Coronavirus: Australia nervously watches Melbourne guinea pig for local lockdowns

Much rests on the outcome of the struggle to control a resurgence of coronavirus in the suburbs of Melbourne.

A member of the Australian Defence Force takes a swab sample at a drive-through COVID-19 coronavirus testing station in the Melbourne suburb of Fawkner on Thursday. Picture: AFP

Much rests on the outcome of the struggle to control a resurgence of coronavirus in the suburbs of Melbourne. The outbreaks are pushing the capacity of public health bodies to test, trace and isolate cases to the limit.

And health authorities in other states, particularly NSW, are watching closely, aware that the battle to suppress a second wave of COVID-19 in Melbourne serves as a test case for the effectiveness of widespread testing and localised lockdowns in stemming the spread of the virus.

NSW has explicitly ruled out a return to a statewide lockdown, even in the event of a second wave of disease. That means the strategy of testing widely, rigorous contact tracing, and isolation will serve as the frontline defence if, as governments have warned is likely, outbreaks occur with some regularity until a vaccine arrives.

Second wave or not

Experts are divided on whether the resurgence of COVID-19 in Melbourne can be characterised as a “second wave”. Daily case numbers are approaching the levels seen at the peak of the first wave in April, and the biggest worry for authorities is there is a high level of community transmission.

“What’s happening in Melbourne doesn’t fulfil a classic definition of a second wave,” says Marylouise McLaws, a professor of epidemiology at the University of NSW and an Adviser to the World Health Organisation.

“We toss this term around, and it has a lot of emotional connotation to it. A classic use of the term would be when the epidemiology within that area had reached close to zero and one thinks that your interventions have been successful, and then the disease comes in again.”

Melbourne residents line up to get a COVID-19 test. Picture: Getty

“And given that our authorities have reminded us that they haven’t been going for zero, you wouldn’t expect a second wave because, if you’re not going for zero, you’ll always have the risk of disease.

“These resurgences will always happen. This happened in SARS, it happened in MERS, it happened in Ebola. So to get cranky with the community is a bit like whistling in the wind. It’s a waste of energy and oxygen. To me it indicates that leaders are getting tired. They should be asking themselves ‘what did I not get right when I was communicating with the public?’.”

The head of the respiratory medicine pathogenesis group at the University of Technology Sydney and the Woolcock Institute, Brain Oliver, describes the resurgence of COVID-19 in Melbourne as a “small blip”.

Infection rates

In the UK at the peak of the outbreak, 73 people per million in the population were infected. At the peak of the first wave in Australia, 13 people per million in the population were infected.

“In Australia, even with this slight blip in Melbourne, we’re probably running at about half a person infected per million population right now,” Professor Oliver says. “So comparatively, on a world scale, this is sort of a really small thing.

“But I think the danger in describing it as being a really small thing is that people then ignore it. What’s occurring in Melbourne, if it were left uncontrolled, could result in a massive outbreak. If we weren’t on top of it, it would escalate.”

From the time that restrictions began to be lifted, the country’s leaders have been at pains to point out that outbreaks of COVID-19 would occur. Australia’s strategy has been one of suppression, not elimination.

The Stamford Plaza hotel in Little Collins Street has been linked to a cluster of cases. Picture: Jay Town

Setting the standard

The commonwealth’s acting chief officer Paul Kelly this week described Victoria’s response to the virus resurgence of widespread testing, contact tracing and quarantining close contacts of cases as the model that would be followed whenever future outbreaks occur.

The methods were used successfully in quelling a large outbreak of COVID-19 in northwest Tasmania, Kelly said.

“All of these things were done in northwest Tasmania, now are being rolled out in Melbourne,” he says. “We learnt then that going hard and going quickly was important. And testing, tracing and isolating are the three main weapons we have, really, to fight this virus, in the absence of a vaccine, in the absence of a universally effective treatment. This is the way it has played in many other countries in relation to these local responses to local outbreaks.”

In hotspot suburbs of Melbourne, health authorities are confident they’re picking up virtually every case of COVID-19 because of the very high level of testing that’s being conducted. Health workers are going door-to-door with test kits, and up to 18,000 tests are being conducted daily, with close to half of the population of affected suburbs estimated to have been tested.

Interstate help has been employed to boost the ranks of contact tracers. The daily tally of new cases has levelled out this week, with hopes rising that cases will start to fall next week. But experts say that the test, trace and isolate strategy will only work if case numbers are kept within certain limits. Once case numbers climb too high, it’s no longer feasible to trace all close contacts.

“This will be a big challenge for our public health infrastructure,” says Gerry FitzGerald, a professor of public health at Queensland University of Technology. “If we can identify all of the cases, make sure we’ve identified the people they’ve been in contact with, make sure those people are isolated and tested, if you do that then you’ve got a chance of actually controlling this outbreak.

“The World Health Organisation, right from the start, has said, very, very consistently that the way to control outbreaks is to identify the cases, to test, test and test again, and track and trace. That message has been consistent and almost dogmatic and, ultimately, that is the way of controlling an outbreak.”

Victorian Premier Daniel Andrews. Picture: Wayne Taylor

Victorian Premier Daniel Andrews has not ruled out a statewide lockdown if cases continue to rise and spread widely to other suburbs. But localised lockdowns could be the norm if outbreaks continue to occur around the country, says the director of the University of Queensland’s Centre for Clinical Research, David Paterson.

“I think our future is that any lockdowns are going to be very focused,” Paterson says. “I think that’s an acceptable trade off. I think everyone is very, very aware of the inadvertent impacts of widespread lockdowns including the impact on mental health, as well as the very significant economic issues that are associated with a broad lockdown.

“But I think targeted geographically-restricted lockdowns are probably going to be part of our future moving forward.”

Human behaviour

The “wildcard” in whether Melbourne will be able to contain its outbreaks of disease is human behaviour, according to Shane Thomas, a professor at the ANU’s Research School of Population Health. He’s concerned that as social distancing restrictions have been eased, a message has been sent that life can go back to normal.

“I think that if you look at what has happened over the last few weeks, qualitatively in the street there’s a lot more people out and they’re not observing the social distancing rules,” he says. “This is a highly infectious disease. People seem to be very blase about it. I think that qualitatively there’s been a very big kind of relaxation in how people are behaving in the street.

“What lockdown does is it forces people to socially distance and to reduce their contact with other people, but that’s something that we should all be doing all of the time, not just in particular geographic locations. The suburbs that are now in lockdown in Melbourne are kind of paying the price for the collective behaviour of the community.”

Together with the localised lockdowns, how effective the strategy of test, trace and isolate has been in Melbourne will be evident over the next week. It’s a method that is likely to have to be deployed on many occasions in the future, says professor of epidemiology at the University of Melbourne, Tony Blakely.

“This has been a big wake up call for the public,” he says. “And these outbreaks will happen again and again and again. That is the reality of living in a suppression world. This virus will keep popping up. What we are seeing now is our reality going forward.”

Professor McLaws says that whilever Australia’s strategy remains one of suppression, not elimination, public health authorities will face a huge challenge containing the spread of disease.

“This will be a sobering lesson for the rest of Australia, that we cannot control this easily if we’re not going to go for close to zero.”