A small number of patients in Western Isles Hospital are currently experiencing diarrhoea and vomiting, and Medical Ward 2 was today closed to admissions.
Visiting hours to the hospital have again been restricted to between 3pm-4pm and 7pm-8pm.
Visitors are asked to wash their hands with soap and water before and after visiting, with only one visitor per patient permitted at any one time.
Visitors are also being urged not to visit more than one ward, to help prevent the spread of infection to other parts of the hospital, and they should not bring flowers or food into the hospital until further notice.
Further, members of the public are being urged to only visit the affected ward where essential. As new cases can potentially arise on a daily basis, you will be advised of restrictions by ward staff.
Members of the public should avoid visiting any healthcare settings if they are experiencing symptoms, which include watery diarrhoea, nausea and vomiting lasting 24 to 48 hours.
Those who have experienced symptoms are asked to wait at least 48 hours after symptoms have stopped before visiting any healthcare premises.
NHS Western Isles Chief Executive Gordon Jamieson stated: "Visiting hours have again been restricted to between 3pm-4pm and 7pm-8pm and we would appreciate the cooperation of members of the public to help prevent the spread of infection within the hospital. Until further notice, we would also appreciate if visitors do not bring flowers or food to patients in the hospital, as a further infection control measure."
Across Scotland, health boards are preparing for the annual onset of Norovirus and the potential closure of wards that may result.
Many parts of Scotland are currently experiencing outbreaks but there is no indication that this year is significantly worse than previous years.