UK scientists confirmed late on Thursday that a swan found dead in Fife, Scotland, died of the deadly H5N1 strain of bird flu.
Experts at an earlier press briefing in London said that other wild birds are almost certain to be infected, and warned poultry farmers to keep their birds indoors if possible to avoid contact with wild birds.
The confirmation establishes that the virus continues its westward march after originating in the Far East. Already, it has been reported in 13 European countries.
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Tests by the UK government鈥檚 Veterinary Laboratories Agency established that the swan tested positive for H5N1, the highly pathogenic form of bird flu which has officially claimed 103 human lives so far.
UK government officials are already undertaking an urgent assessment to decide what measures are needed to stop the virus spreading to the country鈥檚 poultry.
Forcibly housed
鈥淗owever, on the basis of a preliminary risk assessment, it has been concluded that a Britain-wide poultry housing requirement would be disproportionate,鈥� said a joint statement from the UK and Scottish Chief Veterinary Officers.
Poultry have already been forcibly housed within 3 kilometres of the village where the swan was found. Surveillance has been introduced within 10-kilometres. The Scottish Executive is considering whether to extend these measures.
The experts meeting in London warned that other birds are probably infected. 鈥淲e don鈥檛 know if this is the first and only bird infected, or the twenty-first,鈥� said Bob McCracken, past president of the British Veterinary Association.
鈥淎n infected bird will be producing millions of virus particles in its droppings, which can be picked up by other birds, and we should work on the assumption that that鈥檚 already happened,鈥� he said.
According to McCracken, it is likely that there is a small pool of birds in the Fife area carrying the virus.
鈥淲e don鈥檛 know which bird brought it to Fife, but it鈥檚 irrelevant,鈥� said McCracken. 鈥淟et鈥檚 make sure that as we move forward now, we minimise the risk to domestic poultry.鈥�
Cats and dogs
McCracken said that his advice to poultry farmers, and that of the BVA, would be to move birds indoors as soon as possible, before it becomes mandatory. 鈥淲e鈥檙e moving closer to the day when moving birds indoors will be necessary.鈥�
Such measures are necessary to stop poultry and their food being infected by droppings from infected wild birds. This is far more important than vaccination of birds, he says. 鈥淰accination鈥檚 a tool we in the BVA think should remain on the table. It may follow later, but not now.鈥�
Nor is there any scientific justification for keeping cats and dogs indoors, he said, despite a report this week in Nature highlighting the issue of bird flu reaching cats.
Experts also calmed fears that there was an imminent threat to human health. 鈥淔or more than two years we鈥檝e been monitoring the spread of these viruses in East Asian countries, and against the background of 5000 outbreaks in birds there have been only 200 cases of human infection,鈥� said Alan Hay, the director of the UK Medical Research Council鈥檚 World Influenza Centre.
鈥淲hat makes us alarmed is that more than half of these cases have been fatal, but at the present time, it鈥檚 very difficult to contract an infection,鈥� said Hay. 鈥淢ost cases can be put down to very close contact with infected poultry,鈥� he said.
鈥淭he main risk is if this virus becomes part of a pandemic where it becomes virulent,鈥� said Jim Robertson of the National Institutes for Biological Standards and Control. 鈥淏ut that risk doesn鈥檛 change by it being in the UK.鈥�
