Brits were today told to brace themselves for a upsurge in norovirus cases.
Rates of the winter vomiting bug, which can also cause diarrhoea, are up almost a fifth in just a fortnight, figures show.
It means cases for this time of year in England and Wales are more than double the levels seen pre-Covid.
Health chiefs blamed the rise on the recent spell of cold weather and warned people not to work for at least 48 hours after symptoms end.
Experts also said a variant dubbed ‘Kawasaki’, first spotted in Japan, now accounts for almost 70 per cent of all cases.
According to figures released by the UK Health Security Agency (UKHSA), there were 447 confirmed cases of the bug between October 14 and 27.
This is 16 per cent higher than the 384 reported in the previous fortnight.
It is also more than double the five-year average for the same two weeks.
Norovirus can appear similar the symptoms of Covid, with both viruses causing chills, fever and headaches
According to figures released by the UK Health Security Agency (UKHSA), there were 447 confirmed cases of the bug between October 14 and 27
Since the start of the 2024/2025 season, the number of norovirus outbreaks reported in hospital settings is also 26 per cent higher than the five-year average.
However, actual case numbers — which only cover England — may be even higher.
This is because the figures are based on positive laboratory reports and NHS hospitals reporting suspected and confirmed norovirus outbreaks.
Most of those infected suffer nausea, diarrhoea and vomiting and recover at home.
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.
‘The increase of the variant has been observed in other counties and is being closely monitored,’ the health body said.
The bug is spread through close contact with someone who is infected; touching surfaces or objects that have the virus on them, and then touching the mouth; as well as eating food that’s been handled by someone with norovirus.
Regular hand washing is the best way to stop the spread.
Norovirus can show similar symptoms to Covid, with both viruses causing chills, fever and headaches.
The stomach bug usually goes away on its own within two to three days.
But sufferers, who may also experience aching arms and legs, are advised to stay at home until 48 hours after their symptoms have stopped.
In severe cases, however, some people may need to be hospitalised with the elderly and children most at-risk.
Rest and having lots of fluid are often recommended by health chiefs. Paracetamol may also aid a fever or aches and pains.
But last week, one health expert advised people to steer clear of Ibuprofen over fears it could irritate the stomach lining.
The nonsteroidal anti-inflammatory drug (NSAID) could also raise the risk of suffering stomach bleeds and ulcers, Savneesh Bhogal, a healthcare expert at Netex, said.
This is because the medication reduces the production of prostaglandins — hormone-like substances that the body produces — which protect the stomach lining.
The uptick in cases also comes as a new vaccine that could stop people from developing norovirus is being trialled in the UK.
The mRNA vaccine from Moderna has entered its final stages of testing, the Health Secretary has announced, with results so far showing it creates a ‘strong immune response’.
