South Australia can expect to have new COVID-19 cases "every single day" after the opening of the state's borders but remains "greatly concerned" over the Omicron variant of the virus, Premier Steven Marshall says.
SA Health reported four new infections on Monday, one linked to the so-called Norwood cluster taking it to 25.
Two more were found in interstate travellers and one in a returned overseas traveller.
"We should be expecting new cases every single day here in South Australia," Mr Marshall said.
"But the Delta variant is progressing exactly and precisely as we thought, in fact probably at the lower end of the forecast.
"Our big concern at the moment is the Omicron variant."
South Australia's transition committee has so far resisted making major changes to the state's coronavirus measures in response to the new variant but officials have warned borders could be closed again if necessary.
It has moved to require people coming from NSW, Victoria and the ACT to have a COVID-19 on arrival as well as a negative test before travelling.
Quarantine requirements for people arriving from overseas have also increased from seven to 14 days.
Mr Marshall said South Australia was still waiting on more information about Omicron in relation to its transmissibility, the effectiveness of existing vaccines and the severity of symptoms before taking further steps.
"We need to take all of those things into account," he said.
With four new cases, SA has 45 active COVID-19 infections, all being managed in hotel quarantine.
They were revealed as the Australian Medical Association made an urgent call for more personal protective equipment to help doctors cope with the expected surge.
"Doctors and staff need N95 masks and other PPE, and they need to be fit-tested to ensure they are protected and that their patients are protected," AMA state president Michelle Atchison said.
"Instead, we hear of doctors, practices and hospital settings desperately scrambling to find their own PPE, with no idea from where they will find enough to enable them to safely care for patients."
Dr Atchison said the "simmering" issue of PPE supplies had become more problematic since the release of SA's guidelines for dealing with COVID-19 cases.
"If GPs are to support care for 85 per cent of COVID-positive patients as the SA Health strategies outline, as well as patients with other conditions, PPE is a critical piece of the puzzle," she said.
The AMA has also called for SA Health to introduce specific sites or timeslots for healthcare workers to have COVID tests to allow them to get swabs and the results as quickly as possible.
Australian Associated Press