Three Melbourne aged-care facilities are in lockdown after residents tested positive, then negative, to coronavirus.

Hammond Care nursing home at Caulfield, in Melbourne’s south-east, went into lockdown on Monday after a resident in its dementia facility tested positive to COVID-19, before a second swab came back negative.

General manager Angela Raguz said the facility was treating the patient as a positive case while the Department of Health investigated.

“We’re erring on the side of caution,” she told 3AW radio on Tuesday, noting all staff were being tested.

“We’re up in the air a little bit, to be honest.”

The radio station also reported a home in Camberwell, in Melbourne’s east, was another in lockdown after a positive virus test for one resident.

Lynden Aged Care in Camberwell wrote to residents’ families on Monday to alert them to the situation, 3AW said.

The home was testing and tracing residents and staff on Tuesday.

Both cases follow a similar situation at the Villa Maria Aged Care Home at Bundoora, in Melbourne’s north. A resident from the home was taken to hospital at the weekend with a fever but returned an inconclusive COVID-19 test result.

The resident was one of six new coronavirus cases announced in the state on Monday, as Victoria’s Department of Health treats all inconclusive results as positive.

But a subsequent test showed the resident did not have COVID-19.

As a precaution, the facility is in lockdown and the resident is isolating in their room as they await the result of two more tests.

All staff and residents will be tested in coming days and contact tracing is underway.

Meanwhile, 12 McDonald’s outlets were closed after visits from a coronavirus-infected delivery driver.

The fast-food outlets have been shut for deep-cleaning after the truck driver made deliveries while asymptomatic with COVID-19.

No employee has tested positive in connection to the driver.

The driver was an extended family member of a worker at the McDonald’s in Fawkner, where a cluster emerged on May 9.

Eleven cases have been linked to the cluster.

The state’s total COVID-19 infections sits at 1567, about 120 of them active.

-with AAP