Since the earliest reports of human deaths, a trail of myths and rumors about bird flu has spread further across the world than the virus itself. There's nothing like the horror of a global mass killer to pique public interest. Bird flu has caused the death of millions - of poultry - and killed over 90 people to date, inspiring fevered images of an imminent human apocalypse.
Scientists cannot predict whether the highly pathogenic avian influenza H5N1 virus, or bird flu, will develop the necessary genetic characteristics to trigger a human pandemic. But the virus has sparked a pandemic of conjecture that has taken on a life of its own.
So far, there has been evidence of relatively limited transmission to people from poultry, and negligible or unconfirmed transmissibility from one person to another.
But as long as both human and bird influenza viruses are co-circulating, a real possibility exists that the bird flu virus could exchange genetic material with human influenza viruses, resulting in the emergence of a novel strain to which humans have no immunity.
If this novel virus is both highly infectious and deadly, it could spark a human pandemic that could kill millions.
Sceptics believe the probability of such a pandemic is no more likely than the hyped Y2K millennium bug. Others are hoarding food and stockpiling personal supplies of antiviral medication ready for the Big One. And rumour has it there are those who would like to shoot all of Sydney's pigeons as a precaution.
Overreaction or reality?
Professor Peter Curson, medical geographer and director of the health studies program at Macquarie University, says our response to health risks, whether rational or not, reflects differences in human nature that are unrelated to the likelihood of contracting a disease.
"There's no doubt that fear of infection and disease is shaped not by empirical evidence of risk, but by how we view the world around us," Curson says.
"Looking back on the history of epidemic outbreaks in Australia, says Curson, "forcible removal of people into quarantine and the demolishing of slums, such as during the smallpox epidemic of 1881 and the bubonic plague of 1900, increased fear, anxiety and reactivity. I am sure in the debates about bird flu - talk of closing borders and quarantining people at home has raised anxiety and apprehension."
Since Hong Kong reported the first few human deaths in 1997, millions of people have been exposed to bird flu in Asia and eastern Europe, which according to the WHO, has infected over 150 people, with cases confined to those living in close contact with sick birds.
This is a very unusual statistic, says Dr Michael Moore, chief executive officer of the Central Sydney Division of General Practitioners.
"You hear about the 100 or more people that have caught bird flu but you don't hear about the 20 million people that have been living surrounded by contaminated duck secretions that haven't."
"A fact that has barely been reported is that transmission from one human being to another is just about unknown, even now. It is a fairly reassuring fact, but you don't sell newspapers by preaching safety," Moore says.
Public alarm has already sent global supplies of antiviral medication into a spin. During intense media coverage of the advancing epidemic in poultry late last year, unprecedented public demand for Tamiflu (oseltamivir) worldwide left pharmacies out of stock at the start of the northern hemisphere flu season, and ran stocks dry for three months in Australia.
As Curson points out, panic itself becomes infectious.
"The public gets swept up in imitative behaviour and it becomes almost impossible to avoid it," Curson says.
"SARS (Sudden Acute Respiratory Syndrome) was going to be the 'plague to end all plagues', now bird flu is the plague to end all plagues. SARS showed how panic, fear and hysteria at both an individual and official level could totally overwhelm the epidemic itself and I think that's where we are now."
SOURCE: ABC NEWS
BIRD FLU TIMELINE
Note: Figures are correct at time of publication. For the latest statistics, see the World Health Organisation's Avian influenza updates.
1996
Highly pathogenic avian influenza H5N1 virus (bird flu) is isolated from a farmed goose in Guangdong Province, China.
1997
Outbreaks of bird flu reported in poultry at farms and live poultry markets in Hong Kong, resulting in six human deaths. One of these was in a Hong Kong family with a recent travel history to the Fujian Province in China.
December 2003
First wave of bird flu among poultry reported in South Korea, Cambodia, Indonesia, Japan, Laos, Thailand and Vietnam, resulting in three reported human deaths in Vietnam.
2004
Second wave of bird flu reported in poultry flocks in China, Cambodia, Indonesia, Malaysia, Thailand and Vietnam.
Research confirms H5N1 has become progressively more lethal to wild waterfowl, long considered a disease-free natural reservoir, and some mammals.
Evidence suggests asymptomatic domestic ducks are acting as a silent viral reservoir, which may explain why some human infections could not be traced to close contact with infected poultry.
Total of 32 human deaths reported in Thailand and Vietnam.
2005
Bird flu H5N1 causes deaths of more than 6000 wild birds from different species at Qinghai Lake in central China - congregation point for thousands of migratory birds. Tests show bird flu has evolved to become more lethal to wild birds.
Bird flu is carried along winter migratory routes towards Europe.
Russia and Kazakhstan report outbreaks in poultry in western Siberia and adjacent areas. Dead migratory birds are reported in the vicinity of outbreaks.
China, Croatia, Mongolia, and Romania report outbreaks of bird flu among migratory birds.
Turkey, Romania and Ukraine report outbreaks of bird flu among poultry introduced by migratory waterfowl.
Total of 41 human deaths reported in China, Cambodia, Vietnam, Thailand and Indonesia.
January 2006
Seven human deaths reported in Turkey, Indonesia and China.
Iraq reports its first human death.
February 2006
Thirteen new countries report their first H5N1 infections in wild or domestic birds: Iraq, Nigeria, Azerbaijan, Bulgaria, Greece, Italy, Slovenia, Iran, Austria, Germany, Egypt, India and France. Iraq's bird infections were confirmed only after its first human case. So far there are no human cases in the other twelve countries listed.
The latest figures from the WHO report a cumulative total of 170 human infections and 92 human deaths in Cambodia, China, Vietnam, Thailand, Indonesia, Turkey and Iraq since 2003.
Note: To date the WHO has not reported any cases of bird flu in humans, birds or animals in North America, South America, Australia or the South Pacific.
Source: The World Health Organisation
BIRD FLU LINKS:
BIRD FLU - ASK AN EXPERT
http://www.abc.net.au/science/expert/realexpert/birdflu/
AVIAN FLU - USA CENTERS FOR DISEASE CONTROL AND PREVENTION
http://www.cdc.gov/flu/avian/index.htm
PANDEMIC FLU - US GIVERNMENT ORGANIZATION
http://www.pandemicflu.gov/
