The current state of COVID-19 in Australia: importation and spread

Jessica Liebig; Raja Jurdak; Ahmad El Shoghri; Dean Paini

The data published by the WHO shows that the time between the first reported case in a country and the number of cases in that country rising above 20 is on average 11 days. An epidemic is unlikely to fade out without intervention after 20 individuals have been infected and will begin to follow an exponential growth [20] . In Figure 2 we have overlaid the epidemic curves of Australia and the nine countries that have reported the highest number of cases. For comparison, each epidemic curve is plotted from the time the reported number of cases rose above 100 on semi-logarithmic axes. The epidemic curves of the European countries, the United States and Australia closely follow straight lines, suggesting exponential growth rates. The Chinese, Iranian and South Korean curves show an initial exponential growth, for approximately seven days, before the reported number of cases increases less rapidly.