Early signs that COVID-19 is being contained in Australia

Dear Editor,

The COVID-19 pandemic is overwhelming many national healthcare networks and crippling many economies. As of 24 April 2020 (11:08AM GMT), a total of 2721,354 confirmed cases, 191,231 deaths and 745,605 recovered cases have been recorded in over 150 countries.¹ To date, the reported case-fatality varies from 2.3% (in China) to 7.2% (in Italy), with substantially higher fatality among older populations, and those with co-morbidities.²

Australia has a population of approximately 26 million, of whom 15.4% are aged 65 years and above.³ The first case of COVID-19 infection was reported on 26 January 2020. As of 24 April 2020, there were 6675 known cases, and 78 deaths. Both the federal and state/territory governments have enforced strict public health measures to control this outbreak.⁴ In the present study, we report on the epidemiology of the COVID-19 outbreak in Australia observed thus far, as well as the predicted future numbers of cases, deaths and ICU admissions, and associated ICU costs.

In 2018–2019, total ICU capacity across public and private hospitals in Australia comprised 2229 beds, and the mean cost of each ICU bed-day was AUD $5040.^{5 , 6} We forecasted the number of beds required for COVID-19 patients over time and its associated costs by applying the following conditions: (i) allocation of 10%, 30% and 50% of ICU beds for COVID-19; (ii) 3% (as currently observed in Australia), 5% (China) and 12% (Italy) of confirmed cases requiring intensive care⁷; (iii) mean ICU stay between 7 and 14 days; and (iv) mean hospital stay prior to intensive care between 7 and 14 days.⁸

Evaluation of temporal changes in trend and dynamic time series forecasting were performed by Box-Jenkins autoregressive integrated moving average and regression models. Predicted models were validated by review of mean absolute percentage errors and r-squared values.

We estimated the mortality rate by dividing the number of deaths on a given day by the number of patients with confirmed COVID-19 infection (i) on the same day and (ii) seven days before, given that patients who die on any given day were infected much earlier. On this basis, case fatality from COVID-19 infection in Australia is presently between 0.4% to 3.0%. Fig. 1 depicts the number of new cases observed over time. The number of new cases have decreased since 29 March 2020, with New South Wales, Victoria, Queensland and South Australia all reporting less new cases in the three to five days prior (Supplement Figures A and B). Hence the rate of rise in incidence has slowed, mindful of the limitations of applying trends to short periods of time. Based on extrapolation of trends prior to 29 March 2020, the Australian healthcare system would have been over-run by over 12,000 confirmed cases by 12 April 2020 (Supplement Figure C). Furthermore, ICU capacity would have been exceeded by mid to end April 2020 (Supplement Figure D). The associated ICU costs would have amounted to between AUD $8.82 million and $34.38 million if capped at the current maximum number of ICU beds. Notably, Australia has successfully averted these outcomes through timely implementation and strict enforcement of bans on travel and social gatherings, as well as concerted diagnostic and management strategies.

Fig. 1.

Public health measures undertaken to contain COVID-19 in Australia.

The results of our analysis suggest that Australia is on its way joining China and South Korea in ‘flattening the curve’.

Declaration of Competing Interest

None