NSW Health confirmed on Thursday night an eighth Omicron case in a traveller who flew into NSW after being in southern Africa.
That traveller has been in quarantine since arriving on Singapore Airlines flight SQ231 on Sunday night.
The child, who became the state's seventh case on Thursday, sparked a number of new location alerts in the Chatswood area in Sydney's north between November 23 and Wednesday. Full details can be found on the NSW Health website.
Casual contacts need to get tested and isolate while they wait for a negative result, and get tested again if they develop symptoms.
The family is in special health accommodation, but were in the community before rules were changed on Saturday in response to the detection of Omicron cases.
NSW Health is concerned they may have caught the virus while flying into Sydney on Qatar Airways flight QR908 from Doha on Tuesday last week.
The three family members had not been in southern Africa.
The department is contacting other travellers on that flight to get them tested and into isolation.
Eight countries in southern Africa are of particular concern to health authorities.
A sixth case confirmed on Wednesday had been in Nigeria, which is not a country of concern.
They arrived on the same flight on Thursday last week as a woman who had been in southern Africa and visited a number of stores and restaurants in NSW before the rules changed.
The first four cases, and the eighth case confirmed in NSW were placed into special health accommodation before they were found to have Omicron, having arrived after the rules for entry were changed.
On Thursday, NSW reported 271 cases recorded in the 24 hours until 8pm on Wednesday from 81,877 tests.
There were no further deaths.
The state's vaccination rate remained at 94.6 per cent first-dose coverage and 92.6 per cent double-dose.
Restrictions are lifting in NSW on December 15 or when the state hits 95 per cent vaccination rate.
From then, most restrictions will end, including for unvaccinated people.
Density limits will be scrapped, QR check-ins will only be required at high-risk venues, and masks will only have to be worn on public transport, at airports and on planes.
