South Australia will slash COVID-19 quarantine periods and classify fewer people as close contacts while also setting an end date for mask mandates.

Newly elected Premier Peter Malinauskas says barring a significant change in circumstances, mask-wearing will be largely scrapped by Easter.

They will still be required in certain high-risk settings including aged care facilities under a change set to come into effect from April 14.

"I think most South Australians can't wait for the day to come when they are not required to wear masks. That day is coming," he told reporters on Friday.

The quarantine period for household close contacts will be immediately halved to seven days, bringing SA into line with the rest of the nation.

It will apply to people currently in isolation subject to negative PCR or rapid antigen test results.

The decision comes as SA recorded 4549 new cases and four deaths, including that of a man in his 30s.

There are 157 people hospitalised with the virus including six in intensive care.

Other decisions agreed upon by the Emergency Management Council on Friday will come into effect from 12.01am on Saturday.

South Australians are currently deemed to be close contacts if they have face-to-face contact with a COVID-positive person for as little as 15 minutes if no masks are worn.

This period will increase to four hours.

People who contract COVID-19 will be exempt from being classed as a close contact until 12 weeks after their recovery, up from eight weeks.

And masks will no longer be required at Adelaide Oval once patrons are inside the venue, unless they are in a fully enclosed indoor area.

But the premier ruled out extending school holidays despite calls from the teachers' union for an early end to term one.

Mr Malinauskas had asked for further modelling on what the impact would be on case numbers if SA's close contact, isolation and mask-wearing rules were revised.

He had expressed a desire for SA to fall more into line with other states in regard to virus rules but said he would also continue to follow the health advice.

The teachers' union said a survey last week revealed more than three-quarters of schools and preschools had between one and 10 teachers away each day.

There were similarly high rates of absences among support staff.

In response to increasing case numbers, classes in some schools have been combined.

Authorities this week decided that whole classes would be sent home if 10 or more students tested positive.