Up to 100 million people may die within weeks if a bird flu pandemic breaks out, a senior World Health Organisation (WHO) official warned on Monday as he urged nations to make urgent preparations to mitigate its spread.
A global outbreak is almost certain and even widescale vaccination programmes will not be enough to halt its inexorable advance, the WHO director for the Western Pacific, Shigeru Omi, said in Hong Kong.
”The most conservative estimate is that seven to 10 million people would die, but the maximum range will be more — 50 million or even in the worst case 100 million people,” Omi said in his starkest warning yet of the potential peril from a mutation of avian flu to a form that may be transmitted by humans.
”It will come,” he said during a flying visit to the city where the H5N1 flu strain first mutated into a strain lethal to humans.
Omi said it was impossible to predict when a pandemic will happen but said it would not take long to reach all corners of the globe.
”Before it would have taken a year to spread around the world but thanks to globalisation it will take just weeks. If we are not prepared the consequences will be serious.”
Avian flu, he said, appeared to be entrenched in Asia following two huge outbreaks throughout the region earlier this year that killed 32 people in Vietnam and Thailand.
Believed to be transmitted through contact with bird droppings, he said the speed of the virus’s spread and its adaptation to a form that can be carried by pigs and cats had shown conditions were ripe for a devastating pandemic.
”The level of transmission at the moment in unprecedented historically,” he added.
”History has told us that on average every 30 years, at least, a pandemic will occur. The next one is due — some would say it is overdue.”
Omi’s bleak assessment follows a summit of world health leaders in Bangkok last week in which guidelines were laid down for national preparation plans to reduce the effects of a possible pandemic in the coming winter.
The WHO is working on the theory that domestic ducks are the main transmitters of the virus.
Studies suggest the most devastating outbreaks occur where duck populations are highest. They also found that the peak seasonal prevalence of the strain in ducks, during the winter months, coincides with the peak period of human infections.
”Our judgement is that ducks are now playing a major role in terms of transmitting the disease,” Omi said. ”When chickens are infected, they get the symptoms and then they die, but the ducks don’t die and they don’t develop the symptoms.
”In areas where there are more ducks, there are more chicken infections,” he said. ”We would like to know why.”
H5N1 is also less prevalent in areas where ducks and chickens are kept apart — for instance in Hong Kong where separation of different poultry is part of broad flu-prevention laws.
The WHO’s new working theory appears to have backing from the findings of Hong Kong University researchers, who claimed to have traced the virus found in birds killed this year to a virus that originated in ducks from China. – Sapa-AFP