According to Professor Mikhail Prokopenko, Australia is about to reach its COVID-19 peak, but it's essential we continue to adhere to strict social distancing measures to suppress the virus's spread. Credit: Professor Mikhail Prokopenko, University of Sydney

A new edition of a data study by the University of Sydney's Centre for Complex Systems published on prepublication server arXiv, has revealed that Australia is nearing the COVID-19 pandemic's incidence and prevalence peaks.

Led by Faculty of Engineering academic and Centre for Complex Systems Director, Professor Mikhail Prokopenko and using a peer-reviewed simulator, the research team recently found that if 90 percent of the population adopted social distancing, the spread of COVID-19 in Australia could be controlled by July 2020.

“The model updated with most recent data shows that Australia is very close to the incidence peak, and in two weeks’ time may be approaching the prevalence peak," said Professor Mikhail Prokopenko.

“What this means is that the number of new daily cases will begin to steadily reduce from now on. The number of all “active” cases may keep rising until mid-April, and then start to slowly decline," he said.

The data also showed that if Australians continue to comply with social distancing measures, we can expect a total of 8,000-10,000 cases over the course of the pandemic.

“Our research shows that if we continue with current social distancing measures the total number of people who will contract COVID-19 over the course of the pandemic in Australia could be about 8,000 - 10,000 people," said Professor Prokopenko.

"Initially there may have been a short delay with adopting strong social distancing measures, but over the last week we seem to be tracking well," he said.

The data study's new edition also showed that a three-day delay in adopting stronger social distancing measures would result in a lengthening of social distancing measures by approximately three weeks.

“We mustn’t be complacent – the best outcome is a short-term pain, long-term gain scenario. Even a three-day delay in adopting strong social distancing measures (around 90 percent) would cost us a three-week lengthening of the suppression period, meaning we would have to comply with social distancing for longer," said Professor Prokopenko.

“Of course, a rebound in the incidence and prevalence after the suppression period is possible, but it is not unavoidable. By July, more efficient and larger-scale testing methods are expected to be available. This, coupled with continued international travel restrictions, may very well be sufficient to prevent a resurgence of the disease," he said.

How the modelling worked

The AceMod simulator, a peer-reviewed method created by the Centre for Complex Systems, comprises over twenty-four million software agents, each with attributes of an anonymous individual, such as age, gender, occupation, susceptibility and immunity to diseases. Contact rates within different social contexts, such as households, household clusters, local neighbourhoods, schools, classrooms and workplaces are also built into the program.

The set of generated agents captures average characteristics of the real population and is calibrated to 2016 Australian Census data with respect to key demographic statistics.

The interactions result in transmission of the disease from infectious to susceptible individuals: given the contact and transmission rates, the simulation computes and updates agents’ states over time, starting from initial infections, seeded in international airports around Australia

In this scenario, 80 percent social distancing could either mean – any person in one household could go out once in five days, or, one member per family of five could go out daily, but the other four stay at home all the time.

Disclosure

The study, Modelling transmission and control of the COVID-19 pandemic in Australia, was authored by PhD students Sheryl Chang and Nathan Harding, as well as Dr Cameron Zachreson, Dr Oliver Cliff and Professor Mikhail Prokopenko from the University of Sydney’s Centre for Complex Systems, and Marie Bashir Institute for Infection Diseases and Biosecurity.