Those who visited exposure sites and arrived in Victoria after midnight on Friday need to get tested for the virus immediately and isolate for 14 days.
The Victorian government will reveal more advice on Friday for travellers from NSW.
Anyone who has visited exposure sites should contact the Department of Health and Human Services so they can be “supported to safely and appropriately self isolate and get tested”.
“The DHHS will be conducting spot checks on flights arriving from Sydney to remind passengers that anyone who has visited the northern beaches or the other exposure sites must get tested immediately and self isolate,” a department spokesman said.
University of Melbourne epidemiologist Nancy Baxter said the cluster was “extremely concerning”, as the index case of the cluster has not been identified, and would have been in the community.
“You now [have] seven days where this has been circulating … I would anticipate a number of additional people will be identified as having COVID-19,” she told ABC Breakfast.
“I know it’s a hard message to hear around Christmas time, when people do want to socialise, but COVID-19 is waiting for an opportunity.
“Although we’re doing much better in Australia than elsewhere, we can’t let our guard down. It’s not business as usual. We do have to maintain some restrictions and differences than our usual lives, even over the holiday period.”
Tasmania has shut its border to anyone who has been in the northern beaches since December 11.
Queensland and the Northern Territory, like Victoria, have asked people who have been in the northern beaches to self-isolate for 14 days.
Federal Tourism Minister Simon Birmingham called the border closures and newly imposed quarantine procedures for some NSW residents “a little bit premature” on Friday morning.
“[NSW] has demonstrated time and time and time again through 2020 that they contain these things, they get on top of them and they have stopped the spread themselves without really the need for these types of measures during the course of the year,” he told Nine’s Today show.
“It obviously does heighten a lot of uncertainty and there [are] so many Australian jobs dependent on our tourism and travel industry. They just can’t afford to take another hit if this turns out to be an unnecessary hit from some states and territories.”
Ashleigh McMillan is a breaking news reporter at The Age. Got a story? Email me at firstname.lastname@example.org