NSW confirms three locally acquired coronavirus cases to break 12-day streak

Three new mystery coronavirus infections have been confirmed in NSW, bringing to an end the state's streak of 12 days without a locally acquired case.

The positive swabs were returned overnight — after NSW's 8.00pm reporting deadline — and will be included in tomorrow's official numbers.

They were discovered in men and women in their 50s in the Campbelltown, Parramatta and Wollondilly local government areas, and are not believed to be linked.

The sources of their infections remain under investigation.

Contact tracers are still assessing potential exposure sites and close contacts and further updates are expected later today.

NSW Premier Gladys Berejiklian said she was confident authorities could "get on top" of the new infections quickly.

"This is a good reminder, a good wake-up call, that we're living in a pandemic, that we're managing it well, but that we'll never be out of the woods until there's a vaccine," she said.

Testing essential in Campbelltown, Parramatta and Wollondilly

Chief medical officer Kerry Chant said increased testing was now absolutely essential.

"It's important we're not complacent when we have series of no community transmission," she said.

"We're particularly calling out anyone who lives in the Campbelltown, Parramatta and Wollondilly LGAs."

Ms Berejiklian said the three new local cases validated yesterday's findings of COVID-19 fragments in the area's wastewater.

Sewage surveillance from the North Richmond and West Camden treatment plants detected virus material and residents were put on high alert.

"Our suspicions that the virus is always lurking in the community are founded, and we wouldn't have said that if we didn't mean it," she said.

"We're always going to have cases pop up because we're in a pandemic, but we're also in an economy that is open, where people are undertaking their business, where we don't have [closed] borders but for Victoria."

NSW Health this afternoon issued an alert to the public over the following locations visited by the three confirmed cases.

• Kmart, Narellan Town Centre, Narellan on Friday, October 2, between 6:00pm —7:00pm
• Fitness First, Carlingford (all attendees other than those in the pilates class notified below) on Saturday, October 3, between 8:00am — 9:15am
• Penrith Homemaker Centre, Penrith on Sunday, October 4, between 11:00am — 1:00pm
• Guzman y Gomez, Penrith on Sunday, October 4, between 1:30pm — 2:00 pm
• Home Co, Penrith on Sunday, October 4, between 2:00pm — 2:30pm
• Westfield Parramatta on Monday, October 5, between 9:30am — 11:00am
• Castle Towers Shopping Centre, Castle Hill on Monday, October 5, between 12pm — 1:00pm

People who attended the Fitness First Carlingford pilates class on October 3 from 8:15am to 9:15am are considered close contacts and must immediately get tested and isolate for 14 days.

NSW Health is directly contacting those who attended.

NSW new cases are also likely to have implications for the country's borders.

The Queensland Government has previously stated it would not open the border with NSW until there was no locally acquired infections for 28 consecutive days.

Ms Berejiklian has warned this is unlikely to happen.

"Until the end of the pandemic, it's highly unlikely that NSW will ever get to 28 days of no community transmission, because that is not how a pandemic works."

Queensland Deputy Premier Steven Miles today said it was too soon to declare whether the 28-day timer would be reset.

"It's too early to say that — there's certainly enough reason to be concerned," Mr Miles said.

Ms Berejiklian said she was pleased to note an immediate uptick in testing across Western Sydney yesterday after the news that COVID-19 had been found in sewage.

There were no locally acquired COVID-19 cases in the most recent testing period, only three cases among travellers in hotel quarantine.

There were 5,970 tests conducted yesterday.