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Norovirus Gastroenteritis (Gastric Flu)

Gastroenteritis, is a condition characterised by the inflammation of the stomach and intestines.

12 Jul 2018


Understanding Viral Gastroenteritis

Gastroenteritis, is a condition characterised by the inflammation of the stomach and intestines. It can be caused by infection with bacteria, parasites or viruses, such as norovirus, rotavirus, sapovirus or astrovirus. Infection due to viruses; is called viral gastroenteritis, and is also commonly known as “stomach flu”. The most common cause of acute viral gastroenteritis is norovirus.

How norovirus is transmitted

Norovirus is highly contagious and is usually transmitted by:

  • Consuming contaminated food or drink

  • Touching contaminated surfaces or objects and then placing your fingers in your mouth

  • Having contact with an infected person (e.g. caring for or sharing utensils with an infected person)

Symptoms of norovirus gastroenteritis


Symptoms usually appear 12 to 48 hours following infection and generally last for one to three days. The common symptoms are:

  • Nausea

  • Vomiting

  • Diarrhoea

  • Stomach pain

Other symptoms may include fever, headache and body aches.

Risks of norovirus gastroenteritis

Norovirus infection is generally self-limiting but it can cause dehydration, recognisable by the symptoms of:

  • Dry mouth and throat

  • Dizziness when standing up

  • Decreased urination

Dehydration is more common in the elderly, young children and the immunocompromised. It is important to replenish the fluids lost from diarrhoea and vomiting by drinking plenty of liquids. Seek medical attention if necessary.

Protecting against norovirus

  • Wash your hands frequently, especially after going to the toilet, eating/preparing food or changing diapers

  • Wash fruits and vegetables thoroughly before eating

  • Ensure food (especially filter feeders e.g. oysters and shellfish) is thoroughly cooked before eating

  • Disinfect surfaces contaminated with diarrhoea or vomitus immediately by using 1 part 5.25% bleach to 9 parts water

  • Wash contaminated clothing or linens immediately

  • If unwell, do not prepare food for others

What to do if you have norovirus infection

Avoid going to work or school. Refrain from preparing any food for others while you are sick and for at least two days after symptoms resolve.

Treatment for norovirus

There is no specific treatment to treat norovirus illness. Frequent vomiting and diarrhoea may lead to dehydration, especially in young children, the elderly and the immunocompromised. It is important to replenish the fluids lost from diarrhoea and vomiting by drinking plenty of fluids. Seek medical attention if necessary.

For more information:

  • Call the Ministry of Health hotline: 1800-225-4122