Study links mysterious hepatitis to co-infection of two common viruses

Finding the serious liver condition was linked to co-infection of two common viruses, British researchers reported a breakthrough Monday in mysterious hepatitis cases affecting young children.

According to the study AAV2 (adeno-associated virus 2), which cannot replicate itself without another "helper" virus being present, played a significant role and was present in 96 percent of all patients examined.

Offering the best explanation for the severe liver disease, scientists concluded that co-infection with either AAV2 and an adenovirus, or sometimes the herpes virus HHV6.

Emma Thomson, an infectious disease professor at the University of Glasgow and the study's lead author said that "The presence of the AAV2 virus is associated with unexplained hepatitis in children".

It is still unclear whether AAV2 was a biomarker for underlying adenovirus infection that is harder to detect but was the main pathogen or was causing the disease.

Finding that AAV2 was mostly present in those who got the illness, the study looked both at patients who acquired hepatitis and those that did not.

Honing in on differences in their Human Leukocyte Antigen that might explain why some are more susceptible than others, the study further tested genes of children who had become sick and those that did not.

Ruling out recent or prior SARS-CoV-2 infection as a direct cause, scientists said no coronavirus was found in the livers of the patients.

Highlighting that lockdowns could have contributed to the spike of cases by lowering immunity in children, researchers said more work was needed to understand why some children develop severe diseases and require transplantation.