• Health chief\'s warning as WHO declares pandemic
• Minister says people should not be worried
Several million cases of swine flu could develop this autumn in the UK, the chief medical officer warned today as the World Health Organisation declared the first global pandemic in more than 40 years.
Sir Liam Donaldson said the present strategy of identifying and isolating every case, handing out anti-viral drugs to all contacts and closing schools would continue, but that eventually the numbers infected were likely to be too great to contain the pandemic in this way.
"Once we start to see very large numbers, a judgment will have to be made as to whether there is any benefit in the closure of schools," he said. Asked what he meant by "very large numbers", he said "several million".
Announcing the move to the highest state of alert, level 6, Dr Margaret Chan, director general of the WHO, said the world should brace itself for more deaths. She warned that the virus was unpredictable, and those countries that thought they were through the first wave, including Mexico where it began, should prepare for a second.
Countries must maintain vigilance, but, she added: "No previous pandemic has been detected so early or watched so closely right at the beginning."
Donaldson compared the pandemic to those in 1957/8 and 1968/70. Between 12 and 15 million people in the UK became ill in each of them, with 30,000 and 25,000 deaths. Around 4,000-8000 die during a normal winter flu season.
Three scenarios were possible, he said. In the best case, the H1N1 virus spreading across the UK, which is two parts pig, one part human and one part bird, remains unchanged. At the moment it is causing mild illness with some severe cases causing hospitalisation. This will probably lead to an autumn/winter surge.
The second possibility is that the virus changes a little, which could result in more severe cases and definitely lead to a winter surge. The worst-case scenario is that it becomes combined with one of the ordinary seasonal flu viruses. "That would be the start of a new pandemic," he said.
The health secretary, Andy Burnham, said the WHO\'s move should not worry people. "This does not fundamentally alter our approach, so people should not be alarmed," he said.
"The UK has been prepared for this for many months and years. We are recognised as one of the best prepared countries by the WHO and we\'re in a strong position."
The Scottish health secretary, Nicola Sturgeon, said containment alone was no longer an option in Scotland which accounts for more than a third of the UK\'s 822 cases, with the vast majority in Glasgow, where nine people are in hospital, Paisley and Dunoon.
In those areas family doctors are allowed to diagnose swine flu and begin treatment without using specialist laboratory tests. The anti-viral drug Tamiflu will only be given to their closest contacts, to prevent the virus becoming drug-resistant.
Burnham said there was no difference in thinking between Scotland and England. "There is no sense at all that the countries are going their separate ways," he said. Cobra, the UK\'s emergency planning committee, had unanimously decided on Wednesday that public health authorities, in Scotland but also England, should have more flexibility to respond to outbreaks according to their severity.
The pandemic is affecting younger people more than their elders. There are few cases in people over 60. Donaldson said it was possible that the human component of the virus was recognised by the immune systems of older people, because it has been in circulation before.
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