The death toll from swine flu rose to 14 yesterday as the illness tightened its grip on Britain.
About 8,000 people a week are now estimated to be contracting the virus in England, and 335 have been admitted to hospital of whom 43 are in critical care, Sir Liam Donaldson, the Chief Medical Officer said yesterday.
All those who have died or are critically ill had underlying health problems but it was not possible to say whether all the deaths were directly caused by the virus, Sir Liam said. The UK with 9,718 confirmed cases (by laboratory testing) of swine flu yesterday, has the third highest number in the world, after the US and Mexico, but Sir Liam admitted the figures did not take account of those treating themselves at home.
Patients with flu-like illness have been flooding GP surgeries in the last two weeks at levels which are normal for winter but have not been seen in summer for a generation. In London and the West Midlands, the worst affected areas, demand was at "near epidemic" levels, Sir Liam said. Children aged five to 14 are the group principally affected.
Despite the surge in cases, the virus is still mild, in most cases. Early calculations by experts at Imperial College London suggested the death rate could be four times higher than for seasonal flu. But a study based on the latest data published in the journal Eurosurveillance, which compares the death rate with that from annual winter flu over the past 30 years, says it is "relatively low... by historical standards".
The researchers from the University of Otago, New Zealand, say the low death rate may be due to the young age of those affected and the use of "modern treatments for the seriously ill".
The actual number of deaths could turn out to be higher than for seasonal flu if, as expected, the virus infects more people. It could also mutate to a more virulent form, spreading faster and causing more severe illness. Estimates suggest 25 to 50 per cent of the population could be infected with swine flu, compared with about 10 per cent for seasonal flu. Andy Burnham, the Health Secretary, said last week that cases could rise to 100,000 a day by the end of August.
Doctors challenged the Government's strategy of giving the antiviral drugs Tamiflu and Relenza to everyone struck with the virus. In a letter to the British Medical Journal, Peter English of the Public Health Medicine Environment Group and colleagues said: "By using anti-viral drugs so liberally – for what is currently a mild form of flu – we risk generating resistance so that when a more virulent form of flu presents the drugs may no longer be effective."
A Department of Health spokesman defended the policy saying it was impossible to predict who might become seriously ill. "Reduced susceptibility or resistance are a concern with any antiviral treatment and the government policy is based on balancing this risk against the public health benefit of the treatment."
The spread of the illness is being monitored in different ways including laboratory testing on sample groups to check for signs the virus may be mutating.
People a week in Britain are currently contracting the H1N1 swine flu virus.