Perisher among new COVID-19 hotspots, as NSW records 18 new cases

All but two, which are in hotel quarantine, were spread via community transmission, NSW Health said.

Six are under investigation.

The cases are all part of the growing Sydney outbreak, which has mostly been linked to restaurants or licensed venues.

NSW Health's Dr Jeremy McAnulty said two were linked to the funeral gatherings cluster, four are associated with the Thai Rock Wetherill Park cluster and four are associated with The Apollo restaurant in Potts Point.

With the growing number of cases, NSW Health is asking all people who live in, or have visited Potts Point, Carnes Hill shops, Prestons, Bonnyrigg, Wetherill Park, Mt Pritchard, Bankstown City Plaza and Cabramatta in the past two weeks to get tested if they have any symptoms of COVID-19 at all.

NSW Health also identified Perisher among these nine hotspots, despite having no positive tests from the area, after samples collected at the sewage treatment plant there on Wednesday July 22 returned a positive result for the presence of COVID-19.

"The positive sewage result can be due to shedding of the virus by someone who may have previously had the illness, with the virus 'shedding' through their system for up to four weeks later," Dr McAnulty said.

"While no cases of COVID-19 have been identified in Perisher or Thredbo to date, it's important that anyone who was in this area get tested if they have even the mildest of symptoms."

NSW Health said further sampling and analysis was required to assess the significance of this initial positive result.

"Anyone feeling unwell - even with the mildest of symptoms such as a runny nose or scratchy throat - must seek testing and self-isolate until they get the result," the department said.

"Stay at home, and do not go to work or catch public transport until you are cleared of COVID-19."

NSW Health also advised there had been several school and childcare closures in Sydney on Thursday.

Fort Street High School will be non-operational due to a possible case of COVID-19 and Everlearn Childcare Centre in Prestons will be closed today, after a child attended while they may have been infectious. Test results for both of these are pending.

A student at Mary Immaculate Catholic Primary School in Bossley Park and a student at Freeman Catholic College in Bonnyrigg have tested positive for COVID-19. Both students have been in isolation since the weekend.

There are now 89 cases associated with Thai Rock Wetherill Park, 57 cases associated with the Crossroads Hotel cluster, eight cases associated with Batemans Bay Soldiers Club, and 20 associated with the funerals.

There are eleven cases associated with the Potts Point cluster.

The state also recorded its first prison case, with Parklea Correctional Centre placed in lockdown after an inmate tested positive for COVID-19.

The inmate arrived on July 26 after he was refused bail for driving offences. He recently arrived in NSW from Victoria and had been in isolation at the facility.

Meantime Victoria recorded its worst day of the pandemic with 723 new cases and 13 deaths confirmed in the past 24 hours.

The new record eclipsed the previous daily high of 532 on Monday and the state's death toll is now 105 - more than double that of NSW.

With no sign of the outbreak slowing after Melbourne's three weeks in lockdown, Premier Daniel Andrews announced there would be further restrictions imposed on regional Victoria.

From 11.59pm on Thursday, no visitors are allowed to people's homes in the Colac Otway, Greater Geelong, Surf Coast, Moorabool, Golden Plains and Borough of Queenscliff council areas.

Masks will also be mandatory across all of Victoria from 11.59pm on Sunday night.