Health officials are warning that the UK could face another surge in norovirus cases this winter, with people who have already been infected at risk of catching the virus again.
A shift in dominant strains of the highly contagious “vomiting bug” has raised concerns about a fresh wave of infections.
The UK Health Security Agency (UKHSA) reports that while the GII.17 norovirus strain has been the most common in recent months, its dominance is waning. It now accounts for 59% of cases, down from 76% in November. Meanwhile, the GII.4 strain is spreading rapidly, rising from 10% to 29% of cases over the past three months. This change means those who had norovirus earlier in the season may still be vulnerable to reinfection.
Norovirus spreads easily through contaminated food, surfaces, and close contact with infected individuals. Symptoms include sudden vomiting, diarrhea, stomach cramps, and fever. Although the virus usually clears within a few days, it can be more severe in older adults, young children, and people with weakened immune systems.
Hospitals and care homes are seeing the biggest impact, with NHS England reporting nearly 1,134 patients per day hospitalized with norovirus—more than double the number from this time last year. Online searches for information about norovirus have also surged by 40% in the past week, highlighting growing public concern.
Experts emphasize that preventing infection requires proper hygiene. Alcohol-based hand sanitizers are not effective against norovirus, so people should wash their hands thoroughly with soap and warm water. The public is urged to stay home for at least 48 hours after symptoms stop to prevent spreading the virus to others.
While there is no evidence that the new strains cause more severe illness, it remains unclear whether norovirus cases have peaked for the season. Health officials continue to monitor the situation as cases remain at near-record levels.