The number of people thought to have contracted swine flu in the US has topped one million, with infections continuing to rise.
Health officials in America say the H1N1 virus that has triggered a global pandemic is infecting people in the United States well beyond the normal period for influenza season.
Dr Anne Schuchat of the US Centres for Disease Control and Prevention (CDC) said: “We are estimating about a million people in the US or more have gotten this virus at a time of year when people really aren’t continuing to get the seasonal influenza viruses.
“A big question that everybody really has is what kind of illness, hospitalisation and deaths will we see when our winter flu season begins?
“In the US we’re still experiencing a steady increase in the number of reported cases, with 6,000 new cases reported just this week.”
The World Health Organization is now reporting more than 67,000 confirmed cases of H1N1 flu and some 300 deaths worldwide.
In the US there have been 27,717 laboratory-confirmed cases, including more than 3,000 hospitalisations and 127 deaths.
Dr Schuchat said vaccine makers are developing a H1N1 vaccine that will be tested in clinical trials over the summer and the CDC was asking state and local health departments to draw up plans for how to handle its distribution.
CDC researchers said one vaccination scenario could include as many as 600 million doses.
That could place a heavy burden on cash-strapped health departments which would probably have to distribute two doses of the new vaccine – which might be required for full immunity – plus the regular seasonal flu vaccination program.
Dr Schuchat said the CDC is continuing to watch for changes in the virus in the southern hemisphere, where the flu season is now in full swing.
A total of 12 states have reported widespread flu activity, something Dr Schuchat said was unusual for this time of year.
She said flu infections were are even affecting children attending camps, with outbreaks in 34 camps in 16 states and some now closed for the summer.
Elsewhere, Burma, Thailand and Ivory Coast have reported their first cases of swine flu while the number recorded in Australia has now risen to five.
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