The number of deaths from swine flu in Britain has climbed to 59 but infection rates have continued to fall through the summer, according to the Department of Health.
The latest figures released today show the disease on the wane during the holidays with about 260 people still being treated in hospital, fewer than last week. Of those, 30 were in intensive care.
There were an estimated 11,000 people diagnosed with H1N1 flu in England last week, the cases spread uniformly across the country, and representing a sharp decline from the 25,000 cases recorded during the previous week.
After an unusual mid-summer spike in infections, pandemic flu could now be conforming to the normal pattern of seasonal flu which traditionally delivers peak rates of illness during the winter.
Health officials expect a second wave of infections to start building up again in the autumn, though when that will occur, and whether it will be chiefly due to the return of schools or the arrival of colder weather, remains unknown.
Sir Liam Donaldson, the chief medical officer, confirmed that there were no national plans to keep schools closed at the start of term. But he added: "If we get a big surge during the autumn it may be that individual schools will close."
One of the odder aspects of the latest data is that only 10% of those who sought help from a GP or the National Pandemic Flu helpline and subsequently took a swab test actually showed signs of infection.
Health experts said they were not surprised by the low proportion. The estimate of 11,000 new cases takes into account both the observation that not all those seeking medical help were ill and also that many who become infected never contact a doctor.
The government's Scientific Advisory Group for Emergencies (Sage) is assessing the latest fatality and infection rates – which are far lower than initially feared – to develop planning for the severity of the outbreak.
Commenting on the need for a revision, Justin McCracken, chief executive of the Health Protection Agency, said: "It's always best to plan for the worst, not the best."
The number of deaths did show a significant increase last week, rising from 44 to 54 in England. Almost half of those, 25, died in London. With five additional deaths in Scotland, the UK total now stands at 59 deaths.
Donaldson said he could not speculate on the timing of the second wave of swine flu but hoped it would follow the pattern of the 1968-70 pandemic which hit around Christmas time – a progession that would provide the UK with sufficient time to vaccinate as many people as possible, and possibly avoid a second peak altogether.
The chief medical officer said the full picture on how swine flu had affected the UK, including the number of excess deaths, would not be known until after the pandemic had passed.
The UK had taken a much more aggressive policy initially towards tackling the disease than many other countries, he said, enforcing school closures, providing antiviral drugs for contacts of swine flu victims, and checking flight lists to track down further potential contacts.
The development of the pandemic in Australia has been worrying health officials, with as many as 30% of those admitted to hospital being treated in intensive care.
Although infection in the UK appears to be subsiding in the warmer summer weather, Donaldson said it was "exceptional" to have so many flu victims in hospital at this time of year.
Of the 54 people who have died in England, 15% were under 15, a third were aged between 16 and 44, and 29% were over 65.
Of the same group of fatalities, 21% were recorded as having previously been healthy. More than half had severe prior conditions such as leukaemia.
