Pool via Getty Images

Sydney was told on Friday to expect considerably more COVID-19 cases as NSW Health scrambled to trace how an “international strain” of the virus entered the community, throwing Christmas plans into chaos. 

After reporting two new cases in the Sydney suburb of Avalon the previous day, authorities said on Thursday the number had jumped to 17, prompting a request for all 250,000 residents in the Northern Beaches to stay home for three days.

NSW Premier Gladys Berejiklian confirmed the new cluster, which brought an end to a two-week run without any locally acquired cases, is an international strain although experts are yet to work out how it got into the community. 

Greater Sydney is on high alert with the premier calling the next 24-48 hours “critical”. 

“We’re bracing ourselves for more cases today, no doubt about that,” she told ABC’s ‘News Breakfast’.  

“We’re extremely concerned.

“People in the Northern Beaches who may have had the disease and not known about it, may have mingled with people throughout Sydney, we’re taking this extremely seriously. We want to get on top of it as soon as we can, to give people as normal a Christmas as possible.”

People who have visited the following Northern Beaches locations should get tested immediately and isolate until they receive a negative result:

• Woolworths Mona Vale, 25/29 Park St, Mona Vale, 13 December, 12-12.30pm
• Aldi Mona Vale, 13 Bungan St, Mona Vale, 13 December, 12.45-1.30pm
• Avalon Beach Surf Life Saving Club, 13, 14 and 15 December, 9-9.30am
• Palm Beach Rockpool, LOT 1 Rock Bath Rd, Palm Beach, 14 December, 9:30-10:30am
• Woolworths Avalon, 74 Old Barrenjoey Rd, Avalon Beach, 14 December 5-5.30pm
• Chemist Warehouse, 4/74 Old Barrenjoey Rd, Avalon Beach, 14 December 5.20‑5.25pm
• Commonwealth Bank, 47 Avalon Parade, Avalon Beach, 15 December, 12-12.15pm
• Mitre 10, 49 Avalon Parade, Avalon Beach, 15 December, 12-12.20pm
• Roof Racks World, 13/87 Reserve Rd, Artarmon, 15 December, 2-2:30pm
• HongFa BBQ Restaurant, Dee Why, 15 December 4.30-4.45pm
• Dee Why Fruit Market, 33 Oaks Avenue, Dee Why, 15 December, 4.45-4.55pm
• North Avalon Cellars, 4/3 N Avalon Rd, Avalon Beach, 15 December, 6-6.05pm
• Careel Bay Dog Park and Hitchcock Park, Barrenjoey Rd, Avalon, 16 December 7‑7:30am
• Palm Beach Pool, LOT 1 Rock Bath Rd, Palm Beach, 16 December, 8am-9am
• Brot and Wurst, 1442 Pittwater Rd, North Narrabeen, 16 December, 2pm-2:05pm
• Avalon Beach Post Shop, 45 Avalon Parade, Avalon Beach, 16 December 3.30-3.50pm

 A confirmed case also travelled between the following stations on Monday December 14 at the following times: 

• Roseville to Redfern, 6.50-7.40am
• Redfern to Milsons Point, 11.20am-11.45am
• Milsons Point to Roseville, 3.15-3.40pm

Other passengers are considered to be casual contacts, and should get tested and isolate until a negative result is received.

A confirmed case attended the Media City office in Eveleigh on Monday.  People who worked in that building on Monday have been told to get tested. 

People from outside the Northern Beaches were urged not to go there, where people are lining up for kilometers at emergency pop-up test clinics. 

Berejiklian will provide an update with the state’s chief medical officer at 11am. 

Earlier this week NSW formally ended a work-from-home public health order due to low numbers of cases.

Australia has been cautiously opening its internal borders and easing social distancing curbs in recent weeks, due to low or no local cases in most of the eight states and territories.

Is Christmas cancelled for NSW and what’s happening with borders? 

After the NSW authorities reported the new cluster, Western Australia ordered all travellers from NSW to self-isolate and get a COVID-19 test within 24 hours.

Queensland ordered visitors from the Northern Beaches, who have been in the sunshine state since December 11, to self-isolate for two weeks.

Trade and Finance Minister Simon Birmingham urged state and territory leaders to “exercise restraint” when it comes to closing borders due to this latest outbreak. 

“New South Wales has shown a world leading capacity and capability to get on top of these clusters throughout 2020,” he said. 

“Their systems and their processes that lead to the tracing, the contract tracing, the isolating are exceptional and we should have confidence that they can do it again.”

Australia has reported just over 28,000 coronavirus cases and 908 deaths since the pandemic began. Until Wednesday, most active cases in the country were returned overseas travellers in hotel quarantine.