Q&A on hepatitis in children

In recent weeks, a number of cases of severe hepatitis of unknown origin in children have been reported. These have been detected in several countries including the United Kingdom of Great Britain and Northern Ireland, Spain and the United States of America.

It is a term used to describe an acute inflammation of the liver. It can be due to a range of infectious and non-infectious causes. There are 3 main types of acute viral hepatitis – hepatitis A, B and C.  Viral hepatitis D and E are more unusual, particularly in higher income settings.

Severe acute hepatitis is unusual in young children. The initial report of a possible increase in cases came from Scotland. This then led to alerts being raised elsewhere in the United Kingdom and globally, with people then looking for and finding more cases.

What we know is that the common viruses that cause acute viral hepatitis have not been detected in these patients.  Also, international travel or links to other countries, based on the currently available information, have not been identified as important factors.

This should be taken seriously – though these are rare events. Further work is required to identify additional cases, both in currently affected countries, but also elsewhere. The priority is to determine the cause of the illness to be able to further refine control and prevention actions.

We are working with countries and partners to look at a range of possible explanatory factors. A wide number of avenues are being explored. One of the leading hypotheses is adenovirus, which is a group of common viruses spread from person-to-person causing respiratory symptoms, vomiting and diarrhoea in children.

While adenovirus is currently one hypothesis, it does not fully explain the severity of the clinical picture. There have been case reports of hepatitis in immunocompromised children with adenovirus infection, however, it is unusual to be a cause of severe hepatitis in otherwise healthy children.

Factors such as increased susceptibility among young children following a lower level of circulation of adenovirus during the COVID-19 pandemic, the potential emergence of a novel adenovirus, as well as SARS-CoV-2 co-infection have been suggested by the United Kingdom team as possible factors, and need to be further investigated.

SARS-CoV-2 has been detected in several cases. However, COVID-19 circulation is currently widespread in the community in many of the affected countries and the potential contribution of this virus to the clinical presentation is not clear.

There is no evidence that the presentation is linked to vaccination since the vast majority of affected children have not received a COVID-19 vaccine. Other infectious and non-infectious explanations need to be fully assessed to understand and manage the risk.

With continued new notifications of recent onset cases, together with more extensive case searching in other countries, it is very likely that more cases will be detected before the cause can be confirmed and more specific control and prevention measures can be implemented.

It is firstly important to stress that this is not a common disease, but parents should be alert to the symptoms of hepatitis, which are an acute onset of diarrhoea, vomiting, abdominal pain and jaundice – where the skin and whites of the eyes turn yellow – in younger children. Most children do not have a fever. If concerned, we would advise that parents contact their health care professional.

Take the normal measures that help protect against common viruses, so parents should supervise good handwashing and encourage good respiratory hygiene, such as covering up a cough or sneeze, which, taken together, can help reduce the spread.