South Australians have been warned that a COVID-19 cluster that broke out in the community after a quarantine worker infected family members is likely to grow.

Four new locally-acquired virus cases were diagnosed on Sunday after woman in her 80s went to Adelaide’s Lyell McEwin Hospital for testing.

A woman in her 50s and man in his 60s were later tested and also found to be infected.

Another case was confirmed overnight in a Yatala prison staff member.

Mawson Lakes primary and preschool were closed for at least 24 hours after health authorities identified that a student was a close contact of a confirmed case.

“One of those people works in our medi-hotels,” Chief Public Health Officer Nicola Spurrier said.

“This is where we are considering the source to be.


“I am expecting that we will have more cases.”

Prof Spurrier said the infected trio has a very large family and four relatives were showing symptoms with test results expected later in the day.

The older woman lives independently not in an aged care facility and is now in isolation at the Royal Adelaide Hospital.

She is the mother of one of the younger pair, who are in a relationship.

Contact tracing is also under way for about 90 staff and patients at the Lyell McEwin Hospital who may have come into contact with the 80-year-old woman.

Prof Spurrier said the woman also visited Parafield Plaza Supermarket in Adelaide’s north while infectious.


All staff working at SA’s quarantine hotels have been ordered to undertake mandatory virus testing every seven days.

“It’s obvious that this is the highest risk in Australia right now is this risk of importation (of the virus) in our quarantine hotels,” Prof Spurrier said.

The new rule includes police, nurses, concierge, cleaners and security guards.