A small number of staff quarantined after a COVID-19 exposure in one of Canberra Hospital's wards could return to work on Thursday.
A person presented to hospital on September 18 for a procedure while they unknowingly had COVID, Canberra Health Services chief executive Dave Peffer said on Saturday.
The patient shared a room with another person in ward 10A who contracted the virus, with both testing positive on Friday.
Staff linked to the COVID-19 exposure were classified in three categories: low, moderate and high risk. High-risk workers must quarantine for 14 days and are unable to return to duties.
Staff who were at a moderate risk have to quarantine at home for 14 days, but will be permitted to return to work on day five if they return a second negative test.
They will not be permitted to be out in the community during this 14-day period.
A small number may return to work on Thursday, but under strict conditions, which include wearing an N95 face mask and face shield, as well as other hygiene measures.
They will also need to return a negative COVID-19 test every 72 hours.
On Tuesday, Health Minister Rachel Stephen-Smith said there were three cases associated with the cluster, and the ward remained in lockdown.
"There are about 40 doctors and nurses in quarantine for between five and 14 days based on their risk of exposure," she said.
"I think that number has actually increased a little bit over the last couple of days as more investigation has been undertaken after the third person tested positive."
Ms Stephen-Smith said it looked as though the infection prevention and control measures in place, and the good use of personal protective equipment in the Canberra Hospital had worked.
"The fact that we have seen well over 200 staff and patients tested negative so far I think is a good indication of the processes that are in place at Canberra Hospital and their effectiveness."
