London, Dec 13 (IANS) Over 750,000 people in Britain may have been affected by the highly contagious norovirus, popularly known as the "winter vomiting" bug, which has forced many hospitals to stop admitting new patients.
More than 300 hospital wards in England and Wales have been closed to new patients since outbreak began, the Daily Mail reported citing figures released by the Health Protection Agency (HPA).
Cases of the virus are at a five-year high, with more than two-thirds as many people struck down this year as during the same period in 2011.
This week, 140 of over 600 pupils at a school in London fell sick.
The new HPA figures show there have been 2,630 confirmed cases, where samples have been checked since July.
This is 72 percent higher than the same period in the last season when there were 1,533 cases reported.
But the daily said the figure was likely to be only a fraction of the true total as most sufferers do not see their physician.
Officials estimate that for every confirmed case there are around 300 more in the community.
This means that around 750,000 people could be affected by the virus.
Experts said the highly contagious virus arrived early this year. Infections tend to peak in January and February.