Swine flu has affected as many as one million Americans, US health officials have estimated, with six per cent or more of some urban populations infected.
The estimate, voiced by a government flu scientist last week, was no surprise to the experts who have been closely watching the virus.
‘We knew diagnosed cases were just the tip of the iceberg,’ said Dr. William Schaffner, a Vanderbilt University infectious diseases expert who was in Atlanta for the meeting of a vaccine advisory panel.
Lyn Finelli, a flu surveillance official with the Centers for Disease Control and Prevention, made the estimate of one million infections in a presentation to the vaccine panel. The number is from mathematical modeling, based on surveys by health officials.
Regular seasonal flu sickens anywhere from 15 million to 60 million Americans each year.
The United States has roughly half the world’s swine flu cases, with nearly 28,000 reported to the CDC so far. The U.S. count includes 3,065 hospitalisations and 127 deaths.
The numbers again highlight how the young seem to be particularly at risk of catching the new virus. But data also show that the flu has been more dangerous to adults who catch it.
The average age of swine flu patients is 12, the average age for hospitalized patients is 20, and for people who died, it was 37. It seems to be deadliest to people 65 and older, with deaths in more than 2 percent of elderly people infected, Finelli said.
Huge jump in UK cases
Meanwhile, the number of people infected with the virus has soared in England, the BBC reports.
Health officials said Monday that the number of confirmed swine flu cases in England has jumped by nearly 20 per cent in a single day.
The Health Protection Agency statistics show that 535 new cases were confirmed on Friday, bringing the total to 3,364.
Sir Liam Donaldson, the chief medical officer for England, warned last week that the UK could soon expect to see a surge of new cases.
He predicted tens of thousands of cases of swine flu could be emerging each week by the autumn.
Sir Liam said that the UK was likely to receive its first batches of swine flu vaccine in August, rather than in the autumn as first expected.
There have been 13 confirmed cases of the virus in the Cayman Islands, although health officials agree the real number could be much higher as they are no longer asking people with normal flu like symptoms to seek medical attention, meaning many cases are not tested. Local cases have so far remained mild.
There have been almost 71,000 reported cases of H1N1swine flu worldwide, including 311 deaths, the Centres for Disease Control reports.