South Australia has reported another 1027 COVID-19 cases and three more deaths, posting its lowest level of new infections so far this year.

Two of the deaths occurred on January 19 and one on January 7 but have only just been revealed.

There are 214 people in hospital including 18 in intensive care where five people are on ventilators.

Premier Steven Marshall says the number of active infections across the state has fallen to 13,426 and the number of SA Health staff with the virus has dropped to 140.

“We are very much buoyed by these figures. Having that ability to respond is critical,” he told reporters on Monday.

“We’re obviously focused very much on hospital beds but also on the human resources to support those people in beds.

“A couple of weeks ago that was under real strain.”

SA’s dip in case numbers came as all school students returned to classrooms for the first time this year.

Mr Marshall said it was hard to know the exact impact the return of all students would have on virus infections.

He said there was no increase in cases when the first 40 per cent of students returned to classrooms two weeks ago.

“It’s really all to do with people’s behaviour now,” the premier said.

But Mr Marshall said parents and caregivers had a responsibility to ensure children who were sick were not sent to school.

“That’s always our advice, but it’s doubly important at the moment,” he said.

“We really don’t want to have any unwanted spread of the disease in a school setting.”

After the opening of SA’s borders in late November, SA’s daily COVID-19 case numbers peaked at 5679 on January 14, but have declined steadily since then.

– AAP