Quarantine-free travel to WA under a cloud as new Sydney COVID-19 cases emerge

Genome sequencing of the strain was also being expedited for all three cases.

"We will be looking at the trips and the people he's escorted in those transfers between the airport and the hotels, but again his contact in those settings was to basically help people out with their baggage and help them exit the mini van or buses," she said, adding the driver wore a mask.

"He did have symptom onset on Saturday and did work again for a few shifts subsequent to that [before being tested on Tuesday]."

WA Premier Mark McGowan said the state's Chief Health Officer Andy Robertson was in contact with his NSW counterpart to determine the circumstances surrounding the new case.

"At this point in time it's one case, so if there's been community spread obviously we'll find out and that may well influence our decision [with the border arrangements]," he said.

"The controlled border we have in place with all other states allows us to put up a hard border immediately if we need to and if that advice comes back.

"We'll take advice, if we need to take action we will."

Speaking after the driver's positive tests was confirmed on Wednesday, NSW Health Minister Brad Hazzard said the case had expedited a review of how the state managed the 2000 to 3000 international air crew transferring through NSW each week during the pandemic.

"We will be implementing more discussions probably within the next 48 hours ... but the inclination that the NSW government has at the present time is to say to international air crews and airlines, that international air crews coming into NSW will be most likely required to quarantine in the same way as any other international visitors or Australians returning to Australia," he said.

"The difference would be of course that they would be in a quarantine environment, but not necessarily for the full 14 days because they obviously have usually turnarounds between 24 and 72 hours."

Under current guidelines, international air crews must go into hotel quarantine during a lay-over, unless they are a declared crew member which permits them to complete their quarantine at an alternative residence, such as their home.

Transport to and from Sydney Airport must be arranged by the crew's employer.

The Sydney driver is the first locally acquired case in NSW since December 3, when a Sydney hotel quarantine cleaner became infected.

The woman's case was suspected to have originated from a member of a US air crew staying in a hotel during their lay-over.

Dr Robertson permitted the reopening of the state's border with NSW on December 8 despite the cleaner's infection, as tracing revealed the virus had not spread to any of her close contacts.

In Western Australia, international air crews stopping over in Perth must travel in a vehicle provided by their employer directly to The Holiday Inn in Perth to quarantine.

The hotel is closed to the general public.

Crews are only permitted to leave their hotel room to travel directly back to the airport for an outgoing flight, and must wear a mask when transiting through a crowded place.

According to WA's flight crew directions, crew members are not required to be tested for COVID-19.

The required trigger point for WA to have quarantine-free travel with another state is 28 days without a locally acquired case.

WA is currently open to quarantine-free travel with all states and territories except South Australia, which, pending no new local cases, will change on Christmas Day.

Mr McGowan hinted on Wednesday the date for reopening with South Australia could be brought forward.

with Esther Han