The rise of sudden severe hepatitis in children is not linked to Covid-19, new search has found.
The spike of children contracting severe hepatis since Spring has now instead been linked to a virus called adeno-associated virus 2 (AAV2).
Two studies, from researchers in Glasgow and London, looked at more than 60 cases in the UK and found AAV2 present in the majority of those children.
However, AAV2 does not usually cause disease on its own and scientists found it was accompanied by other viruses, most commonly adenovirus or to a smaller degree herpes.
In the UK there have been 268 cases of severe paediatric hepatitis. The majority of children have been under the age of five years old and 12 children have so far required a liver transplant.
The World Health Organisation has reported at least 1,010 probably cases across 35 different countries.
This is the first time Covid-19 has been ruled out as a direct link since the spike in cases in Spring.
Previous research from the UK Health Security Agency had linked adenovirus to the mystery disease however did not rule out Covid-19.
The co-infection of adenovirus and, less commonly herpes virus, researchers believe might be the best explanation of the mysterious onset of cases.
The studies, from researchers in Glasgow and London, show AAV2 was found in 96 per cent of the cases looked at.
Researchers from the University of Glasgow, Royal Hospital for Children in Glashow, Public Health Scotland and the International Severe Acute Respiratory and emerging Infections Consortium looked at nine children.
A team from Great Ormand Street Hospital, University College London Great Ormand Street Institute for Child Health and UKHSA looked at 28 cases across the four nations.
The researchers said they could not be sure why the outbreak is happening now but highlighted the possible peak in adenovirus infections in the general population following lockdown.
Professor Emma Thompson, 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 said: “The presence of the AAV2 virus is associated with unexplained hepatitis in children. This virus can only infrequently 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.”
She said there are still many “answered questions” and larger studies are needed to “urgent” investigated AAVW in paediatric hepatitis cases and to understand more about the circulation of AAV2 which is not routinely monitored.
Professor Judy Breuer, professor of virology at UCL GOS ICH and honorary consultant virologist at GOSH said:“While we still have some unanswered questions about exactly what led to this spike in acute hepatitis, we hope these results can reassure parents concerned about Covid-19 as neither teams have found any direct link with SARS-CoV-2infection.”
“Our data do, however, point to AAV2 in the liver and, or blood of cases as the strongest biomarker for the hepatitis. Additionally, the presence of HHV6 and Adenovirus in the damaged livers, removed from the five children who needed liver transplants, raises questions as to the role of co-infections with these three viruses in the most severe cases”.
