South Australia (SA) has enforced a hard border with residents of Greater Melbourne, as authorities reveal the man at the centre of Melbourne's Covid-19 outbreak likely caught it through aerosol transmission in Adelaide hotel quarantine.
South Australian Premier Steven Marshall. Photo: AFP / Brenton Edwards
An SA Health report into the transmission concluded "there was no high-risk single event or high-risk breach in infection prevention and control practices".
It found the transmission was "highly likely" caused by "the close timing of doors opening and closing between adjacent rooms".
The Melbourne man tested negative to Covid-19 while in hotel quarantine and flew back to Melbourne, where he tested positive six days later.
Victorian authorities have used genomic testing to link the man to the latest cluster in that state.
The report found that "a review of the timing and placement of food/goods/waste/linen outside of guest's rooms is likely to reduce the risk of further episodes of similar transmission events".
"In addition, careful management and placement of guests at higher risk of developing Covid 19 (i.e close contacts) will also likely assist," it noted.
SA closes border to Greater Melbourne
SA Premier Steven Marshall announced people who had been in Greater Melbourne would not be allowed into South Australia from 6pm tonight (Australia time), apart from essential travellers with a permit or returning South Australians.
Those people will need to do a 14-day quarantine.
People who have been in Melbourne since 20 May, will need to get tested on days one, five and 13 of being back in South Australia.
They will need to self-isolate pending a negative result.
People who have been in Bendigo will need to get tested, but will not have to do a 14-day quarantine.
"Our thoughts are with everybody in Victoria at the moment, particularly those in Melbourne," Marshall said.
"Any outbreak in Australia is something we need to take extraordinarily seriously."
Chief Public Health officer Nicola Spurrier said it was "disappointing" to have to put in border restrictions because of the close ties between SA and Victoria, but the number of exposure sites was "concerning".
SA Health has identified three South Australians who were in the MCG rows of most concern at the Collingwood-Port Adelaide game - including one still in Victoria - along with another 464 who were in the "tier two" exposure category at the stadium.
Prof Spurrier urged any other South Australians who had been at the MCG to get tested since they may have come into contact with the infected person in an area away from their seat.
She reported two new cases today in South Australia - a man 50s and another in his 20s, both in hotel quarantine after arriving from overseas.
SA Health has sent 30,000 text messages to people who have been in Victoria since 6 May, asking them to fill in a questionnaire to see if they need to get tested or self-isolate.
Last year, SA Health's investigation into how the state's Parafield cluster broke out of a medi-hotel found a poorly ventilated corridor may have been to blame.
-ABC