The 5 ‘most easily missed’ symptoms of the extremely contagious norovirus strain sweeping the UK
A NEW strain of norovirus is spreading across the UK – but some symptoms could be mistaken for other viruses.
Norovirus, often referred to as the ‘winter vomiting bug’, is a very contagious virus that causes vomiting and diarrhoea.
The latest report on winter illnesses from the UK Health Security Agency (UKHSA) revealed the Kawasaki norovirus, also referred to as variation GII.17, now accounts for 70 per cent of cases.
Kawasaki norovirus was first detected in the city of Kawasaki, Japan, back in 2014, and rapidly established itself as the predominant strain.
GII.17 viruses have been reported since 1978 and they have a unique ability to swap part of their genetic code and create slightly different versions of themselves.
This may have allowed them to survive, adapt and spread in the population over the past few decades.
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.”
Spotting the symptoms of norovirus is key in helping stop the spread.
Dr Bruno Silvester Lopes, a lecturer in microbiology at Teesside University, advised what to look out for.
Norovirus symptoms
The most common symptoms are:
- Nausea
- Vomiting
- Diarrhoea
- High temperature
- Headache
- Aching arms and legs
But other symptoms linked to norovirus could be easily missed or mistaken for something else, said Dr Lopes. These include:
- Chills
- Mild body aches
- Mild stomach discomfort
- General malaise or extreme fatigue
- Diarrhoea without nausea or vomiting
Norovirus treatment
Unfortunately there’s no treatment for norovirus, you have to let it run its course.
The NHS advises staying at home and keeping well hydrated by drinking plenty of fluids.
You can take paracetamol for any aches or pains, and if you feel like eating, try plain foods, such as soup, rice, pasta and bread.
But in some cases, norovirus symptoms can become more severe.
Dr Lopes said: ” Intense vomiting and diarrhoea can lead to dehydration, with symptoms like dizziness and low urine output. Painful stomach cramps, fever, and body aches are also possible.
“Vulnerable groups, such as young children, the elderly, and those with weakened immune systems, may experience more prolonged and serious symptoms, sometimes needing medical attention.”
UKHSA expert advice
Amy Douglas, epidemiologist at UKHSA, said the half-term school break interrupted the upward trend that’s been seen recently in norovirus levels.
But cases are likely to rise again as we head towards Christmas.
She advised: “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.”
What to do if you think you have norovirus - and when to call 999
If you think you have norovirus, stay hydrated, rest, and eat bland foods when you feel better.
Wash hands often, disinfect surfaces, and avoid contact with others until 48 hours after symptoms stop.
Seek medical advice if symptoms are severe or prolonged.
When it comes to treatment, focus on staying hydrated with water or electrolyte drinks.
Rest as much as possible. Eat bland foods like toast or crackers, rice, pasta.
For symptom relief, consult your doctor about over-the-counter options. Symptoms should go away in one to three days.
If you or your child experiences the following, you should call 999 or go to A&E:
- vomit blood or have vomit that looks like ground coffee
- have green vomit (adults)
- have yellow-green or green vomit (children)
- might have swallowed something poisonous
- have a stiff neck and pain when looking at bright lights
- have a sudden, severe headache or stomach ache
Source: Dr Bruno Silvester Lopes, Lecturer in Microbiology at Teesside University and NHS