Australia ‘on track to mirror Europe’ in coronavirus case explosion

New research reveals the vast majority of coronavirus cases may be left undetected in the community.

Head of the biosecurity program at the University of NSW’s Kirby Institute Raina MacIntyre. Picture: UNSW

Experts are warning that Australia is on track to see an explosion of coronavirus cases similar to that being experienced in Europe, with new research revealing the vast majority of COVID-19 cases may be undetected in the community.

An extra 57 COVID-19 cases were confirmed in NSW on Wednesday, bringing the total in the state to 267, while Victoria recorded 27 new cases. Queensland’s case count rose to 94. Western Australia now has 35 COVID-19 cases, South Australia has 32, Tasmania has seven, the ACT three and the NT has one.

Research published on Wednesday in the academic journal Science estimated that as many as 86 per cent of all COVID-19 infections in China prior to lockdowns instituted in late January were not documented.

Undocumented infections are those that are asymptomatic or of such mild symptoms that the ­infected person does not seek medical care or obtain a diagnosis.

The high rate of estimated undiagnosed cases may indicate that the true rate of infection in countries around the world is much higher than official figures.

The head of the biosecurity program at the University of NSW’s Kirby Institute, Raina MacIntyre, said the doubling time of the epidemic in Australia was now three to four days. That was cause for concern, she said.

“The doubling time is now ­faster, which means we’re very much on that sharp upward trajectory of the epidemic curve,” she said. “Early on, it was more like six days, now it’s looking more like three or four days. That means things are going to get a lot worse a lot faster.”

Professor MacIntyre said the impact of social distancing measures announced by the federal government would not be seen for a couple of weeks, and it was only then that we would know whether they were successful in beginning to flatten the curve in case number growth.

“We’re probably where Italy was 20 days ago,” she said. “Whether we get as bad as Italy ­depends on how we handle the ­response from here on and how much we manage to reduce contact between people with the measures we’re undertaking.

“We’re looking like the countries in Europe that are experiencing quite severe surges in cases. It means the epidemic is getting bigger very fast.”

University of Melbourne epidemiologist Kathryn Snow cautioned against comparing Australia’s rate of growth in case numbers with countries like Italy or the US. “I don’t think what’s happened over the past week is necessarily the best predictor of what’s going to happen over the next few weeks,” Dr Snow said.

 

She said the social distancing measures being implemented by the federal government and workplaces may yet have a significant effect on slowing the growth in case numbers.

“I think we’re seeing more cases, and that’s really concerning,” Dr Snow said.

“But I think a lot of what is being reported at the moment is assuming the worst-case scenario is definitely going to happen. Whether it happens depends completely on what we do, and ­whether everyone follows the ­advice that’s being given out.

“I think these social distancing measures are going to have a really big impact, but we won’t see that impact for a couple of weeks.”

Emeritus professor John Dwyer said he remained concerned that the true number of cases in the community was much larger than the official figure, and there was no way to know the true spread of the disease without instituting widespread testing.

The government has now imported an extra 100,000 test kits after pathology labs across the country began running out of chemical reagent used in testing.

“We know that we are grossly underestimating the number of people infected in Australia because we’ve had to ration the testing,” Professor Dwyer said.