sydney gas on aca tonight, page-21

bird flu New theory blames ducks for spreading bird flu

HONG KONG (AFP) - Domesticated ducks may be the main transmitters of the H5N1 bird flu virus that killed 32 people in two major outbreaks in Asia earlier this year, a senior World Health Organisation official said Monday.
Studies suggest the most devastating outbreaks occurred where duck populations were highest, said WHO director for the Western Pacific Shigeru Omi.

"Our judgement is that ducks are now playing a major role in terms of transmitting the disease," Omi said during a visit to Hong Kong. "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."

He said the WHO was working on the theory after discovering that the peak seasonal prevalence of flu in ducks, during the winter months, coincided with the peak period of human infections.

"In areas where there are more ducks, there are more chicken infections," he said. "We would like to know why."

He added that in areas where ducks and chickens were kept apart -- for instance in Hong Kong where separation of different poultry flocks are part of broad flu-prevention laws -- H5N1 was less prevalent.

The WHO director said evidence pointed to a bird flu pandemic among humans in the near future, warning that up to 100 million people could be killed unless preventative measures were taken.