The Victorian government’s snap decision to close its border with NSW may have created a “COVID-19 corridor” with cases coming into the state unchecked, one of the country’s leading epidemiologists has warned.

The last-minute announcement on Thursday created scenes of chaos on the border as Victorians rushed to get home before the closure. Those trying to get back into the state will now be turned away.

It comes amid growing concerns that NSW has not gone sufficiently “hard and fast” to avoid a later, Melbourne-style harsh lockdown. Health officials said the state was “playing the odds” with its response.

@NSWHealth has revised its advice for a western Sydney liquor store visited by confirmed cases of COVID-19. pic.twitter.com/y8kp55KNsc

— NSW Health (@NSWHealth) January 2, 2021

There were seven local coronavirus cases recorded in NSW on Saturday.

AMA chief Omar Khorshid wants the Sydney Test played in an empty stadium. Photo: AMA

While NSW Premier Gladys Berejiklian announced some restrictions – including mandating masks indoors – health experts have pleaded with her to reconsider holding the third Test at the SCG next week.

Australian Medical Association president Dr Omar Khorshid said the match had the potential to “supercharge” the spread of the virus.

In Victoria on Saturday, 10 new cases were recorded, but Deakin University’s chair in epidemiology, Catherine Bennett, said the state was better placed to handle this outbreak.

What does worry Dr Bennett is the way in which the state sealed its border with NSW.

While the contact tracing teams appeared to have a handle on the outbreak, the rushed decision to close the border may have brought in  cases of the virus, she said.

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“What it did was create a 36-hour corridor for people from Sydney to return,” Professor Bennett said.

Previously those who had been in a Sydney red zone were not allowed to re-enter the state at all. 

But that didn’t guarantee no one crossed.

“They announced in the presser themselves that not all the permits were being checked,” Professor Bennett said.

“So did anyone come from Sydney? Will they get tests and quarantine for 14 days? They’ll be relying on that.

“In a step to be safe, we might have opened a risk corridor.”

Victorian residents returning from NSW are being asked to get tested immediately. Professor Bennett said there was a concern the long queues and waits of up to seven hours would deter compliance.

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Victoria’s testing commander, Jeroen Weimar, acknowledged many people had waited in hour-long lines for tests on Saturday.

“I apologise for the extended delays that we have in place,” he said, adding that more staff were being bought on to manage demand.

Professor Bennett said it was vital that people be tested.

“The concern is they go, queue, get sent home because they won’t get to the front of the line before close, and then not come back,” she said.

“That’s a tragedy to lose people.”

Both the NSW and Victorian contact-tracing systems have been working well, and with the help of the community the case numbers should come down, she said.

“Now, more than ever, there is an opportunity to look at both systems, NSW and Victoria, how they are operating and compare them,” Professor Bennett said.

“I’m hoping that will bring out the best in both. Let’s have some healthy competition to show how you can close it down without widespread restrictions.”

‘Playing the odds’

Australian Medical Association vice-president Chris Moy said the NSW government had been “playing the odds” by not putting the whole city in a short, sharp lockdown, as Adelaide did when cases broke out.

“Gladys says she wants to hold her nerve, but by holding the nerve you’re relying on contact tracing, you’re relying on testing,” Dr Moy said.

This was concerning because NSW had had several days of low test numbers, he said.

Australian Medical Association vice-president Chris Moy.

“They’ve had days of 60,000 tests, but there has been days when there have been only 16,000 to 17,000,” Dr Moy said.

More than 137,000 tests have been done across the state this week, but that is down from 299,295 on the previous week.

Dr Moy said it is not enough.

“They need 30,00-40,000 tests a day to have an 80 per cent chance of finding it, and even then you might miss cases,” he said.

“If your testing ability is low, you’re playing the odds … you risk a big outbreak.”

Dr Moy said it had put Sydney and the rest of the country “at risk” of a serious situation that might require an extended lockdown.

“It would be great if I’m wrong,” he said.

“Sydney could get lucky – they could get it under control. But it will still take several weeks.”

Sydneysiders are being encouraged to get tested. Photo: AAP