A highly infectious variant of COVID-19 that has reached Australia and is spreading rapidly around the world has been discovered in the US.

The first Australian case of the South African variant is a woman who arrived in Queensland on December 22 and went straight into hotel quarantine.

“Genome sequencing has come back to show that she has this new variant that has been picked up in South Africa that is thought to be more contagious,” the state’s Chief Health Officer Jeannette Young said.

The woman was on Tuesday transferred by ambulance to the Sunshine Coast University Hospital.

The emergence of the case has prompted calls from leading health experts to call for Australia’s quarantine system to be “streamlined”.

The variant is causing concern around the world because it spreads faster than novel coronavirus, although it’s not necessary more deadly.

The first reported US case of the COVID-19 variant that has also been seen in the United Kingdom has been discovered in Colorado.

The variant was found in a man in his 20s who is in isolation southeast of Denver and has no travel history, state health officials said.

The Colorado State Laboratory confirmed the virus variant, and the Centres for Disease Control and Prevention was notified.

Scientists in the UK believe the new virus variant is more contagious than previously identified strains of the SARS-CoV-2. The vaccines being given now are thought to be effective against the variant, Colorado health officials said in a news release.

The World Health Organisation is yet to determine whether the new variant – and another that developed recently in the UK – could undermine vaccines being rolled out around the world.

The first Australians are set to be vaccinated by the end of March next year.

At least 24 countries around the world have recorded cases of the South African or UK coronavirus variants, including Lebanon, Singapore, Pakistan, India, South Korea, Japan, France, Germany and Italy.

Queensland Health Minister Yvette D’Ath said while other jurisdictions had detected a UK variant of the virus, this was the first time the South African strain had been confirmed in Australia.

“We are absolutely confident that all proper measures were taken at the hotel and in the transfer, and of course at the hospital in relation to this positive case,” she said.

Australia has identified five cases of the British variant in arrivals from the UK, including two in NSW, two in Victoria and one in South Australia.

The confirmation of the South African variant case comes as the federal government said it was considering granting “alternate entry” to Australians returning from overseas if they can prove they have already been vaccinated for the virus.

Immigration Minister Alex Hawke has repeated his threat to deport backpackers or expatriates caught having large parties in breach of public health orders.

“I have asked the Department of Home Affairs to try to identify anybody who has been disobeying public health orders,” he told Seven’s Sunrise program on Wednesday.

“If a person is a temporary visa holder we will cancel those visas or take action against those people.

“There is no excuse at this point. Australians are tired of it and we want to make sure that everyone is doing the right thing.”

Meanwhile, there are fears in NSW that a COVID-19 outbreak in Sydney’s Northern Beaches area could have broken away into the broader community.

The government is urgently trying to identify the sources of the infections of three people outside the virus epicentre of Avalon.

One lives in Wollongong on the state’s south coast but recently visited Sydney. The others live in Sydney’s inner west and north.

So far no immediate link to the northern beaches cluster, which now totals 129, has been found.

As New Year’s Eve approaches, governments across Australia including NSW are warning residents to observe coronavirus restrictions and social distancing.

Sydneysiders have been mostly banned from watching the famous New Year’s Eve fireworks from the harbour with the foreshore fenced off.

The NSW government wants people to stay at home and watch the shortened seven-minute midnight firework show on TV.

Meanwhile, Victorians are being urged not to venture into Melbourne’s CBD to celebrate New Year’s Eve after the state on Tuesday racked up its 60th day without any case of community transmission of coronavirus.

So far, 909 people have died in Australia from coronavirus.

-with AAP