Health authorities have expressed alarm about the "concerning" number of infectious COVID-19 cases in the Hunter community across the past week.
Three of the four Hunter cases announced Thursday were infectious in the community, including a mystery case in Port Stephens.
In the past seven days, at least 20 of the Hunter 26 cases - or more than three quarters - were not in isolation for their entire infectious period.
"This means that all of us have to be particularly careful if we develop any signs or symptoms of COVID," Hunter New England Health public health controller Dr David Durrheim said.
Dr Durrheim also encouraged residents to wear masks when answering their front door after infected tree loppers from Sydney went door to door in the Hunter recently before testing positive.
In response to a question about Hunter residents' frustration with continual exposure from Sydney-siders, NSW Deputy Premier John Barilaro said he was happy to examine that.
"There's a level of goods and services that still must continue," he said. "There's a permit system, there's a testing system in place.
"I accept the frustration. It does make me want to look at what other options we have in place in relation to movement.
"I'm happy to look at those and even come down harder in relation to certain services being offered out of Sydney to the region."
But Mr Barilaro said it would be hard to stop people illegally leaving Sydney.
"I know on many occasions people have left Sydney with no permission, no authority," he said. "There are so many entries and exits out of all these areas that you'll never be able to stop people that are deliberately doing the wrong thing.
"You cannot ever put in place anything or any restriction for people that are willing to break the law.
"I know on a number of occasions a lot of the activities [where people have left Sydney] are criminal activities. People have done the wrong thing, have exposed communities, have caused outbreaks. That sits on them... as much as governments are responsible, the government can't stop everything."
Seven new cases on the Central Coast have also put suburbs close to the edge of Lake Macquarie on alert.
"Three of those were linked to a previously notifiable case but unfortunately all seven were infectious in the community," NSW Chief Health Officer Dr Kerry Chant said in the state's 11am update. "There's also been some unlinked cases in the Central Coast that are raising concern."
She listed Lake Munmorah, Charmhaven, Lake Haven, Gorokan, San Remo and Budgewoi as areas of note.
