More than 250 Australians due to arrive in Western Australia on a flight from South Africa today will be quarantined in Perth, with many sent to Rottnest Island, Premier Mark McGowan has confirmed.

Key points: WA passengers will go to Rottnest and interstate passengers to city hotels

WA passengers will go to Rottnest and interstate passengers to city hotels The Premier said Rottnest Island was a better option for families

The Premier said Rottnest Island was a better option for families Meanwhile WA recorded just one new COVID-19 case overnight

The plane is scheduled to arrive at Perth Airport from Johannesburg via Cape Town in South Africa on Wednesday morning and includes a number of West Australians and interstate passengers.

The 257 passengers will go through a health assessment at the airport and be placed in quarantine for the mandatory 14 days.

Mr McGowan said people from Western Australia would be taken to Rottnest.

"They're generally families," he said.

"If their health condition is good they'll be going back out to the island, where it is I think a much better environment than one of the hotels.

"Certainly for a family to have a unit at the island where you can get a bit of fresh air … it is a pleasant environment."

Interstate passengers and those presenting with complex health needs or illness will remain in city hotels, close to hospitals, or go straight to hospital if required.

Rottnest Island has lots of accommodation options for families. ( Supplied: Rottnest Island Authority )

A Malaysian Airlines flight from Kuala Lumpur arrived at Perth Airport last night.

Mr McGowan said there were about 80-90 people on the flight from Kuala Lumpur, but as far as he knew none had been sent to Rottnest.

It is believed all those passengers were taken to a hotel in the city for a 14-day quarantine.

Mr McGowan said an Air France flight may stop to refuel in Perth on its way to another destination and there could be a flight from India later this week but details were still being confirmed.

He said it was "pretty annoying" some people on these flights had waited so long to come home.

"Sometimes there's circumstances, but you know … this has now been ongoing for two months and people haven't come home," he said.

"Maybe they couldn't get a flight."

McGowan defends WA's testing rate

The Premier again warned there could be a spike in COVID-19 cases "simply because we have hundreds of people coming here from overseas".

Mr McGowan also defended WA's low testing rate compared to other states.

"It may well be that other states are counting what's called a panel test as a COVID test, while we may not be counting that," he said

"But the bigger issue is this. The criteria generally is that if you want to get tested, you have to present with a fever, a respiratory condition or a history of fever and that's pretty common across the country.

"But we have incredibly low rates of flu now, extremely low rates of flu in Western Australia, much lower than anywhere else in the country.

"So far fewer people meet the criteria to get tested in Western Australia than do in other states."

Who should present to COVID-19 clinics? People who have EITHER a fever of 38 degrees Celsius OR acute respiratory infection

People who have Symptoms to look out for include fever, shortness of breath, cough or sore throat

Symptoms to look out for include or Patients who are tested should remain isolated at home until they receive their test results. Major clinics have been set up at Perth hospitals including Royal Perth, Sir Charles Gairdner, Fiona Stanley, Joondalup, Armadale, Rockingham and St John of God Midland. They are open from 8:00am–8:00pm daily. In Southern WA a clinic is operating at Bunbury Health Campus from 10:00am–4:00pm daily. In Northern WA a clinic is operating at Broome Hospital from 8:30am–4:00pm daily. Outside these areas, people with symptoms should present to their local hospital. For more information go to the Health Department website.

Borders to stay closed for 'months and months'

Mr McGowan indicated the closed interstate border would remain in place for "months and months to come".

The intrastate border restrictions would also be in in place for a "considerable period of time".

He said the Government had not worked out when or how they would be brought down.

But he pointed out elective surgery resumed on Tuesday, schools were going back today, gatherings of up to 10 people were now allowed, and home opens and display villages were once again permitted.

"Let's just see how that goes, let's just take it easy at this point in time, see how that goes before we make other significant changes," the Premier said.

"Anything we do will just be based on health advice."

Wife of cruise ship passenger tests positive

One more person, an 80-year-old woman from Perth, has tested positive to COVID-19 in WA.

WA COVID-19 snapshot Confirmed cases so far: 665

Confirmed cases so far: 665 Recovered: 650

Recovered: 650 Deaths: 9

Deaths: 9 Total tests: 405,246 Latest information from the WA Health Department





She is the wife of a passenger on the Costa Victoria cruise ship and is currently in hospital.

Nine more people have recovered from the virus in WA, meaning there are now only 47 active cases in the state.

Of those 28 are from WA, two are from interstate and 17 are from the Artania cruise ship.

There are 16 people in hospital and four remain in intensive care.

Artania cruise ship passengers currently account for 17 of WA's active COVID-19 cases. ( ABC News: Nicolas Perpitch )

So far 35,155 people have tested negative to the virus, including 6,230 in regional WA.

WA has also received another planeload of personal protective equipment, including 500,000 surgical face masks and 120,00 isolation gowns.

Mr McGowan spoke during a media conference at Carine Senior High School ahead of the start of school term two today.

It will be a "soft start" to school, where parents are given a choice as to whether to send their children for the first three weeks.

"I just urge everyone to understand there will be new rules in places, new requirements for hygiene and the like," Mr McGowan said.