Global News

Recent acute hepatitis cases of unknown origin in children have now been linked to the virus AAV2 in two new UK studies, with no evidence of a direct link to SARS-CoV-2 infection.

The two studies were led independently, with one examining cases from Scotland by the MRC-University of Glasgow Centre for Virus Research (CVR) and the Royal Hospital for Children in Glasgow, in partnership with Public Health Scotland and ISARIC (International Severe Acute Respiratory and emerging Infections Consortium) WHO Clinical Characterisation Protocol UK (CCP-UK).

The second studied cases from across the UK at Great Ormond Street Hospital and the UCL Great Ormond Street Institute of Child Health (UCL GOS ICH), in partnership with the UK Health Security Agency.

Professor Emma Thomson, Clinical Professor and Consultant in Infectious Diseases at the MRC-University of Glasgow Centre for Virus Research (CVR), and senior author of the Scottish study, commented: “The presence of the AAV2 virus is associated with unexplained hepatitis in children. This virus can only replicate in the presence of another virus (usually an adenovirus). AAV2 may cause disease itself, or it may be a useful biomarker of recent adenovirus infection which may be the main underlying pathogen, but which can be harder to detect.

“There are many unanswered questions, and larger studies are urgently needed to investigate the role of AAV2 in paediatric hepatitis cases. We also need to understand more about seasonal circulation of AAV2, a virus that is not routinely monitored - it may be that a peak of adenovirus infection has coincided with a peak in AAV2 exposure, leading to an unusual manifestation of hepatitis in susceptible young children.”

Since April 2022, a number of young children worldwide have developed jaundice and acute severe hepatitis of unknown origin. WHO has reported at least 1,010 probable cases in 35 countries.

Children with the condition have commonly had to be hospitalised for a number of days, with 11 children in England and one in Scotland requiring a liver transplant.

In the UK, most of the 268 cases have been under the age of five years old, with nearly 40% of hospitalised cases (74 of 189) requiring admission to intensive care.