Warning of ‘second norovirus wave’ with people catching bug more than once

Health leaders have warned of a “potential second norovirus wave” – with people catching the vomiting bug more than once.

The UK Health Security Agency (UKHSA) said people who have already had the virus this winter could be at risk again due to a shift in which strains are becoming dominant.

The organisation – which tracks lab reports of the sickness bug – said having had one type of norovirus does not fully protect against other strains.

Its data shows the recently emerged GII.17 genotype of norovirus has seen a surge in cases this winter but a different, commonly seen, genotype – GII.4 – is now on the rise.

While the GII.17 genotype remains dominant, accounting for 59% of cases, its prevalence has dropped from 76% since November.

Meanwhile, the GII.4 strain has seen a sharp rise, now representing 29% of cases compared to just 10% three months ago.

The UKHSA reassured people that there is no indication that either GII.17 or GII.4 leads to more severe illness but said it is unclear whether norovirus cases have peaked for this winter.

Amy Douglas, lead epidemiologist at the UKHSA, said: “Norovirus levels are still exceptionally high and now with multiple genotypes spreading at the same time, people could end up getting infected more than once this season.

“We are seeing the biggest impacts in health and social care settings, such as hospitals and care homes.

“Symptoms of norovirus can be more severe in older adults, young children and those who are immunocompromised.

“If you have diarrhoea and vomiting, please do not visit hospitals and care homes or return to work, school or nursery until 48 hours after your symptoms have stopped and don’t prepare food for others, as you can still pass on the virus during this time.

“Alcohol gels do not kill norovirus. Wash your hands with soapy warm water and clean surfaces with bleach-based products where possible to help stop infections from spreading.”

UKHSA lab data – representing a fraction of cases in the community – show confirmed cases in the two weeks from February 3 to 16 were 29.4% higher than the previous fortnight and more than double the five-season average for the same period.

For every case reported in this national data, around 288 cases occur in the community, suggesting around three million cases annually in the UK.

Health and social care secretary Wes Streeting said: “These statistics show that we are still not out of the winter woods, and I want to thank all NHS staff for their hard work in the face of substantial pressures on the health service.

“We have taken important steps to reduce winter pressures this year, including getting doctors back on the frontline, rather than the picket line, and introducing the country’s first RSV vaccination scheme.

“Through the government’s Plan for Change, we will deliver the investment and reform required to turn our health service around, so it will be there for all of us when we need it, once again.”