Ten years ago, a major H5N1 outbreak in Vietnam sparked a global panic
In January 2005 an outbreak of bird flu affected 33 of 64 cities and provinces in Vietnam, forcing a cull of almost 1.2 million poultry. By April it had spread to China; by August, Kazakhstann, Mongolia and Russia reported infections.
By May, 97 cases in humans and 53 deaths were recorded in South East Asia.
On September 29, David Nabarro, the newly appointed Senior United Nations System Coordinator for Avian and Human Influenza warned that a global outbreak could killed between 5 and 150 million people. Soon after, the US Senate allocated $4bn to develop vaccines and treatments for the disease.
By the end of the year, 74 people were dead. The disease would continue to spread over the next couple of years, peaking each time during the 'flu season' between October and April, and would claim almost 300 lives by 2007.
Despite the widespread hysteria it the time, H5N1 has not lingered in public memory. It now stands beside SARS and swine flu among the pandemics that never quite were, with only the occasional outdated public safety posters left to remind us of a threat we were told might kill tens of millions.
But just because the fear has faded, does not mean the disease itself has gone away.
George Hook spoke with John Oxford, Professor of Virology at Queen Mary College, who says H5N1 remains a concern within the biological community
Several cases are still reported each week in Egypt and South East Asia, where chickens are often kept in highly-unsanitary conditions in multi-storey buildings.
“[In Egypt] there’s still children and elderly people – those two groups who look after chickens are still regularly getting infected, regularly ending up in hospital and regularly dying,” he says.
“Not in great numbers... but there are persistent deaths in humans from this virus.”
Outbreaks also continue to occur in the developed world. In the US, a related virus (H5N2) resulted in the deaths of 60 million chickens and turkeys in 20 states over the last six months.
Experts monitor outbreaks like this closely, as only one confirmed transmission is needed to spark an international crisis.
Factory farming and poor animal husbandry is behind these outbreaks, says Oxford:
“Overcrowding in the chicken population is due to our demand for chicken... and the animal farming business is not helping here.”
He says the main development from the bird flu crisis is that it forced us authorities to develop a infrastructure to contain dangerous viruses quickly:
“What we’ve got from the outbreak is this worrying knowledge that viruses can jump from a bird, bat or camel unexpectedly in to a human, and if they have a high mortality rate... everyone gets worried and action has to be taken.”
He gave a recent example of a Saudi man who contracted the Mers virus before flying to South Korea, where he travelled between a number of hospitals seeking treatment. As a result, 18,000 people were rapidly quarantined, with the relatively low death toll of 36 a testament to the power of effective planning.
“We are better prepared now,” says Oxford. “We are more reactive now.”
The swift action to contain the recent outbreak of Ebola is such an example of the work done and lessons learned since the H5N1 crisis.
Oxford highlights a very heartening news that the Chinese Centre For Disease Control And Prevention had agreed to work with France’s Institut Pasteur to help rebuild health infrastructure in Sierra Leone, and to train locals to combat and further outbreaks of Ebola.
The H5N1 virus is considered a significant pandemic threat.
Though prior strains have been recorded, the current strain is significantly different at a genetic level, making its global spread unprecedented.
The current H5N1 strain is a fast-mutating, highly pathogenic avian influenza virus found in multiple bird species. The first known transmission to humans was recorded in Hong Kong in 1987.
Human-to human transmission is rare - the first confirmed case occurred in 2006, when seven members of a Sumatran family contracted the disease from a family member who worked with infected poultry.