What is ‘Kawasaki’ norovirus and how can you avoid it?

Young woman with hair bun holding her head in bathroom. Eating disorder
Cases of norovirus are much higher than average this year. (Getty Images)

A new strain of norovirus has been sweeping across the country, pushing cases of the nasty stomach bug up to double the average for this time of the year.

Cases of norovirus usually go up during autumn and winter, but recent figures show that rates of the winter vomiting virus are rising quickly.

Figures released by the UK Health Security Agency (UKHSA) found there were 447 cases of norovirus in England between 14 and 27 October - 16% higher than the previous fortnight.

It found that the most frequently identified genotype of norovirus in laboratory-tested samples was GII.17, which accounts for 67% of cases. This strain has been nicknamed ‘Kawasaki’.

The health body said: "The increase of the variant has been observed in other counties and is being closely monitored."

Norovirus can result in unpleasant symptoms like vomiting and diarrhoea, which can last for two to three days. (Getty Images)
Norovirus can result in unpleasant symptoms like vomiting and diarrhoea, which can last for two to three days. (Getty Images)

The 'Kawasaki' norovirus strain was first detected in the Japanese city of the same name in 2014. It is also known as the GII.17 genotype.

An increase in cases of this strain has been observed by the UKHSA since June 2024. It reported that GII.17 was the most commonly detected strain in the first 16 weeks of the 2024/2025 season.

Although it is a different strain of norovirus, it is believed to result in the same symptoms as other strains of norovirus.

Norovirus is highly contagious and can spread via:

  • Close contact with someone who is sick with norovirus

  • Eating food that’s been prepared or handled by someone with norovirus

  • Touching surfaces or objects that have the virus on them, then touching your mouth

  • The main symptoms of norovirus include:

  • Feeling sick (nausea)

  • Diarrhoea

  • Being sick (vomiting)

  • A high temperature

  • A headache

  • Aching arms and legs

Symptoms can start suddenly within one to two days of being infected, but usually pass within two to three days. Most cases of norovirus can be treated at home.

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Washing your hands thoroughly with soap and water is important to keep norovirus at bay. (Getty Images)

Norovirus is most infectious from the start of symptoms until 48 hours after symptoms have stopped. Patients may also still be infectious for a short time before and after this period of sickness.

It is therefore advisable to stay at home for at least two days after you’ve had symptoms of norovirus to avoid spreading it to others.

"Do not return to work or send children to school until 48 hours after symptoms have stopped and do not visit your GP or hospital while symptomatic," the UKHSA advises.

It may not always be possible to avoid catching norovirus, but you can take precautions. Washing your hands thoroughly is important in stopping norovirus from spreading.

The UKHSA’s advice to avoid catching norovirus or passing it on to others is to "wash your hands frequently and thoroughly with soap and warm water".

"This is most important following an episode of illness, after using the toilet, before eating and preparing food, as well as cleaning up vomit or diarrhoea."

It is also important to remember that hand sanitisers, even if alcohol-based, do not work to kill norovirus.

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