While the media focus has been on the possible confrontation between Prime Minister Tony Abbott and Russian President Vladimir Putin at the upcoming Brisbane G20 Summit, it is the Ebola crisis that may yet take centre stage.

If the virus outbreak continues to confound international efforts over the next four weeks, G20 leaders may find themselves best placed to coordinate the international crisis response. In a worst-case scenario, the G20 is also the appropriate forum to discuss what conditions are severe enough to warrant policy responses (such as the closing of borders) that could impact on global trade and financial flows. 

Just as with the 2009 London G20 summit, where leaders spoke with one voice on the global financial crisis, it would be imperative for G20 leaders to demonstrate that countries are cooperating and taking action in order to restore confidence.

When Australia took on the G20 presidency and began planning for 2014, no thought would have been given to the Brisbane Summit dealing with a potential global health crisis. But this is an emerging issue that the G20 should confront, and in doing so demonstrate the value of the forum in fostering cooperation to deal with pressing global problems.

Besides the compelling humanitarian case, there is also an economic one. Most visibly this is seen in the devastating human cost of the thousands of lives lost and the detrimental impacts that the World Bank has estimated on the economies and budgets of Guinea, Sierra Leone and Liberia.

In today's interconnected world it has also proven impossible to prevent Ebola from spreading to some advanced G20 economies.

Concerns over widespread infection have triggered debates about what preventative measures are needed, and at what cost. It has also led to some troubling recommendations in the name of containment, such as calls in several countries to unilaterally close borders.

If earlier public health scares such as from swine flu, bird flu and SARS are anything to go by, the largest economic impact of the epidemic will come from people changing their behaviour to reduce their risk of exposure, such as by not traveling (even to Ebola-free countries) or paring back spending to just essential goods to minimise their contact with others. People will take these precautions even if not directly affected by the risks, so it can become a global issue.

Last week my colleague Annmaree O'Keeffe discussed the lessons from these earlier pandemic scares and concluded that international collaboration is critical for an effective response. She argued that it is vital developed nations lend support to developing ones.

The coordinated international emergency response to date has been substantial, headlined by more than US$1.4 billion pledged by the US, China, the UK and EU alone and more than US$700 million committed by the World Bank, IMF and the African Development Bank.  As World Bank President Jim Yong Kim has noted, we're still playing catch up, and there are challenges in containing the outbreak, but the World Health Organisation (WHO) now expects the Ebola epidemic to peak by early December.

WHO Director-General Margaret Chan recently stated that the world is ill-prepared to respond to any severe, global, sustained and threatening public health emergency, and has called for an extensive global public health reserve workforce, contingency funds for public health emergencies, and agreements on the sharing of viruses and vaccines. Coming from the head of an organisation that the world looks to as the front line in addressing health emergencies, this is a disturbing admission. 

In Brisbane, leaders could also ask international organisations, particularly the World Bank and WHO, to identify the gaps in the international institutional structure to manage global public health emergencies and suggest actions G20 members can take to resolve these gaps.  Such a move would be yet another extension of the G20's remit, but a targeted effort could keep the focus on the G20's strength: the international response to cross-border issues. It would also represent the clearest example of mainstreaming a development issue.