UK experts think they have finally identified the cause of a recent outbreak of liver problems affecting young people, thought to be linked to hepatitis.
Children, mostly under the age of five, were experiencing mild symptoms but did not seem to be carrying the viruses that usually cause hepatitis.
Experts from London and Glasgow have been researching the 2022 outbreak and believe they have found a likely cause.
In the large majority of cases, symptoms that children experience are mild, though a handful of more severe incidents have been reported.
Here is everything we know so far.
Hepatitis outbreak in children
In May 2022, cases of hepatitis in young, previously healthy children began to rise unexpectedly.
The UK Health Security Agency (UKHSA) began investigating cases of sudden onset hepatitis in children aged ten and under that have been identified since January.
Alongside Public Health Scotland, Public Health Wales and the Public Health Agency, the health body confirmed that the total number of current cases in the UK are 263, as of July 4.
Of the confirmed cases, 186 are resident in England, 36 in Scotland, 19 are in Wales and 22 in Northern Ireland.
Most of these cases are in children under five, and no children have died.
Extremely severe cases are very rare, and most children who contract these types of viruses recovery quickly.
The viruses that usually cause hepatitis were not found in the children affected by this wave.
What is the cause of the hepatitis outbreak?
Researchers from London and Glasgow have determined that because of coronavirus restrictions, young children missed out on early immunity to two common viruses.
The adenovirus, which normally causes colds and stomach upsets, and the adeno-associated virus two, are both thought to have links to hepatitis.
The latter usually causes no illness and requires a co-infecting virus, such as adenovirus, to replicate.
Genetics may also be the reason that some children have developed liver inflammation.
It has been confirmed by scientists that there is no connection with coronavirus or Covid vaccinations.
Symptoms of hepatitis
Hepatitis symptoms include:
- 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
Is the hepatitis outbreak over?
The outbreak is not completely over as there are still some new cases, but experts believe that fewer new cases are being reported.
However, health professionals are still on alert for any new cases.
Parents are being advised not to worry, but told if a child gets seriously ill and has severe symptoms such as jaundice, they should contact the NHS.
Also, children who have experienced symptoms of a gastrointestinal infection - such as vomiting and diarrhoea - should stay off school until 48 hours after the symptoms have stopped.