Over 100,000 people were struck down with the winter vomiting bug over Christmas.
For every reported case of norovirus in England Wales, an estimated 288 were not flagged up, meaning around 1.12 million could have contracted the illness around Christmas, according to the Health Protection Agency.
This is roughly 100,000 more than the pre-Christmas period - until December 23 - when 1.01 million people were thought to have been struck by the bug.
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