In a statement, the Ministry said the person works at the facility and is not a returnee, so are considered a community case.
The case was reported to the Ministry this afternoon.
It said the person had been tested regularly. They were most recently swabbed on 3 November and returned a negative test the next day.
But the staff member then developed symptoms on 5 November and was tested again that day. That test has returned a positive result.
Contacts of the worker are being traced, isolated and tested.