The Auckland MIQ worker who returned a positive test result as part of routine testing has been confirmed as an Omicron case by the Ministry of Health.
All of the case's seven household contacts identified have already been contacted, isolated and tested, and returned a negative result.
A further 48 close contacts are in the process of being contacted.
Among the close contacts are 39 people who were on two bus trips with the case.
The ministry has now released multiple high-risk locations of interest on its website.
There are 25 new cases of Covid-19 in the community today, and 43 in MIQ.
"The positive case reported yesterday in an Auckland MIQ worker has now been linked to the border through whole genome sequencing," the ministry said in a statement.
"This has provided confirmation that the worker has the Omicron variant. In response, we are taking a conservative approach, and our objective is to stamp out and contain any onward transmission."
Locations of interest linked to the Omicron case include:
* Rail Replacement Bus - Southern Line, Britomart to Takanini, Thursday 13 January 4.50 pm - 6.20 pm
* Rail Replacement Bus - Eastern Line - Panmure to Britomart, Friday 14 January 7.15 am - 7.40 am
* The Warehouse, 30 Walters Rd, Takanini, Wednesday 12 January 6.39 pm - 7.15 pm.
* New World Metro, 125 Queen St, Auckland CBD, Thursday 13 January 12.11pm - 12.30pm and Friday 14 January 12.21pm - 12.30 pm.
* Morrin Road Bakehouse, 66A Morrin Rd, Saint Johns, Friday 14 January 6.30 am - 7.00 am and Monday 10 January 7.10 am - 7.30 am
* Gateway Wholesale Meats, 108 Great South Rod, Tuesday 11 January 3.42 pm - 4.00 pm
* Shosha Takanini, 108 Great South Road, Takanini, Monday 10 January 6.03 pm - 6.15 pm
The two bus trips are identified as high-risk and anyone who was on them at the relevant times should self-isolate and get tested immediately.
Those at the other locations of interest are required to self-monitor for symptoms for ten days after exposure. If symptoms develop, people are required to self-isolate and get a test.
They should then follow any further advice on isolation and testing that will be provided by public health officials.
The case and one household contact are now isolating in a MIQ facility while the remaining close contacts are isolating at locations in Auckland and Taupō.
The MIQ worker who returned a positive result for a routine surveillance test taken on Wednesday afternoon is fully vaccinated, up to date with regular surveillance testing and has co-operated fully with health authorities in helping manage any risks, the ministry said.
The worker is deemed to have been infectious from Monday January 10.
Health officials are working "at pace" to identify any further contacts and exposure events.
Whole genome sequencing has linked the MIQ worker to two returnees within the facility who travelled from India who arrived on January 8 and tested positive two days later.
Auckland Regional Public Health are working with MIQ staff to look for any possible routes of transmission between the returnees and the worker, and staff at this facility are in the process of having an additional test arranged.