Calls for caution on predictions Australia is on track for Italy’s COVID-19 ‘worst-case scenario’

About 8000 people in WA have been tested for the virus. Source: AAP

As worrying graphs charting the spread of the coronavirus across Australia and the world circulate on social media, biostatisticians and epidemiologists say we are still in a position to “flatten the curve”.

Disease experts have warned against sharing worst-case scenario modelling that shows Australia could be on track to experience a coronavirus crisis similar to that in Italy. 

As the government ramps up its response to the COVID-19 pandemic, graphs showing the predicted trajectory of the virus in Australia, based on the number of confirmed cases and data from other countries, have been shared widely on social media.

Many appear to show Australia travelling on a similar curve to Italy just weeks before the number of cases in the European country skyrocketed to almost 28,000 and its national death toll tipped 2,000.

On Wednesday, the number of cases in Australia neared 500 and the national death toll rose to six after an 86-year-old man died at a Sydney hospital

But University of Melbourne epidemiologist Kathryn Snow, who has an interest in health data, told SBS News steadfast comparisons to Italy are misguided as it’s the “worst-case example”. 

“A lot of countries have been at the point that we are at now, and they’ve all had different experiences,” she said, pointing to Singapore and Hong Kong which have avoided a significant spike in cases despite early signs of outbreaks.

“What seems to have happened in Italy is that it took off very, very quickly and the health system wasn’t prepared. We are absolutely doing the right things to head off ending up in that situation.”

She also said it was dangerous for the public to rely on outcome scenarios from unofficial sources.

“Some of the graphs and the modelling that is being shared widely on social media are being done by people who are not infectious disease experts, they’re not mathematical modelling experts, they’re amateur people who are taking an interest in this topic,” she said.

“Infectious disease modelling is very, very complex. It’s something that people learn a lifetime to do and do effectively.” 

Dr Snow described many of the blog posts and viral social media posts as adopting an “inappropriate certainty” when the reality of disease modelling is that it is by nature uncertain and actions, such as the government’s ban on inside gatherings of over 100 people or mass social distancing, could significantly alter the trajectory of the pandemic.

Sydney-based academic and general practitioner Michael Tam is one of many people sharing modelling of the disease from his Facebook page in the absence of detailed predictions from health authorities.

In a graph that has been shared hundreds of times, he predicted the total number of COVID-19 infections in Australia to reach the thousands within two weeks but said the modelling was relying on a number of assumptions that may not be correct.

“It isn’t the future, but it’s a possible estimate of what it could be like assuming that the pattern we’ve seen so far is going to continue,” he told SBS News.

“But hopefully we’re different and don’t follow the Europeans and the United States and things are a lot better … but two weeks is not that far away and in my view, it’s useful to understand that is the sort of thing that could be happening.”

Dr Tam said he first started mapping the data after he noticed that Australia seemed to be entering an “exponential phase” - where the number of cases would rapidly grow - of the outbreak but he hadn’t seen that communicated to the public.

He began by projecting up to Easter Sunday, approximately three and a half weeks away, but on Tuesday reduced the graph to two weeks in the future due to the capacity for things to change long term.

“The further we go, the less likely projections are to be correct. The closer in, the more likely they are to represent reality,” he said. “But what the chart demonstrates is that we are probably not in a holding pattern in Australia, it does appear to have taken off.”

Another post featuring a graph comparing countries’ COVID-19 case growth after 100 infections has been shared more than 12,000 times after it was posted to Facebook last week by clinical immunologist and researcher at the Garvan Institute, Dan Suan, who urged people to take urgent action to slow the curve.

Meanwhile, on Tuesday, ABC News reported that more than 3,500 Australian doctors had signed an open letter to the government, calling for strict lockdowns to be implemented and more health resources.

Dr Snow said it was “totally understandable” that people working on the frontline of the crisis, like doctors, would be fearing the worst-case scenario, but said it wasn’t helpful for the general public to be seeing that in their Facebook and Twitter feeds.

“The worst-case scenario is not necessarily what’s going to happen,” she said. 

Government health authorities have been hesitant to predict specific numbers of expected cases, but comments on the potential spread of the disease from Australia’s deputy chief medical officer Paul Kelly caused widespread panic earlier this week.

Dr Kelly said they were preparing for an infection rate of “somewhere in the range of” 20 to 60 per cent on Monday.

"The death rate is about one per cent, you can do the maths," he said. "This is an infectious disease, the more we can do to separate people and stop that infection spreading the better."

With a 20 per cent infection rate, Australia could see more than 50,000 deaths. 

Biostatistician and epidemiologist Adrian Esterman, who has more than 50 years experience in the field, told SBS News that even the government’s broad estimate is “guessing a bit” as the current true number of cases in Australia is unknown.

“Even very, very good mathematical modellers rely on parameters that they put into their equations,” he said. 

“We don’t know what percentage of the population is infected at the moment. We can guess, but that’s all it is.”

More than 196,000 COVID-19 cases have so far been confirmed across the world. Of these, approximately 80,000 have recovered and more than 7,800 have died.

Dr Snow believes Australia is in a good position globally to handle the pandemic and should be able to avoid a situation like Italy where hospitals have become overwhelmed and people are being forced to go without treatment.

“We definitely will see more cases in Australia, that’s for sure, but what really matters is how quickly those cases happen and that they’re identified well, treated appropriately and that all of us are following the government advice and doing the right thing to slow the epidemic down,” Dr Snow said.

Professor Esterman added that Italy’s large elderly population would have contributed to the stress on hospitals. 

The Department of Health is advising people to practice social distancing to reduce the spread of the virus, which includes staying home if you are feeling unwell, avoiding non-essential large gatherings, keeping a distance of 1.5 metres from other people and minimising contact with at-risk groups, such as older people and people with a pre-existing health condition.

If these measures are implemented, Australia is still in a position to “flatten the curve”, Dr Snow said, referring to an outcome where the number of cases is spread out over a longer period of time to ensure the health care system doesn’t surpass its capacity to treat at-risk people.

“There are a lot of things that all of us can do to protect each other,” Dr Snow said. “It’s not just about protecting ourselves and our families, it’s also about protecting other people and the health system as well.”

Coronavirus symptoms can range from mild illness to pneumonia, according to the Federal Government's website, and can include a fever, coughing, sore throat, fatigue and shortness of breath.

As of Wednesday morning, only people who have recently travelled from overseas or have been in contact with a confirmed COVID-19 case and experienced symptoms within 14 days are advised to be tested.

If you believe you may have contracted the virus, call your doctor, don’t visit, or contact the national Coronavirus Health Information Hotline on 1800 020 080.

If you are struggling to breathe or experiencing a medical emergency, call 000.

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