Today we introduce a new graph to track the spread of COVID-19 in Australia. Grattan Institute currently produces a daily track of the pandemic’s trajectory compared to other countries. It is plotted on a logarithmic scale consistent with the initial spread of disease, where recorded infections doubled every 3-to-4 days.
Our new chart below, inspired by Aatish Bhatia, shows total COVID-19 cases on the horizontal axis and new weekly cases on the vertical axis, both on a log scale.
As exponential growth takes hold in a country, new weekly cases grow so quickly that they make up almost the entire total. Countries on this path move diagonally.
But as new cases start to slow, countries turn a corner.
Five countries are highlighted, some with trajectories like ours, others not so. The United States and United Kingdom had several weeks of exponential growth, with little sign of slow down.
China hit 80,000 total cases and then sharply turned the corner, reducing new cases dramatically. But while new cases have fallen in China, and South Korea like it, new cases have lingered at between 200 and 600 per week. This shows that getting to near-zero new cases is not a given after countries slow the spread.
Singapore minimised the spread of COVID-19 early by tightly controlling its borders and implementing broad contact tracing. But it then had a dreaded ‘second wave’ – a second round of rapid growth in new cases. In response, Singapore has introduced more stringent social or spatial distancing measures, closing schools and ordering non-essential workers to work from home.
Australia has turned a corner, but we cannot afford to become complacent. Relaxing our spatial distancing efforts could result in the number of new COVID-19 cases in the community increasing again. Lifting our restrictions too early could result in a second wave of rapid growth.
The message from Grattan’s new graph is clear: Australia must be careful about when we lift restrictions, what restrictions we lift, and in what order.