The Holiday Inn quarantine facility at Melbourne Airport will close after two staffers at the hotel contracted COVID-19 while on the job.
The accommodation facility will be closed for an indefinite period for a "terminal clean" - the highest of cleaning standards.
As such, all guests currently accommodated at the Holiday Inn will be moved to alternative hotels while the clean is completed.
In addition, anyone who has spent more than 15 minutes inside the hotel, be that residents, workers, or visitors, is now considered a primary close contact of the outbreak and will be required to isolate for two weeks.
"That will be very challenging for those people, but we simply cannot run the risk of this hyper infectious strain of COVID-19 getting out into the community," Victoria Premier Daniel Andrews said.
"An abundance of caution is required in this case."
Victorian Chief Health Officer Professor Brett Sutton explained the Department of Health's working hypothesis about the outbreak within the facility.
He said it occurred due to a medical device called a nebuliser.
"It vaporises medication or liquid into a very fine mist, and it that's breathed in, especially when it's used as medication, and someone is infectious or later tests positive, then that picks up the virus and that mist can then be suspended in the air with very fine aerosolised particles," Sutton said.
"So we think that the exposures are all to that event, the use of a nebuliser, which meant that the virus was carried out into the corridor and exposed the authorised officer, the food and beverage service worker, and also the other resident."
Victoria reported two new locally acquired cases of COVID-19 yesterday: a worker at the Holiday Inn, and a resident of the facility who had left quarantine and tested positive two days later.
Globally there are now more than 107 million confirmed cases of COVID-19, and more than 2.3 million deaths attributed to the coronavirus.
Updated at 11.05am AEDT on 10 February 2021.
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