A highly contagious virus that causes sudden vomiting and diarrhoea and spreads easily through infected food handlers and contaminated food.
A highly contagious virus that causes sudden vomiting and diarrhoea and spreads easily through infected food handlers and contaminated food. Norovirus is a very contagious virus and one of the most common causes of gastroenteritis in Australia. It spreads through the faecal-oral route, meaning tiny amounts of an infected person's vomit or faeces can contaminate hands, surfaces, food and water. It takes only a small number of virus particles to make someone sick, which is why outbreaks spread rapidly in settings like cruise ships, aged-care facilities, childcare centres and restaurants. In food settings the main risk is an infected food handler who prepares food while sick or shortly after recovering. Symptoms come on suddenly, usually 12 to 48 hours after exposure, and include forceful vomiting, watery diarrhoea, stomach cramps and sometimes fever. The illness is unpleasant but generally short, with most people recovering in one to three days, though dehydration can be a concern for young children and older adults. Because it is a virus, antibiotics do not help, and there is no specific treatment beyond rest and fluids. The single most important control in an Australian food business is keeping sick staff away from food. Food handlers with vomiting or diarrhoea must not work with food and should stay away until at least 48 hours after their symptoms have stopped, in line with health department guidance. Thorough handwashing with soap and running water is essential, especially after using the toilet and before handling food, because alcohol-based sanitisers are less effective against norovirus than proper handwashing. Ready-to-eat foods handled directly, such as salads, sandwiches and oysters, carry the highest risk, so bare-hand contact should be minimised. If someone vomits in a food area, the area must be cleaned and disinfected carefully to remove the virus, which is hardy and can survive on surfaces. Businesses should reinforce hygiene training, provide proper handwashing facilities, and have a clear policy that unwell staff report symptoms and stay home. A kitchen hand returns to work the morning after a bout of vomiting, feeling a bit better, and starts assembling sandwiches without realising they are still shedding virus. Over the next day dozens of customers who ate the sandwiches fall ill with sudden vomiting and diarrhoea. The local council traces the outbreak to the venue. Keeping the staff member off food handling until 48 hours after symptoms stopped, plus strict handwashing, would have prevented it.
Frequently asked questions
How does norovirus get into food?
Most often through an infected food handler who prepares food while sick or too soon after recovering, spreading the virus from unwashed hands. It can also come from contaminated water or shellfish such as oysters grown in polluted water.
When can a sick food handler return to work?
They should not handle food while they have symptoms and should stay away until at least 48 hours after vomiting and diarrhoea have stopped, following state health guidance. The virus can still be shed for a time after feeling better.
Do hand sanitisers kill norovirus?
Alcohol-based sanitisers are less effective against norovirus than thorough handwashing with soap and running water. Proper handwashing is the key defence, especially after using the toilet and before handling food.
How long does norovirus illness last?
Symptoms usually start 12 to 48 hours after exposure and last one to three days. Most people recover fully, though young children and older adults need to watch for dehydration.
Why do norovirus outbreaks spread so fast?
It takes only a tiny number of virus particles to cause infection, the virus is hardy on surfaces, and it spreads easily person to person. This makes closed settings like aged care, childcare and food venues prone to rapid outbreaks.
