NSW's COVID-19 management is back on track with the state overcoming a diagnosis hiccup.
Authorities on Saturday reported another 24-hour period without any locally-transmitted cases of coronavirus, and two diagnoses among international travellers in Sydney hotel quarantine.
The state has almost reached 30 days without a locally-transmitted case but the record nearly collapsed on Friday amid concerns a Sydney quarantine hotel cleaner had contracted the virus in the community.
But the woman's infection is likely linked to her workplace, NSW Health said.
"The viral genome sequence from the recent COVID-19 case who works at a Sydney quarantine hotel complex does not match the virus strains seen in recent clusters in Australia," Saturday's statement read.
"The virus may be of US origin. The source of infection may be international aircrew who were self-isolating in the hotel at the time, however investigations are continuing."
Airline crews from overseas stay in quarantine hotels between flights and state and federal authorities are working to try and identify the crew member, who might have since left Australia.
Testing of the woman's contacts is continuing but there have been no further positive results so far.
Those who shared a train carriage with the woman are deemed close contacts and have also been asked to isolate for 14 days from their potential exposure.
A full list of affected train services and carriages is available on the NSW Health website.
The woman's infection sparked widespread alarm on Thursday, with fears Western Australia could withdraw its promise to open its border to NSW and Victoria from Tuesday.
WA Premier Mark McGowan said he will take the weekend to consider the situation.
Queensland authorities say its borders will remain open, after travel restrictions were lifted on Tuesday.
There are 78 active cases of the virus across NSW.
Australian Associated Press
