NSW, Western Australia and Queensland have relaxed some of their key lockdown restrictions.

South Australian health officials have praised residents for playing their part in controlling the coronavirus pandemic.

With SA now reporting no new infections for a week, Chief Public Health Officer Nicola Spurrier says the state is in a good place.

But she says that’s a testament to the efforts of everyone, from health officials and workers to people coming forward to be tested and to those who have followed the restrictions, including social distancing.

“I think many people are surprised in Australia at how well we have done. Really, this is the safest place to be in the world, perhaps other than New Zealand,” she said.

“It’s taken a lot of work and it’s meant that everybody has had to play their part and I absolutely understand how difficult the restrictions have been.

“But it has paid off.”

SA has only 14 active cases remaining and one of two men in intensive care for some time has recovered enough to be moved to a general hospital ward.

So far, South Australia has had 438 confirmed COVID-19 infections but 96 per cent are now considered recovered.

There have still no cases among the 699 Australians repatriated from India last week, though they remain in quarantine at two Adelaide hotels.

HOW DID THEY DO IT?

With the state’s social distancing restrictions not as tough as other states, Premier Steven Marshall attributed the success to two key elements – border control and testing.

South Australia was one of the first states to introduce tough border measures on March 24, and two weeks later its curve began to flatten.

“One of the hallmarks of our response in South Australia has been our strong border restrictions,” Mr Marshall said, 7 News reported.

“Early border control was effective in restricting the number of cases.”

South Australia was also the first state to introduce drive-through testing and at more than 55,000 so far, has the highest testing rate per capita in the country.

“We have had, unequivocally, the highest level of testing in Australia and amongst the highest level of testing, per capita, of anywhere in the world,” Mr Marshall said.

Officials now preparing to expand the testing regime to include particular community groups, including healthcare and aged care workers.