Hepatitis in children explained - why does it happen and what could it mean?

Since April 2022, over 1,000 children in 35 countries have developed acute severe hepatitis of previously unknown origin. In late July, a possible explanation emerged of the cause of that mysterious spate of cases. And on 28 July, observed as World Hepatitis Day, commemorating the birthday of Dr Baruch Blumberg, who discovered the Hepatitis B virus. Though they share a common name, the two events have little in common.

Hepatitis is both the name of a clinical condition – inflammation of the liver – and a collection of viruses that cause liver damage, named Hepatitis A, B, C, D, and E.

World Hepatitis Day is intended to raise awareness of the viruses, while the children were developing liver inflammation as a result of a mechanism that was, until last week, relatively unknown.

How hepatitis hit children

It has emerged that the hepatitis cases in children were caused by a combination of three factors:

1) They all had adenovirus, which is a fairly standard cause of the common cold;

2) They had a sub-strain of adenovirus which only replicates in the presence of a major strain of adenovirus;

3) They appear to have shared a common genetic trait.

These factors combined resulted in serious liver inflammation, with several needing transplants. Fortunately, it seems that this combination is relatively rare, meaning the likelihood of a significant number of child hepatitis cases is low.

More concerningly, however, is the possibility that these illnesses came about as a result of the children’s immune systems that, due to COVID-19, social distancing and school and nursery closures weren’t likely trained to deal with the relatively common adenoviruses.

Our bodies adapt quickly, but mild illnesses in childhood are essential for building strong immune systems that can handle the majority of pathogens thrown at us by the modern world. At present, there is no way of knowing what the long-term consequences will be for a generation of children whose immune systems are comparatively underdeveloped at a young age.

This year’s spate of hepatitis cases could be a one-off. But they could also be the first and most high-profile case of secondary health consequences for children as a result of COVID-19.

It’s important to know the symptoms of liver inflammation hepatitis.