London, Jan 2 (IANS) More than 1.1 million Britons have been affected by the norovirus, commonly known as the winter vomiting bug, BBC reported Wednesday.
The Health Protection Agency said there were 3,877 lab-confirmed cases till Dec 30, 2012, but for each confirmed case there are 288 more infections which go unreported.
The figure was 72 percent higher than at the same point last year.
Norovirus is the most common cause of stomach illness in the country, usually affecting between 600,000 and a million people each year.
Around 12 to 48 hours after becoming infected, the virus causes sudden onset of nausea followed by vomiting and diarrhoea. The virus lives in the gut and is spread by poor hygiene.
Norovirus can spread through contact with contaminated surfaces or objects, by contact with an infected person, or by the consumption of contaminated food or water.