Norovirus Outbreak in UK

According to officials at Great Britain’s Health Protection Agency (HPA), the norovirus is spreading rapidly across the UK and causing many major outbreaks.  In the last month health officials have received twice as many positive samples submitted to laboratories, while hospitals have experienced more outbreaks than usual.

Since the beginning of November, the number of outbreaks has doubled, a sure sign that the norovirus season has begun (generally October to April).

Noroviruses cause gastroenteritis, which is an inflammation of the stomach and both the small and large intestines accompanied by severe diarrhea and vomiting.  It can affect people of all ages, but is most dangerous for young children, seniors and people with compromised immune systems.  Health investigators have been working diligently to control the norovirus outbreak and urge everyone with symptoms of the virus to remain at home so as not to further spread the illness.

Noroviruses are very contagious and are spread through fecal contamination (and through vomitus).  A norovirus infection can be contracted several ways including ingestion of contaminated food or water, contact with an infected person through contaminated hands, or from exposure to surfaces contaminated with the virus by a person with the disease.  This virus can survive on a contaminated surface for extended periods of time and be picked up by another person just from touching that surface.

Because noroviruses are excreted in such very large numbers, only chlorine is capable of killing all parts of the virus before the reactive agent is used up.  Evidence from outbreak investigations and laboratory-based research has shown that there are a limited number of disinfectants, such as chlorine bleach, that are effective against noroviruses.  Bleach destroys these viruses by breaking their outside protein cover and genetic material into inactive fragments.

According to health officials, travelers to the United Kingdom are advised to pay strict attention to personal hygiene.

• Wash hands frequently, using soap and water, or use a hand sanitizer. Be sure to wash hands before eating, after using the bathroom, and before touching your face (eyes/nose/mouth).
• Limit exposure to people who are ill if possible and take extra precautions regarding hand washing and food preparation.
• Infected individuals in your household should be kept away from well people until their symptoms have been gone for 48 hours. Do not allow them to prepare food for others.

Norovirus is a major concern in the US as well and preventing the contamination of hands, surfaces and foods are the keys to keeping the virus from spreading.  Noroviruses are responsible for an estimated two-thirds of all reported foodborne outbreaks of known etiology including 9.2 million infections, 20,000 hospitalizations, and 124 deaths yearly, and thus the economic burden is significant.

Other precautions that can be implemented are:

• Disinfecting bathrooms with a bleach solution, especially following use by a person with the disease.
• Discarding food handled by a person with the virus.
• Washing utensils, dishes and laundry in hot water and detergent.
• Wearing rubber or plastic gloves when handling soiled materials.

(Joan Rose, PhD, is the Homer Nowlin Chair in Water Research at Michigan State University and a member of the Water Quality and Health Council)