Close contacts of a Victorian coronavirus case have started to be traced through the government app, as four aged cares facilities remain in lockdown.
A Victorian health department spokesperson on Wednesday confirmed officials have started using the COVIDSafe app to look for potential contacts of a person who tested positive on Monday.
The patient had the app downloaded and consented to the use of their data to trace people at risk near them.
"Access is strictly limited to trained public health officers carrying out contact tracing functions," the health department spokesperson said.
"With only a small number of cases in Victoria, there have been few opportunities to use the app so far. We hope this continues."
As the government urges Victorians to download the app to help fight the virus, the state's total number of infections rose to 1580 on Wednesday.
Meanwhile, four aged-care facilities in Melbourne remain locked down awaiting coronavirus test results.
HammondCare's Caulfield Village went into lockdown after a resident in its dementia ward tested positive on Monday, before a second swab came back negative on Tuesday.
The woman, 84, had no symptoms or fever and is in good health, HammondCare Chief Executive Dr Stephen Judd told AAP.
"She had a cough and that was the symptom that was seen on Sunday, and out of an abundance of caution, the GP prescribed the test," Mr Judd said.
"We've actually had more than 150 tests, both of residents and also of staff, all of those other tests have come back negative."
Results of the third test of the resident are expected to come back on Thursday.
This follows a similar situation at the Villa Maria Aged Care Home at Bundoora, where a resident who was taken to hospital at the weekend with a fever returned an inconclusive test result.
A subsequent test showed the resident did not have COVID-19.
The facility is in lockdown and the resident is isolating in their room as they await the result of two more tests.
Meanwhile two residents at MiCare facilities Margriet Manor and Overbeek Lodge, both in Kilsyth, have been tested for coronavirus.
The residents had shown "flu-like symptoms", the facility's chief executive Petra Neeleman said in a statement.
Those facilities are in lockdown as MiCare awaits the results.
Another facility told AAP it is in lockdown as it awaits test results for two residents.
A resident at Lynden Aged Care at Camberwell was diagnosed while being treated at a metropolitan hospital, prompting the facility to shut its doors to visitors on Tuesday.
Close contacts of the infected resident have been ordered to quarantine at home, the Department of Health confirmed.
Deputy chief health officer Annaliese van Diemen is expected to give a coronavirus update on Wednesday afternoon.