Scientists identify probable cause of mysterious liver disease in children

More than 1,000 children in 35 countries have developed an unidentified type of severe acute hepatitis – or inflammation of the liver – since the first case was reported in January 2022.

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UK scientists say they have identified the likely cause of a recent outbreak of a mysterious liver disease that has afflicted young children around the world.

A new study suggests that lack of exposure to two common viruses during the Covid-19 pandemic may have increased children’s chances of becoming seriously ill with acute hepatitis.

Learning published on Tuesdaytwo research teams from University College London and the University of Glasgow said lockdown restrictions may have caused some infants to miss out on early immunity to both adenovirus and the newly associated adeno-associated virus 2 (AAV2).

Importantly, both teams said they found no evidence of a direct link between the surge in hepatitis cases and infection with SARS-CoV-2, the cause of Covid-19.

Co-infection of viruses

Most cases were in children aged five years and younger, although diagnoses were made in children under 16 years of age.

Adenovirus, which usually causes a mild cold or flu-like illness, was previously thought to be partly responsible for the mysterious outbreak, as it was the most frequently detected virus in samples taken from sick children.

However, the new study found that adeno-associated virus 2, which normally does not cause disease and cannot reproduce without a “helper” virus such as adenovirus or herpesvirus, was present in 96% of the cases of unknown hepatitis studied in both studies.

Is the mystery solved?

Now, researchers say co-infection with two viruses — AAV2 and adenovirus or, less commonly, the herpesvirus HHV6 — may offer a better explanation for the recent outbreak.

“While we still have some unanswered questions about what exactly led to this spike in acute hepatitis, we hope these results can put some reassurance in parents concerned about Covid-19, as no team has found a direct link to SARS infection.” CoV-2,” Professor Judith. Breuer of the UCL GOS Children’s Health Institute, the report said.

Typically, children are exposed to—and immune to—adenoviruses and other common diseases in early childhood. However, pandemic-related restrictions have largely limited this early impact.

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The findings add to the theories of some health experts that Covid lockdowns reduced public immunity to a number of common diseases. The researchers added that there is no link to coronavirus vaccines.

Two studies were conducted independently and simultaneously using samples from the UK. Dr. Sofia Morfopoulou, professor at the GOS UCL Child Health Institute, said further studies are now needed to compare their results with cases of acute hepatitis detected in other countries.

“Currently, international collaboration is needed to further study and elucidate the role of AAV2 and co-infecting viruses in pediatric unexplained hepatitis in patients from different countries,” she said.