The BBC reports that test on the dead swan discovered in Scotland have confirmed that the swan had the deadly H5N1 virus.
The UK's chief veterinary officer, Debbie Reynolds, said bird flu could stay in Britain for some time.
"We simply don't know, but of course that's why we've got our programme of wild bird surveillance.
"It's been very extensive; over 3,000 wild birds tested already this year, and over 400 swans.
"There are more under way, being tested at the moment, and any wild swan that's reported found dead should be collected and tested," Dr Reynolds said.
Scotland's chief medical officer Harry Burns tried to downplay the discover of the dead H5N1 postive swan.
"So the arrival of one bird in Scotland does not really add to the risk of this virus emerging as a human strain.
"I will be eating chicken tonight but it will be well-cooked chicken. The evidence from the Food Standards Agency is that in properly cooked meat the virus is killed."
The bird flu is expected to continue to spread in birds to more countries including the U.S. The big question is what the disease will do in humans. So far the virus has not mutated into a form that can pass rapidly from human host to human host.