Clare House. Photo: Karen Pasco
According to a letter sent to residents by chief operations officer Jane Smart, the staff member is in isolation while waiting for her tests to return and will remain there until she is symptom-free.
The letter emphasised that the exposure times of the staff member was limited.
Another staff member had tested positive on a Rapid Antigen Test (Rat) and was isolating while waiting for a PCR test to confirm that result.
Other staff and residents have undertaken Rat tests and received negative results.
Since Friday, staff have been wearing N95 masks and increased personal protection equipment (PPE).
The facility was working with the district health board and public health authorities.
Visitors were temporarily barred from the facility and families encouraged to reach out to residents through digital means, the letter said.
