Lockdown!

Shannon Molloy from news.com.au

There are 55 ground crossings, four major arterial roads, 33 bridges and two waterways that extend across the border.

Melbourne will be plunged into a six-week lockdown following yesterday’s news of another surge of coronavirus – but it’s not the figure of 191 new cases in a day that worries experts.

Eighty per cent of the infections recorded on Tuesday, or 154, are being classified as ‘under investigation’ – meaning health authorities aren’t sure of the source of the spread.

Today, another 134 cases were confirmed and of those, 123 also can’t be immediately traced.

It’s a sign of potentially widespread community transmission, which has now been described as “a runaway train”, and adds to a growing trend observed in recent weeks.

Community transmission is a much more complex problem to tackle and will make Victoria’s second wave a bigger challenge than the first outbreak in March, Professor Adrian Esterman, a biostatistics expert and epidemiologist from the University of South Australia, explained.

“The thing is, cases that we know about and can trace, we can isolate those infected and do contact tracing, and basically close the transmission and stop it from spreading,” Prof Esterman said.

“It’s difficult for authorities to work out where the infection has come from. If you can’t do that, it means there are more cases out there.”

Melbourne will be shut down for six weeks as a result of the worrying resurgence of coronavirus in Victoria. Picture: Ian CurrieSource:News Corp Australia

Of the 2824 total cases of COVID-19 recorded in Victoria, infectious disease experts believe 438 are the result of community transmission.

Dr Alex Polyakov, a senior lecturer at the University of Melbourne and consultant at Royal Women’s Hospital, said those rates are cause for alarm.

“Once community transmission takes hold, it is almost impossible to control the spread with the currently implemented measures,” Dr Polyakov said.

Cases in hotel quarantine versus in the community: gross new daily cases. Picture: Covid19data.com.auSource:Supplied

The situation in Victoria is “grave” and locking down the capital and state’s northern border might not be enough to prevent a spread to other states, Professor Raina MacIntyre, head of the Biosecurity Program at the Kirby Institute at the University of NSW, said.

It’s probably too late, Professor MacIntyre said, and the detection of new outbreaks in New South Wales and other states within the next few weeks is likely.

“It is possible there has been seeding of infection to other states, and silent epidemic growth which has not yet being detected,” she said.

“The situation we are in is more serious that late March, because we have community transmission, which is much harder to track than infection in return travellers.”