Noroviruses are part of a group of viruses. In the United Kingdom they are the most common cause of upset stomach (gastroenteritis). Noroviruses are sometimes referred to as SRSV (small round structured viruses), NLV (Norwalk-like viruses), winter vomiting disease, or stomach flu.

Between 600,000 and 1,000,000 people are affected by the norovirus in the UK annually. Outbreaks are more common in confined environments such as schools, hospitals and nursing homes. The virus spreads from person-to-person and can survive for several days in a contaminated area.

There are three ways you can become contaminated:

1. Contact with an infected person.
2. Contact with contaminated surfaces/objects.
3. Consuming contaminated liquids or foods.

After you recover from an infection you are immune for about 14 weeks. This means you can become infected and ill several times. Experts do say that after several recurring bouts your immunity does gradually improve.

What are the symptoms?

Nausea
Vomiting
Diarrhea
Stomach cramping

Additional symptoms may include

Low-grade fever
Chills
Headache
Muscle aches
General fatigue (tiredness)

The illness comes on very quickly and the patient may feel extremely sick. Most people recover within two or three days.

If the diarrhea and/or vomiting is severe some people may be unable to drink enough liquids and they become dehydrated. Some dehydrated patients might need special medical attention. Dehydration is more common among the very young children, the elderly, and people with weakened immune systems.

Is there any treatment?

There is no antiviral medication against norovirus, and there is no vaccination to prevent infection. You cannot treat norovirus with antibiotics – antibiotics fight bacteria, not viruses. The patient needs to make sure he is consuming plenty of liquids if he is vomiting and/or has diarrhea.

Sources – Department of Health (UK), CDC (USA)

Written by Christian Nordqvist