Since May 2022, doctors in 35 countries have diagnosed a mysterious hepatitis in more than 1000 children: Several children died, others needed a liver transplant. Adenoviruses were also suspected to be the cause. Two working groups from London and Glasgow are now confirming the suspicion that adenoviruses triggered the liver inflammation, as they report on MedRxiv and on the NHS server.
Both teams report that they have detected the complete genomes of adeno-associated virus 2 (AAV2) in the liver and blood of most of the patients examined. In addition, they identified two helper viruses that could allow the adenovirus to enter the liver cells and thus increase susceptibility. On the other hand, the parties involved rule out the adenovirus subtype 41F, which was previously considered a potential trigger. The participants tracked down the AAV2 with the help of what is known as metagenomic sequencing. To do this, they sequenced all the genes in the tissue or blood samples of the affected children and then searched for the genetic material of viruses.
Emma Thomson of the Glasgow Center for Virus Research and her team detected AAV2 in all nine blood plasma samples and each of the four liver biopsies examined, taken from some of the first patients admitted to Glasgow Children’s Hospital. In contrast, the tests in children with other infections or with hepatitis of other causes were consistently negative. Sofia Morfopoulou, from the Institute of Child Health at University College London, and her team came to a similar conclusion with the children they studied, five of whom needed a transplant.