting and diarrhoea on Sunday.
At least one scheduled surgery was also postponed as a result of the illness.
Otago District Health Board infection prevention and control charge nurse manager Jo Stodart said a surgical ward in the hospital was closed due to norovirus last week but was reopened on Thursday.
Ms Stodart advised people who experienced vomiting or diarrhoea to stay home for at least two days after the symptoms disappeared as they could still be infectious.
She said strict adherence to hand hygiene was still the most important prevention strategy of contracting the highly contagious virus.