Norovirus is on the rise in schools and nurseries, with outbreaks doubling in the space of a week.
The UK Health Security Agency (UKHSA) is warning people to take action to limit the spread of the vomiting bug as infections also rise in care homes.
It comes after the latest data from the government agency, which monitors outbreaks, shows norovirus outbreaks more than doubled in the second week of March compared to the first.
UKHSA said the increase was primarily down to increased outbreaks in educational settings, which accounted for 54 per cent of outbreaks, and care homes which accounted for 38 per cent.
It added that cases had been on the rise since coronavirus social-distancing rules were relaxed as it warned of a potential “unusual or out-of-season” spike in cases in the coming weeks.
There are six key symptoms of norovirus to look out for, according to Professor Saheer Gharbia, gastrointestinal pathogens and food safety directorate at UKHSA.
What are the symptoms?
Symptoms include sudden onset of nausea, projectile vomiting, diarrhoea, high temperature, abdominal pain and aching limbs.
People are being urged to avoid visiting elderly relatives, especially in hospitals and care homes, if feeling unwell and to use soap and water instead of alcohol gel, which does not kill the virus.
Prof Gharbia said: “Norovirus, commonly known as the winter vomiting bug, has been at lower levels than normal throughout the pandemic but as people have begun to mix more, the numbers of outbreaks have started to increase again.
“Please avoid visiting elderly relatives if you are unwell – particularly if they are in a care home or hospital.
“As with Covid-19 and other infectious illnesses, hand washing is really important to help stop the spread of this bug, but remember, unlike for Covid-19 alcohol gels do not kill off norovirus so soap and water is best.”
Norovirus is highly infectious and causes vomiting and diarrhoea but usually passes in a couple of days.
It is easily transmitted through contact with infected individuals or contaminated surfaces.
The UKHSA said the number of outbreaks increased during four weeks between the end of January and February, initially in educational settings and then in care homes.
The increase in reported outbreaks was initially in educational settings, particularly in nursery and childcare facilities, with 48 per cent more incidents reported to UKHSA than would usually be expected.
Outbreaks in care homes remain below the number expected in a pre-pandemic year, but the UKHSA said they were likely to rise in the coming weeks and a rise in care homes often precedes a rise in hospitals.
There were 113 outbreaks - defined as at least two cases - of the highly infectious bug in educational settings in the two weeks to 13 March.
This is more than double the 50 outbreaks reported a fortnight earlier.
Cases have also risen by a third in care homes, with 80 outbreaks recorded in the most recent period.