The state broke its 12-day streak without locally acquired coronavirus cases on Wednesday, after a Sydney airport driver was confirmed to have the virus and two mystery cases popped up on the northern beaches. Another two cases in the northern beaches were confirmed this morning, as efforts to control the outbreak intensified.

Seven venues on the northern beaches peninsula have been identified as places recently visited by an infected man and woman. People are queuing up at Mona Vale Hospital on Thursday to get tested for the virus, and local aged care facilities will be closed to visitors.

NSW Premier Gladys Berejiklian today said a crackdown on airline and associated workers would be announced in the coming days and the government was taking the outbreak seriously. The van driver was from Sydney’s south.

“At the moment the priority for us is to identify the primary source,” Berejiklian said.

The latest cases have prompted questions about whether the recently opened Queensland and WA borders will again be shut to people from NSW over Christmas. The next 24-48 hours will prove critical.

Acting Queensland Premier Steven Miles said anyone in the state who had been to the northern beaches should check the NSW Health website, while anyone planning on travelling there should be alert to the risk of infection.

”We know there will be many Queenslanders currently planning to head to Sydney for Christmas to see families and friends and relatives,” Miles said.

While the northern beaches outbreak has yet to trigger consideration of Queensland border restrictions, Miles said authorities were closely monitoring the NSW response “and whether they can get on top of it”.

The official definition of a hotspot, warranting travel restrictions, is 30 community-acquired cases over three days.

WA Premier Mark McGowan didn’t rule out reimposing restrictions if further infections were detected in NSW, saying “if the advice comes back that we need to put up a hard border, then we will”.

NSW Health Minister Brad Hazzard today dismissed the need to restrict movements or activities, saying only that it was prudent that northern beaches residents get tested if they held any concerns. He noted that 3000 people were dying of COVID-19 in the United States every day.

The two northern beaches cases confirmed yesterday – a woman in her 60s and a man in his 70s – are close contacts of each other but authorities have not found a source for their infections. Today’s two cases live at opposite ends of the northern beaches and any links have yet to be identified.

Alerts are out for several areas in the northern beaches, particularly Avalon and Palm Beach, after the first two infected locals moved through the community while contagious.

NSW Health is urgently undertaking genomic sequencing and contact tracing to stem the damage and identify the source of the infections. The genome sequencing results will be available on Thursday or Friday.

The cases were identified just hours after a 45-year-old driver transporting international air crew members to and from Sydney Airport and their hotels was confirmed COVID-positive.

NSW is considering changes to quarantining requirements for international air crew.

NSW Chief Health Officer Kerry Chant told reporters on Wednesday the southwest Sydney man worked only with air crew members and was not involved in regular taxi services for the public. He also wore a mask while working.

ButHazzard said a stronger regime for international air crew members may be required to eliminate future risk – likely by placing air crew in full hotel quarantine until their flight back out of Australia.

While they do not have total liberty, air crew have more freedom of movement than returned travellers in hotel quarantine.

Hazzard said NSW may act unilaterally if the national cabinet cannot agree.

“Our inclination is to say to international air crews and airlines … crews coming in to NSW will most likely be required to quarantine in the same way as other international visitors,” the minister told reporters.

At least 2000 international air crew members touch down in Sydney each week, with turnarounds of up to 72 hours before flying out again.

An epidemiologist says airline crew members’ exemption from state-run hotel quarantine procedures is a “potential loophole in the system” that Australia cannot afford, and thinks the risk should be re-assessed in every state.

Flight crews are exempt from mandatory quarantine, and can instead isolate at home or other accommodation under the current guidelines from the Australian Health Protection Principal Committee (AHPPC).

But Burnet Institute epidemiologist Mike Toole said “it just doesn’t make sense” to treat flight crews as less risky than passengers.

“Hindsight is always 20-20, but it seems to me that the risk of airline crew being infected is no lower than the risk of an arriving passenger,” he said.

“Many of them are coming from countries that have very high rates of COVID infection.”

Professor Toole said transporting airline crew on buses was creating another problem, especially if passengers were not wearing masks, given mounting evidence the virus could spread through the air.

“They should be subject to the same conditions as arriving passengers — so either the police or the ADF actually supervise the transport to a hotel, and then the police supervise the whole experience in the hotel,” he said.

“I’m not saying they should quarantine for 14 days, that’s not practical. But when it’s time to go on their next flight, I think they should be transported to the airport using the same precautions as arriving passengers are currently transported from the airport.”

Teri O’Toole, from the Flight Attendants Association of Australia (FAAA), said only a small number of international flights were currently operated by Australian carriers.

O’Toole, the federal secretary of the FAAA’s international division, said when local crews were overseas they were “under strict lockdown” in hotels and entered self-quarantine again when they returned to Australia.

She said there had been no known positive cases among Australian-based international flight crews since earlier this year, around the time of the Ruby Princess debacle.

“We’re doing the very best that we can, working with the airlines to ensure the wearing of masks, provision of personal protective equipment and the procedures the crew are going through keep them as safe as possible and it has been working,” she said.

-AAP