Ward 7A at Raigmore Hospital remains closed due to four patients suffering from diarrhoea and vomiting.
The medical ward, was closed on Wednesday last week after two patients became ill.
Testing has confirmed norovirus and a further two patients are now affected.
Norovirus, which causes diarrhoea, nausea and vomiting, spreads in the air where someone has had diarrhoea or vomited and is extremely infectious. It is important that everyone plays their part in reducing outbreak risks.
Dr Jonty Mills, consultant microbiologist for NHS Highland, said: “By restricting visiting to the affected area it helps hospital staff protect the health, privacy and dignity of our patients.
“We would stress that people do not come to the hospital/s to visit if they have, or live with someone who has, had any vomiting or diarrhoea within the previous 48hrs. To further help us limit the spread we would also ask that bringing children in to visit wards within the hospital is restricted as much as possible.”
If you feel that visiting is essential please contact the ward first by phone before coming to the hospital. Please do not visit the affected ward unless by prior arrangement with the nurse in charge.