SA virus cases surge amid ambo concerns

Seven people are in hospital with one man in his 30s on a ventilator.

SA now has 1214 active infections, most being managed in home isolation.

The big jump in cases came as the Ambulance Employees Association raised concerns over patient care and as the government moved to lift the wider community ban on the use of rapid antigen tests,

The association said suspected and positive coronavirus patients were kept waiting in ramped ambulances outside the Royal Adelaide Hospital overnight in further evidence of the stress on the healthcare system.

Taking to social media it said one crew was sent to three "severely unwell" COVID-19 patients.

It said two patients were ultimately transported in one ambulance while another crew eventually arrived to take the third patient. 

"Treating paramedics almost ran out of oxygen, they ran out of medications," the association said.

"They were calling for intensive care back-up with none available. Our healthcare system is not coping."

But Premier Steven Marshall said all the patients taken to hospital were treated appropriately.

"They were triaged, they were treated within the clinically appropriate time frame," he said.

"Our clinicians treat people in accordance to their acuity and the advice I've received is that's exactly what happened."

Mr Marshall said of the four cases transferred to hospital overnight, three were from the same family, so it was acceptable for them to travel in the same ambulance.

Thursday's virus tally followed 105 cases on Monday, 154 on Tuesday and 198 on Wednesday.

That put the state well over the threshold for an official COVID-19 outbreak based on local modelling released in early November.

The modelling predicted a 27 per cent chance of an outbreak, which was defined as "averaging more than 100 cases per day over any three-day period" after borders opened on November 23.

Mr Marshall said officials were carefully monitoring the significant increase in infections around the country and what that meant for SA.

"We can now see there are many more cases than was originally envisaged," he said.

"Our number one priority is always to keep South Australians safe, so we'll make sure we move swiftly if we need to," he said.

However, the premier said SA would not return to statewide lockdowns or lockouts, noting that the hospitalisation rate remained low.

The increase also put increasing pressure on the government to approve the widespread rollout of rapid antigen tests, with the prohibition lifted on Thursday night.

Under the change, if a person receives a positive result from a rapid antigen test, they must take a PCR test and quarantine until they get a negative result.

Mr Marshall said South Australia had millions of kits on hand, both in government stocks and in pharmacies.