Health authorities say NSW has entered a critical period in its fight against coronavirus, with concerns about low COVID-19 testing rates, undetected cases and people dropping their guard as the festive season approaches.
"As we go into Christmas we know that people are going to be welcoming people into their homes ... and household celebrations (and that will) present challenges for COVID transmission," Chief Medical Officer Kerry Chant said on Wednesday.
NSW Health on Wednesday said a confirmed COVID-19 case, who will be included in Thursday's numbers, had attended venues in south-west and east Sydney.
The venues included Flip Out Prestons Indoor Trampoline Park on October 25 between midday and 1.50pm and Jasmins Lebanese Restaurant in Liverpool on October 25 between 2pm and 3.30pm.
It advised anyone who had also attended the venues for at least one hour to get tested and self-isolate for 14 days.
There was one new case of locally acquired COVID-19 in NSW and seven cases detected in returned travellers in hotel quarantine in the 24 hours to 8pm on Tuesday.
The new local case was a household contact of another case in southwest Sydney who had been isolating before being diagnosed.
Despite low case numbers NSW Premier Gladys Berejiklian urged people not to become complacent.
"We want to make sure we get on top of this before we get into a season where people are more mobile and obviously in closer contact with each other," she said.
"It's really difficult not to let your guard down because it's easy to think that we're immune and the case numbers are low ... (but) the virus is as contagious as ever, as dangerous as ever and it remains undetected in the community."
She urged all businesses to get the QR code to electronically track any visitors to their venue ahead of the Christmas season.
She also welcomed the Tasmanian government's decision to open its borders to people from NSW from November 6 and said she hoped Queensland did likewise in an announcement expected on Friday.
"I also urge the WA government to do likewise because there is no reason why NSW residents shouldn't be welcomed to other states."
She said she'd be monitoring how Victoria goes controlling the spread of COVID-19 over the next two weeks as it emerges from lockdown, before she considers opening the border.
"We're going to keep a close eye on that and if we see that within a couple of weeks of those restrictions being eased the virus is still under control, then we'll have no issue with taking the border down," she said.
"We don't want the border there for a day longer than it needs to be but we also need to be sensible.
Meanwhile, there are guidelines on the NSW Health website on how to participate safely in Halloween on Saturday, including using wrapped lollies, mask-wearing and maintaining social distancing.
Australian Associated Press