The UK Health Security Agency (UKHSA) has confirmed 111 cases of sudden-onset hepatitis, with cases 'predominantly in under 5s who showed initial symptoms of gastroenteritis illness - diarrhoea and nausea - followed by the onset of jaundice'.
Ten children in the UK, where the bulk of cases have been identified to date, have required liver transplants. The WHO has reported 17 liver transplants worldwide - including the UK cases - and one death from the illness.
Investigators have found that the usual viruses that cause infectious hepatitis have not been detected in patients identified - and the UKHSA said that although other possible causes still were being looked into, 'investigations increasingly suggests that the rise in severe cases of hepatitis may be linked to adenovirus infection'.
Sudden-onset hepatitis
Adenovirus was detected in 75% of cases tested, the UKHSA said, and the virus was the 'most common pathogen' found.
A total of 16% of cases were found to have COVID-19 infection, the agency said, although this was 'not unexpected' because of the high background rate at the time of investigation, with COVID-19 cases surging across the UK after the end of pandemic restrictions in late February.
The agency added that there was 'no link to the COVID-19 vaccine', with no confirmed cases in UK under-10s known to have been vaccinated.
Of the UK cases, 81 are resident in England, 14 in Scotland, 11 in Wales and five in Northern Ireland.
The UKHSA said that 'NHS and laboratory data show that common viruses circulating in children are currently higher than in previous years and there is a marked increase of adenovirus, particularly in the 1-4 age group'. Levels of adenovirus circulating fell sharply during the COVID-19 pandemic as restrictions limited social interaction.
Adenovirus infection
Director of clinical and emerging infections at UKHSA Dr Meera Chand said: 'Information gathered through our investigations increasingly suggests that this rise in sudden onset hepatitis in children is linked to adenovirus infection. However, we are thoroughly investigating other potential causes.
'Parents and guardians should be alert to the signs of hepatitis - including jaundice - and to contact a healthcare professional if they are concerned. Normal hygiene measures such as thorough handwashing - including supervising children - and good thorough respiratory hygiene, help to reduce the spread of many common infections, including adenovirus.
'Children experiencing symptoms of a gastrointestinal infection including vomiting and diarrhoea should stay at home and not return to school or nursery until 48 hours after the symptoms have stopped.'
The UKHSA listed the following symptoms of hepatitis:
- Yellowing of the white part of the eyes or skin (jaundice),
- Dark urine,
- Pale, grey-coloured faeces (poo),
- Itchy skin,
- Muscle and joint pain,
- A high temperature,
- Feeling and being sick,
- Feeling unusually tired all the time,
- Loss of appetite,
- Tummy pain.
