SA's new cases on Monday included 2860 detected through PCR swabs and 969 through rapid antigen tests.

The number of people in hospital rose by seven to 227, with 26 in intensive care where five people are on ventilators.

There were no deaths in the past 24 hours with the current number of active infections falling by 3783 to 33,703.

Mr Marshall said the current situation in SA was nothing like what the state was experiencing a few weeks ago when new infections were doubling every couple of days.

"It is very stable at the moment. We can't be complacent, we're still dealing with a highly transmissible variant," he said.

"But we are starting to see some very, very hopeful signs.

"Over the last two days, we've had more people recovered than infected, another indication we are getting towards the peak of this infection."

SA last week released its latest modelling on the trajectory of the current outbreak which suggested the peak would be reached by January 25.

Daily cases were forecast to go as high as 10,000 but that was well below the 40,000 predicted had the state not reintroduced some local restrictions on Boxing Day.

They included a 25 per cent density requirement for most venues, a 10-person cap on family gatherings and continued mask mandates.

The Public Health Association of Australia said if those measures had flattened the Omicron curve in SA they should be imposed in other states.

"If that assessment is true then all other states, and particularly those down the east coast, should as a matter of urgency adopt similar strategies," Chief Executive Terry Slevin said.

"Clearly the South Australian population is far lower than that of NSW, Victoria or Queensland, but on a per 100,000 persons basis, it is clear that virus spread is far lower in SA."

Despite the improving position, concerns remain over the number of cases across SA's aged care sector, which have prompted limits and restrictions on visits from family and friends.

SA currently has 102 outbreaks, defined as at least one COVID-positive resident or two positive staff, in aged care homes with 572 staff and 615 residents having the virus.

Mr Marshall said officials had identified 11 centres that required some significant support, which could include extra protective equipment or assistance with testing.

"We want to help in any way we can," the premier said.

"But we're very confident the aged care community is getting on top of this."

Mr Marshall said the major issue for the sector was the impact on staffing, prompting an upcoming revision of return to work rules to provide a "nuanced" approach to getting workers who may be close contacts back on the job.

"We need to do this in a careful and considered way," he said.

Australian Associated Press