UK experts believe they have identified the cause of the recent spate of mysterious liver problems affecting young children around the world.

Investigations suggest two common viruses made a comeback after pandemic lockdowns ended - and triggered the rare but very serious hepatitis cases.

More than 1,000 children - many under the age of five - in 35 countries are thought to have been affected.

Some, including 12 in the UK, have needed a lifesaving liver transplant.

The two teams of researchers, from London and Glasgow, say infants exposed later than normal - because of Covid restrictions - missed out on some early immunity to:

adenovirus, which normally causes colds and stomach upsets
adeno-associated virus two, which normally causes no illness and requires a coinfecting "helper" virus - such as adenovirus - to replicate