NSW has recorded 22 new locally acquired Covid-19 cases on Wednesday as health authorities warned two "vulnerable" hospitals were at risk of transmission.
Premier Gladys Berejiklian said the latest daily total was further evidence cases were increasing at a "steady rate" and a significant spike in cases had so far been avoided.
"To date our fears about huge escalation haven't materialised and we certainly want to keep it that way," she told reporters.
But she warned it was still "early days" and it was vital residents don't become complacent.
Ms Berejiklian said if people "continued to do the right thing" Sydney was on course to exit lockdown on July 9.
Six of the latest cases were infectious in the community. All 22 are linked to previous cases.
It follows 19 local cases identified on Tuesday.
More than a dozen close contact exposure sites were revealed to the public late on Tuesday as health authorities desperately try and curtail the spread of the Delta variant in the community.
The number of local cases since June 16 now stands at 171.
The state's strong testing rates continued on Wednesday, with a further 68,000 tests in the previous 24 hours.
Two hospitals on high alert
Chief Health Officer Dr Kerry Chant highlighted one case reported after the 8pm cut off that had worked in two separate hospitals while infectious.
The 24-year-old student nurse worked at Fairfield Hospital and also the Royal North Shore Hospital and the affected wards have since been locked down.
Testing to date of close contacts has produced negative results, however Dr Chant said further cases were possible.
"It's much too early to tell, whether we will have any transmission and we have taken a very broad, infectious period because of our concern about the vulnerability of health care settings," she said.
Dr Chant said she was unaware of whether the nurse was vaccinated or not.
It is not known at this stage where she acquired the virus.
Wednesday marks Sydney's fourth full day of its two-week lockdown.
Widespread QR code system to be rolled out
Minister for Customer Service Victor Dominello announced the state's QR code system would be ramped up meaning from July 12 a raft of venues would be required to display a QR check-in at entrances.
All workplaces, gyms, schools, universities and retail businesses will be required to use the system.
"Delta moves at lightning pace, so we need to adjust our circumstances accordingly," he said.
He said he'd called on Woolworths, Coles and other supermarkets to implement them as a "matter of urgency".
Students at schools will not be required to scan in.
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