Economies in America, Asia and Europe are trying to co-ordinate action to hasten recovery from recession. But even the best-laid plans would be vulnerable to a pandemic outbreak.
A pandemic occurs when a new virus appears against which humans have little or no immunity, such as the various H5N1 strains of avian influenza. The World Health Organisation and some epidemiologists have warned that bird flu could be the basis of the next pandemic.
Were it to happen during this recession, the costs to public health, order and economies might be very high, even tipping the world into another Great Depression as panic and dislocation compounded the challenges facing governments and companies as they try to revive growth.
Shortly before he stepped down after 10 years as the WHO's regional director for the Western Pacific, Shigeru Omi wrote in January that in a worst-case scenario, a third of the world's population might fall ill in the next flu pandemic, while another third might isolate themselves out of fear or to nurse the sick. He added that governments could be faced with economies lacking two-thirds of their normal workforce, thus affecting critical services.
In February, US Director of National Intelligence Dennis Blair told Congress that 'the most pressing transnational health challenge for the United States is still the potential for emergence of a severe pandemic, with the primary candidate being a highly lethal influenza virus'.
The first reported human deaths from H5N1 flu were in Hong Kong in 1997. Since the virus re-emerged here in 2003 and then spread widely, avian flu has killed or forced the culling of more than 300 million birds, mainly poultry. It is endemic in some areas, providing an incubator for the virus to flourish, adapt and change.
However, the H5N1 virus has not infected many humans. As of March 10, only 410 human infection cases had been reported to the WHO from 15 countries in Asia, Africa, the Middle East and Europe. The worst affected places have been Indonesia, Vietnam, Egypt, China and Thailand.