Norovirus poster

Viral Gastroenteritis is a stomach illness. It can be caused by a number of viruses. Most cases are caused by a group of viruses called Norovirus.


  • Symptoms usually appear 10-50 hours after contact with a virus
  • The most common symptoms are nausea (feeling sick), stomach cramps, diarrhoea, vomiting, headache, chills and aching muscles
  • Vomiting is more common in children
  • Dehydration may be a problem in the very young, elderly and people with weakened immune systems
  • Symptoms usually last 12-72 hours but some people may be unwell for longer
  • The disease is highly infectious and it is common for other people in your household to develop the symtoms after a day or so

How do people come in contact with viruses?

Gastroenteritis causing viruses are found in high numbers in the vomit and faeces (poos) of people with the infection.

People become infected when they swallow the virus.

This can happen in several ways:

  • Direct contact, e.g. cleaning up vomit or diarrhoea of a sick person
  • Via food, which has been handled by a sick person
  • Via surfaces contaminated with viruses, e.g. taps, towels, utensils
  • Via drinking contaminated water
  • Through airborne viral particles in heavily contaminated environments, e.g. institutions where many people are ill with gastroenteritis

Treatment of viral gastroenteritis

  • Drink plenty of fluids while the diarrhoea lasts, to prevent dehydration
  • See a doctor if vomiting and/or diarrhoea is severe or the illness does not improve
  • The illness is caused by a virus, so antibiotics do not have any effect

Taking time off work or school

Usually people can go back to work and children can return to early childhood centres and school once they have been symptom free for 24 hours.

There may be viruses in your faeces for a week or longer, so it is very important to wash your hands thoroughly and dry them after using the toilet and before preparing food.

How to stop the spread of viral gastroenteritis

Viral gastroenteritis is extremely infectious and people can be contagious for a period of time (1-2 hours) before symptoms start.

Some individuals experience no symptoms, but can still be contagious to others.

The virus can also survive on surfaces.

If you are suffering from or caring for others with viral gastroenteritis, you need to pay special attention to hygiene, especially when:

  • Caring for others
  • Preparing food
  • Cleaning your home

Caring for others

When caring for sick people with gastroenteritis, after using the toilet, or changing a baby's nappy, washing your hands is very important.

Preparing food

  • Food such as shellfish can collect the viruses if the sea water contains human sewage
  • Infected food handlers can contaminate food if they prepare it while ill and do not wash their hands after using the toilet
  • People with diarrhoea and/or vomiting should use separate towels and face cloths while they are unwell, and for 24 hours after they have recovered
  • People with diarrhoea and/or vomiting should not prepare food for others 
  • Food handlers should wait for at least 24 hours after their diarrhoea and/or vomiting stops before returning to work

Cleaning your home

The viruses that cause viral gastroenteritis can survive outside the body and live on surfaces contaminated by vomit and/or faeces.

  • Surfaces in the toilet and bathroom should be cleaned regularly with chlorine-based cleaning agents (follow the instructions on the bottle)
  • Clean and disinfect contaminated surfaces with household bleach after an episode of illness
  • Remove and wash contaminated linen and clothes with hot water and detergent

Prevention tips

  • Wash your hands thoroughly by using plenty of soap, cleaning under fingernails, rinsing hands well and drying with a clean towel after caring for people with gastroenteritis, after using the toilet or changing a baby's nappy and before and after preparing food.
  • People with diarrhoea and/or vomiting should stay away from work and not prepare food for others for at least 24 hours after their vomiting and diarrhoea stops.
  • Food should be cooked thoroughly - the virus dies when food is steaming hot.
  • Shellfish should only be collected from places where there are no signs warning that human sewage is discharged.

More information

For more information about Viral Gastroenteritis contact your doctor or Health Protection Officer from the Population Health Service
Ph: (07) 838 2569 or toll-free 0800 805 977

Information for health professionals