Rapid testing was rolled out at the Galloway Community Hospital in Stranraer this week following the emergence of the virus there.
And a deep clean of the premises was carried out, with particular emphasis on the Garrick and Dalrymple wards.
Routine in-patient visiting has been suspended on both wards as a precaution, with some exemptions, and Garrick has been closed to new admissions
Health bosses say that some services at the hospital may be affected by the actions and that anyone impacted will be contacted directly.
