A 24-year-old woman has become the fifth person to test positive to coronavirus in South Australia, just hours after a 40-year-old woman was confirmed as the fourth in the state.

Key points: SA Health said the 24-year-old would be taken to a metropolitan hospital

SA Health said the 24-year-old would be taken to a metropolitan hospital A 40-year-old was earlier confirmed as the state's fourth case of coronavirus

A 40-year-old was earlier confirmed as the state's fourth case of coronavirus The 40-year-old woman has a young child and touched down in Adelaide on Sunday

SA Health said the 24-year-old woman is not believed to be related to the 40-year-old woman, and both had recently returned to the state from overseas.

The state's chief public health officer Nicola Spurrier said the 24-year-old was admitted to the Royal Adelaide Hospital on Wednesday night.

"[She] also has a travel history and she's from a regional part of South Australia," Dr Spurrier said.

"I've been told she's in a stable condition … we have a team that is also doing the contact tracing for this person."

SA Health is today opening a dedicated clinic for coronavirus patients at the Royal Adelaide Hospital, and said 11 people in South Australia were currently awaiting test results for COVID-19.

The 40-year-old woman who travelled to Australia from Iran via Kuala Lumpur on Malaysia Airlines flight MH139, arriving in Adelaide on March 1, tested positive on Wednesday morning.

She has since been admitted to Flinders Medical Centre.

"She has a child so we need to be thinking about both the care of the mother and also her infant, so it wouldn't necessarily be the right option to go to the Royal Adelaide [Hospital]," Dr Spurrier said.

"It's obviously quite important for us to also have that baby tested."

Iran became one of the first countries outside China to record a surge in coronavirus cases, with hundreds of people affected including the nation's deputy health minister and other high-ranking officials.

South Australian authorities are attempting to get in touch with any close contacts the woman had, including people who were on the same flight as her.

Three other people have tested positive to coronavirus in South Australia since the outbreak, including a couple from Wuhan, but all have since been cleared and discharged from hospital.

"As of 6:00am when I spoke with the Health Minister, I was informed there were no active cases of people living with the coronavirus in South Australia," South Australian Premier Steven Marshall said on Wednesday.

"Later this morning we received notification of a further positive test for coronavirus. This has just come to light.

"I can fully understand why there are increasing levels of anxiety regarding the coronavirus."

Iran has recorded hundreds of cases of coronavirus, including several high-ranking officials. ( AP: Vahid Salemi )

Test result was 'strongly positive'

Dr Spurrier said the 40-year-old woman had been tested on Tuesday and the "strongly positive" result was flagged on Wednesday morning.

She said the woman was currently being interviewed by health authorities, but would not comment on whether her neighbours had been told, nor which suburb the woman lives in.

"We will be making every effort possible to contact all of the potential close contacts of this person," she said.

"We are not providing anything which might break private confidentiality or privacy."

South Australia's other confirmed case was another 24-year-old woman who had been on the Diamond Princess cruise ship.

She woman tested positive on arrival in Darwin from Japan on February 20.

"[She] was transferred to the Royal Adelaide Hospital where she remained in isolation for 14 days," SA Health said earlier this week.

"People should present to their GP if they are displaying any symptoms of COVID-19 and have recently returned from mainland China or Iran.

"The Commonwealth has also advised foreign nationals who are in Iran on or after March 1, 2020, will not be allowed to enter Australia for 14 days, from the time they have left or transited through Iran."