The latest figures from the Health Protection Agency were released as it emerged the number of confirmed cases over Christmas was 72 per cent higher than this time last year.
The dramatic rise was attributed in part to an early outbreak of the illness which closed dozens of hospital wards as it swept across the country.
A total of 3,877 laboratory-confirmed cases of norovirus have now been recorded in England and Wales – up on the 2,255 of last year.
But the HPA said that for every reported case, an estimated 288 were not flagged up, meaning around 1.12 million people could have contracted the illness this season.
This is about 100,000 more than during the pre-Christmas period, which ended on 23 December, when 1.01 million people were estimated to have come down with the bug.
The number of reported cases dropped slightly during the Christmas week but this was in keeping with dips at the same time in previous seasons, the HPA said.
John Harris, an expert in norovirus from the HPA, said: “As we have seen in previous years there has been a dip in the number of confirmed laboratory reports owing to the Christmas and new year period.
“However, in line with other norovirus seasons we will expect to see an increase in the number of laboratory reports in the next few weeks.