Health authorities confirm a third case of coronavirus in Western Australia after a woman in her 30s returning from a holiday in Europe tested positive to the disease.

Key points: The woman isolated herself as soon as she became unwell

The woman isolated herself as soon as she became unwell Authorities say there is no risk of further infection to the public

Authorities say there is no risk of further infection to the public It is the third WA case after a couple who were on a cruise ship in Japan

The woman in her 30s from Perth's southern suburbs returned a positive result after holidaying in Iceland and the UK, and returning to WA via Dubai on Monday.

WA chief health officer Andrew Robertson said the woman had isolated herself when she became unwell and contacted her local GP, who arranged the testing.

She was currently in a stable condition in home isolation.

"She's done exactly the right thing and that is that as soon as she became unwell she self isolated, so there is no risk to the general public," he said.

Dr Robertson said the department was working with Emirates to trace other passengers on flight EK420, but only those seated within two rows of the patient would be at any risk.

"We will contact trace but the risk is probably low in those people because she wasn't symptomatic on the plane," he said.

Two other West Australians have so far been confirmed as coronavirus cases — 78-year-old James Kwan, who died at the weekend, and his 79-year-old wife who remains in a stable condition in Sir Charles Gairdner Hospital.

Both of them contracted the virus after being quarantined on the Diamond Process cruise ship in Japan.

Mr Kwan was diagnosed after the couple were evacuated to Darwin, while his wife tested positive after they were flown back to Perth for treatment.

WA Health Minister Roger Cook said none of the state's cases of COVID-19 had been transmitted internally and 973 people had so far returned negative results.

"All the cases which have occurred in Western Australia have been those that have contracted the disease outside the state, so our ongoing campaign to constrain and isolate in relation to the coronavirus epidemic is still being highly successful," Mr Cook said.

"Obviously you see some growing incidents of community-generated cases in the eastern states and that provides us with a pointer about what we might experience into the future, but just at this stage we are in a good position in relation to that."

Coronavirus clinics to start operating from Tuesday

The WA Government also revealed further details of three specialist coronavirus testing clinics that would open at Perth hospitals next Tuesday.

The so-called "fever clinics" would be staffed by medical specialists and equipped to test adults and children, who would be able to turn up for testing without a GP referral.

Mr Cook said they would operate on a 12-hour time frame from 8:00am to 8:00pm at Royal Perth, Sir Charles Gairdner and Fiona Stanley hospitals.

"They will be scaled up as needed and they will be in a position to receive patients from Tuesday," he said.

Mr Cook said the WA Government would also spend $2.3 million on an extra 50 ventilators to treat seriously ill patients.

"These are ventilators which are used in the context of an ICU [intensive care unit] situation or for patients that need assistance with their respiratory illness," he said.

"This is all part of our ongoing planning to make sure we are continuing to tool up and be in full readiness for COVID-19 and its impact on our community."

The Health Department was also contacting doctors and nurses who currently worked part time to ask them if they would work full time once the full impact of the virus hit.

It was also talking to those who were not currently practicing about temporarily returning the workforce.

"We need to continue to work with our health workforce to first of all spread the rosters, increase the pool of staff that we can work with," Mr Cook said.

Office cleared, Catholic churches cease communion

The global IT company Cisco has sent all employees at its Perth office home, after someone presented there with "flu-like" symptoms.

"Through an abundance of caution, we have closed Cisco's Perth office temporarily," a spokeswoman said.

"Based on medical advice they are being tested for COVID-19."

She said staff were working from home while they carried out further "cleaning protocols".

Catholic parishes in Perth have meanwhile asked churchgoers to stop shaking hands during the sign of peace as an extra coronavirus precaution.

Hand sanitisers have been placed in St Mary's Cathedral in Perth amid fears of coronavirus transmission. ( ABC News: Evelyn Mansfield )

Father Sean Fernandez from Perth's Saint Mary's Cathedral said the parishes have also emptied their holy water fonts and stopped giving out communion from the chalice.

Father Fernandez said the measures had never been done before but the church felt it was an important public health measure.

"The people who have come to the cathedral have felt reassured that we are seeking advice and that we are looking out for the wellbeing of the community," he said.

Travel bans extended, infant infected

News of the third WA infection came on the same day Prime Minister Scott Morrison stepped up travel bans to countries badly affected by the coronavirus outbreak.

A travel ban has been introduced for foreign nationals travelling from South Korea and existing bans on China and Iran have been extended for another week.

The revised bans will be in place until March 14, but could be extended further before that date depending on medical advice.

Australian citizens and permanent residents will be able to enter Australia, but need to isolate themselves for a fortnight.

New cases continue to be confirmed in other states, including an eight-month-old baby in South Australia.

The infant and his mother both returned positive tests yesterday after returning from Iran on Sunday.