NSW reached a coronavirus milestone on Tuesday, when health authorities failed to find a locally acquired case for the first time in more than 100 days.

While two new infections were confirmed in the 24 hours to 8pm Monday, both were returned travellers in hotel quarantine.

It’s the first time since July 8 there have been no locally acquired cases identified in Australia’s most populous state.

At that time, NSW Health was unaware an infected man had visited the Crossroads Hotel in Sydney’s south-west five days earlier, sparking a resurgence of the virus in the state.

Tuesday’s result marks two weeks in NSW without a mystery case – that is, a coronavirus case with an unknown source of infection.

The last mystery case confirmed in NSW was on September 8.

A total of 7616 tests were completed in the 24 hours to 8pm Monday – the lowest number since June 14.

NSW Premier Gladys Berejiklian has previously expressed her wish that testing rates remain in the tens of thousands.

“We will only continue to beat this virus if we’re able to increase the rates of testing,” Ms Berejiklian said on Tuesday.

NSW Health’s Jeremy McAnulty said it was critical testing levels remained above 20,000 a day to “keep the pandemic at bay”.

Dr McAnulty said people in Sydney’s south-west were at particular risk.

“For the sake of your friends and family, get a test,” Dr McAnulty said.

It comes as Queensland Premier Annastacia Palaszczuk confirmed her state’s border would open to people in five NSW local government areas from October 1.

Residents of the Byron Bay, Ballina, Lismore, Richmond Valley and Glen Innes local government areas will be able to enter Queensland as long as they apply for a border pass.

It means people from 41 NSW postcodes will be able to travel into Queensland without completing a mandatory 14-day period of quarantine.

Queenslanders will be able to move freely through those NSW areas and return home without having to self-isolate.

The low transmission of the virus in Sydney has prompted South Australia’s Government to reopen the state’s border with NSW from 12.01am Thursday, as long as no mystery cases are announced tomorrow.

That means NSW residents will no longer need to complete a 14-day mandatory quarantine period when visiting SA.

Meanwhile, July 8 was the last time no locally acquired cases of coronavirus were found in NSW.

In that reporting period, 13 new COVID-19 infections were confirmed.

Eleven of them were in hotel quarantine and the other two were previously identified “probable cases” that were added to NSW’s total as a formality.