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Home News Centre National Press Releases 2011 Press Releases ›  Levels of norovirus within seasonal norms

Levels of norovirus within seasonal norms

19 December 2011

Norovirus is highly contagious and can be transmitted by contact with an infected person; by consuming contaminated food or water or by contact with contaminated surfaces or objects. The virus spreads rapidly in closed environments such as hospitals, schools, nursing and residential homes.

Although people can suffer from norovirus at any time of the year, activity increases in the winter months with the majority of cases occurring between October and April.

Its symptoms include a sudden onset of vomiting and/or diarrhoea. Some people may have a temperature, headache and stomach cramps. The illness usually resolves in one or two days and there are no long-term effects.

Figures from the Health Protection Agency (HPA) show that in the last three weeks, the weekly number of confirmed lab reports for norovirus up to the week ending 11 December 2011 show that they are slightly below the average number in the same weeks for the previous five years.

The number of individual confirmed lab reports for this season overall is higher than in the previous season because of higher norovirus activity in the earliest part of the season from weeks 27 to 35. This then declined over the summer months and now overall laboratory reports are at typical seasonal levels.

As part of infection control measures in hospitals, ward closures are implemented to prevent further transmission and reduce disruption to hospital services.

New guidance from the norovirus working group recommended that patients with norovirus should be managed in single rooms or bays where these are available to avoid having to close the ward. This approach would not be possible in a ‘Nightingale’ style ward where all the beds are in one large room.

John Harris, a HPA epidemiologist specialising in norovirus said: "It is not surprising that we are seeing hospital ward closures due to norovirus as norovirus infections increase during the winter. Because the virus is highly contagious once it is in a hospital, closing wards to reduce the spread is often necessary and we commonly see this measure introduced at this time of the year.

"Hospitals should have a plan in place for managing an outbreak of norovirus and their infection control team will implement strict measures in order to help prevent the virus from spreading to other wards or departments in the hospital.”

Dr Bob Adak, head of epidemiological services in the gastrointestinal diseases department at the HPA, said: “Every year millions of people will be affected by a bout of norovirus and for most people it will be an unpleasant but short lived illness lasting around two days.

“Anyone who thinks they may have it should not to go to their doctor's surgery or A&E as this could spread the illness to vulnerable people and healthcare workers. Take advice from NHS Direct or your local GP practice on managing the symptoms – the most important is to remain hydrated and the symptoms will pass within a couple of days.”

Advice for the public when managing a bout of norovirus:

  • Do not visit your GP surgery or local A&E Unit. Norovirus infection is a self-limiting illness and you will recover naturally without treatment. It is, however, important to take plenty of drinks to replace lost fluids.
  • Use NHS Direct's new diarrhoea and vomiting online health and symptom checker, to get advice on how to manage your symptoms at home or help to access the most appropriate health service.
  • Wash hands thoroughly and regularly at all times, but particularly after using the toilet and before eating.
  • Do not visit friends or relatives in hospitals or residential care homes as there is a real risk that you would introduce the infection putting vulnerable people at risk.



Notes for editors:

  1. The norovirus working party guidelines can be found here:
  2. The Health Protection Agency is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards. In April 2013, subject to the usual approvals procedures for establishing new bodies, the Health Protection Agency will become part of a new organisation called Public Health England, an executive agency of the Department of Health. To find out more, visit our website:
  3. For more information please contact the national HPA press office at Colindale on 0208 327 7901 or email Out of hours the duty press officer can be contacted on 0208 200 4400.

Last reviewed: 19 December 2011