03 avril 2023
Since the spring of 2022, unexplained cases of severe and atypical hepatitis have affected children in around thirty countries. A recent American study brings a new element to explain this wave.
More than 1,000 cases of an unknown form of hepatitis have affected children in 35 countries around the world, including the United Kingdom, the United States and France. A total of 50 required liver transplantation and 22 died. Until now, the most accepted hypothesis to explain this surprising episode remained an adenovirus. And more particularly a type 41 adenovirus (HAdV-41), responsible for gastroenteritis. But without certainty.
Researchers from the University of California San Francisco bring a new element, compatible with this same hypothesis of the adenovirus. Indeed, by carrying out the genotyping of blood, nasal and faecal samples from 14 children who had developed hepatitis, they established two observations. The first is the massive presence – in 93% of cases – of an adenovirus 2 (AAV2), the majority of which is HAdV-41. The second, that in 85.7% of patients, other viral infections co-existed, with other adenoviruses but also the Epstein-Barr virus, herpes and/or enteroviruses.
Scientists therefore associate the occurrence of these hepatitis with these co-infections. In effect, “Adenoviruses are not known to cause hepatitis on their own. They need a ‘helper’ virus in order to replicate in the liver “, they explain.
The confinement in question
But how to explain the sudden and numerous appearance of these liver diseases in children? According to the authors of the study, the explanation lies in the post-lockdown context. “ Upon returning to school, children were more likely to become infected with common pathogens,” from which they had been preserved for months, explain the researchers. Which suggest that a small number of these children, infected with several viruses at the same time, may have been made more vulnerable to severe hepatitis.