The NSW-Victoria border will shut on Wednesday night with residents from 36 hot spots in Melbourne already banned from travelling north.

NSW Health Minister Brad Hazzard has amended the Covid-19 interstate hot spot order to include residents from Greater Melbourne's 36 local government areas.

The order is in force from 12.01am today, July 7.

The health department said: "This means they will only be able to enter NSW for very limited reasons, such as obtaining medical care, or fulfilling a legal obligation."

"Come midnight tonight, for the next 24 hours, the hot spots will extend to all of Melbourne so nobody from Melbourne will be able to cross the border in the next 24 hours," NSW Premier Gladys Berejiklian said on Monday.

"But come midnight tomorrow night, it will be all Victorians."

The NSW-Victoria border will close from 12.01am on Wednesday, July 8.

"The requirement for NSW residents returning from Melbourne hot spots to self-isolate for 14 days will then be extended to anyone returning from Victoria. Heavy penalties and fines apply," the health minister's office said.

"Provisions will be in place for residents of border regions, such as Albury-Wodonga."

Ten healthcare workers have been diagnosed with Covid-19 in the past week in Victoria.

This includes three new cases in staff from separate hospitals, among the 127 infections announced on Monday, the Age reports.

The Department of Health and Human Services said one case was a healthcare worker at the Royal Melbourne Hospital, considered "a close contact of a known case".

The hospital said the case is a nurse in the acute medical unit.

The DHHS said another was a healthcare worker at the Alfred Hospital.

"It's believed the worker attended the site while infectious," it said in a statement.

"Contact tracing is under way and the department is working closely with the hospital to ensure all appropriate public health actions are taken."

A healthcare worker at the Joan Kirner Women's and Children's Hospital at Sunshine Hospital has also reportedly tested positive for Covid-19, along with seven in the Northern Hospital emergency department.

Australia has recorded a total 8397 cases of Covid-19, with 3240 in New South Wales, 2660 in Victoria, 1067 in Queensland, 443 in South Australia, 621 in Western Australia, 228 in Tasmania, 108 in the Australian Capital Territory and 30 in the Northern Territory.

Australia's coronavirus death toll is 106.

There were 140 new cases of Covid-19 recorded across Australia in the 24 hours to 9pm on Monday, according to federal health department figures.

Of these, 127 were in Victoria – the largest daily increase in the state since the pandemic began.

There were 10 cases recorded in New South Wales and three in Western Australia but all 13 diagnosed are travellers in hotel quarantine.

"The new cases are all returned overseas travellers who flew into Perth on July 2," WA Health said.

Later on Monday, NSW Health said it was investigating after two suspected cases of Covid-19 returned positive results on preliminary testing in Albury.

"Further testing is under way while, as a precaution, close contacts have been identified and placed in isolation," the health department said.