HPA update on seasonal norovirus activity: 8 January 2013

8 January 2013

Latest figures from the Health Protection Agency (HPA) show there have been 4,140 laboratory confirmed cases of norovirus this season (from week 27 to week 52 2012). The latest figures are 63 per cent higher than the number of cases reported at this point last year, when there were 2,535 cases.

The downward trend in the number of confirmed cases has continued in line with the previous report although this is to be expected following the Christmas and New Year period. We will expect to see the number of cases increase again over the following few weeks.

During the two weeks up to 6 January there were 33 hospital outbreaks reported, compared to 30 in the previous fortnight, bringing the total of outbreaks for the season to 673.

Cases of norovirus have risen earlier than expected this winter season and this is a trend that has been seen across Europe and other parts of the world. It has not yet been determined why this has been the case and activity varies significantly from year to year.

John Harris, an expert in norovirus from the HPA said: “Our latest figures covering the New Year period show a further decline in the number of cases and this is what we would expect to see. We can never predict how busy a season will be or what will happen in the weeks ahead although, as with other norovirus seasons we will expect to see an increase in the number of laboratory reports in the next few weeks until the end of March when activity begins to fall away.

“If you think you may have the illness then it is important to stay away from hospitals, GP surgeries and care homes to avoid spreading it to people who may have underlying health conditions and already be vulnerable. Maintaining good hand hygiene is also important to help prevent it spreading.”

Norovirus can be transmitted by contact with contaminated surfaces or objects, by contact with an infected person, or by the consumption of contaminated food or water. Symptoms of norovirus 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.

Ends

Notes to editors

Indications from Europe and Japan are that norovirus activity also started to increase early. In Australia the norovirus season also peaks during the winter but this season it has gone on longer than usual and they are seeing cases into their summer. The HPA is following up with colleagues internationally.
The number of laboratory confirmed cases represents just a fraction of the actual amount of norovirus activity as it is estimated that for each confirmed case, there are a further 288 unreported cases, as the vast majority of those affected do not seek healthcare services in response to their illness. Data from The Infectious Intestinal Diseases II (IID II) report can be found at the Food Standards Agency website [external link].
The latest norovirus report can be found from the Norovirus update: 13 June 2013 (PDF, 178 KB) document.
Guidelines for the management of norovirus in acute and community health and social care settings can be found from the Guidelines for the management of norovirus outbreaks in acute and community health and social care settings (PDF, 2.6 MB) document.
Further information about norovirus can be found from the HPA norovirus page.
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: http://www.hpa.org.uk or follow us on Twitter @HPAuk or ‘Like’ us on Facebook at www.facebook.com/HealthProtectionAgency [external link].
For more information please contact the national HPA press office at Colindale on 0208 327 7901 or email colindale-pressoffice@hpa.org.uk. Out of hours the duty press officer can be contacted on 0208 200 4400.

Last reviewed: 8 January 2013