The arrival of the BA.4 and BA.5 Omicron variants is likely to result in a significant jump in cases, with a daily peak of up to 5000 expected around July 12.

A rise in hospitalisation is also possible.

Greens MP Robert Simms said more cases would put the hospital system under increased pressure.

"We know that our hospital system is at breaking point and things are only going to get worse in the months ahead," he said.

"We need to not only retain healthcare workers but also recruit new workers."

Mr Simms said the state government should follow the lead of Victoria and NSW and provide a $3000 thank-you payment to healthcare workers.

He said that would be a simple gesture that would send a positive message.

"It really is the least the government can do given the nightmare unfolding in our state's hospitals," he said.

Revealing the latest modelling on Tuesday, Chief Public Health Officer Nicola Spurrier said it was probably the most uncertain ever provided, with the total number of infections across the community and the ongoing impact of vaccinations adding to the complexity.

Professor Spurrier said the modelling also did not take into account the growing use of antiviral treatments, which could reduce hospitalisations.

"But what is clear is there is a reasonable certainty that we will have another peak in the next month," she said.

"The actual size of that peak, there's a lot of uncertainty around that."

In light of the latest modelling, Premier Peter Malinauskas said the current COVID-19 restrictions in SA would remain in place.

They are limited, but require positive cases to isolate for seven days and for close contacts to get regular testing and wear masks.

Masks also remain a requirement in certain areas including health and aged care facilities and on public transport.

SA reported 2270 new infections on Tuesday along with 11 deaths with some of those dating back to February.

There are 230 in hospital with nine in ICU.

The state's case numbers have been dropping slowly in recent weeks and dipped below 2000 on Sunday for the first time since early March.

Australian Associated Press