Australians are being urged to remain vigilant about coronavirus despite falling infection rates across the country.
Anyone with mild symptoms has been told to get tested.
"I'm worried that testing rates nationally might continue to decline," Deputy Chief Medical Officer Nick Coatsworth said on Monday.
The latest national testing figures show a 30 per cent fall in the past three weeks.
"Regardless of how mild your symptoms are, testing is the way that we find these early cases, that we stop the chains of transmission from growing into clusters, from growing into outbreaks," Dr Coatsworth said.
Victoria recorded just 11 new cases on Monday, along with two deaths.
"This is not just a good day, this is a great day," Premier Daniel Andrews told reporters in Melbourne.
"We are seeing these numbers come down, the strategy is working."
However, Victoria's 11 new cases were detected from just 7164 tests.
Mr Andrews encouraged anyone with a scratchy throat, runny nose or headache to get tested for the virus.
"It is a simple but profoundly important thing you can do for your family and every single Victorian family," he said.
NSW has recorded four new cases of coronavirus including three returned overseas travellers in hotel quarantine and one person linked to a known cluster.
The results were drawn from 7765 tests, which was almost half the number conducted the day before.
NSW Health said while it was not unusual for testing numbers to drop over the weekend, it would like to see levels above 20,000, particularly in southwest Sydney.
There are hopes Victoria's declining case numbers could bring about an early end to lockdowns in Melbourne.
Dr Coatsworth said there was still some way to go.
"When Victorians come out of restrictions, particularly in Melbourne, the complacency has to be avoided," he said.
"We know how to stop this virus, if we limit household gatherings, wash hands frequently and have the COVIDSafe app downloaded and maintain physical distance.
"And of course mask-wearing being mandatory, these things will allow us to lift restrictions safely."
Just as Victoria's falling coronavirus cases provide some cause for optimism, NSW is conducting a major contact tracing exercise after a taxi driver tested positive.
The driver worked across Sydney for more than a week while potentially contagious.
Anyone who took taxis across the city's west and south-west between September 8 and 18 is being urged to monitor for symptoms.
"Fortunately that taxi driver had COVIDSafe installed on their phone, which will be assisting contact tracers at the moment," Dr Coatsworth said.
"They did exactly the right thing by getting themselves tested and now the public health authorities will be working overtime to make sure that those particular cases do not turn into a larger outbreak."
Just one new coronavirus case was recorded in Queensland on Monday, a teenage girl in hotel quarantine after returning from overseas.
