Gisborne Hospital is asking all visitors to stay away as it deals with a suspected Norovirus outbreak.
Tairawhiti District Health says 11 patients are suffering from vomiting or diarrhoea which it suspects is Norovirus, but it is waiting for laboratory results fo confirmation, due on Saturday morning.
Medical Officer of Health Geoffrey Cramp said on Thursday the priority is to limit the number of cases and protect vulnerable patients.
As a precautionary measure, clinical staff are wearing masks and gowns to deal with patients showing symptoms.
Dr Cramp says excellent hand hygiene such as washing hands is crucial to stopping infectious diseases such as Norovirus. It is easily spread on contaminated hands and objects, or food and drink.
He says it is vital people who have recently been unwell or are even just feeling sick do not come to the hospital.
Those who require emergency treatment are still being admitted.