Food poisoning factsheets Viral Gastroenteritis

What is Viral Gastroenteritis?

Viral Gastroenteritis is a term covering a range of viral infections that cause diarrhoea and other stomach upsets. The common viruses are Norovirus, Rotavirus, Adenovirus and Astrovirus. Norovirus is also known as Winter Vomiting Diseases and affects all age groups but can be particularly problematic in schools, care homes and other residential settings. The other viruses mainly affect infants and school children.

How is it caught?

Infections are caught either from another person, a surface contaminated with the virus or from food. They are rarely caught from animals. The virus can survive in the environment for several days and is easy to catch because the vomit and diarrhoea of an infected person contains millions of virus particles while the number needed to transmit Norovirus infection can be as low as 10-100. The time from infection to the development of symptoms is usually one or two days. Viral Gastroenteritis remains infectious during the stage of active vomiting or diarrhoea and for some days afterwards but those with impaired immune systems may excrete the virus for longer.

What are the symptoms of Viral Gastroenteritis?

Typically the symptoms are vomiting, diarrhoea and flu-like symptoms such as fever, headache and muscle pains. Norovirus is unusual in that its main and sometimes only symptom is vomiting. Most illnesses last one to four days but severe cases, as with all other causes of diarrhoea, can lead to dehydration and admission to hospital.

How do you know if you have Viral Gastroenteritis and how is it treated?

Many different kinds of disease can cause diarrhoea so it can only be diagnosed by examining a stool sample in a laboratory.

Viral Gastroenteritis cannot be treated with antibiotics. It’s most important that an affected person gets enough fluids while they have diarrhoea. Food intake is less important.

What can you do to prevent Viral Gastroenteritis?

Viral Gastroenteritis is easily caught from another person so strict hygiene in the household is important, particularly when changing nappies, soiled bedding and clothes. Some viruses can be caught by inhaling tiny vomit particles so extra care is needed when cleaning up after a sick person. A hot wash (60’c or hotter) destroys any virus on bedding/clothing.

Regular and thorough hand washing, especially before preparing or eating food or drink, will help prevent further spread. Wash contaminated surfaces such as toilet flush handles, taps and door handles with detergent followed by a diluted bleach solution. Soft furnishings can be steam cleaned if bleaching would damage them.

Anyone suffering symptoms of Viral Gastroenteritis should not attend nursery, school or work. In particular, there are several groups of people that should not return to school/work until 48 hours after the symptoms have ceased. They should contact their school/employer/supervisor and tell them they are unwell. These groups are:

  • Children under five or any person who cannot maintain good personal hygiene.
  • Those who work with food.
  • Those who work with vulnerable persons such as children, elderly or anyone in poor health.