Deadly flu could infect 40 per cent of UK population: Report

Amid a red alert in Britain on swine flu, top health officials have warned that the deadly virus could infect up to 40 per cent of the UK population in the next six months if the outbreak becomes a pandemic.

"We might expect up to 30 per cent -- 40 per cent of the population to become ill in the next six months if this truly turns into a pandemic," said Professor Neil Ferguson, a member of the World Health Organisation (WHO) taskforce which decided to raise its alert over the virus to level four.

The Evening Standard quoted Prof Ferguson as saying that four in 10 people could be infected if the country is hit by a pandemic.

Earlier, Britons were warned to avoid all but essential travel to Mexico as the WHO said the deadly swine flu virus can no longer be contained and raised its alert to two lower than the maximum of six, signifying a "significant increase in risk of a pandemic", the British daily reported.

"We don't really know what size epidemic we will get over the next couple of months. It is almost certain that, even if it does fade away in the next few weeks - which it might - we will get a seasonal epidemic in the autumn," Prof Ferguson told the BBC Radio 4 Today programme.

The Government today confirmed that 25 possible cases of swine flue had already been investigated. A newly-married British couple who had gone to Mexico for honeymoon are being treated for the killer swine flue even as experts warned a pandemic was "inevitable".