An estimated 10,000 people including 1100 children died of swine flu in the United States in the seven months after the new strain of flu was first detected in April, a top US health official said.

"By November 14th, many times more children and younger adults unfortunately have been hospitalised or killed by H1N1 influenza than happens in a usual flu season," Thomas Frieden, head of the Centres for Disease Control and Prevention (CDC) told reporters.

"Specifically, we estimate there have been nearly 50 million cases, mostly in younger adults and children; more than 200,000 hospitalizations... and sadly, nearly 10000 deaths including 1,100 among children and 7,500 among younger adults," he said yesterday.

The number of hospitalisations was around the same as for an entire year when only seasonal flu is circulating, and the estimated death toll, which is based on a new methodology for calculating fatalities from (A)H1N1 flu that was rolled out last month, was "much higher than in a usual flu season," said Frieden.

The new way of tallying the number of dead from swine flu last month caused the estimated death toll from swine flu to soar to 4,000.