What is the winter vomiting bug?

  • The ‘winter vomiting bug’  or gastric flu, is a virus causing a stomach upset with vomiting and/or diarrhoea. It is most commonly caused by a virus known as the Norwalk-like Virus (NLV). While the virus usually causes short-lasting outbreaks, it can be extremely infectious.
  • The incubation period is usually around 24-48 hours but may be as short as six hours.

The symptoms

  • The first symptoms are often abdominal pain and nausea. These are then followed by vomiting and diarrhoea. The vomiting may be of sudden onset, severe, projectile and very tiring. The diarrhoea is usually quite mild. Other symptoms can include fever, headache and muscle aches. The illness is usually mild, lasting less than 2-3 days; although the symptoms can be quite unpleasant and debilitating in older people.

How is the Virus spread?

The virus is extremely contagious and may be spread by:

  • Person to person – primarily when a person who is ill vomits. This is particularly common in hospitals and nursing homes. Contamination can also occur through transfer of the virus onto people’s hands.
  • Infected food handlers – passing the virus on to people with whom they may come in contact.
  • Water – drinking water that is contaminated and not properly treated may transmit the virus, as may contaminated ice-cubes and swimming in or brushing teeth with contaminated water.
  • Contaminated food – often shellfish, but also fruit and salads that have been washed with contaminated water.

The NLV virus can also remain infectious for several days on surfaces and in fabrics and upholstery.

What to do if you get the vomiting bug?

  • Medications are not normally necessary for winter vomiting disease and as the disease is caused by a virus, antibiotics are ineffective. The affected person normally recovers without medical treatment within a few days. It is important to ensure that you drink plenty of fluids to prevent dehydration.
  • The most important thing is to prevent the virus from spreading to others.

The best advice is that you should wash your hands:

In the bathroom

  • After using the toilet or touching surfaces in the bathroom.
  • After changing nappies - wash the child's hands also.
  • After helping a child go to the toilet.
  • Whenever your hands have come contact with vomit, saliva and runny noses.

In the kitchen

  • Before preparing or eating food, especially food that does not need any further cooking.
  • After touching raw meat, poultry, fish or eggs.
  • After meals and snacks.


  • After touching any animals, even your own pets.
  • After working or playing in the garden.
  • After touching bins and other waste.
  • Whenever your hands are dirty.

It is very important that people who have been ill with vomiting or diarrhoea should stay out of work for at least 2 full days and preferably 3 days after their symptoms have stopped. This and thorough handwashing are two of the very best ways to prevent the spread of the winter vomiting disease.

For more information on management and treatment of the vomiting bug, contact Garvan at Lynch’s Pharmacy on 021-4366923.


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