Norovirus cases at more than double expected number

Norovirus cases in England are currently more than double the expected number for this time of year, the UK Health Security Agency (UKHSA) has said.

Separate data from NHS England showed 898 hospital beds were filled on average every day last week by patients suffering from norovirus-like symptoms - a 15% increase from last week.

Higher case numbers are likely due to a number of factors, the agency has said, including "the emergence of an unusual norovirus genotype" and increased use of testing technology.

Prof Julian Redhead, NHS national clinical director for urgent and emergency care, called the rise a "worrying surge", and the UKHSA said there was a big impact on hospitals and care homes.

"Hospitals remain close to capacity, with almost a fifth of beds filled due to seasonal viruses and delayed discharges to settings like social and community care," Prof Redhead added.

NHS England said pressure on hospital capacity remained high last week with an average of 96% adult beds occupied and a total of 97,567 patients in hospital each day.

Laboratory reports only represent a small proportion of total norovirus cases, and it is estimated that for every case reported to national surveillance in the UK, about 288 in the community go unreported, an annual figure of around 3 million cases.

Norovirus levels are also higher than the same period 12 months ago, when 688 hospital beds were filled with people experiencing diarrhoea and vomiting symptoms, and also January 2023, when 395 beds were used by those with symptoms.

According to UKHSA, some of the higher numbers may be attributable to the use of PCR multiplex technology, which can detect multiple gastrointestinal pathogens in one test.

But it is likely that an unusual norovirus genotype emerging (GII. 17), along with changes in epidemiology following the coronavirus pandemic, are also contributing to the rise in cases.

At present, there is no indication that the genotype leads to more severe illness.

Norovirus symptoms include nausea, vomiting and diarrhoea but a high temperature, abdominal pains and aching limbs are also common. The virus spreads easily, for example through close contact with someone infected or by eating food prepared by someone with it.

Those infected with norovirus can also experience dehydration, which is especially common amongst vulnerable groups including young children and those with weakened immune systems.

Most healthy people recover in a few days, but it can cause serious problems for those in vulnerable groups.

"It's really important that if you have diarrhoea and vomiting that you take steps to avoid passing the infection on," Amy Douglas, an epidemiologist at UKHSA said.

"Avoid visiting people in hospitals and care homes to prevent passing on the infection in these settings".

Ms Douglas advised those suffering to not return to work, school or nursery until 48 hours after symptoms end and do not prepare food for others in that time.

"This is because you can still pass on the virus in the days after you stop being sick."

The advice from UKHSA to avoid passing on norovirus is to wash your hands with soap and warm water and to use bleach-based products to clean surfaces, which will help to stop infections from spreading.

"Alcohol gels do not kill norovirus, so don't rely on those alone," Ms Douglas added.