NSW Health said on Thursday night that a person on a flight from Singapore who had recently been in southern Africa had tested positive for the variant of concern.
They have been in mandatory hotel quarantine but an alert has been issued over their flight.
The fully vaccinated person arrived on flight SQ231 from Singapore to Sydney on Sunday, November 28.
Everybody on that flight should get tested, if they have not already, and isolate until they test negative, NSW Health said.
Under the new isolation rules, they also need to have a test on Day 6 after arrival, which would be Saturday.
Under new rules anybody arriving in Australia from overseas needs to isolate at home for three days, while people who have been in South Africa, Lesotho, Botswana, Zimbabwe, Mozambique, Namibia, Eswatini and Malawi are sent to hotel quarantine.
The latest case comes after it was revealed the Omicron strain had arrived in NSW earlier than previously thought.
NSW Health confirmed the seventh new infection was a child and their COVID-positive parents, who arrived on flight QR908 from Doha to Sydney on November 23.
Previously, it was believed the virus had only arrived in Sydney on November 25.
Urgent genomic sequencing is underway to confirm whether the child’s parents also have the variant.
The child is isolating in Special Health Accommodation with their parents.
The child’s age meant they could not be vaccinated.
Authorities are concerned those travellers caught the virus on the flight, as they have not been in southern Africa.
Health authorities are urging every person who was on flight QR908 from Doha to Sydney on November 23 to get tested and isolate while waiting on further health advice
New exposure site alerts are also in place for venues visited by the family.
Anyone who attended the following venues is now a casual contact.
- Mantra Serviced Apartments in Chatswood from Tuesday November 23 to Wednesday December 1.
- Vodafone, Westfield Shopping Centre in Chatswood, Wednesday November 24 12.25pm to 12.40pm
- Centrelink and Medicare, Chatswood, Wednesday November 24 1pm to 2.30pm
- Priceline Pharmacy, Chatswood Interchange, Wednesday November 24 1pm to 1.10pm
- Woolworths, Chatswood Interchange, Wednesday November 24, 1pm to 2.30pm
If you attended at these times, you must immediately get tested and isolate until a negative test result is received.
It comes as authorities are retesting thousands of COVID-19 swabs for the Omicron variant.
NSW Health will check 2000 positive COVID-19 swabs from recent weeks for signs of the variant.
This is to determine how long Omicron has been circulating in the state.
NSW Health Minister Brad Hazzard said pathology has already retested 500 swabs from people who have arrived from southern African countries in the past two weeks.
“They have now completed 500 cases that have come into NSW since the November 22 and they’ve gone right back through the pathology and I’m pleased to say at the moment none of those proved to be positive to Omicron,” he said.
The fully vaccinated man had recently visited southern Africa and arrived on flight QR908 from Doha to Sydney on November 25.
He was on the same flight as the Central Coast woman who tested positive to Omicron on Tuesday.
The man had spent the last six months in Nigeria, which is not one of the eight African countries subject to the border closure issued on Saturday.
The most vaccinated countries on Earth
All passengers on the QR908 Qatar Airways flight have been directed to get tested and self-isolate for 14 days.
So far, only one of the eight Omicron cases in Australia is not in NSW.
The eighth is a case in quarantine in Howard Springs in the Northern Territory.