A traveller returned from South Africa is among three new Queensland COVID-19 cases detected in hotel quarantine.
All were infected overseas and are being transferred to hospital.
The other two of the trio came from India and Pakistan, with genome sequencing underway to determine viral lineages.
A traveller who returned recently from Ghana has also tested positive to a UK variant of the virus and has been transferred from hotel quarantine to hospital.
Chief Health Officer Jeannette Young says sequencing revealed he was infected with the reportedly more contagious strain.
"Cases are rising at a rapid rate internationally and new variants like this one would be difficult to contain in the community. Our best approach is ensuring potential cases are detected where they pose no risk to other Queenslanders," she said on Thursday afternoon.
The diagnosis comes after a Sunshine Coast woman this week tested positive to a South African variant, also thought to be more contagious,
She is in isolation at Sunshine Coast University Hospital after landing in Brisbane carrying the 501.V2 strain on December 22.
Dr Young said she was closely monitoring the NSW cluster and new Victorian cases.
"I'm urging Queenslanders travelling to these states to reassess their plans, if it is not necessary, then consider staying here," she said.
"The next 24 hours are critical for Victoria and the NSW cluster is growing daily. Queensland is in a good position right now because we acted quickly to declare greater Sydney a hotspot."
Routine testing has found traces of COVID-19 in wastewater at Bundamba in West Moreton and Merrimac on the Gold Coast.
Dr Young said continued positive sewage results were particularly concerning given the NSW cluster and new cases in Victoria.
"It is very important that anyone in the Bundamba and Merrimac catchments who has COVID-19 symptoms, no matter how mild, comes forward for testing," she said.
"With the NSW cluster growing and new cases in Victoria, it's better to be safe than sorry."
Another five locally-acquired coronavirus cases have been identified in Victoria, in addition to three women whose positive tests ended a two-month streak without infections on Wednesday.
NSW reported 10 new cases of community transmission, with five linked to Sydney's northern beaches cluster.
The Queensland border is closed to anyone who has been in the COVID declared hotspots of greater Sydney and surrounding areas in the past 14 days.
Border declaration passes are also needed for travellers who have visited NSW since December 11.