Norovirus

Also called Winter vomiting bug, Stomach flu

The commonest cause of gastroenteritis in the UK. Alcohol gel does not kill it, and that single fact drives most outbreaks.

What it is

Norovirus causes an estimated 3 million cases a year in the UK. It is unpleasant in a healthy adult and dangerous in an older or frail one, mainly through dehydration.

It is extraordinarily infectious. As few as 18 viral particles can cause infection, and an infected person sheds billions. It survives on surfaces for days and it spreads through vomit aerosol, which travels further than people expect.

Here is the fact that matters most in care settings, and it is still not universally known: alcohol hand gel does not kill norovirus. Soap and water, with proper mechanical washing, is the only effective hand hygiene against it. An outbreak controlled with gel alone is an outbreak that continues.

Cleaning needs a chlorine-based product; ordinary detergent is not enough.

Signs you might notice

Sudden onset vomiting, often projectile, and watery diarrhoea.

Stomach cramps, nausea, aching limbs, a mild fever and headache.

Onset 12 to 48 hours after exposure, lasting one to three days.

Signs of dehydration are what matter in older people: reduced urine output, dark urine, dizziness, confusion, drowsiness.

Blood in the stool, high fever or severe pain suggests something else and needs assessment.

How it can affect day-to-day life

Outbreaks close care home wings and hospital wards, and the resulting staff absence compounds the harm to residents.

The 48-hour rule is the key control: nobody, resident or staff, should return until 48 hours after symptoms stop. Returning at 24 hours because a shift needs covering is how outbreaks restart.

In older people, a short bout of vomiting and diarrhoea can cause acute kidney injury quickly, particularly for anybody on diuretics or certain blood pressure tablets. Sick day rules apply.

Supporting someone well

Wash hands with soap and water. Not gel. This is the single most important line in this entry.

Clean with a chlorine-based product, and deal with vomit and diarrhoea spills promptly and thoroughly, including surfaces further away than seems necessary.

Keep symptomatic people away from others, and observe the 48-hour rule strictly for residents and staff alike.

Push fluids in small, frequent amounts, and use oral rehydration salts for older people.

Review medication during illness: some blood pressure and diabetes drugs should be paused during vomiting and diarrhoea. See chronic kidney disease.

Report outbreaks to the local health protection team promptly.

Fiducia Together records fluid intake and observations, which is how dehydration during an outbreak is caught before somebody is admitted.

Where to get help

Call 111 for advice. Most cases need no medical treatment.

Seek help for signs of dehydration, blood in the stool, symptoms lasting more than a few days, or in a frail or immunosuppressed person.

Care settings should contact their local UKHSA health protection team for outbreaks.