Poultry, wild bird trade spread bird flu--experts

By Svetlana Kovalyova

ROME (Reuters) - The multi-billion dollar trade in poultry and wild birds, especially illegal trading, may have helped spread deadly bird flu around the world, leading bird flu experts said on Tuesday.

The virus has killed 127 of the 224 people it has infected since re-emerging in Asia in late 2003, according to the World Health Organisation (WHO).

As the deadly H5N1 virus spread rapidly in the past six months from Asia into parts of the Middle East, Europe and Africa, specialists have been working out how it travels.

"In this outbreak of H5N1, it's a combination - there is no doubt that the wild birds play their role (in spreading the virus), but so do humans," Robert Webster, a leading avian flu expert, told Reuters.

"People acknowledge that probably the most important spreader of influenza overall is the human and the globalisation of trade," Webster, professor at St. Jude Children's Research Hospital in the United States, said on the sidelines of a bird flu conference in Rome, organised by the Food and Agriculture Organisation (FAO) and World Animal Health Organisation (OIE).

He said there was evidence that migrating wild birds helped to spread bird flu to Mongolia from China last year and in general contributed to the spread of the virus from Asia to Europe, the Middle Asia and Africa.

But he said experts should also look carefully into the trading of poultry, both live and frozen, and compare trade maps with the geography of the virus.

Poultry trading is worth billions of dollars. For example, France is the European Union's biggest poultry producer with a 6 billion euro ($7.72 billion) annual turnover.

CLUSTER DEATHS

Turning to a recent case of cluster deaths in one family in a remote village in Indonesia where some believe human-to-human transmission took place, Webster said poultry involvement could not be ruled out.

"There is no evidence that there was poultry involved. But this village is very primitive and it's very difficult to rule out poultry involvement completely," Webster said.

Bird flu remains essentially an animal disease. But after a sudden flurry of human bird flu cases in Indonesia, there has been increased concern about a possible mutation of the virus that could lead to easier human-to-human transmission. William Karesh, director of the Field Veterinary Programme at the Wildlife Conservation Society, said trading in wild birds, legal and illegal, was helping to spread the disease.

Asked about the impact of illegal trading on the spread of bird flu, he told Reuters: "It's probably a small part, but the consequences are tremendous. The costs of cleaning up an outbreak are huge - millions of dollars."

Karesh said an international regulation modelled on the one used for livestock should be put in place to stop the trade in wild birds from spreading the virus, with tests conducted before wild birds can be imported.

"Society has the right to require better controls, quarantine, a testing system. That can solve part of the problem," Karesh said.

Several bird flu experts at the conference said a global system of surveillance and an exchange of information are also needed to help fight the spread of the virus.