Two Common Viruses Linked to Serious Liver Condition in Children

British scientists recently reported a breakthrough in mysterious hepatitis occurrences affecting young kids, discovering the severe liver condition was associated with co-infection of two common viruses, although not the COVID-19 virus.

A ScienceAlert report said that the World Health Organization has at least 1,010 possible cases, which include 46 that necessitated transplants and 22 deaths from the disease, dating back to October last year.

Previous theories had centered on a spike in commonly detected adenovirus infections behind such occurrences.

However, in two new studies conducted separately and simultaneously in Scotland and London, researchers discovered another virus known as adeno-associated virus two or AAV2. This played a vital role and was found in 96 percent of all the patients examined.

Adeno-Associated Virus 2

AAV2 is not typically known to lead to illness and cannot duplicate itself without another "helper" virus.

Both research teams concluded that co-infection with either AAV2 and an adenovirus, or at times the herpes virus HHV6, provided the best explanation for the serious liver disease.

The AAV2 virus is linked to mysterious hepatitis in children, according to Emma Thomson, infectious disease professor at the University of Glasgow, who led the Scottish paper published in the MedRxiv Preprint Server for Health Sciences.

But she warned too that it was not yet sure if AAV2 was causing the disease or was instead a biomarker for underlying adenovirus infection that is more difficult to detect but was the main pathogen.

Link to COVID-19

Both studies may have been posted online, but they still await peer review before publication in journals.

Furthermore, the two studies looked at patients who developed hepatitis and those who did not, discovering that AAV2 was predominantly present in those who didn't.

The Scottish research further examined the DNA of the children who had turned ill and those who didn't, grinding in on differences in their Human Leukocyte Antigen that might explain why some are more vulnerable compared to others.

Moreover, both research teams ruled out recent or previous COVID-19 infection as a direct cause. No COVID-19 virus was detected in the patients' liver, and as the Scottish study showed that two-thirds of the patients had antibodies against COVID-19, that rate was akin to the general population prevalence among young children at that time.

'Coinfection is the Key'

As specified in a UK Research and Innovation report, it remains unclear why hepatitis cases rose recently, although both types of research highlighted the plausibility that lockdowns could have contributed, either by lowering immunity in children or altering the virus circulation patterns.

​Professor of pediatric hepatology Deirdre Kelly from the University of Birmingham, who was not part of the project, said she thinks this is a possible explanation for such cases. It seems that "coinfection is the key," she added.

However, she elaborated, more work was needed to understand why children are developing severe diseases, not to mention necessitating transplantation.

According to Thomson, it was also essential to understand more about the seasonal circulation of AAV2, a virus that's not regularly monitored.

She possibly continued explaining that a peak of adenovirus infection "has coincided with a peak" in exposure to AAV2, resulting in an extraordinary manifestation of hepatitis in vulnerable young children.

Related information about hepatitis in children is shown on ABC News's YouTube video below:

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