NSW has confirmed 919 more local cases of COVID-19 and two more virus-related deaths as wastewater analysis picked up signs of the virus along the south coast.

Wednesday’s tally is a record for the pandemic, while the two deaths take the total number linked to the current outbreak to 76.

They include 30-year-old mother of three, Ianeta Isaako, whose death was announced on Tuesday. She died at her home in western Sydney and her death is being investigated by the coroner.

The other was a man in his 80s from Sydney’s north who died at Hornsby Ku-ring-gai Hospital. He is the third to die from an outbreak at Greenwood Aged Care in Normanhurst.

Deputy Premier John Barilaro said on Wednesday that NSW Health officials were particularly concerned about possible undetected transmission of the virus in regional towns close to the ACT border.

Mr Barilaro said sewage tested pointed to more cases in the area. Merimbula is now under high surveillance, due to its close proximity to Canberra.

“We know that many people from Canberra have moved to the south coast,” he said.

“It’s an area that has been quite clean from COVID for a long time and we are asking the community to come out and be tested immediately, even for the mildest of symptoms.

“Of course, Bateau Bay and Toukley are other areas of concern.”

Tweet from @NSWHealth

Of Wednesday’s 919 cases, 178 have been linked to a known case or cluster while the source of infection for 741 cases is under investigation.

In a continuation of a worrying trend throughout the outbreak, only 106 cases were in isolation throughout their infectious period.

Health officials said 645 cases were in hospital, including 113 people in intensive care and 40 on ventilators.

Amid ongoing debate about when Australia should ease restrictions when 70 per cent of the population has been vaccinated, Premier Gladys Berejiklian and Health Minister Brad Hazzard were pressed on Wedneday to explain if NSW’s health system would be able to cope with the inevitable rise in cases were that to happen.

Mr Hazzard said there was “no question” that the state’s health system was under pressure. But capacity had increased since the beginning of the pandemic.

“I want to assure the community that we have been working as a health system on this since January and February last year – ensuring we have stepped up the number of available ICU beds, and staff working in those intensive care units, [as well as] ventilators,” Mr Hazzard said.

“The hospital system is coping but there are lots of pressures on individual hospitals from time to time,” he said later.

It comes after Westmead Hospital announced to staff that surging demand had forced the hospital into “emergency operations” – a move that would reduce the number of COVID-19 cases it could treat at its hospital.

Ms Berjiklian again urged people to get vaccinated as soon as possible.

The NSW government has expanded priority access to vaccination  to all 16-to-39-year-olds living in the west and south-west of Sydney – not just those living in the high-risk LGAs.

Ms Berejiklian told 2GB radio on Wednesday morning that thousands of bookings were available to residents in these areas. They will be available from as early as Thursday.

“People are waiting for it, this is the opportunity,” she said.

“We’re extending it to all the suburbs in western and south-western Sydney. Obviously the 12 LGAs are absolute priorities, but if people live in surrounding suburbs, they can also go online and book.”

NSW has administered more than 6.1 million vaccine doses.