Acute hepatitis of unknown origin in children

Current situation

A recent increase in cases of severe acute hepatitis of unknown origin in children aged 16 years and younger is reported in several countries.

Viral hepatitis A, B, C, D and E have been excluded as causes in all cases.

A high proportion of cases tested positive for adenovirus; however, other causes have not been ruled out.

There is no link to coronavirus (COVID-19) vaccine.

Paediatricians are watching for cases in New Zealand.

For more information, including updates on overseas case numbers and investigations, please refer to:

About acute hepatitis of unknown origin

Hepatitis is an inflammation of the liver. There are different aetiologies – or causes – that can lead to this inflammation, such as an infection or toxic effects of drugs or other substances. The most frequently implicated infectious agents are the viruses responsible for hepatitis A, B, C, D and E.

Acute hepatitis is when inflammation develops rapidly, and a patient becomes symptomatic. It is named “acute hepatitis of unknown origin” as the cause of this hepatitis in children is under investigation.

Who is at risk

Cases have been reported worldwide in otherwise healthy patients aged between one month and 16 years, predominantly children under five years of age.

Currently no particular risk factors have been identified; however, investigations are ongoing. 

Symptoms

Most cases showed initial symptoms of gastroenteritis (diarrhoea, nausea and vomiting) followed by the acute onset of hepatitis which include fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-coloured stools (poop) and jaundice (yellowing of the skin and the eye) as well as elevated liver enzymes on blood testing. Other children have had initial signs of a respiratory illness with cough, cold, runny nose.

Management of suspected cases of acute hepatitis of unknown origin

Parents

Parents and guardians should be alert to the symptoms of hepatitis and seek seek prompt medical attention.

Normal hygiene measures such as thorough handwashing, covering coughs and sneezes, and teaching children to avoid touching the eyes, nose, or mouth help to reduce the spread of many infections.

Children experiencing gastrointestinal symptoms should not return to childcare or school until 48 hours after their symptoms have resolved. 

Children with acute hepatitis should be excluded from attending childcare or school for one week after the onset of jaundice and until they are well, or as advised by their doctor.

Primary health care

Be aware of potential cases of acute hepatitis in children aged 16 years and under.

All suspected or confirmed (ie raised serum ALT or AST) cases of acute viral hepatitis should be discussed with a paediatrician or paediatric hepatologist/gastroenterologist who can direct further testing and arrange admission or transfer as necessary.

All staff involved in the care of these children should use standard infection prevention and control precautions.

Case detection in New Zealand

To find out if we have cases in New Zealand and appropriately investigate them, the New Zealand Paediatric Surveillance Unit has started to look for cases (both historic and ongoing) through their paediatrician-based active surveillance system, aligning with international investigation into this emerging condition. Our surveillance is broader although can be filtered to WHO definition based on the World Health Organization (WHO) case definition.

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