The chances of bird flu virus mutating into a form that spreads between humans are "very low", the government's chief scientific adviser has said.
AREA ON ALERT
Poultry owners within wild bird risk area must keep birds indoors or, if not possible, ensure they are kept away from wild birds
Bird transport within 6 mile (10km) surveillance zone will be curbed
Poultry within 1.8 mile (3km) protection zone must be kept indoors and will be tested
Sir David King said any suggestion a global flu pandemic in humans was inevitable was "totally misleading".
No more wild birds have tested positive for the deadly H5N1 strain since a case was found in a swan in Fife last week.
Experts are still testing birds found near Cellardyke, and a UK helpline has had thousands of reports of dead birds.
Speaking for the first time about the case, Scotland's first minister Jack McConnell has defended the response, saying it had been "fast, effective and well coordinated".
Two newspapers have printed details of government plans to cope in the event of a human pandemic.
They include a leaked letter from Chief Medical Officer Sir Liam Donaldson to Schools Minister Jacqui Smith - published in the Sunday Times - in which he suggested an estimated death toll among school children of 100,000 could be halved with school closures.
But a health spokesman said: "This is still a disease of birds, not humans."
These sentiments were echoed by John Oxford, a professor of virology at Queen Mary's School of Medicine, in London.
He told BBC Radio Five Live: "We're not expecting a human case from this swan - nor are we really expecting human cases from chickens."
He said the focus of attention in future would be more likely to be southeast Asia, not Fife.
The Sunday Telegraph reported that government plans included calling off-duty fire fighters and retired lorry drivers into service to ensure food supplies were delivered.
Documents reportedly outlined concerns about a lack of preparation among food firms, and a potential shortage of HGV drivers willing to go into infected areas.
A Downing Street spokesperson refused to comment directly but said, "obviously you would expect the government to be doing contingency planning for what would happen in a serious flu pandemic."
The H5N1 virus cannot pass easily from one person to another and therefore currently does not pose a large-scale threat to humans.
But experts fear the virus could gain this ability if it mutates. They say it could trigger a flu pandemic in its new form, potentially putting millions of human lives at risk.
Speaking on ITV1's Jonathan Dimbleby programme Sir David King said bird flu was not among the human population.
He said the government was preparing for it as a "very low possibility".
He added: "We have got a virus in the bird population that has gone on since 1996, and in Asia particularly there has been a lot of contact between human beings and the birds that have got that virus."
Despite that, a human virus had not developed, he said.
Sir David said bird flu was "absolutely not" present among poultry, and said he was "fairly optimistic" it was absent in wild birds.
He stressed that so far one dead bird had been washed ashore with H5N1, which may have come from a previously infected part of Europe.
BIRD FLU FACTFILE
Bird flu viruses have 16 H subtypes and nine N subtypes.
Four types of the virus are known to infect humans - H5N1, H7N3, H7N7 and H9N2
Most lead to minor symptoms, apart from H5N1
H5N1 has caused more than 100 deaths in Cambodia, China, Indonesia, Thailand, Turkey and Vietnam
The World Health Organisation says not all H5 or H7 strains are severe, but their ability to mutate means their presence is "always a cause for concern"
"The one swan doesn't mean it has arrived here," he said.
The infected swan found in Fife had a "very similar" strain to one which infected more than 100 birds in Germany, tests showed.
Shadow health secretary Andrew Lansley said the government's pandemic plans left questions unanswered, such as whether schools should be closed in the first wave of an outbreak and whether the public should be advised to avoid public transport.
"The economic and human consequences of these decisions are immense," he said.
He said there should be an open public debate the issues prior to the onset of any pandemic.
A six-mile (10km) surveillance zone and 1.8 mile (3km) protection zone in place around Cellardyke will remain for at least 30 days from the day the swan was found.
A wild bird risk area of 965 square miles (2,500km) has also been established which includes 175 registered poultry premises, containing 3.1 million birds, 260,000 of which are free-range.
A total of 2,500 calls have been made to the authorities by members of the public reporting dead birds since the flu scare began.
Cobra, the government's crisis management committee is set to meet on Monday.
If you find a dead swan, goose or duck; or three or more dead wild or garden birds in the same place, you should call the Defra helpline on 08459 335577.