Norovirus ‘Kawasaki’ variant behind 40% surge in grim diarrhoea cases – as health officials warn group at highest risk
A SURGE in cases of a nasty diarrhoea bug norovirus has been driven by a variant dubbed ‘Kawasaki’.
Cases of virus that causes sudden and violent vomiting and diarrhoea have spiked by 41 per cent in two weeks, according to the UK Health Security Agency.
Norovirus is highly contagious bug that tends to spike in winter months.
Symptoms of nausea, vomiting and watery stools often strike suddenly, within a day or two of being infected.
UKHSA said: “Norovirus activity has remained high this season and has started to increase in recent weeks.”
It comes as health bosses also warned of a looming “quadrupledemic” of winter bugs.
In the two weeks between October 7 and 20, reports of norovirus infections rose by 41 per cent compared to the previous two-week period.
The total number of reports was more than double the amount of cases usually seen at this time of year, the health watchdog added.
A total of 2,419 norovirus cases have been reported so far this year, compared to 993 this time last year.
Meanwhile, 447 cases were detected between October 7 and 20, compared to 167 in the same period in 2023.
UKHSA noted that the surge in cases had been largely driven by variant known as GII.17.
The strain has been nicknamed ‘Kawasaki’ as it was first detected in the Japanese city in 2014.
It was a “a major cause of gastroenteritis outbreaks in China and Japan” at the time, a study published in the journal Eurosurveillance said.
More recent research from 2024 suggests that the strain may be replacing other more common variants of the bug – known as GII.4 – in England, France, Austria, Finland and the US.
Discussing the recent spike in norovirus cases, UKHSA said: “There has been an increase GII.17 variant since April 2024, and during the first 16 weeks of the 2024/2025 season this was the most commonly detected norovirus genotype.
“The increase of the variant has been observed in other counties and is being closely monitored.”
When to call 111 and 999 for norovirus
NOROVIRUS usually goes away on its own after a couple of days and doesn't require medical attention.
But you might need to speak to a doctor if:
- You’re worried about your baby who is younger than 12 months
- Your child stops breast or bottle feeding while they’re ill
- You think your child under five might be dehydrated – signs could include fewer wet nappies
- You’ve used rehydration sachets but still have signs of dehydration
- You or your child keep being sick and can’t keep fluids down
- You or your child have bloody diarrhoea or start bleeding from the bottom
- You or your child have diarrhoea for more than seven days or are vomiting for more than two days
And if you spot any of the following signs, it’s vital to seek urgent care:
- Blood in your vomit
- Vomit that looks like ground coffee
- Green vomit (adults) or yellow-green vomit (children)
- A stiff neck
- Pain when looking at bright lights
- A sudden, severe headache or stomach ache
Source: NHS
Reports have been rising across all age groups compared to previous seasons’ activity, but case numbers have been highest in adults – particularly those aged 65 and over – in recent weeks.
Gauri Godbole, deputy director for gastrointestinal infections at UKHSA, said: “We are heading into the winter season with norovirus levels higher than usual, and we expect norovirus to spread more in the coming weeks.
“Recently, we’ve seen the biggest rise in cases in adults, especially those aged 65 and over.”
Norovirus outbreaks in hospitals have also increased by 37 per cent compared to numbers usually seen around this time of year.
Who is most vulnerable to norovirus?
As norovirus can cause vomiting and diarrhoea – both of which deplete the body of fluids – it can leave people dehydrated.
Young children and older people or those with compromised immune systems are most vulnerable to this.
If you do get ill it is important to drink plenty of fluids during that time, UKHSA warned.
As the virus is highly contagious, it’s also important help reduce its spread as much as possible.
The bug tends to linger on surfaces and objects, so it can be passed on if you bring your hands to your mouth after touching contaminated things.
You can also catch it from close contact with someone with norovirus or eating food that’s been prepared or handled by someone with norovirus.
Dr Godbole said: “To help reduce the spread of norovirus you can take steps to avoid passing the infection on.
“If you have diarrhoea and vomiting, do not return to work, school or nursery until 48 hours after your symptoms have stopped and don’t prepare food for others in that time either.
“If you are unwell, avoid visiting people in hospitals and care homes to prevent passing on the infection in these settings.
“Washing your hands with soap and warm water and using bleach-based products to clean surfaces will also help stop infections from spreading.
“Alcohol gels do not kill norovirus so don’t rely on these alone.”