Swan may have caught the virus a month agoIan Sample and James Meikle
Saturday April 8, 2006
The dead swan that signalled the arrival of highly pathogenic bird flu on British soil is believed to have contracted the disease up to a month ago, experts said yesterday. The carcass was so badly decomposed that it had probably been dead for three weeks when it tested positive for the H5N1 virus, having become infected several days earlier, they said.
Efforts to check whether the virus had spread to other birds were stepped up yesterday. Veterinarians were swabbing birds in poultry farms and officials were scouring for dead birds in the 3km protection zone around Cellardyke, where the swan was discovered.Tests on 12 swans and two other wild birds found dead in Scotland revealed that nine had died of other causes. The results of the other tests were unknown last night. Scotland's chief veterinary officer, Charles Milne, said: "There is no indication that any of these results are positive. We will have to wait until the laboratory tests are completed."
Dead birds from other parts of Britain were also being tested by scientists at Defra's Veterinary Laboratories Agency in Weybridge, Surrey, but were not being considered as high priority.
Scottish farmers already hit by restrictions said yesterday they may press for changes in EU rules on free-range status.
The timing of the swan's infection coincides with the arrival of bird flu in France and Germany after unusually cold weather had forced many infected waterfowl to desert the Black Sea region in search of warmer conditions.
Andre Farrar, of the Royal Society for the Protection of Birds, said: "The bird was heavily decomposed when it was found and swan corpses take some time to get that bad. It will have been three weeks to a month ago that it picked up the disease and that puts it in a timeframe consistent with the main crop of outbreaks in other parts of Europe."
The Guardian understands that the condition of the bird forced Defra officials to order genetic tests to confirm whether or not it was a mute swan, as suspected, or another species. In response to fears of the infection spreading, staff at the Royal Parks have drawn up plans to quarantine birds. Enclosed areas are being prepared at sites including a newly built section in St James's Park and a breeding house in Regent's Park, both in London.
A Royal Parks spokeswoman said: "We are receiving advice from Defra and if there is a threat of bird flu in the region, we do have quarantining areas for birds."
The Scottish executive said lab work was in progress to see if the 1 virus that killed the swan matched viruses isolated from other dead animals where the infection has taken hold in bird populations.
"By comparing the virus with others they might be able to work out where it came from," said Professor John Oxford, a leading virologist at Queen Mary, University of London.
A total of 45 organic and free-range poultry farms with 250,000 birds are among the 195 in Scotland already ordered to bring their 3.1m birds under cover. Free-range status is dependent on giving daily access to open runs and this requirement of EU rules can be suspended for as long as three months.
Sir David King, the government's chief scientist, told the BBC that farming practices might change if the virus spread among wild birds: "There would no longer be outdoor birds. That means free-range farming and organic farming would effectively come to an end."
Patrick Holden, director of the Soil Association, said Sir David appeared to have "an unreconstructed attitude against nature-friendly and health-promoting forms of livestock farming". "The big issue is what kind of attitude we have," he said. "Whether it is calm and sophisticated or hysterical, draconian and fear inducing."
The association had been assured by Defra officials in March that 10m doses of vaccine were being ordered as a contingency to protect some poultry. That was on top of 2m doses already on standby for zoo and exotic birds.
Organic growers have dispensation to use nets over runs rather than bringing birds indoors. "Obviously it is not quite as failsafe as shutting them in but we think it is enough," Mr Holden said.