Row over wild birds' flu role

There is little evidence to suggest migrating birds are spreading avian flu, a conservation group has said.

BirdLife International said that even though winter migration was well under way across the world, there had not been widespread bird flu outbreaks.

Concerns about wild birds were sparked by the death earlier this year of 5,000 migratory birds in north-west China.

"Migratory wild birds were blamed for spreading bird flu west from Asia, yet there's been no spread back eastwards, nor to South Asia and Africa this autumn," Dr Michael Rands, director and chief executive of BirdLife International said in a statement.

Dr Rands acknowledged the recent outbreaks in eastern Europe were on southern migratory routes, but said it was more likely they were caused by other factors, such as importing fowl.

"The hypothesis that wild birds are to blame is simply far from proven," said Dr Rands. "Wild birds occasionally come into contact with infected poultry and die: they are the victims not vectors of H5N1 bird flu."

But Dr Joseph Domenech, chief veterinary officer at the UN's Food and Agriculture Organization (FAO), said it was too early to dismiss the theory that wild birds could be spreading the disease.

He said that there were "quite good indications" that the disease had arrived in a series of countries, including Romania, as a result of wildlife.

'Wait and see'

He stressed that the FAO had always said that there needed to be more study of this, but at this stage it was too early to dismiss the hypothesis.

He also said outbreaks in certain regions were harder to monitor as the countries involved had poorer surveillance.

"If at the end of the [migratory] season, birds are going back to the Northern countries and no outbreaks have been identified, then we will be able to say the hypothesis... may be not true," he said, adding that such return journeys would begin at the beginning of February.

Dr Rands said in his statement that better "biosecurity" - concentrating on the risks involved in the trade of poultry and caged birds - was the key to halting the spread of bird flu.

Dr Domenech said that the FAO agreed that this was the most important area to concentrate on.

Fears about the H5N1 virus have led to the slaughter of millions of chickens and ducks across Asia in the last 18 months.

The UN is alarmed that the more the virus spreads, the greater the chances it could mutate into a form capable of causing a flu pandemic.